Abstract 184: The Etiology of Postarrest Mortality Stratified by Location of Arrest

Introduction: Proposed study and treatment of post-cardiac arrest (CA) patients is often organ-specific. It remains unclear whether post-CA patients routinely expire from neurologic injury, refractory hemodynamic instability, or other reasons. Furthermore, there may be differences related to location of the arrest. Therefore, identifying principal reasons for death (a concept yet to be incorporated into Utstein guidelines) in post-arrest populations is essential. Objective: To develop a classification scheme for post-CA mortality and compare etiologies for death based on location of arrest. Methods: Secondary analysis of a prospective, observational study of CA patients. Inclusion criteria: 1) Age >18 2) CA with ROSC 3) In-hospital death. Traumatic arrests were excluded. Medical records were reviewed independently by 2 MDs and causes of death were classified: 1. Primary neurologic withdrawal of care 2. Presumed neurologic withdrawal of care with other co-morbidities/organ-injury 3. Refractory hypotension 4. Sudden CA. Simple descriptive statistics were used. Results: We evaluated 204 post-CA patients. Mean age was 67 (+/- 17) and 32% were female. Median downtime was 20 (IQR: 10-33) min. Overall in-hospital mortality was 50.5%. Of 103 deaths, 91% fell into 4 broad categories. Main cause of death for out of hospital cardiac arrest (OHCA) patients who had ROSC but did not survive hospitalization was primary neurologic withdrawal of care. Main cause of death for in-hospital cardiac arrests (IHCA) with ROSC which occurred in the ED or ICU was refractory hypotension. Among those with IHCA on the wards, the reasons for death were similar to the OHCA group. Conclusion: These data provide a simple classification scheme of reasons for death in post-arrest patients. There may be differences based on location of arrest but further study is needed. Investigators may need to consider principal reasons for death when matching therapeutic interventions to a given population.