Abstract 309: Prediction Chart for Neurological Outcomes of Elderly Patients with Out-of-hospital Cardiac Arrest and the Corresponding Time to Termination of Resuscitation: Evidence from a Japanese Nationwide Population-based Cohort Study

Abstract

Introduction: Neurological outcomes and the appropriate duration from call receipt to termination of resuscitation (TOR) in patients with out-of-hospital cardiac arrest (OHCA) could differ according to patient characteristics. Hypothesis: We hypothesized that a prediction chart comprising prehospital variables, including age, could be useful for predicting neurological outcomes and determining the time to TOR in the field or at the emergency department. Methods: We evaluated 19,829 elderly patients with OHCA (age ≥65 years) of cardiac origin who achieved prehospital return of spontaneous circulation (ROSC). Data were obtained from the prospectively recorded All-Japan Utstein Registry between 2011 and 2016. Patients with OHCA witnessed by emergency medical service providers were excluded. The primary outcome was 1-month neurologically intact survival, defined as a cerebral performance category (CPC) score of 1-2. Patients with OHCA were divided into 12 groups according to shockable rhythm (YES/NO), witness status (YES/NO), and age (65-74, 75-89, or ≥90 years). The time from call receipt to ROSC was calculated and categorized by 5-min intervals. The time from call receipt to ROSC at which the probability of 1-month CPC 1-2 decreased to <1% was defined as the call to TOR duration. Results: The overall 1-month CPC 1-2 rate was 18.9% (n = 3,756). When stratified by patient characteristics, the 1-month CPC 1-2 rates ranged from 52.3% in patients aged 65-74 years with shockable rhythm and witnessed OHCA (best-case scenario) to 1.6% in patients aged ≥90 years with non-shockable rhythm and un-witnessed OHCA (worst-case scenario). The corresponding call to TOR duration ranged from 35 to 10 min (Table). Conclusions: Neurological outcomes and the appropriate call to TOR duration differed according to patient characteristics, including age. Our prediction chart for elderly patients with OHCA could be useful for determining TOR in the field or at the emergency department.