Cause analysis of injury-related out-of-hospital cardiac arrest in the elderly

Background: The purpose of this study was to investigate the causes of injury-related out-of-hospital cardiac arrest (OHCA) in patients; the differences between elderly and younger patients were investigated. We believe that identifying the causes of cardiac arrest in different patient groups, may help emergency physicians to make better decisions and thus improve the development of preventive strategies in the future. Methods: A retrospective review was carried out of injury-related OHCA patients who were > 17 years old, and who were admitted to the emergency department (ED) of a medical center in northern Taiwan, between January 1 and December 31, 2005. Details of demographics, witness reports, mode of transport, outcome, and cause of injury-related OHCA were collected and analyzed. Results: Ninety-four patients met our inclusion criteria; 5 patients (5.3%) survived to hospital discharge, but all had significant neurological deficits. Twenty patients were > 65 years old, and were defined as elderly; 74 patients, who were defined as adults, were between 18 and 64 years old. The survival rate in the elderly group was 15.0% (3/20), and in the adult group was 2.7% (2/74); there was no significant difference between the elderly and adult groups (p = 0.063). In the adult group, the leading cause of injury-related OHCA was a traffic accident, but in the elderly group, the leading cause was mechanical airway obstruction (choking); these results are statistically significant. Conclusion: In this study, choking was found to be the leading cause of injury-related OHCA in the elderly and traffic accidents were the leading cause in adults. Five patients (5.3%) survived, but all had significant neurological deficits. Because of the poor outcomes of injury-related OHCA patients, it is proposed that prevention may be the best strategy for these patients' survival.