Printable list of all airway management SAQs

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Question 2 - 2000, Paper 1

You are intubating an hypoxic patient with rapid sequence induction.   

You are unable to visualise the cords during laryngoscopy. What is your plan to manage this problem

College Answer

This question required a safe management plan that would cover the possible contingencies. The candidate should have mentioned that proper planning and assessment is the key but details of preparation were not specifically asked for.

Thus one approach is:

(a)  If one is able to ventilate the patient:
•   optimise laryngoscopy -extra pillow, McCoy blade, laryngeal manipulation etc.
•   consider alternatives to laryngoscopy- fiberoptic laryngoscopy
•  blind nasal, light wand
•  call for expert help
•   awaken patient

(b} If one is unable to ventilate the patient:
•   call for expert help
•     insert guedel airway and attempt ventilation with PEEP
•    insert LMA and attempt ventilation
•    if successful go to (a)
•   if unsuccessful attempt to establish a transtracheal airway
-     retrograde wire, cricothyrotomy, tracheostomy.

lt was assumed that suction. s .ECG, BP measurements were all preoptimised

Discussion

Again, this is a question regarding the difficult intubation algorithm.

  • call for expert help
  • Why cant you see the cords?
    • position the patient corectly
  • if you can ventilate, try one of the following:
    • get an assistant to manipulate the larynx
    • get a McCoy blade
    • get a videolaryngoscope
    • prepare a bronchoscope
    • consider waking the patient up, and using CPAP until help arrives
  • If you cannot ventilate:
    • Insert a nasopharyngeal airway and/or an oropharyngeal airway
    • Attempt two-handed mask technique with an assistant
    • If this is not working, convert to an LMA.
    • If LMA ventilation is sucessful, one can prepare for a repeat attempt at intubation.
    • If LMA ventilation is not successful, one needs to urgently proceed to needle cricothyroidotomy and jet oxygenation
      • If jet oxygenation can be accomplished, one has some time to set up for a Seldinger dilation and insertion of an ETT, or for a retrgrade intubation.
      • If jet ventilation cannot be accomplished, one must assess the difficulty of anterior neck anatomy.
        • if the anatomy is easy, one can proceed to a scalpel-bougie technique (where one makes an incision in the cricothyroid membrane and railroads the tube in over a hollow jet ventilation bougie)
        • if the anatomy is difficult, one must perform a scalpel-needle cricothyroidotomy (where the cricothyroid membrane is identified by palpation through an incision, so that the jet cannula can be inserted)
      • Either way, once the needle is in the airway it can be easily dilated and "up-sized" to a cricothyroidotomy.
      • A Griggs forceps tracheostomy (blind, without bronchoscope guidance) is also an option, and in some skilled hands it can be performed in 30 seconds (at least when the people who developed this technique are doing it).

References

Question 7 - 2000, Paper 1

Nursing staff report that they are suctioning nasogastric feeds from the tracheostomy of a patient with cuffed tube in situ. How will you manage this problem?

College Answer

A practical problem. It may be addressed thus: 

(a) Sit the patient up if possible. 
(b) Determine if the patient is actually aspirating NG feed by mixing food dye or methylene blue with feeds and repeat ETI suctioning intermittently. 
(c) Check tracheal cuff pressures and absence of air leak. presence of seal. Ensure appropriate size tracheostomy in situ. Check tracheostomy tube position above carina and that cuff is at least 2 em below the cords. 
(d) Check position of NG tube in stomach. 
(e) If all the above conditions are satisfactory and the patient still appears to be aspirating, the feeds will have to be ceased and investigations for a trachco-oesophageal fistula may need to be instigated.

Discussion

The causes of aspiration may numerous. One must identify which of the follwoing problems is present:

  • Simple feed intolerance with regurgitation
  • Impaired swallowing of oral contents
  • failure of the tracheostomy cuff to maintain a sealed airway (i.e. cuff is failing to maintain pressure, or the whole tracheostomy has migrated out of the stoma and there is nothing in the trachea)
  • Tracheo-oesophageal fistula.

A practical approach would resemble the following sequence:

  • Ensure the airway equipment is not at fault:
    • Check tracheostomy position on CXR
    • Check the cuff for absence of leak
    • Check the seal of the cuff for presence of air leak 
  • Ensure the feeding tube is not at fault:
    • Check NGT position on Xray
    • Ensure that the NGT is not fractured and leaking into the oral cavity
  • Ensure that there is no feed intolerance
    • Check gastric residal volumes
    • Consider changing to a post-pyloric tube
  • Confirm that aspiration of feeds is taking place
    • This is a step which may be omitted.
    • Historically, the "blue dye test" had been used. Evan's Blue had been mixed with the NG feeds, and the tracheal aspirates were observed for blueness. This test is far from reliable, and has been largely abandoned as it neither identifies nor excludes all aspiration, and may give a false sense of security
  • Investigate oesophageal intergrity, motility, and swallow coordingation: the gold standard is videofluoroscopy, or the modified barium swallow.

References

Elpern, Ellen H., et al. "Pulmonary aspiration in mechanically ventilated patients with tracheostomies." CHEST Journal 105.2 (1994): 563-566.

 

Bone, David K., et al. "Aspiration pneumonia: prevention of aspiration in patients with tracheostomies." The Annals of thoracic surgery 18.1 (1974): 30-37.

Thompson-Henry, Sheri, and Barbara Braddock. "The modified Evan's blue dye procedure fails to detect aspiration in the tracheostomized patient: five case reports." Dysphagia 10.3 (1995): 172-174.

Question 9 - 2000, Paper 2

List the advantages and disadvantages of three commonly used techniques for percutaneous tracheostomy•

College Answer

Commonly used techniques include: Ciaglia, Griggs (portex}, a combination of  these, and the Translaryngeal approaches.

Ciaglia:

Advantages: initial technique, widely used, well known, well documented complication rate (low),
gradual dilatation, able to insert any type of tracheostomy tube

Disadvantages: need experienced operator and airway operator, endotracheal tube positioning may damage vocal cords or lose PEEP/minute ventilation/protection of airway, takes minutes to dilate
and spray of blood stained respiratory gases with each inspiration unless hole completely covered each time, damage to posterior wall of trachea with initial perforation and subsequent dilatations (? minimised by use of bronchoscope)

Griggs (Portex):

Advantages: less steps in technique, faster dilatation (may be used in emergency), able to insert any
type of tracheostomy tube

Disadvantages: need experienced operator and airway operator, needs sterilization of forceps if previously used, endotracheal tube positioning may damage vocal cords or  lose PEEP/minute ventilation/protection of airway, more abrupt dilatation (may cause more tracheal damage), spray of blood stained respiratory gases with each inspiration unless hole completely covered, damage to posterior wall of trachea with initial perforation and subsequent dilatations (? minimised by use of bronchoscope), may want to insert different tracheostomy tube (wasting tube in pack)

Translaryngeal:

Advantages: well documented complication rate (very low, especially bleeding), has been safely used with marked coagulopathy, initial tracheal puncture under vision from inside trachea, avoids damage to posterior wall of trachea, allows ventilation (separate tube) throughout procedure, can be done as one person technique

Disadvantages: less widely known technique out of Europe, more fiddly technique, need experienced operator, requires Light sowce and scope (rigid or flexible), ventilation may be difficult
with small endotracheal tube, pulling through the tracheostomy  tube may damage vocal cords, only able to insert one type of tracheostomy tube (not tube with inner cannula), need to use different technique to change type of tube

Discussion

This answer, as a table:

 

Advantages

Disadvantages

Classical Ciaglia
(multiple dilators)

  • Well known
  • Well studied
  • Well practice
  • Complication rate is notoriously low
  • Multiple sequential dilators ensure that little force and little pressure is required
  • Thus, less risk of posterior wall puncture
  • Less tracheal trauma
  • Supraglottic ETT position may result in loss of PEEP or loss of the airway altogether
  • Potential of posterior tracheal wall puncture
  • Exposes operators to blood spray
  • Increases exposure to aerosolised airway secretions
  • Prolonged procedure
  • Multiple steps: difficult to learn
  • Long straight dilators lend themselves to posterior tracheal wall laceration
  • Multiple manipulations of the guidewire can result in dislodgement of the wire out of the trachea.
Ciaglia Blue Rhino
  • Faster than the classic technique
  • Fewer steps
  • Curved dilator: less risk of posterior wall puncture
  • Single large dilator: risk of tracheal trauma
  • All the same problems with ETT being above the cords (see above)

Griggs forceps technique

  • Faster technique – less dilatations (potentially, the fastest)
  • Less blood spray exposure (potentially)
  • Potential for more tracheal damage
  • Requires sterile forceps
  • Less researched
  • More potential for infectious complications
  • Greater potential for guidewire loss
Cianchi balloon dilation technique
  • No risk of injuring the posterior wall
  • No sequential dilators: one balloon only
  • No forceful pushing required
  • Takes longer
  • More steps are required
  • Tracheostomy tube is more difficult to pass into the dilated opening
Frova and Quintel (PercuTwist) technique
  • Less risk of injuring the posterior wall
  • No sequential dilators: one balloon only
  • No forceful pushing required
  • Single dilator technique
  • No specific protection againt posterior wall lacerations or cartilage fractures
  • Not widely available
  • No speed advantage over Griggs or other single-dilator techniques

Translaryngeal (Fantoni)

  • Very low complication rate
  • Can be a one-person technique
  • No pressure is directed towards the posterior wall
  • Largely unknown technique
  • Relies on small endotracheal tube to ventilate
  • Requires additional equipment
  • Chance of vocal cord damage
  • At one point, you are expected to have no airway whatsoever.

Essentially, in the Ciaglia technique one dilates the trachea sequentially using a series of dilators, whereas in the Griggs technique one ends up dilating most of the trachea using forceps.

The Fantoni technique is different. in this one you use a Seldinger technique to pass a guidewire though the trachea and up through the mouth. Then, through the mouth the tracheostomy tube is advanced on an armoured trochar which is pushed to pierce though the wall of the trachea, and to emerge hideously out of the neck like the Alien. Weirdly, it seems to be the safest approach. The main benefit is that one is able to ventilate the patient thoughout this process by using the thin-walled ETT which comes with the set.

References

Byhahn, C., V. Lischke, and K. Westphal. "Translaryngeal tracheostomy in highly unstable patients." Anaesthesia 55.7 (2000): 678-683.

 

Ambesh, Sushil P., et al. "Percutaneous tracheostomy with single dilatation technique: a prospective, randomized comparison of Ciaglia Blue Rhino versus Griggs’ guidewire dilating forceps." Anesthesia & Analgesia 95.6 (2002): 1739-1745.

 

Antonelli, Massimo, et al. "Percutaneous translaryngeal versus surgical tracheostomy: A randomized trial with 1-yr double-blind follow-up*." Critical care medicine 33.5 (2005): 1015-1020.

Question 13 - 2000, Paper 2

Outline the role of monitoring  in the management of upper airway obstruction.

College Answer

Monitoring should  be  considered as  either  part  of  routine  examination (clinical  monitoring) or requiring  additional equipment or  investigations. Assumed in  this  case  that  the  presence of  an endotracheal tube or tracheostomy would prevent upper airway obstruction.

Clinical: essential part  of monitoring. Clinical  criteria more likely  to lead to decision to intervene. Consider  importance of  assessment of  level  of  consciousness, extent  of  obstruction (soft  tissue iodrawing- suopraclivular, tracheal  tug,  intercostal muscles), and  ability  to cope  with  increased work of breathing (tachycardia, tachypnoea, sweating).

Equipment:  pulse   oximetry  (limited   information,  better   with   lower   FlO2), 

 ECG  (rhythm, ischaemia),  capnograph   (respiratory  rate,  pattern    of   expiratory   flow),    invasive   pressures (IA/CVP/PAWP - may  help  assess  extent  of  intrathoracic pressure  change and therefore work  of breathing).

Investigations: arterial  blood  gases (direction of  change may  assist  in  decision to intervene eg. CO2/pH).

Discussion

it is difficult to come up with a systematic answer to this weird question.

Upper airway obstruction ca potentially result in the loss of the whole airway, and this would manifest in a number of ways.

Physical examination findings (such as worsening stridor or tachypnoea) suggest that this patient should undergo serial examinations.

The earliest machine-monitored sign that the patient cannot breathe (or that the airway is closing) would be continuous capnometry.

Pulse oximetry would alert you to when it is already too late, and the patient is desperately hypoxic.

ABG analysis will tell you when the patient is tiring of breathing though their obstructed airway, and this may lead you to finally intubate them.

References

Question 3 - 2002, Paper 1

Outline your plan of management for a rapidly deteriorating patient with severe airflow obstruction who is a known difficult intubation.

College Answer

Initial management should ensure assessment and management of airway, breathing and circulation, as well as level of consciousness.   Must be prepared for difficult intubation (essential equipment should be listed, checked and ready; adequate skilled assistance should be present; backup plans are essential).   Specific plan should be elucidated with relation to reason for difficult intubation (eg. limited mouth opening, versus high anterior larynx etc.).  Main difficulty is that bag-valve-mask ventilation  or laryngeal  mask ventilation  may be impossible.   The use of facemask  CPAP may provide some time if not contraindicated by deteriorating neurologic state.  Bronchoscopic or blind nasal intubation may be reasonable if operator adequately skilled in techniques.   Paralysis may otherwise be essential.  Early resort to surgical airway may be appropriate if problems develop.

Discussion

This question is another one of those "how do you manage a difficult airway" questions.

The answer would need to be systematic.

History

  • Why is the patient a difficult intubation?
    Look through previous anaesthetic records, if time permits.
  • Why does the patient need intubation?
    This step helps assess the likely complications (eg. in Question 1c from the first paper of 2004 the patient is having emergency gastroscopy for an upper GI bleed, and the likely complications inevitably include aspiration).

Examination

  • Assess for difficulty of intubation, to determine which specific features were problematic.
  • Assess for difficulty of bag-mask ventilation.
    This is all discussed in the chapter on recognising the difficult airway.
  • Look at the most recently available ABG or venous biochemistry: specifically, the PaCO2 helps determine the dose of anaesthetic induction agent, and the serum K+ level helps select the muscle relaxant.

Planning

  • Decide beforehand what the algorithm is going to be, depending on what is available locally.
  • Have a plan for intubation
  • Have a plan for oxygenation
  • Have a backup plan (or two) for each
  • Have a clear idea of what the locally available cricothyroidotomy kit looks like and roughly how long it takes to set up (given that pretty much all of the algorithms lead to cutting the throat).

Preparation of the staff

  • Choose a competent assistant to assist with the airway: somebody who knows what BURP is and how to correctly do cricoid pressure
  • Choose a competent assistant to give drugs
  • Assign a staff member to act as “access”, i.e. somebody to run around and get equipment
  • Inform standby staff to be ready (eg. inform ENT surgeon, senior anaesthetist)
  • Discuss the plan with the team to ensure everyone is aware of what is going to happen (eg.  “OK people, Plan A is videolaryngoscopy with bougie, Plan B is Fastrach”).

Preparation of the equipment

  • Plan A equipment should be ready for use
  • Plan B equipment should be available within 60 seconds (which means, in the room, within arm’s reach, and wherever possible unwrapped and lubricated).
  • Drugs should be drawn up, including a couple of adrenaline ampoules in case CPR becomes a part of the rapid sequence induction.
  • An end-tidal CO2 monitor should be within reach
  • The equipment should be checked, and its operability ensured (i.e. those CMAC batteries better be charged).

Specific equipment (the contents of the difficult intubaton trolley)

  • A selection of oropharyngeal airways
  • A selection of nasopharyngeal airways
  • Macintosh laryngoscope blades size 3 and 4.
  • Alternative laryngoscope blades (eg. a Kessel blade)
  • A short laryngoscope handle (for fat or big-breasted people)
  • An endotracheal tube introducer
  • A malleable blunt atraumatic stylet.
  • Normal LMAs of different sizes
  • Intubating LMA kids, eg. Fastrach
  • A selection of specialised ETTs, eg. long flexometallic, nasal, etc.
  • A long airway exchange catheter.
  • A surgical cricothyroidotomy kit
  • A kink resistant cricothyroidotomy cannula and jet ventilation kit
  • A capnograph, capnometer or colorimetric end-tidal CO2 detector.

Preparation of the patient

  • Explain to the patient what the plan is (if they are conscious and capable of processing this information, it would be helpful to have them on your side).
  • Commence high flow oxygen
  • Preoxygenate for a minimum of 3 minutes. The utility of this is debated.
  • During this time, either position the patient for intubation, or (if they cannot tolerate that position) prepare equipment and assistants to put them into that position as soon as the induction is commenced.

References

ANZCA have a statement on the equipment which should be available to manage a difficult airway.

Nørskov, Anders Kehlet, et al. "Diagnostic accuracy of anaesthesiologists’ prediction of difficult airway management in daily clinical practice: a cohort study of 188 064 patients registered in the Danish Anaesthesia Database." Anaesthesia 70.3 (2015): 272-281.

 

Apfelbaum, Jeffrey L., et al. "Practice Guidelines for Management of the Difficult Airway An Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway." The Journal of the American Society of Anesthesiologists 118.2 (2013): 251-270.

 

Frerk, C., et al. "Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults." British journal of anaesthesia 115.6 (2015): 827-848.

Heidegger, T. "The 2015 Difficult Airway Society guidelines: what about the anticipated difficult airway." Anaesthesia 71 (2016): 592-3.

 

 

Law, J. Adam, et al. "The difficult airway with recommendations for management–part 2–the anticipated difficult airway." Canadian Journal of Anesthesia/Journal canadien d'anesthésie 60.11 (2013): 1119-1138.

Walls, Ron M., and Michael Francis Murphy, eds. Manual of emergency airway management. Lippincott Williams & Wilkins, 2008.

 

Lim, M. S., and J. J. Hunt-Smith. "Difficult airway management in the intensive care unit: Practical guidelines." (2003): 43.

 

Caldiroli, D., and P. Cortellazzi. "A new difficult airway management algorithm based upon the El Ganzouri Risk Index and GlideScope® videolaryngoscope: a new look for intubation." Minerva Anestesiol 77.10 (2011): 1011-1017.

 

El-Ganzouri, Abdel Raouf, et al. "Preoperative airway assessment: predictive value of a multivariate risk index." Anesthesia & Analgesia 82.6 (1996): 1197-1204.

 

Zaouter, C., J. Calderon, and T. M. Hemmerling. "Videolaryngoscopy as a new standard of care." British journal of anaesthesia 114.2 (2015): 181-183.

Question 6 - 2002, Paper 1

Compare and contrast percutaneous and surgical tracheostomy.

College Answer

Surgical tracheostomy is the time-honoured approach.   Best operating conditions (coping with complexities of anatomy), best control of bleeding and airway. Requires operating time and staff, and  transport  to  operating  theatre.    Lower  incidence  of  peri-operative  complications.    Higher incidence of tracheal stenosis, postoperative bleeding and stomal infection.

Percutaneous tracheostomy refers to a number of different techniques.  In particular the gradual dilatation   [Ciaglia],   forceps  dilation   [Griggs],   Rhino   and  translaryngeal   techniques.     Most comparative   data  is  for  the  Ciaglia   technique.      Blind   external   technique   (which   can   be bronchoscopy assisted to improve visualization/placement) which seems to be significantly operator dependent.    Some  neck  anatomy  problems  provide  relative  contraindications.  Permits  smaller incision, but lesser exposure and not usually performed with diathermy available.  Only require intensive care staff, though airway maintenance is probably more critical, with respiratory acidosis and loss of airway more likely.  No delays due to theatre requirements, no transport required, and takes less time to perform.  Higher incidence of anterior tracheal wall injury and posterior wall perforation.  Lower incidence of postoperative haemorrhage, infection and tracheal stenosis.

Discussion

This question lends itself well to a tabulated answer.

 

Surgical tracheostomy

Percutaneous tracheostomy

Advantages

  • Gold standard for difficult anatomy
  • Better control of bleeding
  • Fewer intraoperative complications
  • Less postprocedural complications such as accidental decannulation,  bleeding  and wound infection. (Dulguerov et al, 1999)
  • Less bleeding risk (smaller hole)
  • Lower incidence of tracheal stenosis
  • Lower incidence of tracheal infection
    Johnson-Obaseki et al (2016)
  • The cosmetic effect is better
  • No transfer, thus no risks of transfer
  • Cheaper
  • Faster (10-15 minutes)
  • More easily available in the ICU
  • Decreases length of stay in ICU (if early tracheostomy:  Griffiths  et al, 2006)

Disadvantages

  • More postprocedural complications
  • Higher incidence of tracheal stenosis
  • Higher incidence of stomal infections
  • Expensive; requires the operating theatre to be fully staffed
  • Takes longer to roganise
  • Exposes patients to risk of transfer
  • Inadequate backup for major complications or difficult anatomy.
  • Much of the technique is essentially blind.
  • Diathermy is not available in ICU
  • Cardiothoracic surgical support is lacking
  • Bronchoscopy is required for safety 
  • The bronchoscope may get damaged
  • Disposable percutaneous kits cost more than a bedside surgical tracheostomy
  • There is a greater risk of death and cardiac arrest. (Dulguerov et al, 1999)
  • Some intraoperative complications are unique to percutenous technique (eg. knotted guide wire)

References

Durbin, Charles G. "Indications for and timing of tracheostomy." Respiratory care 50.4 (2005): 483-487.

Kilic, Dalokay, et al. "Article When is Surgical Tracheostomy Indicated? Surgical “U-shaped” versus Percutaneous Tracheostomy." Ann Thorac Cardiovasc Surg 17.1 (2011): 29-32.

De Leyn, Paul, et al. "Tracheotomy: clinical review and guidelines." European Journal of Cardio-thoracic Surgery 32.3 (2007): 412-421.

Friedman, Yaakov, et al. "Comparison of percutaneous and surgical tracheostomies." CHEST Journal 110.2 (1996): 480-485.

Dulguerov, Pavel, et al. "Percutaneous or surgical tracheostomy: a meta-analysis." Critical care medicine 27.8 (1999): 1617-1625.

Duann, Chi‐Wei, et al. "Successful percutaneous tracheostomy via puncture through the thyroid isthmus." Respirology Case Reports 2.2 (2014): 57-60.

Friedman, Yaakov, et al. "Comparison of percutaneous and surgical tracheostomies." CHEST Journal 110.2 (1996): 480-485.

Dulguerov, Pavel, et al. "Percutaneous or surgical tracheostomy: a meta-analysis." Critical care medicine 27.8 (1999): 1617-1625.

Griffiths, John, et al. "Systematic review and meta-analysis of studies of the timing of tracheostomy in adult patients undergoing artificial ventilation." Bmj 330.7502 (2005): 1243.

Johnson‐Obaseki, Stephanie, Andrea Veljkovic, and Hedyeh Javidnia. "Complication rates of open surgical versus percutaneous tracheostomy in critically ill patients." The Laryngoscope (2016).

Dempsey, Ged A., et al. "Long-Term Outcome Following Tracheostomy in Critical Care: A Systematic Review." Critical Care Medicine (2016).

 

Question 3 - 2002, Paper 2

Outline how you would assess a patient for potential difficulty with endotracheal intubation.

College Answer

•    History: of previous difficulty with intubation, infections/swelling affecting mouth or neck, problems with mouth opening or neck movement (arthritis, cervical spine injury), problems with teeth (especially caps/crowns, law wiring etc.).
•    Examination (multiple components) consider:
o teeth (maxillary anterior to mandibular; length of upper incisors; ability to prognath mandible; inter-incisor distance [need > 3 cm])
o Pharynx (ability of visualise uvula and tonsillar pillars; height and narrowness of palate).
o Mandibular space (thyromental distance 2: 3 fingerbreadths [6 cm]; compliance and distensibility of submandibular space).
o Length of neck (qualitative: short neck more difficult eg. syndromes).
o Thickness of neck (qualitative: thick neck decreases ability to align planes).
o Range of motion (of head and neck: eg. sniffing position)
•    Consider also the ability to assess potential difficulties by actually having a look with a laryngoscope.

Discussion

This question was recycled as Question 11 in the first paper of 2006. To simplify revision, the answer to that SAQ is reproduced below.

Anaesthetic history:

  • History of difficult intubation in previous attempts
  • History of airway-altering changes since the last anaesthetic, eg. significant weight gain, C-spine surgery, head and neck radiotherapy, etc.

Patient characteristics:

  • Obesity
  • Obstructive sleep apnea
  • History of snoring

Specific pathologies associated with difficult intubation:

  • Recent intubation (oedema, trauma, etc)
  • Angioedema
  • Airway trauma
  • Airway infection
  • Mediastinal mass, eg. retrosternal goitre
  • Ankylosing spondylitis
  • Acromegaly
  • Degenerative arthritis (i.e. of the C-spine or jaw)
  • Subglottic stenosis
  • Lingual hypertrophy (i.e. big fat tongue)
  • Syndromic appearance:
    •  Treacher-Collins syndrome: Auricular and ocular defects, malar and mandibular hypoplasia
    •  Pierre Robin syndrome: micrognathia, macroglossia,  cleft soft palate
    •  Down syndrome: small mouth; macroglossia
    • Goldenar’s syndrome: malar and mandibular hypoplasia
    • Kippel-Feil syndrome: congenital C-spine fusion

Physical examination: general features

  • Level of consciousness (i.e. is the patient cooperative enough for an awake intubation?)
  • Level of comfort (i.e. can the patient be positioned properly, or are they to short of breath?)
  • Pregnancy (makes everything difficult)
  • Syndromic appearance

Mouth, face and jaw examination

  • Long upper incisors (“buck teeth”)
  • No teeth (edentulous patients are easier to intubated, but harder to bag-mask ventilate)
  • Prominent overbite
  • Inability to “prognath”, i.e to voluntarily protrude the mandible
  • Small mouth opening (3cm is the minimum to comfortably admit a laryngoscope blade).
  • Mallampati score more than 2 (i.e. a barely visible uvula)
  • Arched or narrow palate
  • Compliance of the mandible and mandibular space (i.e. is it possible to manipulate it, or is it relatively fixed by some sort of disease process, eg. a submandibular abscess)
  • Beard
  • Patency of nares: polyps, deviated septum etc.

Neck and posture

  • Thyromental distance (“three ordinary finger breadths”, or 6cm)
  • Mandibulo-hyoid distance of less than 4cm
  • Sternomental distance of less than 12cm
  • Thick short neck
  • Restricted range of neck motion
  • Kyphosis

LEMON is a nice short way of remembering what to look for. It certainly seems to be reliable in predicting difficult intubation. 

Look:

  • Does the patient look like the stereotypical difficult intubation?

Evaluate: 3:3:2 rule

  • 3 fingers width of mouth opening
  • 3 fingers width of thyromental distance (from the thyroid cartilage to the mental process of the mandible, colloquially referred to as the chin)
  • 2 fingers width of distance from the hyoid to the thyroid

Mallamati score

  • amount of pharynx which can be seen by opening the mouth

Obesity and obstruction

  • Is the patient morbidly obese?
  • is there some sort of obstruction, eg abscess?

Neck mobility

  • this determines how easy it will be to align the planes

References

Arne, J., et al. "Preoperative assessment for difficult intubation in general and ENT surgery: predictive value of a clinical multivariate risk index." British journal of anaesthesia 80.2 (1998): 140-146.

Wilson, M. E., et al. "Predicting difficult intubation." British Journal of Anaesthesia 61.2 (1988): 211-216.

Cattano, D., et al. "Anticipation of the difficult airway: preoperative airway assessment, an educational and quality improvement tool." British journal of anaesthesia 111.2 (2013): 276-285.

Reed, M. J., M. J. G. Dunn, and D. W. McKeown. "Can an airway assessment score predict difficulty at intubation in the emergency department?." Emergency medicine journal 22.2 (2005): 99-102.

Apfelbaum, Jeffrey L., et al. "Practice Guidelines for Management of the Difficult AirwayAn Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway." The Journal of the American Society of Anesthesiologists 118.2 (2013): 251-270.

Nørskov, Anders Kehlet, et al. "Diagnostic accuracy of anaesthesiologists’ prediction of difficult airway management in daily clinical practice: a cohort study of 188 064 patients registered in the Danish Anaesthesia Database." Anaesthesia 70.3 (2015): 272-281.

Williamson, Dominic, and Jerry Nolan. "Airway assessment." Emergency Airway Management (2015): 41.

Huitink, J. M., and R. A. Bouwman. "The myth of the difficult airway: airway management revisited." Anaesthesia 70.3 (2015): 244-249.

Gupta, Sunanda, Rajesh Sharma, and Dimpel Jain. "Airway assessment: predictors of difficult airway." Indian J Anaesth 49.4 (2005): 257-262.

Question 1c - 2004, Paper 1

A 60-year-old woman has a right hemi-hepatectomy for invasive cholangio-carcinoma. She has been admitted to your unit for postoperative care

c)        On day 6 she has a massive melaena requiring urgent endoscopy in the Intensive Care Unit. She requires endotracheal intubation. How will you perform this?

College Answer

There probably will be hypovolaemia, a potentially full stomach, hepatic, renal dysfunction and encephalopathy. The safest method of intubation is mandatory.

Consider: Preparation of intubation (what equipment, help, drugs,), what monitoring, description of probable rapid sequence induction with cricoid pressure.

Discussion

This is another one of those "how would you prepare for intubation" questions.

  • Preparation of equipment
    • Laryngoscope is check and working
    • there is a backup laryngoscope with a macintosh blade
    • there is a fully charged videolaryngoscope available
    • monitoring equipment is online and attached tot he patient
  • Preparation of staff
    • skilled staff are available, and briefed about the procedure
    • backup is available, in the form of a senior anaesthetist
  • Preparation of drugs
    • propofol
    • fentanyl
    • muscle relaxant (suxamethonium is preferred)
    • reversal agent (sugammadex)
  • Preparation of patient
    • assess the level of cooperation to be expected (eg. delirium)
    • get consent
    • explain procedure
    • position the patient comfortably
  • Specific features of the procedure
    • rapid sequence induction with cricoid pressure and no bag ventilation
  • Post-procedure considerations
    • Any hepatic or renal dysfunction will delay the clearance of anaesthtic agents, and will delay extubation

References

Question 7 - 2004, Paper 1

Outline the potential advantages and disadvantages of a tracheostomy in the weaning of patients from mechanical ventilation.

College Answer

Limited actual clinical trial data is available to support the performance of a tracheostomy over maintaining prolonged endotracheal intubation. Purported advantages include: less laryngeal pathology (not supported by the literature); improved patient comfort including reduced respiratory work of breathing and less sedation requirements for tube tolerance; improved communication (speech not possible with ETT), enhanced nursing care (including mouth care & mobility), ease of replacement of tracheal tube, ease of removal/reinstitution of ventilatory support, facilitate transfer to ward (with airway protection and ready airway access for suctioning).

Potential disadvantages include: requirement for surgical procedure and therefore associated peri-operative and post- operative procedural risks including haemorrhage, pneumothorax, tracheal perforation, and even death; increased aspiration risk, increased incidence of nosocomial pneumonia; increased risk of subglottic stenosis and granuloma formation; infection of stoma; occlusion of tracheostomy tube (posterior tracheal wall, granulomata, secretions [if not regular change of tube or inner cannula and/or problems with humidification]); problems associated with decannulation (either elective or emergent: including complicate emergency airway management).

Discussion

Local resources for this topic:

Published literature:

Advantages of tracheostomy

  • Improved patient comfort
    • Decreased sedation requirement
    • Enhanced ability to communicate
    • Improved positioning and mobility
  • Avoidance of orotracheal tube-related complications
    • Less vocal cord damage
    • Less risk of laryngeal stenosis
    • Better recovery of voice quality
    • Less damage to the tongue and lips
  • Improved mechanics of ventilation
    • Lower resistance to air flow
    • Decreased work of breathing
    • Decreased apparatus dead space
    • Improved respiratory function parameters:
    • More rapid weaning from mechanical ventilation 
  • Advantages in airway care and secretion control
    • Lower incidence of tube obstruction
    • Better oral hygiene
    • Better clearance of secretions by suctioning
    • Lower incidence of VAP
  • Advantages for upper airway function
    • Better preservation of swallowing
    • Earlier oral feeding
    • Preservation of "glottic competence"
    • Decreased aspiration risk 
  • Pragmatic advantages
    • Less skilled insertion
    • Less skilled care
    • Deferral of end-of-life decisions to a better time

Disadvantages of tracheostomy

  • Disadvantages related to safety and complications
  • Disadvantages related to care for the artifical airway
    • Complication of emergency airway management
    • Skilled care is still required
  • Ethical implications
    • Failure to wean despite tracheostomy is still possible
    • There is no mortality benefit from tracheostomy

References

Durbin, Charles G. "Indications for and timing of tracheostomy." Respiratory care 50.4 (2005): 483-487.

Sue, Richard D., and Irawan Susanto. "Long-term complications of artificial airways." Clinics in chest medicine 24.3 (2003): 457-471.

Davis, Kenneth, et al. "Changes in respiratory mechanics after tracheostomy." Archives of surgery 134.1 (1999): 59-62.

Pierson, David J. "Tracheostomy and weaning." Respiratory care 50.4 (2005): 526-533.

De Leyn, Paul, et al. "Tracheotomy: clinical review and guidelines." European journal of cardio-thoracic surgery 32.3 (2007): 412-421.

Clec’h, Christophe, et al. "Tracheostomy does not improve the outcome of patients requiring prolonged mechanical ventilation: A propensity analysis*." Critical care medicine 35.1 (2007): 132-138.

Frutos-Vivar, Fernando, et al. "Outcome of mechanically ventilated patients who require a tracheostomy*." Critical care medicine 33.2 (2005): 290-298.

Manthous, Constantine A., and Gregory A. Schmidt. "Resistive pressure of a condenser humidifier in mechanically ventilated patients." Critical care medicine 22.11 (1994): 1792-1795.

Question 2a - 2004, Paper 2

A 45-year-old intellectually handicapped man is admitted to your Intensive Care Unit for airway management.  He was nasally intubated for evacuation of a large dental abscess, which had caused airway compromise.

(a)        Describe how you would assess him for extubation.

College Answer

(a)        Describe how you would assess him for extubation.

Readiness for extubation requires an assessment of factors that necessitated intubation in the first place, and standard criteria. Standard criteria would include:
·           adequacy of oxygenation (usually on low level of FIO2 [eg. 0.4] and PEEP [eg. 5]),
·           ventilation (minimal respiratory supports eg. low level of pressure support [eg. :: 10]
or tube compensation; some other ventilatory indices may be used [eg. VE < 10
L/min, tidal volume :respiratory rate ratio, maximal inspiratory force [negative pressure]),
·           protection of airway (adequate cough ± gag),
·           ability to clear secretions (sputum production and cough), and
·           appropriate neurological state (usually/preferably obeys command, orientated). Specifics for this man would also include:
·           an assessment of the airway swelling (supraglottic) via direct questioning (limited) and direct or indirect visualisation(laryngoscopy, endoscopy). Discussion with treating surgical team critical, especially with regard to timing, as swelling likely to increase over the first 48 hours. Uncommonly need more formal imaging.
·           acceptable neurological state given his intellectual handicap (limited ability to understand and/or co-operate may alter threshold for the previously mentioned criteria).

Discussion

This question closely resembles Question 11 from the second paper of 2011. In order to simplify revision, the answer to that question is duplicated below.

The normal criteria for extubation readiness are as follows:

Assessment of the Readiness for Extubation
Basic pre-conditions
  • Resolution of the condition which had required the intubation and ventilation
  • Patient-directed mode of ventilation (eg. PSV)
  • Haemodynamic stability (the patient is unlikely to need massive fluid resuscitation in the near future, and their cardiac function is satisfactory to endure the increased demand from hard-working respiratory muscles)
  • Adequate muscle strength
Airway protection assessment
  • Good cough reflex on tracheal suctioning
  • Good gag reflex on oropharyngeal suctioning
  • Adequate neurological performance (obeying commands, or at whatever cognitive baseline previously permitted spontaneous breathing)
Gas exchange criteria
  • Adequate oxygenation: SpO2 over 90%  on FiO2 under 40%
  • Normal acid base status (pH >7.25), i.e. no significant respiratory acidosis
Lung mechanics criteria
  • Adequate oxygenation: FiO2 40%
  • PEEP less than 8 cmH2O
  • Satisfactory tidal volume: VT > 5ml/kg
  • Satisfactory vital capacity: VC > 10ml/kg
  • Satisfactory MIP: less than 20-25 cmH2O (i.e pressure trigger)
  • Satisfactory RSBI: an  fR/VT less than 105 breaths.min-1L-1

... in the model answer, one may also want to mention that 30% of patients who DONT satisfy these criteria can still be successfully extubated.

The Specific criteria for this patient

  • Direct laryngoscopy to visually assess airway oedema should reveal an improvement in the swelling and predict the difficulty of reintubation laryngoscopy.
  • There should be a surgical plan for ongoing management of swelling
  • The neurological criteria for extubation should be adjusted (one cannot expect everybody to obey commands and be orientated)

Things to consider before a difficult extubation:

  • Perform a cuff leak test. The cuff leak is a good indicator: if it is present, there is little likelihood of post-extubation stridor . Sure, the patient may fail for a hundred other reasons, but at least they will not br stridorous. In fact, failing the cuff leak test does not preclude a successful extubation (Kriner et al, 2006), but in a patient with a difficult airway one would want to be extra careful.
  • See the airway before extubation. This is particularly important in cases where some sort of primary airway problem was the main reason for intubation. An excellent example of such a scenario is the a 45 year old "intellectually handicapped man" from the college SAQs (Question 11  from the second paper of 2011 and Question 2a from the second paper of 2004). The man had a large dental abscess which affected his airway. Before extubating him, the wise candidate would ask for direct laryngoscopy in order to
  • Scan the airway before extubation. This is an extension of direct laryngoscopy, which can only ever show you the intubated larynx. If there is some sort of sublaryngeal pathology (eg. subglottic stenosis) a CT would reveal it, whereas laryngoscopy or bronchoscopy would not.
  • Prepare for management of post-extubation stridor: these techniques are discussed in greater detail elsewhere, but briefly listed they consist of the following:
    • Dexamethasone
    • Adrenaline nebs
    • Extubation on to NIV
    • Extubation on to heliox
    • Extubation in the operating theatre with ENT on standby
  • Extubate over an airway exchange catheter. These are long hollow polyurethane tubes. You can extubate the patient, leaving one in situ (or just the guidewire from one, sitting above the carina). If the patient gets into respiratory trouble, the end of the catheter can be attached to a standard 15mm conector, and the patient may be ventilated by this method while a definitive airway is beign established. Historically, they seem to improve reintubation success rates in cohorts of difficult airway patients. For example, Loudermilk et al (1997) reported a high rate of successful first-time reintubation with these devices.
  • Postpone extubation. Extubation, as the DAS point out, is an entirely elective procedure. There is no such thing as a "crash extubation". There is never any rush. A delay may improve the degree of airway oedema, or allow for expert staff to assemble so that the best chance of reintubation is afforded.
  • Electively convert to tracheostomy. In some circumstance, it is clear that the upper airway problem is persisting and is unlikely to resolve of the medium-term. Prolonged intubation has its own numerous disadvantages and will cause vocal cord oedema eventually, so to keep the patient intubated for an excessively long time is not an option either. In some cases, extubation to you own airway will be impossible and a tracheostomy is inevitable.

References

Andrew D Bersen wrote chapter 27 of the Oh's Manual, which regards mechanical ventilation.

Table 27.3 on page 363 of the 6th edition of Ohs Manual is a nice list of the various indices meantioned above (eg. the rapid shallow breathing index).

On page 362, Bersen references this Chest article from 2001, where the evidence for extubation criteria is summarised.
MacIntyre NR (chairman), Evidence-based guidelines for weaning and discontinuing ventilatory support: a collective task force facilitated by the American College of Chest Physicians; the American Association for Respiratory Care; and the American College of Critical Care Medicine. CHEST December 2001 vol. 120 no. 6 suppl 375S-396S.

Recommendations regarding which conditions favour extubation has been put forward in a 2007 practice guidelines statement by the AARC:
AARC GUIDELINE: REMOVAL OF THE ENDOTRACHEAL TUBE; RESPIRATORY CARE •JANUARY 2007 VOL 52 NO 1 

Karmarkar, Swati, and Seema Varshney. "Tracheal extubation." Continuing Education in Anaesthesia, Critical Care & Pain 8.6 (2008): 214-220.

Mitchell, V., et al. "Difficult Airway Society Guidelines for the management of tracheal extubation." Anaesthesia 67.3 (2012): 318-340.

Kriner, Eric J., Shirin Shafazand, and Gene L. Colice. "The endotracheal tube cuff-leak test as a predictor for postextubation stridor." Respiratory care 50.12 (2005): 1632-1638.

Loudermilk, Eric P., et al. "A prospective study of the safety of tracheal extubation using a pediatric airway exchange catheter for patients with a known difficult airway." CHEST Journal 111.6 (1997): 1660-1665.

Question 22 - 2005, Paper 1

Outline the role of the Laryngeal Mask Airway in the critically ill patient.

College Answer

The Laryngeal Mask Airway has a number of potential roles in the ICU:

•    Most important role is as part of the difficult airway algorithm (use to ventilate when cannot intubate; easily taught, good success rate, buys time)

•    Can be used as a conduit for bronchoscopy and/or intubation in a patient who is difficult to intubate

•    Could be  considered as  part  of  cardiac arrest  management as  an  alternative in establishing airway and ventilation by practitioners not expert in the use of the endotracheal tube

•    Can  be  used  to  maintain  airway  and  ventilation  during  the  performance  of  a percutaneous tracheotomy

•    As an alternative airway during procedures in the ICU

Other variations have been developed (including the intubating laryngeal mask, which is one of the techniques that could be used for the patient who is difficult to intubate).

Discussion

The above list is almost complete.

In summary, the ICU uses of the LMA are:

  • As a backup for "can't intubate, cant ventilate" scenarios
  • You can intubate though it
  • You can pass a bronchoscope through it for tracheostomy
  • You can temporarily ventilate somebody during a procedure
  • You can use it during an arrest instead of an ETT, if skilled staff are not available

References

Question 23 - 2005, Paper 2

List the potential adverse effects of endotracheal intubation, and briefly outline how they can be minimised.

College Answer

The answers provided by the candidates were very disappointing. Endotracheal intubation is so fundamental to Intensive Care practice that a high standard was expected in this question to obtain a pass mark. A list of the major complications and some suggestions regarding prevention were required. Very few candidates included myocardial ischemia, elevation of ICP, the potential for spinal cord injury in the presence of an unstable spine, or even failed intubation. Few candidates listed pre-oxygenation as potentially helpful in preventing hypoxia.

Potential adverse effects included:

Hypoxia, Failed intubation, Oesophageal intubation, Endobronchial intubation, Aspiration, Bronchospasm, Structural damage (including Cord injury/False passage), Foreign body aspiration, Bacteraemia, Hypertension/tachycardia/arrhythmias/myocardial ischaemia, Raised ICP, Hypotension/exacerbation of shock state, Other drug side-effects, Sputum retention / pneumonia, Sub-glottic stenosis, Tracheo-oesophageal fistula.

Discussion

The candidate, who is preparing for their fellowship, does not need to hear how disappointing the college finds the previous candidates. Even among the genre of college feedback, which is notoriously unhelpful, such comments are especially pointless. Must we open a window on this? Sure, not one of the candidates achieved the "high standard" which the examiners considered a pass mark. But some might say that the candidates, all being senior ICU staff, by definition have a superlative understanding of intubation, and that the question was worded in such a profoundly stupid manner that this knowledge did not have a chance to spill out onto the answer booklet. 

Perhaps one might have asked:

"What are the acute physiological consequences of a successful endotracheal intubation? How might these impact adversely on the critically ill patient?

What might be the adverse consequences of a failed intubation attempt?

"Describe some steps which might be taken to protect the patient from these consequences."

"You may tabulate your answer."

Complication

Preventative measure

Failure of intubation

Oesophageal intubation

  • Visual confirmation of ETT position
  • Capnometry
  • Auscultation of the chest

Right main bronchus intubation

  • auscultation of both lungs
  • chest Xray
  • Bronchoscopic confirmation

Broncospasm

  • Pre-intubation nebulised salbutamol or adrenaline

Hypoxia

  • Pre-oxygenation
  • Continuous pulse oximetry

Aspiration

  • Cricoid pressure (debatable)
  • Aspiration of stomach contents by NG tube
  • Fasting the patient in preparation
  • Careful bag-mask ventilation to prevent gastric inflation
  • Alternatively: do not bag-mask ventilate (RSI)

Pneumothorax and tension pneumothorax

  • Use of moderation in bag-mask ventilation volumes
  • Post-intubation CXR

Cuff leak

  • Select a size-appropriate tube

Myocardial ischaemia

  • Use of opiate analgesics as part of intubation drug cocktail to prevent the sympathetic response to laryngoscopy
  • Anaesthtising the vocal cords

Spinal injury

  • Correctly identify patients at risk of spinal injury, and use of inline stabilisation
  • Fiberoptic bronchoscopy

Increased intracranial pressure

  • Use of opiate analgesics as part of intubation drug cocktail to prevent the sympathetic response to laryngoscopy
  • Hyperventilation with bag to decrease CO2 post intubation

Increased intraocular pressure

  • Use of opiate analgesics as part of intubation drug cocktail to prevent the sympathetic response to laryngoscopy
  • Anaesthtising the vocal cords

Structural damage:

-lips
-teeth
-tongue

  • Skilled practitioner
  • Limit the number of attempts by unskilled practitioners
  • Videolaryngoscopy
  • Avoid the use of stylet or bougie
  • Ensure the tip of the stylet is well within the ETT when it is advanced (i.e. not sticking out past the end of the ETT)

References

Griesdale, Donald EG, et al. "Complications of endotracheal intubation in the critically ill." Intensive care medicine 34.10 (2008): 1835-1842.

Rashkin, Mitchell C., and Tern Davis. "Acute complications of endotracheal intubation. Relationship to reintubation, route, urgency, and duration." CHEST Journal 89.2 (1986): 165-167.

Divatia, J. V., and K. Bhowmick. "Complications of endotracheal intubation and other airway management procedures." Indian J Anaesth 49.4 (2005): 308-18.

Question 11 - 2006, Paper 1

Outline how you would assess a patient for potential difficulty with endotracheal intubation.

College Answer

History: of previous difficulty with intubation, infections/swelling affecting mouth or neck, problems with mouth opening or neck movement (arthritis, cervical spine injury), problems with teeth (especially caps/crowns, jaw wiring etc.). Review of a previous anaesthetic chart.

Examination (multiple components) consider:

•    Teeth (maxillary anterior to mandibular; length of upper incisors; ability to prognath mandible; inter-incisor distance [need > 3 cm])

•    Pharynx (ability of visualise uvula and tonsillar pillars; height and narrowness of palate).

•    Mandibular space (thyromental distance 2: 3 fingerbreadths [6 cm]; compliance and distensibility of submandibular space).

•    Length of neck (qualitative: short neck more difficult eg. syndromes).

•    Thickness of neck (qualitative: thick neck decreases ability to align planes).

•    Range of motion (of head and neck: eg. sniffing position)

•    Consider also the ability to assess potential difficulties by actually having a look with a laryngoscope. (10 marks)

In some situations specific investigations may also be indicated (eg. neck X-rays etc.)

Discussion

There are numerous anatomical and historical features which predict difficult intubation.

Anaesthetic history:

  • History of difficult intubation in previous attempts
  • History of airway-altering changes since the last anaesthetic, eg. significant weight gain, C-spine surgery, head and neck radiotherapy, etc.

Patient characteristics:

  • Obesity
  • Obstructive sleep apnea
  • History of snoring

Specific pathologies associated with difficult intubation:

  • Recent intubation (oedema, trauma, etc)
  • Angioedema
  • Airway trauma
  • Airway infection
  • Mediastinal mass, eg. retrosternal goitre
  • Ankylosing spondylitis
  • Acromegaly
  • Degenerative arthritis (i.e. of the C-spine or jaw)
  • Subglottic stenosis
  • Lingual hypertrophy (i.e. big fat tongue)
  • Syndromic appearance:
    •  Treacher-Collins syndrome: Auricular and ocular defects, malar and mandibular hypoplasia
    •  Pierre Robin syndrome: micrognathia, macroglossia,  cleft soft palate
    •  Down syndrome: small mouth; macroglossia
    • Goldenar’s syndrome: malar and mandibular hypoplasia
    • Kippel-Feil syndrome: congenital C-spine fusion

Physical examination: general features

  • Level of consciousness (i.e. is the patient cooperative enough for an awake intubation?)
  • Level of comfort (i.e. can the patient be positioned properly, or are they to short of breath?)
  • Pregnancy (makes everything difficult)
  • Syndromic appearance

Mouth, face and jaw examination

  • Long upper incisors (“buck teeth”)
  • No teeth (edentulous patients are easier to intubated, but harder to bag-mask ventilate)
  • Prominent overbite
  • Inability to “prognath”, i.e to voluntarily protrude the mandible
  • Small mouth opening (3cm is the minimum to comfortably admit a laryngoscope blade).
  • Mallampati score more than 2 (i.e. a barely visible uvula)
  • Arched or narrow palate
  • Compliance of the mandible and mandibular space (i.e. is it possible to manipulate it, or is it relatively fixed by some sort of disease process, eg. a submandibular abscess)
  • Beard
  • Patency of nares: polyps, deviated septum etc.

Neck and posture

  • Thyromental distance (“three ordinary finger breadths”, or 6cm)
  • Mandibulo-hyoid distance of less than 4cm
  • Sternomental distance of less than 12cm
  • Thick short neck
  • Restricted range of neck motion
  • Kyphosis

LEMON is a nice short way of remembering what to look for. It certainly seems to be reliable in predicting difficult intubation:

Look:

  • Does the patient look like the stereotypical difficult intubation?

Evaluate: 3:3:2 rule

  • 3 fingers width of mouth opening
  • 3 fingers width of thyromental distance (from the thyroid cartilage to the mental process of the mandible, colloquially referred to as the chin)
  • 2 fingers width of distance from the hyoid to the thyroid

Mallamati score

  • amount of pharynx which can be seen by opening the mouth

Obesity and obstruction

  • Is the patient morbidly obese?
  • is there some sort of obstruction, eg abscess?

Neck mobility

  • this determines how easy it will be to align the planes

References

Arne, J., et al. "Preoperative assessment for difficult intubation in general and ENT surgery: predictive value of a clinical multivariate risk index." British journal of anaesthesia 80.2 (1998): 140-146.

Wilson, M. E., et al. "Predicting difficult intubation." British Journal of Anaesthesia 61.2 (1988): 211-216.

Cattano, D., et al. "Anticipation of the difficult airway: preoperative airway assessment, an educational and quality improvement tool." British journal of anaesthesia 111.2 (2013): 276-285.

Reed, M. J., M. J. G. Dunn, and D. W. McKeown. "Can an airway assessment score predict difficulty at intubation in the emergency department?." Emergency medicine journal 22.2 (2005): 99-102.

Apfelbaum, Jeffrey L., et al. "Practice Guidelines for Management of the Difficult AirwayAn Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway." The Journal of the American Society of Anesthesiologists 118.2 (2013): 251-270.

Nørskov, Anders Kehlet, et al. "Diagnostic accuracy of anaesthesiologists’ prediction of difficult airway management in daily clinical practice: a cohort study of 188 064 patients registered in the Danish Anaesthesia Database." Anaesthesia 70.3 (2015): 272-281.

Williamson, Dominic, and Jerry Nolan. "Airway assessment." Emergency Airway Management (2015): 41.

Huitink, J. M., and R. A. Bouwman. "The myth of the difficult airway: airway management revisited." Anaesthesia 70.3 (2015): 244-249.

Gupta, Sunanda, Rajesh Sharma, and Dimpel Jain. "Airway assessment: predictors of difficult airway." Indian J Anaesth 49.4 (2005): 257-262.

 

 

Question 1 - 2008, Paper 1

Outline the anatomical relations of the cervical trachea relevant to performing a percutaneous tracheostomy.

College Answer

•    Trachea is attached superiorly to the cricoid cartilage, by the cricotracheal membrane
•    Trachea is covered anteriorly by skin, superficial fascia, strap muscles
(sternohyoid, sternothyroid), and deep (pretracheal) fascia.
•    2nd to 4th rings of the trachea are covered by isthmus of the thyroid anteriorly.
•    Branches of the superior thyroid artery run along the superior aspect of the thyroid isthmus, anterior to the trachea.
•    Lateral lobes of the thyroid lie between the trachea and the carotid sheath and its contents.
•    Oesophagus lies posterior to the trachea.
•    Carotid sheath containing carotid artery, jugular vein, and vagus nerve lie posterolateral to the trachea.
•    Recurrent laryngeal nerves lie posterolaterally in the grove between the trachea and the oesophagus.
•    Anterior jugular veins are often connected by a vein that runs superficially across the lower neck.
•    Inferior thyroid veins lie anterior to the lower part of the cervical trachea, posterior to the strap muscles.

Discussion

A picture is worth a thousand words. Instant Anatomy does it best.  However, if words are called for... Trauma.org has an excellent tutorial on this technique. ANZICS also has a position statement for percutaneous tracheostomy.

In short:

  • Anterior to the second and third rings of the trachea, is merely skin, subcutaneous tissue, sternothyroid and sternohyoid muscles, and pretracheal fascia.
  • Sometimes, there is an anterior communicating jugular vein which also travels through this space.
  • Posteriorly lies the oesophagus.
  • Posterolaterally, on either side of the oeseophagus lie the recurrent laryngeal nerves
  • Laterally, on both sides there are the vagus nerves, carotid arteries and the jugular veins, covered by the carotid sheath
  • Superiorly is the cricoid cartilage and the cricothyroid membrane
  • Inferiorly lies the isthmus of thyroid and the inferior thyroid veins

See?

Superficial anatomy of the neck for percutaneous tracheostomy

References

Muhammad, Joseph Kamal, Edward Major, and David William Patton. "Evaluating the neck for percutaneous dilatational tracheostomy." Journal of Cranio-Maxillofacial Surgery 28.6 (2000): 336-342.

Epstein, Scott K. "Anatomy and physiology of tracheostomy." Respiratory care 50.4 (2005): 476-482.

Question 27 - 2008, Paper 2

What are the risk factors for the development of post-extubation stridor? Briefly outline the treatment of post extubation-stridor.

College Answer

Risk factors:
1)  Duration of IPPV > 5 days
2)  Traumatic or difficult intubation
3)  Prior history of self extubation
4)  Trauma, surgery or infection of upper airways
5)  History of agitation
6)  Female sex
7)  High BMI
8)  Over inflated cuff
9)  Older age group
10) Elevated APACHE
11) Low GCS
12) Large ETT size

Treatment: 
1)  Adrenaline nebs: constrict arterioles, reduce oedema, useful in acute stridor.
2)  Steroids: May be more useful in prevention rather than treatment, commenced 12 hr prior to extubation (recent Lancet paper). Also useful in children
3)  CPAP – relief of symptoms, reduction in work of breathing (needs to be done with caution)
4)  Heliox – improved patient comfort, shown to reduce need for intubation
5)  If all above fail, endotracheal intubation and ventilation

Discussion

A good article is available which details the predictors of stridor following intubation. Another specifically addresses the risk factors for laryngeal oedema and failure of extubation. The last one also contains a discussion of all the management strategies listed in the college answer.

Risk factors for post-extubation stridor

  • The major risk factors for post-extubation stridor listed below have been pillaged from Table 2, Pluijms et al (2015). They are as follows:
    • Prolonged ventilation
    • Female gender
    • Under-sedation (i.e. insufficiently deep; too awake)
    • Difficult intubation (multiple attempts)
    • Self-extubation
    • High BMI (over 26.5)
    • Ratio of tube size to laryngeal size in excess of 45%
    • High cuff pressure
    • High SAPS II score (i.e. severe illness)
    • Medical patient (i.e. it was not an elective perioperative intubation)
  • LITFL also list the following risk factors:
    • prolonged intubation attempt (>10min)
    • oroendotracheal intubation
    • larger tubes
    • short neck
    • trauma patients
    • known airway pathology (tracheal stenosis, tracheomalacia)
    • children
    • small height:internal diameter ETT ratio
    • agitation while intubated
    • recurrent intubations
  • Finally, the college answer to Question 27 from the second paper of 2008 lists several more, which have not been mentioned in either the old (2009) or the more recent (2015) systematic reviews.
    • Trauma, surgery or infection of upper airways
    • Older age group
    • Elevated APACHE

Management of post-extubation stridor

References

Jaber, Samir, et al. "Post-extubation stridor in intensive care unit patients."Intensive care medicine 29.1 (2003): 69-74.

Efferen, L. S., and A. Elsakr. "Post-extubation stridor: risk factors and outcome." Journal of the Association for Academic Minority Physicians: the official publication of the Association for Academic Minority Physicians 9.4 (1997): 65-68.

Wittekamp, B. H., et al. "Clinical review: post-extubation laryngeal edema and extubation failure in critically ill adult patients." Crit Care 13.6 (2009): 233.

Pluijms, Wouter A., et al. "Postextubation laryngeal edema and stridor resulting in respiratory failure in critically ill adult patients: updated review." Critical Care 19.1 (2015): 1-9.

Question 7.2 - 2010, Paper 1

This is an image of a 13 year old boy who rode his motorbike into a single strand of fencing wire, was thrown off and walked 500 metres for help. He now complains of difficulty in breathing. On examination he has stridor.

(a)        How would you manage stridor in this boy?

(b)        How will you secure his airway? Give reasons.

College Answer

(a)        How would you manage stridor in this boy?

•     Oxygen
•    Maintain spont vent in position of comfort until airway secure
•    Nebulised adrenaline
•     Heliox
•    Prepare difficult airway equipment
•    Call for assistance

(b)        How will you secure his airway? Give reasons.

Options 
•    Awake fibreoptic intubation -may risk further laryngotracheal separation
•    Tracheostomy under LA – the safest option available
•    Gas induction with surgeon present for emergency tracheostomy
•    Avoid cricothyroidotomy -  risk of further damage
•    RSI contraindicated – cricoid pressure may cause laryngotracheal separation

Discussion

This boy has either an acute traumatic upper airway injury (eg. fracture of laryngeal cartilage or hyoid) or injury to the surrounding tissues which is now causing airway obstruction due to swelling. Either way, he needs to be intubated.

This question benefits from a systematic approach.

a)

  • Administer oxygen, to preoxygenate
  • Administer nebulised adrenaline
  • Prepare for difficult intubation:
    • Get the difficult intubation equipment trolley
    • Contact senior anaesthetic staff and ENT surgeon
    • Organise drugs for an awake fiberoptic intubation

Generic measures for the management of stridor may apply:

b)

  • Ideally, emergency tracheostomy should be performed (in the operating theatre, by a skilled surgeon and under local anaesthesia), as this is the procedure which is least likely to result in further laryngeal trauma; furthermore it allows the ENT surgeon unobstructed access to the larynx.
  • Awake fiberoptic intubation; why?
    • allows visualisation of the damage to laryngeal structures
    • least likely to produce further laryngeal injury
    • HOWEVER: railroading the tube might result in further damage.
  • Totally unfeasible approaches:
    • RSI (cricoid is contraindicated)
    • Cricothyroidotomy (the larynx is injured and distorted)

References

Schaefer, Steven D. "Management of acute blunt and penetrating external laryngeal trauma." The Laryngoscope 124.1 (2014): 233-244.

This article is probably more useful:

Peady, "Initial Airway Management of Blunt Upper Airway Injuries: A Case Report and Literature Review" Australasian Anaesthesia 2005

Question 21 - 2011, Paper 1

A  40  year  old  man  with  a  history  of  ankylosing  spondylitis  and  known difficulty with intubation on previous elective surgery is admitted to your ICU for hypoxic respiratory failure.   A decision to perform a semi-elective,  awake fiberoptic intubation in the ICU has been made.

Describe how you will prepare for this procedure.

College Answer

(a)       Preparation of patient

•    Consent/explanation  of procedure
•    Obtain history of previous airway difficulty, technique used, complications, etc. (from patient,  letter  from  anaesthetist).H/o  allergies-esp.  to  local  anaesthetics.  Fasting status. Other co-morbidities, eg. coagulopathy.
•    Clinical assessment- of airway itself, mouth opening, nasal cavity/septum, range of neck movement, mental status including ability to understand and cooperate with proposed procedure, degree of hypoxia and ability to pre-oxygenate.

(b)        Preparation of environment/personnel

•    Appropriate lighting with ability to dim.
•    Monitoring - ECG, pulse oximetry, arterial line, capnography set up.
•    Adequate and working IV access
•    Establish comfortable and adequate patient position, pillows, etc.
•    Request help and ensure availability as appropriate- eg. Anaesthetist
•    Ensure presence  of adequate  skilled assistants.  Inform them in detail of steps of procedure  and  assign  roles,  as  appropriate.(eg.  observation  of  patient, administration of sedatives, optimisation of patient position, injection of LA, etc)
•    Discuss a plan B, if technique were to fail.
•    Keep  resuscitation  trolley  easily  available  and  ensure  difficult  airway  equipment available.

(d)        Preparation of drugs

•     Systemic-
o   Antisialagogue- eg. glycopyrrolate
o   Consider proton pump inhibitor.
o   Midazolam/Fentanyl  as appropriate (small doses as patient should be able to cooperate)

•    Local  anaesthetics-  Very  important  in  order  to  achieve  success.  Ensure  not  to exceed recommended doses and allow adequate time to act.
o   Nasal  cavity  and  nasopharynx-  10%  lignocaine  spray  with  phenylephrine spray or cotton tipped pledgets soaked in 4% cocaine or nebuliser filled with
5ml of 4% lignocaine.
o   Oral cavity and oropharynx- 10% lignocaine spray or 2% lignocaine viscous gargles.

•    Extra   local   anaesthetic   may   be   required   to   spray   during   advancement   of bronchoscope.

Discussion

This question separates the dual trainees in ICU and anaesthetics from those who don't routinely have their hands on a bronchoscope.

  • Preparation of equipment
    • bronchoscope is cleaned and checked
    • monitoring equipment is attached
    • Plan B equipment is at the ready (eg. cricothyroidotomy kit)
    • drugs are ready, including local anaesthetics, general anaesthetics, sedatives, opiates, muscle relaxant
  • Preparation of staff
    • skilled staff are available, and briefed about the procedure
    • backup is available, in the form of a senior anaesthetist
  • Preparation of patient
    • get consent
    • explain procedure
    • position the patient comfortably
    • administer mild sedative (eg. small dose of midazolam)
  • Preparation of airway
    • administer glycopyrrolate or atropine to dry secretions
    • spray 10% lignocaine with phenylephrine using atomiser

References

Walsh, Mary E., and G. D. Shorten. "Preparing to perform an awake fiberoptic intubation." The Yale journal of biology and medicine 71.6 (1998): 537.

Question 11 - 2011, Paper 2

A 45-year-old intellectually handicapped man is admitted to your Intensive Care Unit for airway management. He is currently nasally intubated following an evacuation of a large dental abscess that had caused airway compromise. Describe how you would assess his readiness for extubation.

College Answer

Readiness for extubation requires an assessment of factors that necessitated intubation in the first place and standard criteria.


Standard criteria would include:
• Adequacy of oxygenation (usually on FiO2 ~ 0.4 and PEEP 5)
• Ventilation (minimal respiratory support eg low level of PS £ 10). Some other ventilatory indices may be used (eg rapid shallow breathing index, negative inspiratory force, P0.1, CROP, Vt 4-6 ml/kg, Vmin 10-15 L/min)
• Protection of airway (adequate cough ± gag)
• Ability to clear secretions
• Appropriate neurological state (obeys command, orientated)
• Stable haemodynamics not requiring support
• Sepsis controlled
• Metabolic / biochemical parameters normal


Specifics for this man would also include:
• Assessment of airway swelling with direct/indirect visualization
• Discussion with treating surgical team regarding timing and management of ongoing swelling
• Adjust criteria for neurological state given his intellectual handicap

Discussion

This is a straightforward question about criteria for extubation. A curveball is thrown in the form of an intellectual handicap, but it is not anything too extraordinary.

The normal criteria for extubation readiness are outlined below.

Assessment of the Readiness for Extubation
Basic pre-conditions
  • Resolution of the condition which had required the intubation and ventilation
  • Patient-directed mode of ventilation (eg. PSV)
  • Haemodynamic stability (the patient is unlikely to need massive fluid resuscitation in the near future, and their cardiac function is satisfactory to endure the increased demand from hard-working respiratory muscles)
  • Adequate muscle strength
Airway protection assessment
  • Good cough reflex on tracheal suctioning
  • Good gag reflex on oropharyngeal suctioning
  • Adequate neurological performance (obeying commands, or at whatever cognitive baseline previously permitted spontaneous breathing)
Gas exchange criteria
  • Adequate oxygenation: SpO2 over 90%  on FiO2 under 40%
  • Normal acid base status (pH >7.25), i.e. no significant respiratory acidosis
Lung mechanics criteria
  • Adequate oxygenation: FiO2 40%
  • PEEP less than 8 cmH2O
  • Satisfactory tidal volume: VT > 5ml/kg
  • Satisfactory vital capacity: VC > 10ml/kg
  • Satisfactory MIP: less than 20-25 cmH2O (i.e pressure trigger)
  • Satisfactory RSBI: an  fR/VT less than 105 breaths.min-1L-1

... in the model answer, one may also want to mention that 30% of patients who DONT satisfy these criteria can still be successfully extubated.

The Specific criteria for this patient

  • Direct laryngoscopy to visually assess airway oedema should reveal an improvement in the swelling and predict the difficulty of reintubation laryngoscopy.
  • There should be a surgical plan for ongoing management of swelling
  • The neurological criteria for extubation should be adjusted (one cannot expect everybody to obey commands and be orientated)

Things to consider before a difficult extubation:

  • Perform a cuff leak test. The cuff leak is a good indicator: if it is present, there is little likelihood of post-extubation stridor . Sure, the patient may fail for a hundred other reasons, but at least they will not br stridorous. In fact, failing the cuff leak test does not preclude a successful extubation (Kriner et al, 2006), but in a patient with a difficult airway one would want to be extra careful.
  • See the airway before extubation. This is particularly important in cases where some sort of primary airway problem was the main reason for intubation. An excellent example of such a scenario is the a 45 year old "intellectually handicapped man" from the college SAQs (Question 11  from the second paper of 2011 and Question 2a from the second paper of 2004). The man had a large dental abscess which affected his airway. Before extubating him, the wise candidate would ask for direct laryngoscopy in order to
  • Scan the airway before extubation. This is an extension of direct laryngoscopy, which can only ever show you the intubated larynx. If there is some sort of sublaryngeal pathology (eg. subglottic stenosis) a CT would reveal it, whereas laryngoscopy or bronchoscopy would not.
  • Prepare for management of post-extubation stridor: these techniques are discussed in greater detail elsewhere, but briefly listed they consist of the following:
    • Dexamethasone
    • Adrenaline nebs
    • Extubation on to NIV
    • Extubation on to heliox
    • Extubation in the operating theatre with ENT on standby
  • Extubate over an airway exchange catheter. These are long hollow polyurethane tubes. You can extubate the patient, leaving one in situ (or just the guidewire from one, sitting above the carina). If the patient gets into respiratory trouble, the end of the catheter can be attached to a standard 15mm conector, and the patient may be ventilated by this method while a definitive airway is beign established. Historically, they seem to improve reintubation success rates in cohorts of difficult airway patients. For example, Loudermilk et al (1997) reported a high rate of successful first-time reintubation with these devices.
  • Postpone extubation. Extubation, as the DAS point out, is an entirely elective procedure. There is no such thing as a "crash extubation". There is never any rush. A delay may improve the degree of airway oedema, or allow for expert staff to assemble so that the best chance of reintubation is afforded.
  • Electively convert to tracheostomy. In some circumstance, it is clear that the upper airway problem is persisting and is unlikely to resolve of the medium-term. Prolonged intubation has its own numerous disadvantages and will cause vocal cord oedema eventually, so to keep the patient intubated for an excessively long time is not an option either. In some cases, extubation to you own airway will be impossible and a tracheostomy is inevitable.

References

Andrew D Bersen wrote chapter 27 of the Oh's Manual, which regards mechanical ventilation.

Table 27.3 on page 363 of the 6th edition of Ohs Manual is a nice list of the various indices meantioned above (eg. the rapid shallow breathing index).

On page 362, Bersen references this Chest article from 2001, where the evidence for extubation criteria is summarised.
MacIntyre NR (chairman), Evidence-based guidelines for weaning and discontinuing ventilatory support: a collective task force facilitated by the American College of Chest Physicians; the American Association for Respiratory Care; and the American College of Critical Care Medicine. CHEST December 2001 vol. 120 no. 6 suppl 375S-396S.

Recommendations regarding which conditions favour extubation has been put forward in a 2007 practice guidelines statement by the AARC:
AARC GUIDELINE: REMOVAL OF THE ENDOTRACHEAL TUBE; RESPIRATORY CARE •JANUARY 2007 VOL 52 NO 1 

Karmarkar, Swati, and Seema Varshney. "Tracheal extubation." Continuing Education in Anaesthesia, Critical Care & Pain 8.6 (2008): 214-220.

Mitchell, V., et al. "Difficult Airway Society Guidelines for the management of tracheal extubation." Anaesthesia 67.3 (2012): 318-340.

Kriner, Eric J., Shirin Shafazand, and Gene L. Colice. "The endotracheal tube cuff-leak test as a predictor for postextubation stridor." Respiratory care 50.12 (2005): 1632-1638.

Loudermilk, Eric P., et al. "A prospective study of the safety of tracheal extubation using a pediatric airway exchange catheter for patients with a known difficult airway." CHEST Journal 111.6 (1997): 1660-1665.

Question 22 - 2012, Paper 2

You are called urgently to the Emergency Department to review a 63-year-old male with chronic airflow limitation who is rapidly deteriorating. He is spontaneously breathing and a known difficult intubation.

Outline the priorities in this man’s management.

College Answer

This is an emergency situation with the following key issues:

Rapid deterioration in a patient with airflow limitation 
Preparation for a difficult intubation

Management comprises simultaneous resuscitation and assessment to diagnose the cause(s) of the rapid deterioration in this patient and initiation of supportive and definitive management and at the same time calling for help and preparing for a difficult intubation.

Prompt diagnosis and appropriate focussed management of the underlying cause(s) may obviate the need for intubation in this patient but should not delay intubation if this needs to be done.

Help should be sought from the most appropriate resources available (senior ED or anaesthetic colleague, ENT, skilled anaesthetic technician)

Diagnosis of underlying cause depends on history, examination and specific investigations. Possible causes of rapid deterioration in this patient include tension pneumothorax, worsening bronchospasm, pneumonia and septic shock, pulmonary embolus, myocardial ischaemia. Treatment measures may include thoracocentesis / insertion ICC, bronchodilators, fluid and vasopressor resuscitation and antibiotics, thrombolysis, reversal coronary ischaemia.

Consideration should be given to a trial of NIV but again this should not delay necessary intubation.

If the underlying problem is not readily reversible, proceed to securing the airway with preparation for difficult intubation.

Preparation for difficult intubation involves the following:

Location 
Patient unsuitable for transfer to OT so use well-equipped resus bay in ED

Equipment

Standard intubation equipment plus difficult airway trolley including equipment for emergency surgical airway, resuscitation equipment and full monitoring and ETCO2

Drugs

Sedatives, muscle relaxants, resuscitation drugs and local anaesthetics

Personnel

Experienced assistants for airway equipment, drugs, cricoid pressure and general help Experienced colleague (ICU, anaesthesia, ED, ENT)

Technique

Assess patient’s airway and information regarding previous intubations and nature of difficulty and ease of bag-mask ventilation. It may be appropriate to perform immediate tracheostomy or cricothyroidotomy under local anaesthesia. Difficult to intubate BUT easy to ventilate increases options.

  • Plan A: attempted intubation under direct laryngosopy optimizing position and using adjuncts and if fails: 
  • Plan B: Intubating LMA and if fails:
  • Plan C: able to ventilate via LMA, controlled surgical airway OR if unable to ventilate via LMA emergency surgical airway (cricioidotomy or cricoidostomy)

Discussion

Whenever one is asked to "outline the priorities", one shoud probably begin with attention to the immediate ABCs of management.

After that, the priorities here are firstly the management of acute respiratory failure, and secondly the preparation for a difficult intubation.

Immediate attention to ABCs:

  • Assessment of the need for immediate intubation
  • Support of airway with airway adjuncts eg Guedel or nasopharyngeal airway
  • Support of oxygenation with high-flow oxygen and/or NIV
  • Assessment of coexisting circulatory failure with rapid bedside TTE and lung ultrasound to exclude immediately reversible causes eg. pneumothorax and cardiac tamponade or acute decompensated heart failure
  • Support of circulation with appropriate vasoactive agents

Management of respiratory failure:

  • Detailed history and thorough physical examination
  • ABG, ECG and CXR +/- CTPA (if permited by patients condition)
  • Support of oxygenation with titrated FiO2
  • Support work of breathing with NIV
  • Support ventilation by titrating NIV pressures to enhance CO2 clearance
  • Manage bronchospasm with bronchodilators and steroids
  • Manage infective aetiology with appropriate antibiotics

Preparation for a difficult intubation:

  • Transfer patient into controlled monitored environment - resus bay, ICU or operating theatre
  • Contact appropriate airway experts - a senior anaesthetist and ENT surgeon are sensible consults
  • Organise the difficult intubation equipment trolley
  • Prepare skilled staff to assist
  • Prepare equipment and brief patient regarding the need for intubation
  • Assess the airway and investigate past history of intubation to determine what equipment was required in previous instances
  • Options for intubations:
    • Awake bronchoscopic intubation is the gold standard
    • If the expertise for this is not available:
      • Plan A: Video-assisted laryngoscopy with availability of gum elastic bougie
      • Plan B: insertion of intubating LMA and intubation via LMA or ventilation with LMA until the necessary expertise becomes available
      • Plan C: percutaneous cricothyroidotomy or formal surgical airway

A generic list of difficult airway equipment to have ready:

  • A selection of oropharyngeal airways
  • A selection of nasopharyngeal airways
  • Macintosh laryngoscope blades size 3 and 4.
  • Alternative laryngoscope blades (eg. a Kessel blade)
  • A short laryngoscope handle (for fat or big-breasted people)
  • An endotracheal tube introducer
  • A malleable blunt atraumatic stylet.
  • Normal LMAs of different sizes
  • Intubating LMA kids, eg. Fastrach
  • A selection of specialised ETTs, eg. long flexometallic, nasal, etc.
  • A long airway exchange catheter.
  • A surgical cricothyroidotomy kit
  • A kink resistant cricothyroidotomy cannula and jet ventilation kit
  • A capnograph, capnometer or colorimetric end-tidal CO2 detector.

References

Hyperglycemic Comas by P. VERNON VAN HEERDEN from Vincent, Jean-Louis, et al. Textbook of Critical Care: Expert Consult Premium. Elsevier Health Sciences, 2011.

Oh's Intensive Care manual: Chapter 58  (pp. 629) Diabetic  emergencies  by Richard  Keays

Umpierrez, Guillermo E., Mary Beth Murphy, and Abbas E. Kitabchi. "Diabetic ketoacidosis and hyperglycemic hyperosmolar syndrome." Diabetes Spectrum15.1 (2002): 28-36.

ARIEFF, ALLEN I., and HUGH J. CARROLL. "Nonketotic hyperosmolar coma with hyperglycemia: clinical features, pathophysiology, renal function, acid-base balance, plasma-cerebrospinal fluid equilibria and the effects of theraphy in 37 cases." Medicine 51.2 (1972): 73-94.

Gerich, John E., Malcolm M. Martin, and Lillian Recant. "Clinical and metabolic characteristics of hyperosmolar nonketotic coma." Diabetes 20.4 (1971): 228-238.

Kitabchi, Abbas E., et al. "Hyperglycemic crises in adult patients with diabetes." Diabetes care 32.7 (2009): 1335-1343.

Kitabchi, Abbas E., et al. "Hyperglycemic crises in adult patients with diabetes a consensus statement from the American Diabetes Association." Diabetes care 29.12 (2006): 2739-2748.

Ellis, E. N. "Concepts of fluid therapy in diabetic ketoacidosis and hyperosmolar hyperglycemic nonketotic coma." Pediatric clinics of North America 37.2 (1990): 313-321.

Pinies, J. A., et al. "Course and prognosis of 132 patients with diabetic non ketotic hyperosmolar state." Diabete & metabolisme 20.1 (1993): 43-48.

Question 13 - 2013, Paper 1

Critically evaluate the timing of elective tracheostomy in adult Intensive Care patients.

College Answer

Introduction

Tracheostomy is performed in critically ill adults requiring prolonged invasive ventilation as a strategy to reduce respiratory tract injury, improve patient confort and/or to facilitate weaning. Timing of tracheostomy has been a subject of debate and may be considered as “early” at <10 days or “late” >10 days although these definitions may vary.

Rationale

There has been debate as to whether “early” trache may confer advantages of reduced morbidity and mortality Disadvantages of tracheostomy include airway trauma, bleeding and death and this may be increased by doing an “ early” tracheostomy in patients who may otherwise die or be extubated before 10 days. 
Early tracheostomy is a consideration in patients with neurological issues (brain injury, GBS, CVA etc.) and shortens time on ventilator and time in ICU.

Evidence

Many studies and meta-analyses of variable quality have evaluated this issue. Methodological issues include differences in “early” and “late” timing, prediction of which patients will require “long-term” ventilation, exclusion/inclusion of specific patient groups and diagnosis of end-points such as VAP.

Cochrane Review 2012 considered 4 studies (latest 2010) to meet inclusion criteria. Conclusions were that quality of evidence to date was poor and results conflicting. Recent RCT Tracman Study from UK – tracheostomy at 1-4 days v >10 days invasive ventilation. Early tracheostomy associated with shorter duration of sedation but increased number of procedures and associated complications with no beneficial effect on overall mortality not ICU/hospital LOS.

Studies have evaluated patients with respiratory failure and not those intubated for neurological injury.

Own Practice

Any reasonable approach acceptable.

Summary

Lack of evidence to support early v late trache overall. Selected patients eg neurotrauma, GBS, stroke may benefit from early. 
Probably best decided on case by case basis.

Involves invasive procedure with attendant risks and complications and needs appropriate expertise.

Discussion

The timing of tracheostomy is well discussed in a recent meta-analysis. Sure, its PLOS, and sometimes people only value the advice they have to pay for, but I think it is of a high quality. The model answer makes reference to TracMan, a trial which had not yet been published at the time of the exam, and so could not have been expected as a part of an answer to this question. If this question were repeated in future papers (eg. Question 13 from the second paper of 2017)  modern data expected of the candidates would probably come from the 2015 meta-analysis article by  Andriolo et al and Szakmany et al, which arrived at essentially the same conclusions (in three words, early vs late tracheostomy makes no difference to any parameters of interest when you homogenise the ICU population). 

Introduction:

  • Typically tracheostomy is performed on patients with difficulty weaning.
  • Some argument exists whether patients who are likely to require prolonged weaning should have this procedure early, and whether this improves their outcome
  • No agreement exists regarding the definition of what is late and what is early tracheostomy
    • the 10 day cutoff is mentioned by the college, and it probably comes from TracMan.
  • No agreement exists as to the selection of patients who might benefit

Rationale for early tracheostomy:

  • Early tracheostomy exposes the patient to the various advantages of tracheostomy, which are:
    • decreased dead space
    • decreased airway injury
    • lower airway resistance and improved work of breathing
    • decreased sedation requirements and improved comfort
    • avoidance of complications of prolonged intubation
    • earlier oral feeding
    • decreased incidence of VAP
    • decreased length of ICU stay
    • avoidance of the perils of prolonged intubation
  • The argument is that the earlier this is performed, the better.

Rationale for delaying tracheostomy:

  • The counter-argument is that patients who would have otherwise been successfully extubated would undergo an unnecessary tracheostomy. Such a practice would expose them to the risks of tracheostomy, which are:
    • bleeding and wound infection
    • potential for periprocedure complications, such as tracheo-oesophageal fistula
    • tracheomalacia and tracheal stenosis
    • potential for dislodgement and airway failure
  • Some patients may end up being extubated after a prolonged intubation
  • A long period of intubation allows these patients to be more easily identified. 
  • Risks of prolonged intubation are probably overstated
  • Futile care may be perpetuated by tracheostomy. 
  • Length of ICU stay is largely a financial rather than medical consideration, and some might argue that it is inappropriate to let such matters influence decisions regarding patient care.

Evidence:

Cochrane review  by Andriolo et al (2015):

  •   n=1977, of which 909 were from TracMan.
  • There was a statistically significant mortality benefit associated with early tracheostomy (47% vs 53%); the NNT was 11. This mortality benefit was seen at the longest reported follow-up, rather than at 30 days.
  • The early group had a higher chance of being discharged from the ICU on day 28.
  • There was no statistically significant effect on the duration of mechanical ventilation.
  • The early group had decreased duration of sedation.
  • Data regarding risk of pneumonia could not be subjected to meta-analysis due to heterogeneity.

Own practice:

  • An impression of the likelihood of a patient requiring tracheostomy can form early in their stay (eg. poor neurological recovery, permanent loss of airway reflexes, or existing chronic lung disease). Such patients should be offered tracheostomy early, and to delay it would expose them to the risks of of prolonged intubation. Each case should be evaluated according to its own unique features, and risk must be weighed against benefit.

Summary:

  • Broadly speaking, early tracheostomy does not influence outcome in ICU patients.
  • Some ICU patients may still benefit from an early tracheostomy, but features which identify them are not well established, and the decision still relied on case-by-case analysis and clinical experience.

References

Huang, Huibin, et al. "Timing of Tracheostomy in Critically Ill Patients: A Meta-Analysis." PloS one 9.3 (2014): e92981.

Young, Duncan, et al. "Effect of early vs late tracheostomy placement on survival in patients receiving mechanical ventilation: the TracMan randomized trial." Jama 309.20 (2013): 2121-2129.

Longworth, Aisling, et al. "Tracheostomy in special groups of critically ill patients: Who, when, and where?." Indian Journal of Critical Care Medicine 20.5 (2016): 280.

Baron, David Marek, et al. "Tracheostomy is associated with decreased hospital mortality after moderate or severe isolated traumatic brain injury." Wiener klinische Wochenschrift (2016): 1-7.

Hosokawa, Koji, et al. "Timing of tracheotomy in ICU patients: a systematic review of randomized controlled trials." Critical Care 19.1 (2015): 1-12.

Gomes Silva, Brenda Nazaré, et al. "Early versus late tracheostomy for critically ill patients." Cochrane Database Syst Rev 3 (2012).

Andriolo, B. N., et al. "Early versus late tracheostomy for critically ill patients." Cochrane Database Syst Rev 1 (2015).

Szakmany, T., et al. "Effect of early tracheostomy on resource utilization and clinical outcomes in critically ill patients: meta-analysis of randomized controlled trials." British journal of anaesthesia 114.3 (2015): 396-405.

Question 24 - 2013, Paper 1

An 18-year-old male presents following a bicycle crash with obvious facial injuries. He has profuse bleeding from the mouth and nose and insists on sitting up at 90 degrees. He has bruising under both eyes, his face is significantly swollen and his mid-face is mobile. His breathing is “noisy”.

His vital signs are as follows:

  • HR 105 beats/minute;
  • BP 115/60 mmHg;
  • RR 30 breaths/min;
  • SpO2 92% on room air.

His GCS is 15. He has no cervical spine injury and no other significant injuries.

List the possible techniques for securing the airway in this patient, and the pros and cons of each.

College Answer

Rapid Sequence Induction:

Pro:

Rapid technique - may be only option if patient peri – arrest No special expertise required 
May be best technique with ENT/Surgical backup at bedside to perform immediate tracheostomy if intubation fails.

Con:

Obscured / absent landmarks (potential to lose airway with RSI)

  1. Airway swelling
  2. Haematomata and ongoing haemorrhage
  3. Bony and soft tissue trauma

Co-existing upper airway / tracheal injuries Patient unable to lie flat 
Left lateral position may be preferred but increases degree of difficulty Limited respiratory reserve 
Pre-oxygenation, bag-mask ventilation problematic

Likely to become haemodynamically unstable with sedation

Cricothyroidotomy / Awake tracheostomy:

Pro:

Safe – no risk of losing airway

Patient breathing throughout

Con:

May be difficult without sedation Positioning may be problematic

May be technically challenging in the setting of local tissue damage and haemorrhage

Fibreoptic intubation:

Pro:

No risk of losing airway 
Patient breathing throughout

Con:

Likely to be extremely challenging in the setting of ongoing haemorrhage

Attempted nasotracheal intubation could result in nasocranial passage of tube and/or severe nasal haemorrhage 
Need expert/experienced airway assistance

Awake direct laryngoscopy / intubation:

Pro:

Quick – no time wastage

Reduced risk of losing airway 
Patient breathing throughout 
Uses standard intubating equipment 
May be method of choice with senior operator

Allows easy transition to a back-up technique

Con:

Technically challenging 
Needs adequate local anaesthesia 
Positioning patient problematic

Credit given to discussion of any sensible technique and any relevant introductory or concluding statement giving a summary of the issues.

Discussion

This patient is suffering from fractures of the mid-face.

There are several options for securing the airway in this patient.

Firstly, does he need intubation? It seems he does, as his respiratory rate is rapid, and his oxygenation is poor. Likely, he has inhaled some blood. And NIV is absolutely contraindicated in such people. So yes, he does need intubation - largely for airway protection, to prevent vast quantities of blood and snot from seeping into his lungs.

And the savvy candidate will have arrived at this conclusion without a half a page of introductory gibberish.

So, the question asked by the college really is "how do you intubate a hypoxic patient with facial injuries".

They ask for pros and cons, which lends itself well to a tabulated answer.

Technique Advantages Disadvantages
Rapid sequence induction
  • requires less skill
  • requires little preparation
  • If the airway is difficult, it may be disastrous
  • This airway is likely to be difficult
  • pre-oxygenation is going to be interesting (the patient cant lie flat)
  • bag-mask ventilation is impossible (facial fractures)
Fibreoptic intubation
  • patient is awake and breathing throughout the procedure
  • gold standard for difficult airways
  • Requires skilled staff
  • Takes time to prepare
  • Might be difficult if blood and debris is in the airway
  • cannot be performed nasally (fractured face)
Percutaneous cricothyroidotomy
  • patient is awake and breathing throughout the procedure
  • Little chance of airway loss
  • Hghly invasive procedure, may be poorly tolerated
  • cannot lie flat

Then, the college asks for a sensible concluding statement, without demonstrating what one should look like.

In summary, this patient requires intubation by skilled technicians, with backup equipment available. If the patient is peri-arrest, there is not time for any technique other than RSI. Ideally, a videolaryngoscope should be available. Otherwise, the first attempt should be an awake fiberoptic orotracheal intubation, with the opportunity to convert to RSI. In the event that both techniques fail, a percutaneous cricothyroidotomy should be the approach of last resort.

In addition to this "model answer" (pfft) I have also found unusual trivia around the medical literature. There are many ways to approach intubation in the patient with midfacial injuries.

For instance, a submental approach is a well-recognised approach. Retrograde intubation may be attempted, which might be even bloodier than the cricothyroidotomy. These techniques and others are discussed in a good 2009 review article of airway management in facial trauma.

References

Caron, Guy, et al. "Submental endotracheal intubation: an alternative to tracheotomy in patients with midfacial and panfacial fractures." Journal of Trauma and Acute Care Surgery 48.2 (2000): 235-240.

Barriot, P. A. T. R. I. C. K., and B. R. U. N. O. Riou. "Retrograde technique for tracheal intubation in trauma patients." Critical care medicine 16.7 (1988): 712-713.

Mohan, Raja, Rajiv Iyer, and Seth Thaller. "Airway management in patients with facial trauma." Journal of Craniofacial Surgery 20.1 (2009): 21-23.

Question 10 - 2014, Paper 1

A 67-year-old male has been intubated and ventilated in your ICU for the last 15 days following an upper GI bleed and banding of oesophageal varices. He is obese (BMI 31), has alcoholic liver disease and smokes heavily. He has been assessed as unsuitable for transplantation. His ICU stay has been complicated by aspiration pneumonia, acute kidney injury and ongoing encephalopathy.
 
Discuss the potential benefits and risks of percutaneous dilatational tracheostomy (PDT) in this patient.

College Answer

PDT is a common procedure in Australasian ICUs to facilitate airway management and/or weaning from MV. PDT in this man may be helpful in this regard, but presents significant problems related to body habitus and acute and chronic comorbidities.
Benefits:
 May help facilitate ventilatory weaning
 Increased patient comfort
 Improved management of secretions
 May facilitate mobilisation during weaning
 Potentially reduced sedation requirements

 Provide a secure airway in the setting of a fluctuating conscious state

Risks:

Difficult placement / maintenance:
o Should mention potentially difficult airway
o May have difficult neck anatomy as obese/increased risk of malposition or tracheal injury
o High risk of dislodgement later on if standard trache tube used

Bleeding risk
 Likely coagulopathy secondary to CLD
 Likely thrombocytopenia secondary to portal hypertension / hypersplenism.
 May have systemic venous hypertension (portosystemic shunting, alcoholic cardiomyopathy etc.)

Infection risk
 Increased in setting of chronic liver disease
 Increased in obesity
 Poor wound healing in heavy smoker

General risks
 Loss of airway
 Pneumothorax
 Hypoxaemia (defer if FiO2 > 0.6 and PEEP > 10)
 Cardiac arrest
 Death

Wisdom issues
 Prognosis guarded at best even with tracheostomy; long-term outlook is poor and it will not treat any of this man's underlying issues: therefore requires due consideration / deliberation.
 Number of prior presentations for the same problem are also a factor
 Patient's previously expressed wishes a consideration but ultimately a medical decision
 Risk/benefit ratio may not be favourable: ongoing aggressive treatment of encephalopathy with view to primary extubation may be better.
 If deemed appropriate to proceed, surgical tracheostomy may be a safer alternative

Examiners' comments: Some candidates discussed PDT in general rather than issues as they related to this patient.

Discussion

Local resources for this topic:

Published literature:

Advantages of "PDT in general" are offered below:

Advantages and Disadvantages of Tracheostomy

Advantages of tracheostomy in general

  • Improved patient comfort
    • Decreased sedation requirement
    • Enhanced ability to communicate
    • Improved positioning and mobility
  • Avoidance of orotracheal tube-related complications
    • Less vocal cord damage
    • Less risk of laryngeal stenosis
    • Better recovery of voice quality
    • Less damage to the tongue and lips
  • Improved mechanics of ventilation
    • Lower resistance to air flow
    • Decreased work of breathing
    • Decreased apparatus dead space
    • Improved respiratory function parameters:
    • More rapid weaning from mechanical ventilation 
  • Advantages in airway care and secretion control
    • Lower incidence of tube obstruction
    • Better oral hygiene
    • Better clearance of secretions by suctioning
    • Lower incidence of VAP
  • Advantages for upper airway function
    • Better preservation of swallowing
    • Earlier oral feeding
    • Preservation of "glottic competence"
    • Decreased aspiration risk 
  • Pragmatic advantages
    • Less skilled insertion
    • Less skilled care
    • Deferral of end-of-life decisions to a better time

Disadvantages of tracheostomy in general

  • Disadvantages related to safety and complications
  • Disadvantages related to care for the artifical airway
    • Complication of emergency airway management
    • Skilled care is still required
  • Ethical implications
    • Failure to wean despite tracheostomy is still possible
    • There is no mortality benefit from tracheostomy

Arguments against tracheostomy in this specific patient:

  • Difficulty:
    • Morbid obesity makes the procedure more risky
    • Morbid obesity also makes future dislodgement more likely
    • Agitation from encephalopathy makes dislodgement more likely
    • Coagulopathy from liver disease makes the procedure more risky
  • Futility:
    • Ineligibility for transplant makes long-term prognosis poor
    • Multi-organ system failure in this (presumably, Child-Pugh class C) patient is associated with a near-100% in-hospital mortality (see the chapter on Staging and prognosis of chronic liver disease in ICU)

References

Durbin, Charles G. "Indications for and timing of tracheostomy." Respiratory care 50.4 (2005): 483-487.

Sue, Richard D., and Irawan Susanto. "Long-term complications of artificial airways." Clinics in chest medicine 24.3 (2003): 457-471.

Davis, Kenneth, et al. "Changes in respiratory mechanics after tracheostomy." Archives of surgery 134.1 (1999): 59-62.

Pierson, David J. "Tracheostomy and weaning." Respiratory care 50.4 (2005): 526-533.

De Leyn, Paul, et al. "Tracheotomy: clinical review and guidelines." European journal of cardio-thoracic surgery 32.3 (2007): 412-421.

Clec’h, Christophe, et al. "Tracheostomy does not improve the outcome of patients requiring prolonged mechanical ventilation: A propensity analysis*." Critical care medicine 35.1 (2007): 132-138.

Frutos-Vivar, Fernando, et al. "Outcome of mechanically ventilated patients who require a tracheostomy*." Critical care medicine 33.2 (2005): 290-298.

Manthous, Constantine A., and Gregory A. Schmidt. "Resistive pressure of a condenser humidifier in mechanically ventilated patients." Critical care medicine 22.11 (1994): 1792-1795.

Question 13 - 2016, Paper 1

A 40-year-old male with a history of ankylosing spondylitis and known difficulty with intubation with previous elective surgery is admitted to your ICU for hypoxic respiratory failure. A decision to perform a semi-elective, awake fibre-optic intubation in the ICU has been made.

Describe how you will prepare for this procedure.

College Answer

Preparation of patient

  • Consent/explanation of procedure
  • Obtain history of previous airway difficulty, technique used, complications, etc. (from patient, letter from anaesthetist).H/o allergies-esp. to local anaesthetics. Fasting status. Other co-morbidities, e.g. coagulopathy.
  • Clinical assessment – of airway itself, mouth opening, nasal cavity/septum, range of neck movement, mental status including ability to understand and cooperate with proposed procedure, degree of hypoxia and ability to pre-oxygenate.

Preparation of environment/personnel

  • Appropriate lighting with ability to dim
  • Monitoring - ECG, pulse oximetry, arterial line, capnography set up.
  • Adequate and working IV access
  • Establish comfortable and adequate patient position, pillows, etc.
  • Request help and ensure availability as appropriate- e.g. Anaesthetist
  • Ensure presence of adequate skilled assistants. Inform them in detail of steps of procedure and assign roles, as appropriate. (E.g. observation of patient, administration of sedatives, optimisation of patient position, injection of LA, etc.) Discuss a plan B, if technique were to fail.
  • Keep resuscitation trolley easily available and ensure difficult airway equipment available.

Preparation of equipment

  • Check oxygen source and suction
  • Check equipment for bronchoscopy- Intubating bronchoscope, light source, lubricant, suction for bronchoscope, (oxygen can be applied alternately through same port using 3-way tap) and injection port for local anaesthetic. Apply defogging solution, if available.
  • Airway equipment- range of oral and nasal armoured tubes of appropriate size, oral intubating airways, soft nasopharyngeal airways, and appropriate size laryngeal mask airway. Depending on choice of oral or nasal intubation, check, lubricate and load chosen tube onto bronchoscope. Equipment required for plan B.

Preparation of drugs

  • Systemic-
    • Antisialagogue – e.g. glycopyrrolate.
    • Consider proton pump inhibitor.
    • Midazolam/Fentanyl as appropriate (small doses as patient should be able to cooperate)
  • Local anaesthetics - very important in order to achieve success. Ensure not to exceed recommended doses and allow adequate time to act.
    • Nasal cavity and nasopharynx- 10% lignocaine spray with phenylephrine spray or cotton tipped pledgets soaked in 4% cocaine or nebuliser filled with 5ml of 4% lignocaine.
    • Oral cavity and oropharynx- 10% lignocaine spray or 2% lignocaine viscous gargles.
    • Extra local anaesthetic may be required to spray during advancement of bronchoscope.

Discussion

This question is identical to Question 21 from the first paper of 2011. The answer offered here is also identical.

  • Preparation of equipment
    • bronchoscope is cleaned and checked
    • monitoring equipment is attached
    • Plan B equipment is at the ready (eg. cricothyroidotomy kit)
    • drugs are ready, including local anaesthetics, general anaesthetics, sedatives, opiates, muscle relaxant
  • Preparation of staff
    • skilled staff are available, and briefed about the procedure
    • backup is available, in the form of a senior anaesthetist
  • Preparation of patient
    • get consent
    • explain procedure
    • position the patient comfortably
    • administer mild sedative (eg. small dose of midazolam)
  • Preparation of airway
    • administer glycopyrrolate or atropine to dry secretions
    • spray 10% lignocaine with phenylephrine using atomiser

References

Walsh, Mary E., and G. D. Shorten. "Preparing to perform an awake fiberoptic intubation." The Yale journal of biology and medicine 71.6 (1998): 537.

Question 11 - 2016, Paper 2

Describe your  management  of  a  patient who  develops  neck  swelling with  palpable crepitus, difficulty  in ventilation and rapid desaturation  immediately following  a percutaneous tracheostomy.

College answer

  • This is a life-threatening emergency. Declaration of the emergency and communication to all members of the team. 
  • The most likely diagnosis is misplacement of the tracheostomy tube. 
  • Differential diagnosis includes (tension) pneumothorax, (tension) mediastinum, secondary to lung injury major airway injury – e.g. from dilatation / bougie / bronchoscopy / ETT etc. used in procedure or endotracheal tube exchange.
  •  
  • First priority is to establish the tracheostomy is in place with ETCO2 / bronchoscopy (should have been used in tracheostomy insertion so readily available).
  •  
  • If tracheostomy is in place, A=Airway is established, and problem is related to large airway/lung leak. This is likely to be under tension requiring decompression.  
  •  
  • If tracheostomy not in place, or unable to confirm then patient should be re-intubated with ETT from above and distal tip advanced below the tracheostomy site, and ventilation confirmed.  

Immediate assessment and resuscitation

  • Will need management by a multi-disciplinary team. May need to summon help from senior anaesthetist +/- ENT surgeon. Multiple co-ordinated simultaneous actions.
  • Check position of the tracheostomy tube (confirm misplacement)
    • Check capnography
    • Pass a bronchoscope down tracheostomy tube

Reintubation

  • Cease ventilation via tracheostomy
  • Remove tracheostomy tube.
  • Gentle ventilation by bag valve mask +/- oro-pharyngeal airway if possible.
  • Remove tracheostomy tube.
  • Prepare for re-intubation. (including difficult airway Kit)
  • Position the oral ETT more distally so that the hole in the trachea is excluded from circuit.
  • Confirm position of ETT with capnography and bronchoscope.
  • CXR post reintubation to check for pneumothorax.

Further management:

Assess for other related damage:

  • Trachea
  • Oesophagus
  • Venous
  • Arterial
  • Thoracic duct

Re-evaluate need for tracheostomy

  • Re-do by ENT or most experienced operator
  • Consideration for use of Uniperc / adjustable flange if regular tube too short for thick neck

Thorough answer should consider –

  • Care of the patient NOK- including open disclosure etc.
  • Systems issue- e.g. incident reporting, case review, adherence to guidelines or lack of
  • Prevention of future events.

Additional Examiners‟ Comments:

A significant number of candidates described removal of the tracheostomy tube without checking position/patency and/or did not mention use of capnograph or bronchoscope.

Discussion

Important differentials:

  • Dislodgement
  • Pneumothorax
  • Posterior tracheal puncture
  • Oesophageal puncture
  • Wound too wide (escape of air)

Immediate management:

  • Increase the FiO2 to 100%
  • Disconnect from the ventilator, and manually bag-ventilate them.
  • If the bag ventilation is difficult, one must conclude that the patient or the tracheal cannula are the problem.

If the bag ventilation is easy and the patient improves with it:

  • The differentials are posterior tracheal perforation, oesophageal perforation, or escape of gas into the subcutaneous tissues though a wound which is too wide.
  • Solutions to these problems do not need to be sought in a panic. The patient is improving.
  • First:
    • Tighten sutures around the wound (or, if there are no sutures, add them)
    • Inflate the cuff to a higher pressure
    • Decrease the PEEP as much as is permitted by the patient's condition
  • Next: one may perform imaging
    • Bronchoscopy or nasendoscopy to exclude tracheal tear and bronchial injury
    • CT of the neck and chest to investigate oesophageal injury (endoscopy is probably a stupid idea, given that it would require manipulation and potentially gas inusfflation of a damaged oesophagus)

If the bag ventilation is difficult and the patient is still unwell:

  • Exclude tension pneumothorax
    • Check trachea: is it in midline?
    • Auscultate the chest.
    • Obviously, if you find a tension pneumothorax, you decompress it.
  • Attempt bronchoscopy to assess patency
    • If the tracheostomy was just inserted, the bronchoscope should still be nearby
    • This will rapidly exclude tracheostomy dislodgement
  • If no bronchoscope is available, attempt to pass a suction catheter
    • Does it pass easily?
    • Does ventilation improve with suction?
    • Suction the patient, looking for fresh blood and clots
  • If the catheter is difficult to pass
    • Consider that the tracheostomy is blocked. Check the inner cannula: is it blocked with clot or secretions? Is the patient easier to bag without the inner cannula?
    • Consider that the tracheostomy is dislodged.

If the tracheostomy being dislodged is a real possibility:

  • If the tracheostomy is fresh (i.e. less than 7 days old), do not attempt to reinsert it, blindly or via bougie. It is safest to re-intubated orally.
  • Remove the tracheostomy
  • Place an occlusive dressing over the wound
  • Ask an additional staff member to keep pressure on the wound
  • Bag-mask ventilated the patient in preparation for oral intubation
  • After intubation, contact ENT surgical team to revise the tracheostomy in a controlled setting.

Options for reinserting an "older" tracheostomy

  • Direct (just shove it in)
  • Fingertip-guided (use the finger to find the hole in the trachea, then guide the tube into the hole)
  • Nasogastric tube as a guidewire (i.e. using the NGT to guide the tube in, Seldinger-style)

Collateral damage:

  • Make sure you remember to sedate the patient for all this
  • Assess for possible complications of a poorly positioned tracheostomy:
    • Posterior tracheal tear
    • Tracheal cartilage fracture
    • Oesophageal perforation
    • Venous or arterial vessel damage
    • Thoracic duct injury
    • Thyroid isthmus injury

Wisdom issues

  • Does this patient even need a tracheostomy?
    • Re-do by surgical team, ENT or a more experienced intensivist
    • Use of a different tube (eg. adjustable flange tube if the problem was an excess of pretracheal tissue)
    • Consideration for delayed extubation - perhaps the patient nears a possible safe extubation, and may only require another week of ventilator weaning.
  • "How could this have happened?", etc
    • Incident management system to be launched, eg. root cause analysis
    • Open disclosure to family and patient
    • Review of tracheostomy insertion and care guidelines

References

HUTCHINSON, ROBERT CHARLES, and RODNEY DICKSON MITCHELL. "Life-threatening complications from percutaneous dilational tracheostomy." Critical care medicine 19.1 (1991): 118-119.

Eisenhauer, Brenda. "DISLODGED TRACHEOSTOMY TUBE." Nursing2015 26.6 (1996): 25.

Seay, Shirley Jordan, Sonja L. Gay, and Melvin Strauss. "Tracheostomy Emergencies: Correcting accidental decannulation or displaced tracheostomy tube." AJN The American Journal of Nursing 102.3 (2002): 59-63.

Pattanong, Paradorn. "Dislodged tracheostomy." The Journal of Prapokklao Hospital Clinical Medical Education Center-วารสาร ศูนย์ การ ศึกษา แพทยศาสตร์ คลินิก รพ. พระ ปก เกล้าฯ 24.4 (2012): 304-308.

Chew, John Y., and Robert W. Cantrell. "Tracheostomy: complications and their management." Archives of Otolaryngology 96.6 (1972): 538-545.

Casserly, P., et al. "Assessment of healthcare professionals' knowledge of managing emergency complications in patients with a tracheostomy." British journal of anaesthesia 99.3 (2007): 380-383.

Question 18 - 2016, Paper 2

An 18-year-old male presents following a fight in a bar with obvious facial injuries. He has profuse bleeding from the mouth and nose and insists on sitting up at 90°. He has bruising under both eyes, his face is significantly swollen and his mid-face is mobile. His breathing is "noisy".

His vital signs are as follows:

  • Heart rate 105 beats/min
  • Blood pressure 115/60 mmHg
  • Respiratory rate 30 breaths/min
  • Sp02 92% on room air
  • Glasgow Come Scale 15

He has no cervical spine injury and no other significant injuries.

List the possible techniques for securing the airway in this patient and the pros and cons of each.

College answer

Rapid Sequence Induction: 
 
Pro: 
Rapid technique - may be only option should patient‟s condition deteriorate to peri-arrest 
No special expertise required 
May be best technique with ENT/Surgical backup at bedside to perform immediate tracheostomy if intubation fails.  
 
Con: 
Obscured / absent landmarks (potential to lose airway with RSI) 
•    Airway swelling  
•    Haematomata and ongoing haemorrhage 
•    Bony and soft tissue trauma 
Co-existing upper airway / tracheal injuries 
Patient unable to lie flat 
Left lateral position may be preferred but increases degree of difficulty 
Limited respiratory reserve 
Pre-oxygenation, bag-mask ventilation problematic 
Likely to become haemodynamically unstable with sedation 

 Cricothyroidotomy / Awake tracheostomy  

Pro: 
Safe – no risk of losing airway 
Patient breathing throughout 

Con: 
May be difficult without sedation 
Positioning may be problematic 
May be technically challenging in the setting of local tissue damage and haemorrhage 
 

Fibreoptic intubation 
 
Pro: 
No risk of losing airway 
Patient breathing throughout 
 
Con: 
Likely to be extremely challenging in the setting of ongoing haemorrhage 
Attempted nasotracheal intubation could result in nasocranial passage of tube and/or severe nasal haemorrhage 
Need expert/experienced airway assistance 
 
Awake direct laryngoscopy / intubation 
 
Pro: 
Quick – no time wastage 
Reduced risk of losing airway 
Patient breathing throughout 
Uses standard intubating equipment 
May be method of choice with senior operator 
Allows easy transition to a back-up technique 
 
Con: 
Technically challenging 
Needs adequate local anaesthesia 
Positioning patient problematic 
 
Credit was given to discussion of any sensible technique and any relevant introductory or concluding statement giving a summary of the issues. 
 
Additional Examiners‟ Comments: 
In general, well-answered, using a good structure. 

Discussion

Apart from certain cosmetic differences (bar fight vs bicycle crash) this question is identical to Question 24 from the first paper of 2013.

The discussion section from 2013 is reproduced below, with minimal modification.

Thus:

This patient is suffering from fractures of the mid-face.

There are several options for securing the airway in this patient.

Firstly, does he need intubation? It seems he does, as his respiratory rate is rapid, and his oxygenation is poor. Likely, he has inhaled some blood. And NIV is absolutely contraindicated in such people. So yes, he does need intubation - largely for airway protection, to prevent vast quantities of blood and snot from seeping into his lungs.

And the savvy candidate will have arrived at this conclusion without a half a page of introductory gibberish.

So, the question asked by the college really is "how do you intubate a hypoxic patient with facial injuries".

They ask for pros and cons, which lends itself well to a tabulated answer.

Technique Advantages Disadvantages
Rapid sequence induction
  • requires less skill
  • requires little preparation
  • If the airway is difficult, it may be disastrous
  • This airway is likely to be difficult
  • pre-oxygenation is going to be interesting (the patient cant lie flat)
  • bag-mask ventilation is impossible (facial fractures)
Fibreoptic intubation
  • patient is awake and breathing throughout the procedure
  • gold standard for difficult airways
  • Requires skilled staff
  • Takes time to prepare
  • Might be difficult if blood and debris is in the airway
  • cannot be performed nasally (fractured face)
Percutaneous cricothyroidotomy
  • patient is awake and breathing throughout the procedure
  • Little chance of airway loss
  • Hghly invasive procedure, may be poorly tolerated
  • cannot lie flat

Then, the college asks for a sensible concluding statement, without demonstrating what one should look like.

In summary, this patient requires intubation by skilled technicians, with backup equipment available. If the patient is peri-arrest, there is not time for any technique other than RSI. Ideally, a videolaryngoscope should be available. Otherwise, the first attempt should be an awake fiberoptic orotracheal intubation, with the opportunity to convert to RSI. In the event that both techniques fail, a percutaneous cricothyroidotomy should be the approach of last resort.

In addition to this "model answer" (pfft) I have also found unusual trivia around the medical literature. There are many ways to approach intubation in the patient with midfacial injuries.

For instance, a submental approach is a well-recognised approach. Retrograde intubation may be attempted, which might be even bloodier than the cricothyroidotomy. These techniques and others are discussed in a good 2009 review article of airway management in facial trauma.

References

Caron, Guy, et al. "Submental endotracheal intubation: an alternative to tracheotomy in patients with midfacial and panfacial fractures." Journal of Trauma and Acute Care Surgery 48.2 (2000): 235-240.

Barriot, P. A. T. R. I. C. K., and B. R. U. N. O. Riou. "Retrograde technique for tracheal intubation in trauma patients." Critical care medicine 16.7 (1988): 712-713.

Mohan, Raja, Rajiv Iyer, and Seth Thaller. "Airway management in patients with facial trauma." Journal of Craniofacial Surgery 20.1 (2009): 21-23.

Question 17 - 2017, Paper 1

Describe the advantages and disadvantages of the available methods for allowing speech in a patient with a tracheostomy tube in situ.

College answer

1.    Cuff deflation
Simple cuff deflation may allow patients to speak.

  • Advantages
    • Simple, no additional equipment required
    • Can allow mechanical ventilation to continue
  • Disadvantages
    • May compromise gas exchange
    • Aspiration risk
    • Patient may not be able to generate sufficient air flow if large diameter trache tube in situ
    • Loss of PEEP

2.    Capping tube
Cuff is deflated and patient or caregiver places finger over tracheostomy tube.

  • Advantages
    • Simple, no additional equipment required
  • Disadvantages
    • Does not allow mechanical ventilation to continue
    • Patient may not manage with increased resistance to expiration
    • Requires patient or caregiver to manually occlude tube

3.    Speaking valve e.g. Passy Muir
One-way valve attached to tracheostomy tube.
Gas enters tracheostomy during inspiration but is directed through larynx in expiration.

  • Advantages
    • Simple, tube change not required
    • Can allow mechanical ventilation to continue
    • Provide some PEEP
  • Disadvantages
    • Requires cuff deflation – aspiration risk
    • Risk  of  airway  obstruction  and  death  if  cuff  left  inflated  (major  point  in marking)
    • Loss of humidification
    • Dependant on tube size, laryngeal size, patient may not manage with increased resistance to expiration

4. Sub glottis air insufflation e.g. Pitt tube/Speaking

Tube Gas line with an outlet above the cuff and a thumb port. Patient or caregiver can occlude the port which directs gas through the larynx allowing speech.

  • Advantages
    • Can allow mechanical ventilation to continue
    • Cuff remains inflated reducing risk of aspiration
  • Disadvantages
    • Requires tube change (unless inserted initially)
    • Voice quality poor
    • Requires practice by patient
    • Can be uncomfortable
    • Needs someone to occlude port

5. Fenestrated tube

Specialised tube with fenestration and inner cannula that allows gas to pass to larynx when tube occluded.

  • Advantages
    • Inner cannula can be swapped for non-fenestrated if mechanical ventilation required
    • Can be used with cuff inflated if aspiration risk
    • Allows suction of secretions
  • Disadvantages
    • May require tube change if not inserted originally
    • Increases work of breathing
    • Fenestrations may occlude leading to obstruction risk
    • Difficult to get fenestrations of tube and inner cannula to line up

6. Electronic larynx

Specialised equipment that is held to patient's neck and vibrates when activated and mechanically resonates when words or sounds are mouthed. Uncommon in ICU but has been described.

Additional Examiner Comments:

This was answered poorly. Several candidates failed to mention that the cuff must be delated prior to use of a speaking valve; this omission could lead to serious clinical consequences.

Discussion

Discussion of advantages and disadvantages always benefits from a table-like structure. This table was composed using the excellent 2005 article by Dean R Hess.

Advantages and DIsadvantages of Various Methods for

Allowing Speech in Tracheostomy Patients

Method Advantages Disadvantages

Cuff up, fenestrated tube:
Gas flow is via an additional port above the cuff; 4-6L/min flow. The pt. remains ventilated

  • Allows speech with an inflated cuff
  • Decouples speech and breathing: no loss of ventilation during speech
  • Unless this tube is already in situ, this will require a tube change.
  • Voice quality is poor (whisper) unless you increase the flow to an uncomfortable level
  • Secretions from above can clog the tube
Cuff down, speaking valve:
Gas only exits through the upper airway during exhalation
(one way valve)
  • No need to change the tracheostomy tube
  • Flow rate is good: speech volume resembles normal speech
  • Speech is possible during inspiration and expiration, if ventilated and on PEEP
  • Works best if the patient is not on a ventilator
  • With a ventilator, need to compensate for a high volume of leak (most ventilators will not tolerate this)
  • The cuff needs to be deflated (i.e. the airway is not protected from aspiration)
  • There are many contrandications to such a speaking valve
Cuff down, no speaking valve
i.e. gas freely exists via both the tracheostomy and the upper airway
  • No need to change the tracheostomy tube
  • Flow rate is good: speech volume resembles normal speech
  • Only works in ventilated patients 
  • Only able to speak in inspiration, unless PEEP is high
  • Again, there is a large volume of leak
  • The leak may affect ventilation (i.e. PaCO2 may rise)
Cuff down, finger occlusion - i.e. the patient blocks the tracheostomy and exhales using the upper airway instead
  • No need to change the tracheostomy tube
  • Flow rate might be good (depending on muscle strength)
  • Requires a lot of coordination
  • With the cuff down, no protection from aspiration

References

Hess, Dean R. "Facilitating speech in the patient with a tracheostomy."Respiratory care 50.4 (2005): 519-525.

Morris, Linda L., et al. "Restoring speech to tracheostomy patients." Critical care nurse 35.6 (2015): 13-28.

Question 19 - 2017, Paper 1

You are preparing to intubate a morbidly obese patient for respiratory failure.

Describe the strategies for minimising hypoxaemia in the period immediately pre- and post-intubation.

College answer

 Ensure optimal treatment of the underlying cause of respiratory failure where possible, e.g.

• Diuretics and CPAP for acute pulmonary oedema

• Bronchodilators for asthma 
 
1. Optimise pre-oxygenation/ intra procedure oxygenation

• Longer time of pre-oxygenation  

• Use of PSV or CPAP pre-intubation (peak Pi not >15 cmH2O recommended)

• Nasal prong and/or high-flow oxygenation during intubation (e.g. THRIVE or simple prongs at 15l/min)

• Monitoring end tidal oxygen; target FeO2 >80% 
 
2. Minimising time to first breath

• Positioning  (essential point to mention)

• Ramping (or similar) achieving tragus-sternal angle in horizontal plane Important in obese patient

• Experienced operator

• Equipment ready (expect candidate to have fall-back equipment such as VL, bougies, second generation LMA. No specific right or wrong re which device they should use first)

• Use of rapidly acting skeletal muscle relaxant (or use of spontaneously breathing technique e.g. LA) • Monitoring for intra-tracheal placement of ETT; capnography

• Ventilator set up with appropriate settings for immediate use including FiO2 1.0 and appropriate level PEEP, Vt and inspiratory airway pressure  

• Teamwork management – clear roles in primary and backup plans

• NB: Delay with use of video-laryngoscopy 
 
3. Rescue strategies

• Plan A, Plan B, Plan C

• Preparations for supraglottic and infraglottic rescue (more credit if specific algorithm is mentioned e.g. Vortex, DAS) 
 
4. Optimise cardiac output for improved V/Q matching

• Judicious fluid loading

• Vasopressors (e.g. Nor-adrenaline, metaraminol)

• Awareness of fall in output with induction of anaesthesia and institution of IPPV

• Invasive arterial pressure monitoring 
 

Discussion

The details of this answer are explored in the chapter on the prevention of hypoxia during airway management. For a proper literature reference, the time-poor candidate is directed to  "Preoxygenation and prevention of desaturation during emergency airway management" by Weingart and Levitan (2011).

Positioning

  • Head up 20-25° (especially valuable in the obese patients)

Denitrogenation

  • 100% FiO2
  • Deep breaths × 8
  • Or, 3-4 minutes of breathing the oxygen-rich mixture
  • The effect is enhanced by positive airway pressure
  • There is no benefit in extending this period beyond 4 minutes

Positive pressure

  • Use NIV unless contraindicated
  • PEEP 5-10 cm H2O
  • Not to exceed 25 cm H2O
  • Alternatively, use a PEEP valve on the bag-valve mask

Minimisation of metabolic demands

  • Use generous amounts of muscle relaxant
  • The use of non-depolarising agents is preferred, as fasciculations can increase the total body oxygen demand 

Anticipation of hypoxia

  • Preparation of staff and equipment for rapid desaturation

Apnoeic oxygenation

  • Continued application of CPAP during the apnoeic period (i.e. while waiting for optimal intubating conditions)
  • Use of bag-valve mask to gently ventilate the patient, promoting flow of fresh oxygen into the FRC

Preparation for failure

  • Extend invitation to ENT or senior anaesthetic staff to be present at the intubation
  • Make surgical airway equipment easily available

References

Weingart, Scott D., and Richard M. Levitan. "Preoxygenation and prevention of desaturation during emergency airway management." Annals of emergency medicine 59.3 (2012): 165-175.

Heller, Morris L., and T. Richard Watson Jr. "Polarographic study of arterial oxygenation during apnea in man." New England Journal of Medicine 264.7 (1961): 326-330.

Cherniack, NEIL S., and G. S. Longobardo. "Oxygen and carbon dioxide gas stores of the body." Physiological reviews 50.2 (1970): 196-243.

Enghoff, H., and L. RISHOLM. "Diffusion respiration in man." Nature 168.4280 (1951): 830-830.

Draper, William B., and Richard W. Whitehead. "The Phenomenon of Diffusion Respiration.." Anesthesia & Analgesia 28.6 (1949): 307-318.

Lane, S., et al. "A prospective, randomised controlled trial comparing the efficacy of pre‐oxygenation in the 20° head‐up vs supine position." Anaesthesia 60.11 (2005): 1064-1067.

Ramkumar, Venkateswaran, Goneppanavar Umesh, and Frenny Ann Philip. "Preoxygenation with 20º head-up tilt provides longer duration of non-hypoxic apnea than conventional preoxygenation in non-obese healthy adults.Journal of anesthesia 25.2 (2011): 189-194.

Mort, Thomas C. "Preoxygenation in critically ill patients requiring emergency tracheal intubation." Critical care medicine 33.11 (2005): 2672-2675.

Mort, Thomas C., Barbara H. Waberski, and Jonathan Clive. "Extending the preoxygenation period from 4 to 8 mins in critically ill patients undergoing emergency intubation." Critical care medicine 37.1 (2009): 68-71.

Nielsen, Niels D., et al. "Apneic oxygenation combined with extracorporeal arteriovenous carbon dioxide removal provides sufficient gas exchange in experimental lung injury." ASAIO journal 54.4 (2008): 401-405.

Eger, E. I., and J. W. Severinghaus. "The rate of rise of PaCO2 in the apneic anesthetized patient." Anesthesiology 22.3 (1961): 419-425.

Russotto, Vincenzo, et al. "Respiratory support techniques to avoid desaturation in critically ill patients requiring endotracheal intubation: A systematic review and meta-analysis.Journal of Critical Care (2017).

Altermatt, F. R., et al. "Pre-oxygenation in the obese patient: effects of position on tolerance to apnoea." British journal of anaesthesia 95.5 (2005): 706-709.

Dixon, Benjamin J., et al. "Preoxygenation Is More Effective in the 25° Head-up Position Than in the Supine Position in Severely Obese PatientsA Randomized Controlled Study." The Journal of the American Society of Anesthesiologists 102.6 (2005): 1110-1115.

Duggan, Michelle, and Brian P. Kavanagh. "Atelectasis in the perioperative patient." Current Opinion in Anesthesiology 20.1 (2007): 37-42.

Baillard, Christophe, et al. "Noninvasive ventilation improves preoxygenation before intubation of hypoxic patients." American journal of respiratory and critical care medicine 174.2 (2006): 171-177.

Tang, L., et al. "Desaturation following rapid sequence induction using succinylcholine vs. rocuronium in overweight patients." Acta Anaesthesiologica Scandinavica 55.2 (2011): 203-208.

Question 13 - 2017, Paper 2

Critically evaluate the timing of elective tracheostomy in ICU patients. 

College answer

Introduction 
Tracheostomy is performed in critically ill adults requiring prolonged invasive ventilation as a strategy to reduce respiratory tract injury, improve patient comfort and/or to facilitate weaning. Timing of tracheostomy has been a subject of debate and may be considered as “early” at <10 days or “late” >10 days although these definitions may vary  
 
Rationale There has been debate as to whether “early” trache may confer advantages of reduced morbidity and mortality Disadvantages of tracheostomy include airway trauma, bleeding and death and this may be increased by doing an “early” tracheostomy in patients who may otherwise die or be extubated before 10 days 
Early tracheostomy is a consideration in patients with neurological issues (brain injury, GBS, CVA etc.) and shorten time on ventilator  
 
Evidence    
Many studies and meta-analyses of variable quality have evaluated this issue. Methodological issues include differences in “early” and “late” timing, prediction of which patients will require “long-term” ventilation, exclusion/inclusion of specific patient groups and diagnosis of end-points such as VAP Cochrane Review 2012 considered 4 studies (latest 2010) to meet inclusion criteria. Conclusions were that quality of evidence to date was poor and results conflicting. Recent RCT TracMan Study from UK 2013 – tracheostomy at 1-4 days v >10 days invasive ventilation. Early tracheostomy associated with shorter duration of sedation but increased number of procedures and associated complications with no beneficial effect on overall mortality not ICU/hospital LOS 
Studies have evaluated patients with respiratory failure and not those intubated for neurological injury  
 
Own Practice 
Any reasonable approach acceptable  
 
Summary 
Lack of evidence to support early v late trache overall. Selected patients e.g. neurotrauma, GBS, stroke may benefit from early. 
Probably best decided on case by case basis 
Involves invasive procedure with attendant risks and complications and needs appropriate expertise 
 

Discussion

This question is identical to Question 13 from the first paper of 2013, with the exception that in 2013 they specifically asked about adult Intensive Care patients. The discussion section for that question is reproduced below with minimal modification, in keeping with the college's own complete verbatim replication of their 2013 model answer, complete even with their reference to the "recent RCT Trac Man", a  2013 publication which in early 2013 was not yet published and in late 2017 is no longer recent. 

The timing of tracheostomy is well discussed in a recent meta-analysis. Sure, its PLOS, and sometimes people only value the advice they have to pay for, but I think it is of a high quality. The 2013 model answer makes reference to TracMan, a trial which had not yet been published at the time of the exam, and so could not have been expected as a part of an answer to this question. If this question were repeated in future papers, modern data expected of the candidates would probably come from the 2015 meta-analysis article by  Andriolo et al and Szakmany et al, or the 2016 meta-analysis by Meng et al. All of them arrived at essentially the same conclusions (in three words, early vs late tracheostomy makes no difference to any parameters of interest when you homogenise the ICU population),

Introduction:

  • Typically tracheostomy is performed on patients with difficulty weaning.
  • Some argument exists whether patients who are likely to require prolonged weaning should have this procedure early, and whether this improves their outcome
  • No agreement exists regarding the definition of what is late and what is early tracheostomy
    • the 10 day cutoff is mentioned by the college, and it probably comes from TracMan.
  • No agreement exists as to the selection of patients who might benefit

Rationale for early tracheostomy:

  • Early tracheostomy exposes the patient to the various advantages of tracheostomy, which are:
    • decreased dead space
    • decreased airway injury
    • lower airway resistance and improved work of breathing
    • decreased sedation requirements and improved comfort
    • avoidance of complications of prolonged intubation
    • earlier oral feeding
    • decreased incidence of VAP
    • decreased length of ICU stay
    • avoidance of the perils of prolonged intubation
  • The argument is that the earlier this is performed, the better.

Rationale for delaying tracheostomy:

  • The counter-argument is that patients who would have otherwise been successfully extubated would undergo an unnecessary tracheostomy. Such a practice would expose them to the risks of tracheostomy, which are:
    • bleeding and wound infection
    • potential for periprocedure complications, such as tracheo-oesophageal fistula
    • tracheomalacia and tracheal stenosis
    • potential for dislodgement and airway failure
  • Some patients may end up being extubated after a prolonged intubation
  • A long period of intubation allows these patients to be more easily identified. 
  • Risks of prolonged intubation are probably overstated
  • Futile care may be perpetuated by tracheostomy. 
  • Length of ICU stay is largely a financial rather than medical consideration, and some might argue that it is inappropriate to let such matters influence decisions regarding patient care.

Evidence:

Cochrane review  by Andriolo et al (2015):

  •   n=1977, of which 909 were from TracMan.
  • There was a statistically significant mortality benefit associated with early tracheostomy (47% vs 53%); the NNT was 11. This mortality benefit was seen at the longest reported follow-up, rather than at 30 days.
  • The early group had a higher chance of being discharged from the ICU on day 28.
  • There was no statistically significant effect on the duration of mechanical ventilation.
  • The early group had decreased duration of sedation (re-demonstrated by Meng et al, 2016)
  • Data regarding risk of pneumonia could not be subjected to meta-analysis due to heterogeneity.

Own practice:

  • An impression of the likelihood of a patient requiring tracheostomy can form early in their stay (eg. poor neurological recovery, permanent loss of airway reflexes, or existing chronic lung disease). Such patients should be offered tracheostomy early, and to delay it would expose them to the risks of of prolonged intubation. Each case should be evaluated according to its own unique features, and risk must be weighed against benefit.

Summary:

  • Broadly speaking, early tracheostomy does not influence outcome in ICU patients.
  • Some ICU patients may still benefit from an early tracheostomy, but features which identify them are not well established, and the decision still relied on case-by-case analysis and clinical experience.

References

Huang, Huibin, et al. "Timing of Tracheostomy in Critically Ill Patients: A Meta-Analysis." PloS one 9.3 (2014): e92981.

Young, Duncan, et al. "Effect of early vs late tracheostomy placement on survival in patients receiving mechanical ventilation: the TracMan randomized trial." Jama 309.20 (2013): 2121-2129.

Longworth, Aisling, et al. "Tracheostomy in special groups of critically ill patients: Who, when, and where?." Indian Journal of Critical Care Medicine 20.5 (2016): 280.

Baron, David Marek, et al. "Tracheostomy is associated with decreased hospital mortality after moderate or severe isolated traumatic brain injury.Wiener klinische Wochenschrift (2016): 1-7.

Hosokawa, Koji, et al. "Timing of tracheotomy in ICU patients: a systematic review of randomized controlled trials.Critical Care 19.1 (2015): 1-12.

Gomes Silva, Brenda Nazaré, et al. "Early versus late tracheostomy for critically ill patients.Cochrane Database Syst Rev 3 (2012).

Andriolo, B. N., et al. "Early versus late tracheostomy for critically ill patients." Cochrane Database Syst Rev 1 (2015).

Szakmany, T., et al. "Effect of early tracheostomy on resource utilization and clinical outcomes in critically ill patients: meta-analysis of randomized controlled trials." British journal of anaesthesia 114.3 (2015): 396-405.

Meng, Liang, et al. "Early vs late tracheostomy in critically ill patients: a systematic review and meta‐analysis." The clinical respiratory journal 10.6 (2016): 684-692.

Question 17 - 2019, Paper 1

A 47-year-old female patient is in your ICU having had a prolonged wean from mechanical ventilation following severe head and chest injuries sustained in a motor vehicle collision. She has a tracheostomy and has been breathing spontaneously, free from ventilatory support, on an FiO2 of 0.3 via a tracheostomy mask for 24 hours.

Describe how you will assess whether the tracheostomy tube can be safely removed.
 

College answer

Assessment will involve history, examination and targeted investigations and may involve a trial period with the tracheostomy “capped” or occluded (with the cuff deflated!) to ensure that it can be safely removed.

The tracheostomy can be safely removed if the patient:
•    Has a patent upper airway
•    Has a protected upper airway
•    Can adequately clear her secretions
•    No longer requires mechanical ventilation
 
Patent upper airway
•    History
o    Upper airway trauma
o    Duration of translaryngeal intubation
o    Indication for tracheostomy (was it placed for upper airway obstruction)
o    Known grade of intubation or difficulty with intubation
•    Examination
o    Facial or airway trauma or recent surgery
•    Investigations (if indicated, not routine)
o    Direct or fibreoptic laryngoscopy
o    CT scans if available may offer some information

Protected upper airway
•    History
o    Severity of brain injury
o    Focal brainstem injury
•    Examination
o    Current neurological status
    Level of consciousness
    Lower cranial nerves including cough and gag reflex
•    Investigations
o    Neurological imaging inc CT and MRI
o    Barium swallow or fibreoptic assessment for aspiration

Adequate clearance of secretions

History
o    Injuries that may impair cough
    Spinal cord injury
    Multiple rib fractures with flail segment
    Diaphragmatic injury
    Severe lung trauma
    Recurrent pneumonia or lung abscess
o    Co-morbidity
    Lung disease e.g., bronchietcasis
    Neuromuscular weakness
    Sleep apnoea

Examination
o    Respiratory
    Frequency of suctioning
    Nature and volume of secretions
    Presence of flail segment
o    Neurological assessment
    Peripheral neuromuscular function
    Cough assessment (strength, ability to cough secretions past tube)

Investigation
o    Ultrasound of diaphragm (if problem suspected)
o    Fibreoptic examination of vocal cord function

No requirement for mechanical ventilation
•    History
o    Background and co-morbidities (OSA, smoking, lung or heart disease….)
o    Nature and extent of chest injury and other injuries
o    Requirement for any ongoing surgery
o    Pattern and duration of weaning from ventilation (24hours of spontaneous ventilation would be a minimum for trache removal)

•    Examination
o    Respiratory and cardiovascular examination
o    Tertiary survey

•    Investigations
o    CXR
o    CT chest
o    ABG off ventilation
o    Spirometry

Notes
The answer template is not exhaustive, merely indicative and this level of detail in this template was not required. To pass the candidate needed to demonstrate awareness of the requirement for all of:
1.    Patent upper airway
2.    Ability to clear secretions with a mention of cuff deflation
3.    Adequate level of consciousness
4.    Adequacy of spontaneous ventilation

Examiners Comments:

Superficial approach. Lack of systematic approach to a common procedure done in ICU. Cuff deflation missed most often.
 

Discussion

This college answer has left little room for improvement. One may only try to rearrange the points into something which is not specific to a trauma patient with head and chest injuries, i.e. a more generic approach to anybody with a tracheostomy. One must caution against this formulaic templated approach in the actual exam, as the examiners often complain about how the trainees have not read their carefully worded question text. It would be always important to include case-specific details in one's answer to demonstrate one's engagement with the question.

  • Adequate gas exchange while off mechanical ventilator support:
    • Surviving off the ventilator for at least 24 hours
    • Requiring minimal oxygenation support:
      • "blow over" of humidified gas, i.e. a T-piece trial
      • HME with room air or minimal supplemental oxygen, eg a "Swedish Nose". 
    • No planned procedures in the near future which may require mandatory mechanical ventilation
  • Preconditions for a decannulation trial: 
    • Secretion volume
      • Fewer than 4 suction episodes in the last 24 hours
      • No intercurrent suppurative lung disease
    • Intact airway reflexes
      • Gag reflex present
      • Cough reflex present
    • Intact sensorium
      • Level of consciousness should be high enough to sustain cooperation with physiotherapy and nursing staff in the post-decannulation period
    • Satisfactory muscle power
      • Maximum expiratory peak flow of over 160 L/min with cough
    • If the patient does not meet these preconditions, the cuff deflation trial will need to be delayed
  • Cuff deflation trial 
    • Deflate the tracheostomy cuff
    • Ensure adequate oxygenation and ventilation with the tracheostomy still patent
    • Then, occlude the tracheostomy
    • Observe for 72 hours 
      • If unsuccessful, perform videoendoscopy or CT imaging of the upper airways to determine the cause
    • Test for aspiration during this time (blue dye test)

References

Heffner, J. E. "The technique of weaning from tracheostomy. Criteria for weaning; practical measures to prevent failure." The Journal of critical illness 10.10 (1995): 729-733.

Christopher, Kent L. "Tracheostomy decannulation." Respiratory Care 50.4 (2005): 538-541.

O'Connor, Heidi H., and Alexander C. White. "Tracheostomy decannulation." Respiratory Care 55.8 (2010): 1076-1081.

Singh, Ratender Kumar, Sai Saran, and Arvind K. Baronia. "The practice of tracheostomy decannulation—a systematic review." Journal of intensive care 5.1 (2017): 38.

Clini, Enrico, et al. "Long-term tracheostomy in severe COPD patients weaned from mechanical ventilation." Respiratory care 44.4 (1999): 415-420.

Chadda, Karim, et al. "Physiological effects of decannulation in tracheostomized patients." Intensive care medicine 28.12 (2002): 1761-1767.

Epstein, Scott K. "Anatomy and physiology of tracheostomy." Respiratory care 50.4 (2005): 476-482.

Ceriana, Piero, et al. "Weaning from tracheotomy in long-term mechanically ventilated patients: feasibility of a decisional flowchart and clinical outcome." Intensive care medicine 29.5 (2003): 845-848.

Enrichi, Claudia, et al. "Clinical criteria for tracheostomy decannulation in subjects with acquired brain injury." Respiratory care 62.10 (2017): 1255-1263.

Rumbak, Mark J., et al. "Tracheostomy tube occlusion protocol predicts significant tracheal obstruction to air flow in patients requiring prolonged mechanical ventilation.Critical care medicine 25.3 (1997): 413-417.

Donzelli, Joseph, Susan Brady, and Michele Wesling. "Using Modified Evan's Blue Dye Test to predict aspiration." The Laryngoscope 114.9 (2004): 1680.

Belafsky, Peter C., et al. "The accuracy of the modified Evan's blue dye test in predicting aspiration." The Laryngoscope113.11 (2003): 1969-1972.

Cameron, John L., J. Reynolds, and G. D. Zuidema. "Aspiration in patients with tracheostomies." Surg Gynecol Obstet 136.1 (1973): 68-70.

Shen, K. Robert, and Douglas J. Mathisen. "Management of persistent tracheal stoma." Chest surgery clinics of North America 13.2 (2003): 369-73.

Bach, John R., and Louis R. Saporito. "Indications and criteria for decannulation and transition from invasive to noninvasive long-term ventilatory support." Respiratory care 39.5 (1994): 515.

Question 14 - 2020, Paper 1

A tracheo-innominate artery fistula (TIF) is a rare but life-threatening complication of tracheostomy.

a)    What are the contributing  factors for TIF formation?    (30% marks)

b)    What are the clinical features that make you suspect a TIF and how would you confirm the diagnosis?    (30% marks)

c)    What is your management  of a TIF?    (40% marks)
 

College answer

  1. Contributing factors
    • High pressure cuff (ideally < 20mmHg
    • Low tracheostomy – below the 3rd or 4th tracheal ring
    • Prolonged tracheostomy duration
    • Neck/chest deformity
    • Anomalous/high anatomic location of innominate artery
    • Prolonged use of steroids/immunosuppression
    • Localised infection
  1. Clinical features
    • Bloody secretions/haemoptysis/haemorrhagic shock
    • Sentinel bleeding occurs in approximately 50% of patients, often pulsatile
    • Time frame is usually > than 48 hours since tracheostomy insertion Confirm diagnosis
    • Bronchoscopy –> bleeding from right anterior wall at site of 6/7 tracheal rings
    • Angio/CTA reveal blush from artery into trachea if appropriate to perform
  1. Management of TIF (combination of call for help, resuscitate and try and stop bleeding awarded marks)
    • Call for senior assistance including ENT/Cardiac surgeon as appropriate for institution
    • Activate MTP/ensure blood products available
    • Secure airway and compress artery with cuff
      • Bronchoscopy to position tracheostomy (if able to advance) or replacement with ETT are acceptable
      • Adjust the depth of the tracheostomy/ETT to put cuff pressure over the bleeding site
      • Hyperinflate the cuff
    • If unable to compress artery with tube cuff, position ETT distal to bleeding to secure airway and provide digital pressure through the tracheostomy opening against the sternum to try and compress
    • Endovascular stenting or surgical ligation as definitive management

Examiners Comments:

This was not well answered overall with a poor knowledge of this complication demonstrated.

Discussion

Contributing factors to the formation of tracho-innominate fistula: 

  • A particularly low tracheostomy
  • Surgical tracheostomy where excessive dissection interrupts the blood supply
  • Mediastinal tracheostomy
  • Excessive tension on the tracheostomy (eg. where the tube selected is too short for the pre tracheal tissues)
  • Unusual patient anatomy or behaviour, eg. an abnormal ectatic or tortuous trachea, or unusual patient posturing with frequently extreme neck extension (eg. cerebral palsy)
  • Hyperextension of the neck during tracheostomy:  marked retraction of the head brings the innominate vessels closer to the level of the suprasternal notch
  • A propensity towards poor wound healing: 
    • Prolonged episodes of hypotension
    • Extensive use of vasopressive agents
    • Radiation therapy to the neck
    • Steroid therapy
    • Protein malnutrition 
    • Localised infection at the insertion site
  • Problems with the tracheostomy device:
    • Overinflated high pressure cuff
    • A tracheostomy tube which is excessively curved anteriorly (eg. a fixed 90 degree bend), or one which is tied or sutured in a way which angles it anteriorly.

Clinical features of tracheo-innominate fistula

  • Airway bleeding is clearly the main feature. 
  • A pulsatile tracheostomy tube is occasionally reported
  • Infection around the site is an associated feature

Management of tracheo-innominate fistula

  • First, overinflate the tracheostomy cuff. In their 2006 review, Grant et al  recommended overinflating the tracheostomy cuff as the optimal first line management, while waiting for the cardiac surgical team to prepare for theater. 
  • Next, as the bleeding should be controlled well enough for you to set up for it, intubate the patient orally.  It may be necessary to do this in an emergency anyway, particularly if the blood is coming from the tracheostomy itself, rather than around it. To intubate the patient from above prevents soiling of the lower respiratory tract. Somebody should remove the tracheostomy just as you're advancing the ETT, i.e. at the very last minute. 
  • Next, gain control of the haemorrhage by digital compression. This "Utley manoeuvre" (Utley et al, 1972) requires you to stick your index finger into the tracheal stoma, blunt-dissect down along the tracheal wall to separate the artery and the trachea, and put pressure on the innominate artery, compressing it up against the posterior wall of the manubrium. Just like this:
    Utley technique of compressing the innominate artery
  • Obviously, this is not going to be a particularly long-term solution. The person with their finger in the patient's mediastinum should get themselves into a comfortable position. They will remain in place until theatres are ready, and then they will escort the patient there. A full median sternotomy will usually follow. Most often, repair is not attempted, and the innominate artery is ligated and resected where it overlies the trachea, so that the arm is now perfused by retrograde flow from the right carotid.

References

Grant, C. A., et al. "Tracheo-innominate artery fistula after percutaneous tracheostomy: three case reports and a clinical review." British journal of anaesthesia 96.1 (2006): 127-131.

Goldenberg, David, et al. "Tracheotomy complications: a retrospective study of 1130 cases." Otolaryngology—Head and Neck Surgery 123.4 (2000): 495-500.

Chew, John Y., and Robert W. Cantrell. "Tracheostomy: complications and their management." Archives of Otolaryngology 96.6 (1972): 538-545.

Allan, James S., and Cameron D. Wright. "Tracheoinnominate fistula: diagnosis and management." Chest Surgery Clinics 13.2 (2003): 331-341.

Schlaepfer, Karl. "Fatal hemorrhage following tracheotomy for laryngeal diphtheria." Journal of the American Medical Association 82.20 (1924): 1581-1583.

Utley, Joseph R., et al. "Definitive management of innominate artery hemorrhage complicating tracheostomy." Jama 220.4 (1972): 577-579.

Question 19 - 2020, Paper 1

You are asked to review a 46-year-old female on the surgical ward who has stridor 4 hours after a total thyroidectomy.

a) List six possible causes for this. (30% marks)


b) You determine intubation is necessary. Outline your approach to securing her airway and justify it.
(70% marks) 


 


 

College answer

Causes

  • airway obstruction secondary to haematoma,
  • stridor secondary to hypocalcaemia ( less likely so early)
  • airway obstruction due to recurrent laryngeal nerve injury – unilateral versus bilateral,
  • post extubation stridor – vocal cord edema
  • airway collapse secondary to tracheomalecia if long term goitre
  • Anaphlaxis/any other cause examiner is happy with,

Approach:

 Immediate oxygenation measures:

Administer High flow Oxygen / Hudson mask with rebreath bag at 15L. Sitting up position better tolerated than lying flat

Can try Heliox – though to be effective will need 79% Helium, 21% Oxygen mix which may be inadequate if patient has poor gas exchange / pulmonary oedema

Declare Airway emergency – get help: Surgeon, Anaesthetist, Nursing staff

Decide on location for intubation: In ward, theatre or ICU – depending on distance to be moved and patient stability

Decide on and communicate plan of airway intervention including plan for failure: Plans A,B,C highlighting each approach

Ensure Team members are aware of roles & sequence of events and emergency responses

Check Equipment for familiarity and correct function

 

Be clear about pros and cons of approaches for airway management (Must justify one)

  • IV bolus induction – Facilitates rapid airway access but loss of control of airway possible with need for rescue using front of neck access.
  • Slow IV propofol infusion induction – maintains respiratory efforts, but familiarity with propofol kinetics and pumps needed.
  • Slow Gas induction – maintains respiratory efforts, but an operating theatre and familiarity with anaesthetic machine needed.
  • Awake intubation – maintains respiratory efforts, uses local anaesthesia, opiate, sedation avoiding paralysis – not possible in extremis, may hinder adequate view
  • Awake Fibreoptic intubation – not appropriate in stridor where scope often obstructs airway inlet in stridorous awake patient.

Outline plan for failure: then front of neck access:

  • Scalpel bougie technique (landmarks palpable)
  • Midline incision, finger dissect, tracheal access (landmarks impalpable)

Discussion

Possible causes of stridor in a patient returning from thyroidectomy are more than likely going to be related to the thyroidectomy, or less likely to the drugs which have been given around the time of the thyroidectomy. In any case, it is still probably worthwhile reasoning through this as if it were an exercise in generating differentials:

  • Haematoma or pseudoaneurysm (most likely)
  • Infection (unlikely)
  • Tracheomalacia: an idiopathic cause related to the goitre (Chi et al, 2011)
  • Drug-related causes:
    • Incomplete reversal of muscle relaxant (i.e. was reversed with neostigmine, which subsequently wore off, leaving behind the for-some-reason-prolonged effects of some long-acting curare toxin)
  • Immunological causes:
    • Anaphylaxis to a dose of prophylactic antibiotics
    • Delayed allergic reaction to drugs given in theatre
  • Trauma:
    • Perforation of the trachea, with subcutaneous emphysema and pneumomediastinum
    • Tracheal haematoma due to retraction trauma
    • Vocal cord paralysis due to recurrent laryngeal nerve damage
    • Vocal cord oedema
  • Endocrine and electrolyte abnormalities:

To throw a coat of peer-review varnish over this unprofessional gibberish, one could point to an excellent article by Ayandipo et al (2016), which discusses a case series of airway complications from a high-volume ENT service in Nigeria. The most common reason for the reintubation was tracheomalacia, which was observed in something like 5% of the total cases. 

Approach to securing the airway is an exercise in demonstrating a level of caution and anxiety to the examiners, so as to give the appearance of a safe practitioner. Specific noises which one needs to make to generate this impression are:

  • Unless completely impractical (i.e. patient is blue), insist on doing the reintubation in theatre
  • Ideally, invite the surgeon who operated on the patient to join you there, as there is a nonzero chance that they will need to reopen the neck
  • Access the services of an airway specialist, ideally an anaesthetist who routinely does ENT and head-and-neck lists

So, the ideal approach here would be:

  • In theatre
  • Surgeon on standby
  • Awake fibreoptic intubation by anaesthetics

However, the college asked for "your approach to securing her airway", not "your approach to avoiding having to handle her airway". Frequently, this scenario plays out after-hours. Consider that a complex total thyroidectomy may take all day, finish at 8pm, and then stridor comes at midnight. One might be working with a skeleton staff and with no theatre available, plus the surgeon is now on his private island and is not inclined to return to the hospital. In short, you're it.

Examination

  • Assess for difficulty of intubation, to determine which specific features were problematic.
  • Assess for difficulty of bag-mask ventilation.
  • Look at the most recently available ABG or venous biochemistry: specifically, the PaCO2 helps determine the dose of anaesthetic induction agent, and the serum K+ level helps select the muscle relaxant.

Planning

  • Decide beforehand what the algorithm is going to be, depending on what is available locally.
  • Have a plan for intubation
  • Have a plan for oxygenation
  • Have a backup plan (or two) for each
  • Have a clear idea of what the locally available cricothyroidotomy kit looks like and roughly how long it takes to set up (given that pretty much all of the algorithms lead to cutting the throat).

Preparation of the staff

  • Choose a competent assistant to assist with the airway: somebody who knows what BURP is and how to correctly do cricoid pressure
  • Choose a competent assistant to give drugs
  • Assign a staff member to act as “access”, i.e. somebody to run around and get equipment
  • Inform standby staff to be ready (eg. somebody whom you've nominated as the front-of-neck person)
  • Discuss the plan with the team to ensure everyone is aware of what is going to happen (eg.  “OK people, Plan A is videolaryngoscopy with bougie, Plan B is FONA”).

Preparation of the equipment

  • Plan A equipment should be ready for use
  • Plan B equipment should be available within 60 seconds (which means, in the room, within arm’s reach, and wherever possible unwrapped and lubricated).
  • Drugs should be drawn up, including a couple of adrenaline ampoules in case CPR becomes a part of the rapid sequence induction.
  • An end-tidal CO2 monitor should be within reach
  • The equipment should be checked, and its operability ensured (i.e. those CMAC batteries better be charged).

Preparation of the patient

  • Explain to the patient what the plan is (if they are conscious and capable of processing this information, it would be helpful to have them on your side).
  • Commence high flow oxygen
  • Preoxygenate for a minimum of 3 minutes. The utility of this is debated.
  • During this time, either position the patient for intubation, or (if they cannot tolerate that position) prepare equipment and assistants to put them into that position as soon as the induction is commenced.

References

Scanlon, Edward F., Stephen F. Sener, and E. Dennis Murphy. "Early onset of tetany following thyroidectomy: report of two cases." Journal of surgical oncology 29.4 (1985): 222-223.

Jeong, Jee Yeon, et al. "Respiratory difficulty at a postanesthesia care unit after total thyroidectomy: a case report." Korean J Anesthesiol 45.4 (2003): 540.

Ayandipo, O. O., T. A. Adigun, and O. O. Afuwape. "Airway Complications and Outcome after Thyroidectomy in Ibadan: A 15 year review." Arch Med 8 (2016): 4.

Law, J. Adam, et al. "The difficult airway with recommendations for management–part 2–the anticipated difficult airway." Canadian Journal of Anesthesia/Journal canadien d'anesthésie 60.11 (2013): 1119-1138.

Question 26 - 2020, Paper 2

A 68-year-old male remains intubated four days after an out of hospital cardiac arrest. He is agitated on low dose propofol and only intermittently follows commands. His ventilation is pressure support (PSV) with FiO2 0.45, PS 10 cmH2O and PEEP 8 cmH2O. He is generating tidal volumes of 460 mls with a respiratory rate of 22 breaths/min and oxygen saturations of 94%.

Outline how you would determine his readiness for extubation.
 

College answer

Not available.

Discussion

This patient is at risk of extubation failure. Firstly, some might say that an FiO2 45% is still too high to consider extubation, and others might point to the relatively brisk four day course since his cardiac arrest. This question is functionally indistinguishable from Question 11  from the second paper of 2011, which asked you to extubate a "45-year-old intellectually handicapped man". The basic issue is the same: this patient's neurology is difficult, and you have to adjust your expectations. And, as in all such cases, to a considerable extent his readiness for extubation would be related to your readiness to reintubate him. 

First: assure yourself that the basic preconditions are met:

  • The resolution of the condition which had required the intubation and ventilation (hypoxic brain injury) is still in progress. 
  • Haemodynamic stability, specifically his cardiac function needs to be satisfactory to endure the increased demand from hard-working respiratory muscles
  • Adequate muscle strength (this might be challenging in an uncooperative patient, but he at least intermittently obeys commands)

Determine that the gas exchange is adequate:

  • Decrease the FiO2 to 40% or lower
  • Observe the SpO2 and respiratory rate to assure yourself that a high FiO2 is not required

Determine that the chest wall mechanics are adequate:

  • This patient recently had CPR. Assure yourself that he does not have a flail segment of clinically significant chest wall injuries.

Assess airway protective reflexes

  • Good cough reflex on tracheal suctioning
  • Good gag reflex on oropharyngeal suctioning

Assess airway patency

  • Perform a cuff leak test
  • Ideally, perform it under direct laryngoscopy vision, assuring yourself that a) there is definitely space in the airway, and b) that you can perform direct laryngoscopy on this patient if push comes to shove

Reassess neurology

  • Cease the propofol entirely and transition the patient to another agent, eg. dexmedetomidine
  • Cease any other agents which might depress the level of consciousness
  • Reassess neurology and readjust your expectations
  • Realistically, this patient may remain confused for some days to come, and he does not need to spend all of those days intubated

Consider postponing extubation. 

  • Extubation is an entirely elective procedure.
  • A delay may improve the degree of airway oedema, or allow for expert staff to assemble so that the best chance of reintubation is afforded.

References

On page 362, Bersen references this Chest article from 2001, where the evidence for extubation criteria is summarised.
MacIntyre NR (chairman), Evidence-based guidelines for weaning and discontinuing ventilatory support: a collective task force facilitated by the American College of Chest Physicians; the American Association for Respiratory Care; and the American College of Critical Care Medicine. CHEST December 2001 vol. 120 no. 6 suppl 375S-396S.

Recommendations regarding which conditions favour extubation has been put forward in a 2007 practice guidelines statement by the AARC:
AARC GUIDELINE: REMOVAL OF THE ENDOTRACHEAL TUBE; RESPIRATORY CARE •JANUARY 2007 VOL 52 NO 1 

Karmarkar, Swati, and Seema Varshney. "Tracheal extubation." Continuing Education in Anaesthesia, Critical Care & Pain 8.6 (2008): 214-220.

Mitchell, V., et al. "Difficult Airway Society Guidelines for the management of tracheal extubation." Anaesthesia 67.3 (2012): 318-340.

Kriner, Eric J., Shirin Shafazand, and Gene L. Colice. "The endotracheal tube cuff-leak test as a predictor for postextubation stridor." Respiratory care 50.12 (2005): 1632-1638.

Question 12 - 2021, Paper 1

This is an image (Figure 12) of a 13-year-old male who rode his motorbike into a single strand of fencing wire, was thrown off and walked 500 metres for help. He now complains of difficulty in breathing. On examination he has stridor.

a)    List the potential associated injuries possible in this patient.    (30% marks)

b)    Discuss the specific management options for securing his airway. Include in your answer the advantages and disadvantages of each and your preferred option.    (70% marks)
 

College answer

Not available.

Discussion

This question is virtually identical to Question 7.2 from the first paper of 2010. Presumably they used the same image of the boy (this dude would surely be in his thirties by now). In another act of what appears to be a slow process of improving the phrasing of old SAQs,  the colloquial "How will you secure his airway? Give reasons" has given way to "Discuss the specific management options for securing his airway". Also, the list of potential injuries is new.

List of potential injuries: This is essentially blunt trauma to Zone II of the neck; or rather, one's knowledge of neck anatomy is tested here; one must think, "what could possibly have gotten in the way of that fence wire?". Thus:

  • Laryngeal or cricoid injury
  • Tracheal injury (eg. cartilage fracture)
  • Trauma to the internal jugular veins (could lead to thrombosis)
  • Carotid or vertebral artery dissection
  • Brachial plexus nerve root injury
  • Recurrent laryngeal nerve injury 
  • Spinal cord and C-spine injury
  • Thyroid contusion
  • Soft tissue haematoma of the neck

Management options for securing his airway are numerous.

Strategy Advantages Disadvantages
Do nothing 
  • Noisy breathing is better than no breathing
  • Could be better to buy time with pharmacological management of airway swelling (eg. nebulised adrenaline)
  • Requires no additional airway skills 
  • Could be the safest option of all if senior ENT/anaesthetic help is available but delayed
  • Delays potentially inevitable intubation
  • During the delay, swelling/haematoma might get worse, making the subsequent intubation difficult or impossible 
  • Airway trauma progresses towards obstruction insidiously, over hours
  • It may be difficult to detect impending airway failure 

Modified rapid sequence induction

  • No cricoid pressure: laryngeal injuries may be exacerbated by cricoid pressure
  • Passive pre-oxygenation (no manual bagging)
  • No positive pressure until the cuff is up
  • The intubation may convert a partially transected trachea into a completely transected trachea
  • C-spine precautions could make it more challenging
  • Presence of airway swelling may make it impossible

Awake fiberoptic bronchoscopy

  • Avoids the potential loss of airway with anaesthetic-related loss of airway tone 
  • Allows inspection of the airway structures on the way in
  • Airway swelling decreases access
  • The patient may be obtunded and uncooperative
  • Copious blood and mucus in the airway will frustrate the view
  • There may not be time to set up the appropriate equipment
Elective tracheostomy or cricothyroidotomy
  • Bypassess the injured sections of the upper airway 
  • A definitive solution to upper airway trauma
  • Appropriate if the upper airway cannot be traversed with a tube, or where laryngoscopy is difficult because of swelling
  • Unskilled or blind approach could produce a complete disruption of a partially disrupted trachea
  • A disrupted trachea will retract into the thorax, and will need to be surgically retrieved.

"Own practice" could consist of something like...

  • Initially, do nothing:
    • Start the patient on oxygen and give an adrenaline neb
    • Take the patient to CT to image the airway
  • If the CT is non-reassuring, or the patient's condition is deteriorating, go to Plan B:
    • Plan B is modified RSI with a second operator preparing for airway scalpel/bougie/tube rescue
    • "Modified" because:
      • No cricoid pressure: laryngeal injuries may be exacerbated by cricoid pressure
      • Passive pre-oxygenation (no manual bagging)
      • No positive pressure until the cuff is up
  • If CT is relatively reassuring, proceed with Plan A:
    • Plan A is to have a fiberoptic intubation with anaesthetics and ENT in theatre

References

Caron, Guy, et al. "Submental endotracheal intubation: an alternative to tracheotomy in patients with midfacial and panfacial fractures." Journal of Trauma and Acute Care Surgery 48.2 (2000): 235-240.

Barriot, P. A. T. R. I. C. K., and B. R. U. N. O. Riou. "Retrograde technique for tracheal intubation in trauma patients." Critical care medicine 16.7 (1988): 712-713.

Mohan, Raja, Rajiv Iyer, and Seth Thaller. "Airway management in patients with facial trauma." Journal of Craniofacial Surgery 20.1 (2009): 21-23.

Schaefer, Steven D. "Management of acute blunt and penetrating external laryngeal trauma." The Laryngoscope 124.1 (2014): 233-244.

Peady, "Initial Airway Management of Blunt Upper Airway Injuries: A Case Report and Literature ReviewAustralasian Anaesthesia 2005

Kelly, James P., et al. "Management of airway trauma I: Tracheobronchial injuries." The Annals of thoracic surgery 40.6 (1985): 551-555.

Kelly, James P., et al. "Management of airway trauma II: combined injuries of the trachea and esophagus." The Annals of thoracic surgery 43.2 (1987): 160-163.

Shearer, Vance E., and A. H. Giesecke. "Airway management for patients with penetrating neck trauma: a retrospective study." Anesthesia & Analgesia 77.6 (1993): 1135-1138.

Devitt, J. Hugh, and Bernard R. Boulanger. "Lower airway injuries and anaesthesia." Canadian journal of anaesthesia 43.2 (1996): 148-158.

Jain, Uday, et al. "Management of the Traumatized Airway." The Journal of the American Society of Anesthesiologists 124.1 (2016): 199-206.

Bhojani, Rehal A., et al. "Contemporary assessment of laryngotracheal trauma." The Journal of thoracic and cardiovascular surgery 130.2 (2005): 426-432.

Kummer, Carmen, et al. "A review of traumatic airway injuries: potential implications for airway assessment and management." Injury 38.1 (2007): 27-33.