Resuscitation That’s (Un)Shockable: Time to Get the Adrenaline Flowing

Authors: Donnino MW et al., BMJ 2014 May 20; 348:g3028

Inpatients who experience nonshockable cardiac arrest are more likely to survive when epinephrine is administered early.

A large and increasing percentage of patients with cardiac arrests exhibit initial nonshockable rhythms (asystole or pulseless electrical activity [PEA]; 82% in 2009 vs. 69% in 2000; NEJM JW Hosp Med Nov 14 2012). Cardiac arrest guidelines recommend early use of epinephrine to manage patients with nonshockable rhythms (Circulation 2010; 122:S729), but this recommendation lacks strong evidence to support efficacy.

Investigators retrospectively evaluated more than 25,000 patients (at 570 U.S. hospitals) with in-hospital cardiac arrests who were not in intensive care units or emergency departments and who exhibited initial rhythms of asystole or PEA. Half of patients received their first dose of epinephrine greater than 3 minutes following the start of resuscitation. Delayed administration of epinephrine was associated significantly with lower chance for survival to hospital discharge, in stepwise fashion (12%, 10%, 8%, and 7% survival, respectively, for patients receiving their first epinephrine dose less than 3 minutes, 4–6 minutes, 7–9 minutes, and greater than 9 minutes after arrest). Neurologically intact survival to hospital discharge was significantly more likely after earlier epinephrine administration.

Comment

Most cardiac arrests have initial nonshockable rhythms. A focus on time to epinephrine administration — in addition to high-quality chest compressions — might be the best early intervention and, possibly, the next (or only) quality metric in PEA and asystole arrests.