Abstract 234: Validation of a Termination-of-resuscitation Rule for Patients with Refractory Out-of-hospital Cardiac Arrest at an Emergency Department in Japan

Abstract

Introduction: In Japan, emergency medical service (EMS) providers are prohibited from cardiopulmonary resuscitation (CPR) termination in the field and must transport all out-of-hospital cardiac arrest (OHCA) patients to a hospital, regardless of the return of spontaneous circulation (ROSC). We previously developed a termination of resuscitation (TOR) rule for emergency department physicians (ED-TOR) treating OHCA patients using data from the All-Japan Utstein Registry between 2005 and 2009, when CPR was performed according to the 2005 guidelines. The ED-TOR rule recommends CPR termination when patients in the emergency department meet all of the following criteria: initial unshockable rhythm, arrest unwitnessed by bystanders and no prehospital ROSC. Hypothesis: We aimed to validate the ED-TOR rule using more recent data, where CPR was performed according to the 2010 and 2015 guidelines, comparing the relevance of the ED-TOR rule with the universal basic life support TOR (BLS-TOR) rule, which consists of the following criteria: no prehospital ROSC, unwitnessed arrest by EMS providers and no shock received. Methods: We analysed 552,554 OHCA patients (age ≥ 18 years) treated by EMS providers. OHCA patients witnessed by EMS providers were excluded. Data were obtained from a prospectively recorded All-Japan Utstein Registry from 2013 to 2017. The study endpoints were specificity and a positive predictive value (PPV) for predicting 1-month mortality after OHCA with the ED-TOR and BLS-TOR rules. Results: The overall 1-month survival rate was 4.3% (23,733/552,554). The proportions of OHCA patients who fulfilled the ED-TOR and BLS-TOR criteria were 59.6% and 83.8%, respectively. The specificity and PPV of the ED-TOR and BLS-TOR rules for predicting 1-month mortality were 93.2% (95% confidence interval [CI], 92.8%-93.5%) and 99.5% (95% CI, 99.5%-99.5%) and 82.6% (95% CI, 82.1%-83.1%) and 99.1% (95% CI, 99.1%-99.1%), respectively. Conclusions: The ED-TOR rule was successfully validated using more recent data from a Japanese registry where CPR was performed according to the 2010 and 2015 guidelines. The ED-TOR rule was slightly superior to the BLS-TOR rule in Japanese EMS systems showing high specificity and PPV for predicting 1-month mortality.