Naloxone for Opioid Associated Out of Hospital Cardiac Arrest

The investigator's long-term goal is to conduct Naloxone for Opioid Associated out of Hospital Cardiac Arrest (NOPACA), a randomized, double blind, controlled trial to determine the efficacy of naloxone vs. placebo in Opioid Associated out of Hospital Cardiac Arrest. The investigative team plan to randomize patients in OHCA to early naloxone administration vs. placebo after initial resuscitation and measure ROSC and survival. Challenges to designing NOPACA include uncertainty regarding: 1) the available pool of participants and number of EMS agencies needed to meet enrollment targets; 2) acceptability among patients, EMS and Emergency Medicine provider stakeholders, and 3) estimates of the study outcomes needed for sample size estimates. Toward obtaining the necessary information to design NOPACA, the investigators propose a pilot RCT of participants at high risk for OA-OHCA to verify a reasonable recruitment rate; treatment fidelity and acceptability; and adequate retention and measurement of outcomes at follow up. The investigators propose incorporating hypothesis testing of the feasibility outcomes to determine progression to a definitive trial.