Printable list of all airway management SAQs

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

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.

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

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:

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.

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.

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.

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).

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.

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

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:

• Advantages and disadvantages of tracheostomy

Published literature:

• Durbin (2005)
• De Leyn(2007)

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
  • The complications of the percutaneous and surgical tracheostomy
  • Potential for dislodgement
  • Humidification is inadequate
  • Passive humidifiers increase the work of breathing
  • Blockage with secretions
• 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

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:

... 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 

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

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."

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.

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.

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?

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.

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

• Corticosteroids
•  Nebulised adrenaline
• Non-invasive ventilation
• Helium-oxygen gas mixture
• Reintubation (but this may be more difficult)
• If all else fails, emergency tracheostomy

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.

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:

• Corticosteroids
•  Nebulised adrenaline
• Helium-oxygen gas mixture
• Non-invasive ventilation is contraindicated; the patient may have laryngeal mucosal injury and positive pressure may dissect into the tissues, causing subcutanous emphysema and impairing the laryngoscopy. One presumes that this is what the college meant when they recommended to maintain "spont vent" in the model answer.

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

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.

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

The normal criteria for extubation readiness are outlined below.

... 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.

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.

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.

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.

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.

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:

• Advantages and disadvantages of tracheostomy

Published literature:

• Durbin (2005)
• De Leyn(2007)

Advantages of "PDT in general" are offered below:

References

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.

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

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.

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

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.

References

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

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

College answer

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.

College answer

References

College answer

References

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

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.

"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

College answer

Not available.

Discussion

This has appeared before, as Question 17 from the first paper of 2017.

The author has also been present at attempts to facilitate speech by attaching low flow wall oxygen to the above-cuff suction port of the tracheostomy, thereby directing a flow of gas up into the mouth through the vocal cords. The first time you do this, you should expect to have a Yankeur sucker ready, as god-awful filth will rise bubbling from the nethermost hell of that long term patient's airway, forced out by the gas pressure. The author was subsequently surprised to discover that this was not a Mad Hatter sign of senior intensivist cognitive deterioration, but in fact a described technique (McGrath et al, 2016). It was left out of the table above mainly because most people would agree that it does not form a part of the normal spectrum of practice.

References

College answer

Not available.

Discussion

The first two marks of this question are dedicated to a topic which, during the COVID pandemic, had a remarkable amount of ink spilled over it. Trainees may recall how countless airway management policies were hastily drafted and revised to minimise staff exposure to aerosols, draping the patient in various plastic sheets, clamping tubes and performing checklist rituals. This "infection control measures during the airway procedure" section expects those same trainees to purify the last two years of confusing and rapidly mutating guidelines into some kind of point-form condensate, for under fifty words.

The best resource for this that probably crosses the most international boundaries is the NEJM video from 2021 by Shrestha et al. To narrow things even more, for COVID patients with difficult airways, this 2021 set of guidelines from the Society of Airway Management spells out all the issues that need to be considered. The reader is warned that these are not standard guidelines by any means, i.e the recommendations they make may not be endorsed by every jurisdiction around the world, and every airway expert is likely to have their own  opinion on this situation. As the result, the possible range of answers to this question is quite broad, and what follows should be viewed as a guide or suggestion for how to approach this SAQ rather than any sort of model answer

Infection control measures

• Potential difficulties:
  • The patient may have COVID, which places staff at risk of exposure
  • The intubation is likely to be difficult, meaning that it will likely take longer, require more staff and equipment, and involve more aerosol-generating procedures
• Solution:
  • Move the patient into a single-bed negative pressure room
  • Minimise staff in the room (four should be enough), bring only essential equipment
  • PPE for all staff (N95, hat, goggles, face shield, gloves, gown)
  • No bag-valve-mask ventilation after relaxant
  • And/or: viral filter on the BVM apparatus
  • Clamp ETT following intubation, unclamp when connected to the ventilator

Preparation for intubation

• Potential difficulties:
  • Severe respiratory failure, with minimal margin for error and a considerable potential for profound hypoxia during intubation
  • Potentially a difficult airway given the history of ankylosing spondylitis
• Management of respiratory failure:
  • Maximise periprocedural oxygenation:
    • Well-sealed face mask with viral filter and EtCO₂ module
    • Preoxygenation on NIV and apnoeic oxygenation with HFNP is an alternative, but thought to be the inferior option and is not routinely recommended
• Management of the airway:
  • Assess the airway, anticipating problems with neck extension
    • Determine whether bag-valve-mask ventilation is also likely to be difficult
  • Consider options
    • Awake fibreoptic intubation would be ideal, but is a highly aerosol-generating procedure, and should be avoided if possible
    • Videolaryngoscopy with alternative curved blade and tube over flexible metal stylette
  • Prepare the patient
    • Brief patient regarding the need for intubation
    • Explain the steps which you will take
  • Prepare personnel
    • Help from the most senior airway technician should be sought, in addition to standard personnel for drugs, airway assistance, etc
    • A non-PPE runner should be available to fetch equipment, waiting outside the negative pressure room
  • Prepare equipment
    • Standard intubation equipment
    • difficult airway trolley (LMA, including intubating LMA)
    • equipment for emergency surgical airway
    • resuscitation equipment
  • Prepare the scenario
    • Go through the checklist of equipment
    • Discuss the plans (A, B and C) with all the staff
    • Example plans:
      • Plan A: rapid sequence induction and videolaryngoscopy with "D" blade CMAC or similar
      • Plan B: intubating LMA
      • Plan C: 
      • Emergency rescue: scalpel-bougie-tube

References