Effect of location on out-of-hospital cardiac arrest involving elderly persons in Hong Kong

Abstract

Article in press not for public dissemination: Introduction: The majority of out-of-hospital cardiac arrests in Hong Kong involve elderly persons. Chance of survival varies according to location. This study sought to identify patient and bystander characteristics and timing of interventions which would affect the prevalence of shockable rhythm and survival outcomes of cardiac arrests involving elderly persons in homes, streets and other public places. Methods: This was a secondary analysis of a territory-wide historical cohort study using data collected by the Hong Kong Fire Services Department from 1st August 2012 to 31st July 2013. Results: Bystander CPR was mostly performed by relatives in homes but not in non-residential locations. Time taken to activate EMS, initiate CPR and perform defibrillation were longer for cardiac arrests in homes. The median interval for EMS to reach patients inside homes was 3 minutes longer than for patients in the street (p<.001). Forty-seven percent of patients who developed cardiac arrest in streets had a shockable rhythm during the initial 5 minutes after EMS activation. Defibrillation within 15 minutes of EMS activation was an independent predictor of 30-day survival (p=.02). Fifty percent of patients who received defibrillation within 5 minutes in non-residential locations survived. Conclusion: There were significant differences in patient and bystander characteristics, interventions and outcomes between cardiac arrests involving elderly occurring at different locations. There was a high proportion of shockable rhythm in the early period after cardiac arrest. Good survival outcomes from OHCA involving the elderly can be achieved through early bystander defibrillation and intervention.