Question 27

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

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.