Differential outcomes following successful resuscitation in cardiac arrest due to drug overdose

Background: Data pertaining to clinical characteristics and outcomes of cardiac arrest (CA) due to drug overdose (ODCA) are limited. We hypothesized that patients with ODCA would have binary outcomes (brain death or functional recovery) compared to patients in whom CA was due to another etiology. Methods: We performed a retrospective analysis of CA cases from a single academic institution from 2012 to 2017. ODCA cases were ascertained by admission notes strongly suggestive of OD or positive toxicology screens not explained by medication administration. Clinical characteristics and outcomes were extracted from medical records, and regression modeling was used to compare ODCA and non-ODCA patients. Results: Of the 300 CA cases in this analysis, 28 (9%) were attributed to drug overdose, with opioids accounting for 54%. ODCA patients were younger, had fewer comorbidities, were less likely to have witnessed arrests or bystander cardiopulmonary resuscitation, and had longer downtimes. Inpatient mortality did not differ between cohorts (79% ODCA, 73% non-ODCA, p = 0.66), but ODCA was associated with higher rates of brain death (43%, 6%, p < 0.001). Of patients who survived to discharge, there was no difference in the likelihood of favorable neurological recovery, defined as Cerebral Performance Category score of 1-2 (7%, 7%, p = 1.00) or modified Rankin Scale score of 0-3 (7%, 9%, p = 1.00). Conclusions: Despite similar neurological recovery and survival rates to hospital discharge, ODCA patients were more likely than non-ODCA patients to progress to brain death. Larger prospective studies analyzing ODCA are needed to better understand potential treatment options and prognostic tools in this cohort.