Abstract 225: Hands-off Fraction Is Not Negatively Impacted by Deployment of the AutoPulse During Out-of-Hospital Cardiac Arrest
Background: Deployment of mechanical chest compression devices is suspected to increase hands-off fraction. A potential benefit of mechanical devices is defibrillation during compressions, but it is unknown if this is utilized in the field. Our objectives were to compare hands-off fraction between manual CPR (M-CPR) and integrated AutoPulse CPR (iA-CPR), and to determine if providers will defibrillate during mechanical compressions.
Methods: An international randomized clinical trial of EMS treated adult cardiac arrests of cardiac origin was conducted at 5 sites from March 2009 to January 2011. All EMS providers received 4 hours of training in providing high quality CPR and AutoPulse deployment. After initial manual compressions, patients were randomized to iA-CPR or M-CPR. ECG and impedance or accelerometer data were analyzed to determine the number of compressions per minute, and hands-off fraction was calculated at 10 and 20 minutes. Descriptive statistics and 95% CI were calculated.
Results: A total of 4,232 subjects were enrolled. Electronic data were available for 4,135 (98%) cases (2,055 M-CPR, 2,080 iA-CPR). There were 117 (3%) cases with no compression data (69 M-CPR, 48 iA-CPR). There were more compressions per minute in the M-CPR arm (table). The mean hands-off fraction at 10 minutes was 20.4% M-CPR and 21.5% iA-CPR (difference 1.1%; 95% CI 0.5% to 1.7%) and at 20 minutes was 20.2% M-CPR and 19.6% iA-CPR (difference -0.6%; 95% CI -1.2% to 0.1%). Average time to AutoPulse start after defibrillator on was 172 seconds (±183). In 84% of the iA-CPR cases the device was not stopped during the first cycle of resuscitation. 74% of the defibrillated iA-CPR cases were shocked during compressions.
Conclusion: This is the first study to document operational deployment of the AutoPulse. There was no difference in hands-off fraction between M-CPR and iA-CPR. Providers without prior experience using the AutoPulse shocked through compressions in the majority of cases.
- © 2011 by American Heart Association, Inc.