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Factors associated with failed intubation attempts in the ED – Difficult Airway

ResearchBlogging.org
 

As with any procedure, each attempt at intubation increases the chance of harm to the patient.

What can we do to minimize the possibility of making more than one attempt at intubation?
 

The aim of this study was to identify factors associated with successful second and third attempts in adults following a failed first intubation attempt to support an effective rescue attempts strategy in the ED.[1]

 

Click on images to make them larger.
 

The success rate for each attempt was about 80% for the first, second, and third attempts. Several factors seem to have influenced that success rate, but the most important appears to have been the presence of a difficult airway.
 

The 6 academic EDs were equipped with core airway devices and drugs, one or more extraglottic devices, one or more video laryngoscopes and fiberscopes, RSI drugs, and one or more cricothyrotomy sets or kits.[1]

 

All intubations were supervised by a senior physician, so they should be well prepared for difficult airways.
 

A difficult airway was defined as a case in which the first intubator anticipated the difficult airway considering 3 dimensions of difficulty: difficult laryngoscopy and intubation, difficult bag-mask ventilation, and difficult cricothyrotomy.[1]

 

In the discussion, the authors suggest that they may have come up with higher rates of difficult airways for the first intubation attempt due to using three criteria to identify difficult airways.

This should not suggest that their conclusions about difficult airways are weakened. The opposite is more. They were less likely to miss a difficult airway. Difficult bag-mask ventilation may not be predictive of a difficult airway, but the increasing proportion of difficult airways among the failed intubations suggests that these airways were difficult.
 


 

Perhaps if we view the difficult airways as a proportion of the successes and failures of each intubation attempt, it will make things more clear.
 


 

Only 26.3% of first intubation attempt failures, but 36.5% of second intubation attempt failures, and increasing dramatically to 64% of third intubation attempt failures.

This does raise the question of why 36% of third intubation attempt failures were not considered difficult intubations?

Were they only going by the initial assessment of difficult intubation?

Shouldn’t we be reevaluating as we get further information as the Reverend Thomas Bayes advises?[2]

Footnotes:

[1] Factors associated with successful second and third intubation attempts in the ED.
Kim JH, Kim YM, Choi HJ, Je SM, Kim E; on behalf of the Korean Emergency Airway Management Registry (KEAMR) Investigators.
Am J Emerg Med. 2013 Jul 29. doi:pii: S0735-6757(13)00395-1. 10.1016/j.ajem.2013.06.018. [Epub ahead of print]
PMID: 23906622 [PubMed – as supplied by publisher]

[2] Bayesian inference
Wikipedia
Article

Kim JH, Kim YM, Choi HJ, Je SM, Kim E, & on behalf of the Korean Emergency Airway Management Registry (KEAMR) Investigators (2013). Factors associated with successful second and third intubation attempts in the ED. The American journal of emergency medicine PMID: 23906622

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Comments

  1. This does raise the question of why 36% of third intubation attempt failures were not considered difficult intubations?

    Were they only going by the initial assessment of difficult intubation?

    One nice side effect of using video laryngoscopy is the ability to record the intubation attempts (at least in theory). Maybe for another study (planned and not retrospective) the videos of the multiple-failure airways can be compared to see if/how the airways become “more difficult” with repeated attempts.

    It’ll also be interesting to see how difficult BVM ventilation tracked airway failures by itself (as opposed to one of three criteria); might give some insight as to how often difficult BVM ventilation indicates a difficult airway.

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