Abstract 301: Reasons for Death Following In- and Out-of-Hospital Cardiac Arrest

Introduction: There is no standard method for reporting reasons for death in cardiac arrest patients. Categorizing reasons for death is important for comparing outcomes across cardiac arrest trials, assessing the benefits of targeted interventions in in-hospital (IHCA) and out-of-hospital (OHCA) cardiac arrest patients, and developing quality-improvement initiatives. We developed and tested a method for categorizing reasons for death in post-cardiac arrest patients, assessed inter-rater reliability, and compared reasons for death between IHCA and OHCA. Methods: Single-center, retrospective, cohort study of patients who had return of spontaneous circulation (ROSC) after an OHCA or IHCA between 2008 and 2017, but died before hospital discharge. Traumatic arrests and patients with a “do-not-resuscitate” order prior to their initial arrest were excluded. Two independent investigators reviewed medical records and assigned each patient to one of five predefined categories of reasons for death. Inter-rater reliability was assessed using Fleiss Kappa. For final categorization, discrepancies were resolved by discussion with a third investigator. Categorical data was compared by Fisher’s Exact Test, and continuous data by Wilcoxon Rank-Sum Test. Results: There were 182 IHCA and 227 OHCA included, with the initial rhythm being non-shockable in 77% and 69% of cases (p=0.07), respectively. Median time to ROSC was shorter in IHCA compared to OHCA (10 [IQR: 6-20] vs 30 [IQR: 21-42] min, p<0.01). Median time to death was 3.3 (IQR: 1.4-8.7) days in IHCA vs 3.5 (IQR: 1.8-5.9) days in OHCA (p=0.92). The Kappa for reasons for death was 0.62 for IHCA and 0.61 for OHCA. Reasons for death for IHCA and OHCA were: neurological withdrawal of care (28% vs 72%, p<0.01), comorbid withdrawal of care (36% vs 4%, p<0.01), refractory hemodynamic shock 24% vs 18%, p=0.11), respiratory failure (1% vs 2%, p=0.47), and sudden cardiac death (11% vs 4%, p<0.01). Conclusion: Five categories for reasons for death in post-cardiac arrest patients were developed. The primary reason for death was neurological withdrawal of care after OHCA and comorbid withdrawal of care after IHCA. Categorizing reasons for death may be important for investigators when targeting an IHCA vs an OHCA population.