Resuscitation characteristics and outcomes in suspected drug overdose-related out-of-hospital cardiac arrest

Introduction: We sought to compare characteristics of emergency medical services-treated out-of-hospital cardiac arrests resulting from suspected drug overdose with non-overdose cases and test the relationship between suspected overdose and survival to hospital discharge.

Methods: Data from emergency medical services-treated, non-traumatic out-of-hospital cardiac arrests from 2006 to 2008 and late 2009 to 2011 were obtained from four EMS agencies in the Pittsburgh, Pennsylvania metropolitan area. Case definition for suspected drug overdose was naloxone administration, indication on the patient care report and/or indication by a review of hospital records. Resuscitation parameters included chest compression fraction, rate, and depth and the administration of resuscitation drugs. Demographic and outcome variables compared by suspected overdose status included age, sex, and survival to hospital discharge.

Results: From 2342 treated out-of-hospital cardiac arrests, 180 were suspected overdose cases (7.7%) and were compared to 2162 non-overdose cases. Suspected overdose cases were significantly younger (45 vs. 65, p<0.001), less likely to be witnessed by a bystander (29% vs. 41%, p<0.005), and had a higher rate of survival to hospital discharge (19% vs. 12%, p=0.014) than non-overdoses. Suspected overdose cases had a higher overall chest compression fraction (0.69 vs. 0.67, p=0.018) and higher probability of adrenaline, sodium bicarbonate, and atropine administration (p<0.001). Suspected overdose status was predictive of survival to hospital discharge when controlling for other variables (p<0.001).

Conclusion: Patients with suspected overdose-related out-of-hospital cardiac arrest were younger, received different resuscitative care, and survived more often than non-overdose cases.