Early vs Late Airway Management for OHCA

Advanced airway is seen as a definitive and reliable means of establishing protected ventilation and oxygenation. It has been shown to improve ROSC and neurological outcomes. The main deterrent to the traditional ABC model, is the potential pauses in CPR, whilst attempting to establish airway. Because of this, we have moved to a delayed airway model  during resuscitation, not establishing advanced airways until ROSC has been achieved. 

Is it time to reassess? We review this study ahead of print.

Amagasa S. et al. Early versus late advanced airway management for adult patients with out-of hospital cardiac arrest: A time dependent propensity score-matched analysis. Acad Emerg Med 2024 April.

Question asked

Is early airway management associated with favourable neurological outcomes and survival in patients with out of hospital cardiac arrest (OHCA)?

What they did

This was a retrospective registry study of adult patients with OHCA in Japan.  They used time-dependent propensity score analysis to examine the relationship between early advanced airway management and outcomes. The aim was to reduce resuscitation-time bias, which is a form of systematic error, whereby those patients receiving a longer duration of CPR, were more likely to have an advanced airway.

In this study advanced airway included:

• tracheal intubation
• supraglottic airway
• oesophageal obturator

Early was defined as airway being established within 10 minutes of emergency services attending to the patient, or if already in attendance, from the onset of cardiac arrest.

N = 41,101

• N =  21,446 in the early advanced airway management group
• N = 19,655 in the late advanced airway

Primary Outcome: Favourable neurological outcome defined as 1 or 2 on the Cerebral performance Category (CPC) Score, which is recovery to good or moderate cerebral disability.

Secondary Outcome: Survival at one month after cardiac arrest.

What They Found

Most causes of cardiac arrest in this study, were cardiogenic and the most prevalent rhythm was asystole, followed by PEA.

When looking at early advanced airway (< 10 minutes) vs late (>10 minutes) and 1 month outcomes they found:

• Early advanced airway management was associated with favourable neurological outcome (RR 0.997 (95% CI 0.995-0.999))
• Early advanced airway management was associated with improved survival (RR 0.990 (95% CI 0.986-0.994))

In a sensitivity analysis, early airway management (< 5 minutes) was associated with increased and favourable neurological survival, at 1 month.

My Take on This

Although this study demonstrated a statically significant difference, when early advanced airway management was performed, the relative risk was very close to 1.0. A relative risk of 1.0 implies that the there is no difference between early and late intervention. The authors acknowledge this.

This study is limited, primarily because it is an observational study and because it is a registry study. this means that confounders cannot be identified or controlled. We don't know the numbers of failed intubations, or failed first pass intubations, nor do we know the characteristics of the ventilation supplied.

Will it change my practice?

Here is an excerpt from a previous blog I've written looking at the different modes of airway management:

"There is no doubt, that the quality of chest compressions during cardiac arrest and early defibrillation of ventricular tachycardia (VT) or ventricular fibrillation (VF), play a major role in the return of spontaneous circulation (ROSC) and cardiac arrest outcomes. Ventilation and oxygenation of the patient are an important part of CPR. The number and volume of breaths, can determine outcomes, by their effect on thoracic distension and resultant cardiac venous return.

Although the literature shows mixed results, it is generally accepted that no significant difference exits between airway management techniques ie., BVM, SGA, or endotracheal intubation (ETI). However some studies using subgroup analysis, do show definite benefits with ETI, including neurologically favourable survival to hospital discharge."  (Airway Management During Cardiac Arrest)

In terms of the timing my approach is simple:

• If I have video laryngoscopy and can intubate early and it will not interrupt CPR, I do it.
• If I have a patient with a respiratory arrest, I will attempt to intubate early, because perhaps, I can oxygenate and the CPR may be more effective if we address the oxygenation issues. 
• If I have a patient who has arrested with significant anaemia, secondary to acute or chronic blood loss, I will certainly make giving blood my first priority, however I will intubate early, so I can maximally oxygenate the blood volume they have.
• In all other cases, I am happy to bVM or use a supraglottic airway, until a definitive airway is established.

What does this all mean? ..... We have to tailor resuscitation to the individual patient. One size does not fit all. Resuscitation should not be an algorithm. It should be a thinking game, changing and adapting what we do to get the best results.

References

1. Amagasa S. et al. Early versus late advanced airway management for adult patients with out-of hospital cardiac arrest: A time dependent propensity score-matched analysis. Acad Emerg Med 2024 April; Ahead of Print.
2. Benoit JL et al. Timing of advanced airway placement after witnessed out of hospital cardiac arrest. prehospital Emerg Care. 2019;23:838-846.
3. Jabre P, et al. Effect of Bag-Mask Ventilation vs Endotracheal Intubation During Cardiopulmonary Resuscitation on Neurological Outcome After Out-of-Hospital Cardiorespiratory Arrest: A Randomized Clinical Trial. JAMA 2018;319:779–87.
4. Benger JR, et al. Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of- Hospital Cardiac Arrest on Functional Outcome: The AIRWAYS-2 Randomized Clinical Trial. JAMA 2018;320:779–91.
5. Wang HE, et al. Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72- Hour Survival in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial. JAMA 2018;320:769–78
6. Wang HE, Szydlo D, Stouffer JA, et al. Endotracheal intubation versus supraglottic airway insertion in out-of-hospital cardiac arrest. Resuscitation 2012;83:1061–6.
7. McMullan J, Gerecht R, Bonomo J, et al. Airway management and out-of-hospital cardiac arrest outcome in the CARES registry. Resuscitation 2014;85:617–22.
8. Benoit JL, Gerecht RB, Steuerwald MT, McMullan JT. Endotracheal intubation versus supraglottic airway placement in out-of-hospital cardiac arrest: A meta-analysis. Resuscitation 2015;93:20–6.