The Use of Naloxone in Cardiac Arrest Management

Introduction: Naloxone is a mu-opioid receptor antagonist that is best known for reversing opioid overdose by restoring spontaneous respirations and level of consciousness. It has been postulated that naloxone may possess antiarrhythmic properties as well as the ability to reverse endogenous opioid-related myocardial depression and stimulate catecholamine release, suggesting utility in cardiac arrest. The survivability of cardiac arrest is relatively low, and the impact of opioid toxicity deaths is staggeringly high. Optimizing the medical management of patients in cardiac arrest, particularly in the context of opioid use, is a priority.Research Question: Does naloxone improve rates of return of spontaneous circulation (ROSC) and survival to hospital discharge when administered during cardiac arrest?Methods: Pubmed and EMBase were searched with 187 articles progressing to the screening stage. Inclusion criteria included cardiac arrest patients receiving naloxone pre-hospital or in-hospital with outcomes relating to resuscitation rates and/or survival. Exclusion criteria included traumatic cardiac arrests and pediatrics. Eleven articles were chosen following title and abstract screen, full text review, and data extraction.Results and Discussion: Five randomized controlled trials with animals found that intra-arrest naloxone improved rates of ROSC, particularly when combined with epinephrine. Two human case reports describe patients receiving naloxone during cardiac arrest and experiencing spontaneous improvement in cardiac rhythm, neither with favourable neurological outcomes. Over the past five years, evidence includes a retrospective cohort study, two observational studies, and one case-control study. Two reported higher ROSC rates and improved survival to discharge with naloxone, while the others found no significant differences between exposure groups.Conclusion: Currently, there is conflicting evidence on whether naloxone improves rates of ROSC and survival to hospital discharge. Although naloxone does not appear to be harmful when administered in the context of cardiac arrest, further research is needed to determine its efficacy for this indication.