OSCE 7

This is a procedure station where you will demonstrate your skill and knowledge of the practical aspects of the procedure percutaneous tracheostomy.

What are the advantages of tracheostomy?

Question 7 from the first paper of 2004 asked the candidates to "outline the potential advantages and disadvantages of a tracheostomy in the weaning of patients from mechanical ventilation.

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

How would you define "early" and "late" tracheostomy?

The college answer to Question 13 from the first paper of 2013  reports that tracheostomy "may be considered as “early” at <10 days or “late” >10 days", which is a definition probably adopted from the 2012 Cochrane review by Gomes et al. 

What would be the advantages of early tracheostomy?

• Avoidance of the perils of prolonged intubation: having an endotracheal tube for a prolonged period exposes patients to a host of complications from which the tracheostomy should theoretically be free. Realistically, the main improvement is in terms of patient comfort, which permits the sedation to be weaned - with follow-on effects for haemodynamics and ventilator support.
• Maximise the advantages of tracheostomy - there are numerous positive effects from tracheostomy which the patient could benefit from, so why deny them these benefits for an artificially prolonged period? May as well get all the benefits early, when it might still make a difference to the course of their illness.
• Decrease the length ICU stay:  with one of the supposed benefits of tracheostomy being a more rapid ventilator wean, the earlier you do the tracheostomy the sooner the patient can be weaned and discharged from the ICU. This has implications for resource utilisation in ICU.

What would be the advantage of delaying tracheostomy?

• Some patients may end up being extubated after a prolonged intubation:  we just don't know which ones. Presently, there is no satisfactory method to identify them, but broadly speaking patients with reversible (and severe) cardiac and respiratory pathology can be expected to eventually get better, and they may be better served by waiting for a "late-term" extubation.
• A long period of intubation allows these patients to be more easily identified.  The more we spend observing the progress of somebody's illness, the more confidently we can discuss their prognosis. Delaying a tracheostomy therefore improves the quality of decisionmaking. The patients who receive a tracheostomy because they are not progressing at day 10-14 of ventilation can be described as more "deserving" - the indications for tracheostomy are clearer the longer you wait.
• Risks of prolonged intubation are overstated: it is not clear that prolonged intubation is as harmful as it is made out to be, as much of the data regarding protracted mechanical ventilation comes from a bygone era when high-pressure tube cuffs were used. In this day of low-pressure high-volume cuffs, subglottic suction ports, selective digestive tract decontamination, aggressive physiotherapy and posture therapies, as well as rational sedation - these days the risks of staying ventilated for a long time are relatively minor.
• Tracheostomy exposes patients to certain procedural risks, and the practice of routine early tracheostomy exposes more patients to these risks (many of whom would have been extubated after two or three weeks).
• Futile care may be perpetuated by tracheostomy. A tracheostomy may commit a severely disabled or persistently unconscious patient to the ongoing unpleasantness of their survival. The fact that a patient might end up in this category may not be clear in the initial stages of their admission. If the prognosis becomes obvious only after the tracheostomy, the tracheostomy then becomes a part of their unnecessary aggressive management.
• 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. If early tracheostomy decreases the length of ICU stay at the cost of numerous inappropriate tracheostomies, then this is not how we should practice medicine.

What evidence is available to guide decisionmaking with regards to early vs. late tracheostomy?

Pre-TracMan

A Cochrane review from 2012 (Gomes et al) is a good representation of the data which existed at this stage:

• Improved mortality with early tracheostomy (which did not reach statistical significance)
• More time off the ventilator (and more success weaning; NNT = 11)
• Slightly shorter ICU stay (by about 1 day)
• No change in duration of hospital stay
• A decreased incidence of pneumonia (12.3% vs 21.9%) with early tracheostomy
• A greater incidence of tracheal stenosis at 10 weeks

However, there was such heterogeneity of findings among the four remaining trials that Gomes et al were unable to pool the data. "Evidence is of low quality" they complained.

TracMan trial (Young et al, 2013)

In response to the desperate need for high quality trials, TracMan enrolled 909 patients from 72 British ICUs. 

• Patients were randomised to undergo tracheostomy on day 10, or immediately (as they were randomised before day 5)
• In the late group, 55% of the patients did not need to undergo tracheostomy- they ended up being extubated before day 10.
• There was no mortality difference, but the early group had more ventilator-free days (1.7 days less), supporting the idea that tracheostomy improves weaning.
• 7% of the tracheostomised patients had significant bleeding

In the wake of TracMan

Recently, the abovementioned Cochrane review has been revisited by Andriolo et al (2015). In the three years since the last review, more RCTs were performed and eight studies were included (n=1977, of which 909 were from TracMan). The analysis results were as follows:

• 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.

What patient factors might affect your decision to perform an early or late tracheostomy?

• Neurological and neurosurgical patients may benefit from early tracheostomy, as it reduces the incidence of VAP and reduces their length of ICU stay. However, there is no effect on mortality or neurological outcome. If one were arguing against a tracheostomy for a neurocritical ICU patient with likely poor neurological prognosis, one might bring up this point.
• Cardiothoracic ICU patients do not seem to develop deep-seated mediastinal infections or sternal wound infections as a result of their tracheostomies, and therefore in this group there is probably no reason to delay tracheostomy (i.e. treat this group the same as any other patient group).
• Burns patients with > 60% BSA burns or airway burns  require either multiple trips to theatre or prolonged airway rest, or both. That said, there will be no influence on mortality or length of ICU stay (these will be determined by numerous other factors).
• Trauma patients with severe injuries will require prolonged ventilation for their multiple rib fractures. One may be able to identify these unextubatable patients by their admission CT report. In these people, earlier tracheostomy may be of benefit.

 

Please describe the neck anatomy as relevant to percutaneous tracheostomy

The following text is from Question 1  from the first paper of 2008:

•    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.

Where is the ideal insertion point for a percutaneous tracheostomy?

From the ANZICS statement: pierce the trachea "between 1st & 2nd or 2nd & 3rd tracheal ring"

Surgical tracheostomy may involve the removal of a cartilaginous ring.

What is the reason for this choice of spaces?

The main reason for this choice of spaces is to avoid hitting the thyroid, though it seems to be a fairly benign complication.Duanne et al reported on a "successful percutaneous tracheostomy via puncture through the thyroid isthmus" which did not bleed as torrentially as one might expect

When assessing a patient for percutaneous tracheostomy, what would you look for? Which features would suggest that the procedure will be easy?

• Good neck extension
• History of having a straightforward laryngoscopy
• No history of major scarring in the anterior neck which might frustrate dilation or prevent normal healing (classically, a history of burns or neck radiotherapy makes tracheostomy difficult)
• Ample space below the cricoid cartilage
• Easily palpated tracheal rings
• Absence of obvious dilated vessels on gross inspection
• Ultrasound confirmation of the absence of those aforementioned vessels
• The absence of a massive pulsating goitre
• The absence of a tracheal bruit (which might make you think of such a goitre)

What are the advantages and disadvantages of surgical tracheostomy? Which is better, the surgical or the percutaneous approach?

	Surgical tracheostomy	Percutaneous tracheostomy
Advantages	Gold standard for difficult anatomy Better control of bleeding Fewer intraoperative complications	Less postprocedural complications such as accidental decannulation,  bleeding  and wound infection. (Dulguerov et al, 1999) Less bleeding risk (smaller hole) Lower incidence of tracheal stenosis Lower incidence of tracheal infection Johnson-Obaseki et al (2016) The cosmetic effect is better No transfer, thus no risks of transfer Cheaper Faster (10-15 minutes) More easily available in the ICU Decreases length of stay in ICU (if early tracheostomy:  Griffiths  et al, 2006)
Disadvantages	More postprocedureal complications Higher incidence of tracheal stenosis Higher incidence of stomal infections Expensive; requires the operating theatre to be fully staffed Takes longer to roganise Exposes patients to risk of transfer	Inadequate backup for major complications or difficult anatomy. Much of the technique is essentially blind. Diathermy is not available in ICU Cardiothoracic surgical support is lacking Bronchoscopy is required for safety  The bronchoscope may get damaged Disposable percutaneous kits cost more than a bedside surgical tracheostomy There is a greater risk of death and cardiac arrest. (Dulguerov et al, 1999) Some intraoperative complications are unique to percutenous technique (eg. knotted guide wire)

What is the evidence regarding the choice between surgical and percutaneous tracheostomy?

In terms of immediate and early complication rates

"With regard to rates of mortality, intraoperative hemorrhage, and postoperative hemorrhage, there was no statistically significant difference between the two techniques" - this was the conclusion of the meta-analysis by Johnson-Obaseki et al (2016). The same authors found that the post-procedure infection rate was lower with the percutaneous technique. The difference between this meta-analysis and the meta-analysis by Dulguerov et al (1999) probably reflects how the safety of the percutaneous technique has improved over time, thereby decreasing the intraoperative complication rate. The comparatively lacklustre performance of the surgical technique can perhaps be attributed to the fact that these days only the most technically difficult tracheostomies are being performed surgically.

In terms of resource utilisation

The abovementioned meta-analysis from Johnson-Obaseki et al (2016) found that the procedure time was faster for the percutaneous technique.

In terms of late complications

The risk of tracheal stenosis was found to be higher for surgical tracheostomy - though only as a trend, rather than a firm association (Dempsey et al, 2016)

What  methods of percutaneous tracheostomy are known to you? What are their advantages and disadvantages?

	Advantages	Disadvantages
Classical Ciaglia (multiple dilators)	Well known Well studied Well practice Complication rate is notoriously low Multiple sequential dilators ensure that little force and little pressure is required Thus, less risk of posterior wall puncture Less tracheal trauma	Supraglottic ETT position may result in loss of PEEP or loss of the airway altogether Potential of posterior tracheal wall puncture Exposes operators to blood spray Increases exposure to aerosolised airway secretions Prolonged procedure Multiple steps: difficult to learn Long straight dilators lend themselves to posterior tracheal wall laceration Multiple manipulations of the guidewire can result in dislodgement of the wire out of the trachea.
Ciaglia Blue Rhino	Faster than the classic technique Fewer steps Curved dilator: less risk of posterior wall puncture	Single large dilator: risk of tracheal trauma All the same problems with ETT being above the cords (see above)
Griggs forceps technique	Faster technique – less dilatations (potentially, the fastest) Less blood spray exposure (potentially)	Potential for more tracheal damage Requires sterile forceps Less researched More potential for infectious complications Greater potential for guidewire loss
Cianchi balloon dilation technique	No risk of injuring the posterior wall No sequential dilators: one balloon only No forceful pushing required	Takes longer More steps are required Tracheostomy tube is more difficult to pass into the dilated opening
Frova and Quintel (PercuTwist) technique	Less risk of injuring the posterior wall No sequential dilators: one balloon only No forceful pushing required Single dilator technique	No specific protection againt posterior wall lacerations or cartilage fractures Not widely available No speed advantage over Griggs or other single-dilator techniques
Translaryngeal (Fantoni)	Very low complication rate Can be a one-person technique No pressure is directed towards the posterior wall	Largely unknown technique Relies on small endotracheal tube to ventilate Requires additional equipment Chance of vocal cord damage At one point, you are expected to have no airway whatsoever.

What are the immediate complications of percutaneous tracheostomy?

Complications of the percutaneous technique

• Haemorrhage
• Subcutaneous emphysema
• Injury to neurovascular structures
• Thyroid injury
• Loss, kinking, fracture or knotting of the guide wire
• Lateral stoma placement
• Tracheal ring fracture
• Fracture of the cricoid
• Oesophageal injury
• False passage, nontracheal tube placement
• Conversion to open tracheostomy

Complications of airway failure

• Inadvertant extubation
• Indaventant decannulation
• Loss of airway

Complications of depressurisation

• Derecruitment
• Pulmonary oedema
• Hypoxia
• Cardiac arrhythmia
• Bradycardia
• Haemodynamic instability
• Cardiac arrest and death

Complications of foreign material in the airway

• Bronchospasm
• Aspiration pneumonitis

What are the long- and medium-term complications of tracheostomy?

• Poor secretion management; secretions obstructing the tube (sputum plugging)
• Dislodgement of a previously well-placed tube
• Infection, tracheitis, mediastinitis, sternal wound infection
• Swallowing difficulty
• Ulceration of the tracheal mucosa
• Tracheal stenosis
• Tracheomalacia
• Tracheo-innominate  fistula
• Tracheo-oesophageal fistula
• Persistent stoma
• Sternoclavicular osteomyelitis
• Pneumonia

Disclaimer: the viva stem above may be an original CICM stem, acquired from their publicly available past papers. Or, perhaps it is a slightly altered version of the original CICM stem. Or, it is a completely original viva stem, concocted by the monstrously amoral author of Deranged Physiology for nothing more than his own personal amusement. In either case, because the college do not make the main viva text or marking criteria available, almost everything here has been confabulated. It might sound like a plausible viva and it could be used for the purpose of practice, but all should be aware that it does not represent the "true" canonical CICM viva station.