Pre-hospital Adrenaline via the System of Dispatching a Physician; Outcomes among Patients with Cardiac Arrest

Abstract

We evaluated whether pre-hospital adrenaline with a dispatched physician is associated with higher proportion of return of spontaneous circulation after out-of-hospital cardiac arrest, compared to pre-hospital care without physician presence. We conducted a retrospective observational study of patients with out-of-hospital cardiac arrest in Japan. Included were patients who were at least 18 years of age, were transported to hospitals by emergency medical service personnel of the Hiroshima City Fire Services between July 2 2018 and December 31 2021, and were administered pre-hospital adrenaline. Data were obtained from transport records written by emergency medical service personnel and medical records created by dispatched physicians from Hiroshima Prefectural Hospital. The primary outcome was the return of spontaneous circulation after out-of-hospital cardiac arrest. We performed multivariable logistic regression analysis using the propensity score as an explanatory variable. Among analyzed 464 patients, 317 patients received resuscitation by "emergency medical service personnel" group, and 147 patients received resuscitation by "emergency medical service personnel and a dispatched physician" group. The time from emergency call to first administration of adrenaline with the presence of a dispatched physician was significantly shorter compared to absence of a pre-hospital physician [25.0 minutes vs. 28.0 minutes, (95% confidence interval: -4.37 to -0.48)]. Adjusted odds ratio of the primary outcome did not differ significantly between groups (1.20; 95% confidence interval: 0.61 to 2.36). The system with a dispatched pre-hospital physician was associated with significantly shorter time to the first pre-hospital administration of adrenaline compared with absence of a pre-hospital physician. There was no significant difference in patient outcomes.