Naloxone Improves Out-of-Hospital Cardiac Arrest Survival

TOPLINE:

Naloxone administration by emergency medical services (EMS) is associated with increased rates of return of spontaneous circulation (ROSC) and survival to hospital discharge in patients with out-of-hospital cardiac arrest (OHCA).

METHODOLOGY:

• The data of a cohort of 8195 adults with OHCA treated by EMS clinicians in three counties in Northern California between 2015 and 2023 were retrospectively analyzed.
• The primary outcome was survival to hospital discharge, and the secondary outcome was sustained ROSC, which was defined as the presence of a detectable pulse for at least 20 minutes or at the end of EMS care.
• Age, sex, initial cardiac rhythm, comorbid conditions, whether the arrest was witnessed, and whether the cause of arrest was drug related, as determined by the treating EMS clinicians, were included as covariates.

TAKEAWAY:

• Naloxone was administered to 14.2% patients.
• Naloxone administration was found to be associated with a 15.2% and 11.8% absolute increase in the rate of ROSC and a 6.2% and 3.9% increase in the rate of survival to hospital discharge on nearest neighbor propensity score matching and inverse propensity –weighted regression adjustment, respectively.
• Naloxone administration was associated with increased rates of survival to hospital discharge in both presumed drug-related OHCA (odds ratio [OR], 2.48; 95% CI, 1.34-4.58) and non–drug-related OHCA (OR, 1.35; 95% CI, 1.04-1.77) groups.

IN PRACTICE:

“EMS-administered naloxone was associated with clinically significant improvements in ROSC and survival to hospital discharge. Additional work is needed to examine the association between naloxone and OHCA outcomes, including prospective interventional studies of naloxone as a potential component of cardiac arrest care,” the authors wrote.

SOURCE:

The study was led by David G. Dillon, MD, PhD, Department of Emergency Medicine, University of California, Davis, California. It was published online on August 20, 2024, in JAMA Network Open.

LIMITATIONS:

The observational nature of the study may have introduced potential for bias, and full adjustment for all confounding factors was not possible. Selection bias could have influenced results, as EMS clinicians were more likely to administer naloxone to patients with suspected drug-related OHCA. Younger patients with fewer comorbidities were more likely to receive naloxone and were independently more likely to survive to hospital discharge. Moreover, the study could not account for naloxone administered by bystanders or non-EMS first responders, which may have biased the results toward no difference between the exposed and unexposed groups. The cohort was limited to a single area in the United Staes, which may have limited generalizability.

DISCLOSURES:

Juan Carlos C. Montoy reported receiving grants from the Substance Abuse and Mental Health Services Administration, outside the submitted work. David G. Dillon was supported by the National Heart, Lung, and Blood Institute, outside the submitted work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.