Out-of-hospital cardiac arrest (OHCA) is a leading cause of death in the United States, and efforts have been made to develop termination of resuscitation protocols utilizing clinical criteria predictive of successful resuscitation and survival to discharge. A termination of resuscitation protocol utilizing longer resuscitation time and end-tidal carbon dioxide (EtCO2) monitoring criteria for termination was implemented for Emergency Medical Service (EMS) providers in an urban prehospital system in 2017. This study examines the effect the modified termination of resuscitation protocol had on rates of patient transport to a hospital, return of spontaneous circulation (ROSC), and survival to discharge.

A retrospective analysis was performed utilizing data from the Cardiac Arrest Registry to Enhance Survival (CARES) database. A total of 1,005 prehospital cardiac arrest patients 18 years and older from 2016 through 2017 were included in the analysis. Patients with traumatic cardiac arrest or had valid do-not-resuscitate orders were excluded. Unadjusted analysis using chi-square statistics was performed, including an analysis stratified by Utstein style reporting. Adjusted analysis was also performed using logistic regression with multiple imputation for missing values.

Unadjusted analysis showed a significant decrease in ROSC on emergency department (ED) arrival (30% versus 13%; P <.001) following the change in protocol. There was no significant difference in patient transport rate (62%) and a statistically non-significant decrease in overall survival (15% versus 11%). When stratified by Utstein style analysis, statistically significant decreases in ED arrival with ROSC were seen for unwitnessed asystolic, as well as bystander witnessed asystolic, pulseless electrical activity (PEA), and shockable OHCA. Adjusted analysis showed a decreased likelihood of ROSC with the protocol change (0.337; 95% CI, 0.235-0.482).

The modification of termination of resuscitation protocol was not associated with a statistically significant change in transport rate or survival. A significant decrease in rate of arrivals to the ED with ROSC was seen, particularly for bystander witnessed OHCA.