We all spend a significant amount of time and effort in training in and practicing advanced airway management. One of the reasons that it is such an important skill, for the emergency physician or trainee, is so that we can address the A in DRSABC, in the event of a patient in cardiac arrest.
Over the last few years the ABC dictum has been questioned, albeit in murmured tones, by many senior clinicians.
Do advanced airway management techniques really lead to better outcome in cardiac arrest?
The latest ARC guidelines state that in the event that the rescuer is unable or unwilling to perform rescue breaths, compression only CPR, is acceptable.
Would we be better opening the airway and using simple techniques such as bag valve mask or apnoeic oxygenation and concentrate of good quality compressions and definitive management of the underlying cause?
This problem has been examined in JAMA in Jan 2013:
Hasegawa K, Hiraide A, Chang Y, Brown DF. Association of prehospital advanced airway management with neurologic outcome and survival in patients with out-of-hospital cardiac arrest. JAMA : the journal of the American Medical Association 2013; 309 (3): 257-66
A very large prospective, nationwide, population-based study involving 649 654 consecutive adult patients in Japan who had an out of hospital cardiac arrest was undertaken. The results are fascinating.
Approximately 43% were given Bag-Valve-Mask(BVM) respiratory support, 6.5% were intubated(ETT) and 37% received supraglottic airway(LMA) support.
The statistical analysis included multivariable logistical regression to adjust odds ratio of survival with favourable neurological outcome for the obvious variables such as primary documented rhythm, bystander CPR, use of AED, aetiology of arrest, age and sex.
The results showed an odds ratio in favour of BVM with both ETT and LMA leading to odds ratio of favourable neurological outcome 1 month after an OHCA, defined as cerebral performance category 1 or 2, of 0.45 (ETT) and 0.36 (LMA) 95% CI.
This is an interesting result suggesting we should be concentrating on doing the basics right and getting the OHCA arrest patient to hospital as fast as possible with minimal delay for interventions.
A couple of comments from Peter Kas:
Thanks for that Blog Will. This is a very important topic that you’ve covered. A very interesting paper, that supports the results from several other studies. A couple of years ago I had the opportunity to speak on this topic at the Annual Scientific Meeting and spoke on “Guidelines Sschmidelines: Tell Me How to Use Them” The talk was really about understanding the details of and using the resuscitation guidelines properly.
The papers on cardiocerebral resuscitation (Ewy et al Resuscitation. 2003;58:271-271 and then other papers following such as, Garza et al Circulation. 2009; 119:2597-2605), showed a better survival, with less airway intervention. Intubation was shown to increase mortality.
We don’t know if airway makes a difference. Intuitively, we think it must. Is there a decreased survival because it interrupts CPR, or is there some other reason? There are so many questions to be answered.
A lot of work still to be done. Only now, are we finding out more about approaches to airway. We don’t have a best approach to intubation. There are no studies as to when the best time to intubate is. In an arrest, are we sure that the endotracheal tube is in the trachea given the low end-tidal CO2, that naturally occurs?
My approach(and I know this is also Will’s) is, no tube and continue resuscitation with bag-valve-mask or laryngeal mask. When return of spontaneous circulation occurs, then intubate.
I’ll be speaking on this topic “Cardiac Arrest: Are we doing it right?” at EMCORE 2013.