Adrenaline or Airway first in cardiac arrest?

Cardiac arrest has a poor survival rate. In this study Okubo et al(1) tried to address the question of adrenaline or airway first, in out of hospital cardiac arrest?

We appear to be forever looking to change the variables we have ie., adjust airway, or adrenaline dose, or something else, because we don’t have much else. ECMO for all may be the best approach, but not a realistic one.

The push for cardio-cerebral resuscitation with its emphasis on circulation before airway, may give better results in adult cardiac arrest, as the majority of adult arrests are cardiac and not respiratory in origin (compared to paediatric arrests) meaning that these patients are not hypoxic at the time of arrest.

The use, dose and timing of adrenaline is an area that is being questioned. Although we know that that is of greater benefit in non-shockable rhythms, we are almost certain that giving adrenaline to patients with a shockable rhythm, results in a worst outcome.

We know that intubation may not confer any benefit over supraglottic airway or even bag valve mask in the early stages of an arrest. There is also uncertainty as to the rate and volume of ventilation.

What they did

 This was a retrospective cohort analysis of out of a hospital cardiac arrest registry data, where they analysed the sequence of IV adrenaline administration and advanced airway management.

 N=259,237 patients.

 Primary Outcome

1 month survival

Secondary outcomes

• Prehospital ROSC
• One month survival with good neurological outcome

 What they found

Receiving adrenaline before an advanced airway, resulted in an increased 1 month survival, irrespective of the initial rhythm:

1. Shockable rhythm (odds ratio [OR], 1.19; 95% CI, 1.09-1.30)
2. Non-shockable rhythm (OR, 1.28; 95% CI, 1.19-1.37)

Author’s Conclusion

“..we found that epinephrine-first strategy was associated with an increased likelihood of 1 month survival with favourable functional status and prehospital ROSC for both shockable and nonshockable rhythms compared with the AAM(advanced airway management – first strategy”

Limitations of this study:

• This was a registry study and we know from past experience that registry studies do not always provide the best results.
• The events were not randomised.
• The data on unsuccessful events was not captured.
• We do not know if failing to establishing IV access, was an important determinant in airway being undertaken before adrenaline.
• The was no data on post resuscitation care and how this may have influenced outcome.

Given these limitations, I can’t see it altering what I do and am sure what most of you do:

• BVM or supraglottic airway (plus ETCO2) first.
• Intubation only occurring post ROSC, or with VL and experienced operator and no interruption to CPR.
• POCUS Pulse/ ECHO during a rhythm check to look for output.
• Shockable rhythm? Shock first before adrenaline.
• Non-shockable rhythm- Give adrenaline.
• Limit the use of adrenaline.
• Femoral arterial line inserted during third cycle

References

Okubo M et al. Sequence of Epinephrine and Advanced Airway Placement After Out-of-Hospital Cardiac Arrest. JAMA Network Open. 2024;7(2):e2356863.