Cardiovascular
Evaluating the Impact of Mechanical CPR in OHCA Patients in a Large Urban EMS System Madeline Cannon* Madeline Cannon Cannon Cannon Cannon Fire Department of the City of New York (FDNY)
Background: While use of a mechanical chest compression device for cardiopulmonary resuscitation (CPR) enhances crew safety, it is unclear whether it results in better survival outcomes for out-of-hospital cardiac arrest (OHCA) patients. In 2023, the Fire Department of the City of New York Emergency Medical Services (FDNY-EMS) implemented a citywide phased rollout of a mechanical CPR device (Stryker LUCAS® 3 chest compression system) onto Basic Life Support (BLS) ambulances, creating a natural experiment which emulated a stepped wedge cluster randomized trial.
Methods: Mechanical CPR devices were installed sequentially onto municipal BLS ambulances in each of New York City’s nine EMS divisions over seventeen weeks. The device was used during transport only. To estimate the effect of mechanical CPR on sustained return of spontaneous circulation (S-ROSC) at emergency department arrival, we used multilevel mixed-effects logistic regression models clustered by EMS division and adjusted for time and other potential confounders. We additionally used two-stage residual inclusion (2SRI) to estimate the local causal effect among “compliers” (those who would be treated with mechanical CPR if assigned to the mechanical CPR group).
Results: Our study included 1,317 non-traumatic OHCA patients at least 15 years of age who were treated and transported by FDNY-EMS municipal BLS ambulances between 8/6/2023 and 12/30/2023. Compliance with protocol was 80% in the mechanical CPR group and 99% in the manual CPR group. S-ROSC was achieved in 275 (35%) patients in the mechanical CPR group and 188 (36%) patients in the manual CPR group (AOR=0.83, 95% CI 0.59-1.16). In the 2SRI analysis, mechanical CPR was associated with lower odds of S-ROSC, though the association was not statistically significant (OR=0.61, 95% CI 0.34-1.09).
Conclusions: We did not observe a significant difference in S-ROSC to emergency department arrival among patients treated with mechanical CPR vs. manual CPR.