The Impact of a High-Performance Cardiopulmonary Resuscitation Protocol on Survival From Out-of-Hospital Cardiac Arrests Witnessed by Paramedics

Aim: In this study, we examine the effect of a high-performance cardiopulmonary resuscitation (HP-CPR) protocol on patient outcomes following out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical services (EMS) personnel. Methods: We performed a retrospective cohort study of adult, EMS witnessed OHCA patients of medical aetiology in Victoria, Australia. Patients treated after the introduction of a HP-CPR protocol and training programme between February 2019 and January 2020 were compared to historical controls between January 2015 and January 2019. The effect of a HP-CPR protocol on survival to hospital discharge was examined using logistic regression models adjusted for arrest factors. Results: A total of 1,561 and 420 EMS witnessed OHCA patients were treated in the control and intervention periods, respectively. Baseline characteristics were mostly balanced across study periods, except for an initial arrest rhythm of asystole which was more frequent during the intervention period (20.2% vs 15.9%; p-value = 0.04). Unadjusted survival to hospital discharge was similar across control and intervention periods for the overall population (32.1% vs 29.4%, p-value = 0.27), but significantly higher during the intervention period for initial shockable arrests (76.9% vs 66.6%; p-value = 0.03). After adjustment for confounders, cases in the intervention period were associated with an improvement in the adjusted odds of survival to hospital discharge for overall arrests (adjusted odds ratio [AOR] 1.37, 95% CI: 1.00–1.88) and initial shockable arrests (AOR 1.70, 95% CI: 1.03–2.82). Conclusion: The implementation of a HP-CPR protocol was associated with a significant improvement in survival from EMS witnessed OHCA. Efforts to improve CPR performance could yield further improvements in patient outcomes.