Improved survival outcome with continuous chest compressions with ventilation compared to 5:1 compressions-to-ventilations mechanical cardiopulmonary resuscitation in out-of-hospital cardiac arrest

Background: Fewer pauses and better chest compression quality are thought to improve overall survival following cardiac arrest. This study aimed to measure the outcomes of adult nontraumatic out-of-hospital cardiac arrests (OHCAs) treated with 5:1 compressions-to-ventilations (Thumper 1007) or continuous chest compressions with ventilation (Thumper 1008 CCV) mechanical cardiopulmonary resuscitation (CPR) within a specified period of time. Methods: A retrospective observational cohort study of 515 adults with OHCA was conducted at the emergency department of an urban tertiary hospital. There were 307 patients in the Thumper 1007 phase (January 2008 to December 2009) and 208 patients in the Thumper 1008 CCV phase (January 2010 to May 2011). Return of spontaneous circulation (ROSC) and survival to hospital discharge were the primary outcome measures. Results: Patients in the Thumper 1007 and Thumper 1008 CCV phases had comparable results with the following exceptions: less hypertension (42.4% vs. 62.0%), cerebrovascular accidents (11.4% vs. 25.0%), and faster emergency medical service response time intervals (mean, 3.7 vs. 4.5 minutes) with the Thumper 1007. The average ambulance transport time was 6.1 minutes in both phases. The rates of ROSC [35.1% vs. 23.5%; adjusted odds ratio (OR), 1.616; 95% confidence interval (CI), 1.073-2.432] and survival to hospital discharge (10.1% vs. 4.2%; adjusted OR 2.431; 95% CI, 1.154-5.120) were significantly higher with the Thumper 1008 CCV than with the Thumper 1007. Favorable neurologic outcome upon discharge, defined as cerebral performance category scores of 1 (good performance) or 2 (moderate disability), was not significantly different between the two phases [1.6% (5/307) vs. 1.9% (4/208); p = 0.802]. The Thumper 1008 CCV provided significantly faster average chest compression rates and shorter no-chest compression intervals than the Thumper 1007 after activation. Conclusion: In an emergency department with short ambulance transport times, continuous chest compressions with ventilation through mechanical CPR showed improved outcomes, including ROSC and survival to hospital discharge, in an adult with OHCA. However, there are a variety of confounding influences that may affect the validity of conclusions that have been drawn.