Abstract 2664: A CPR Assist Device Increased Emergency Department Admission and End Tidal Carbon Dioxide Partial Pressures during Treatment of Out of Hospital Cardiac Arrest
OBJECTIVE: EVAC Ambulance, serving Volusia County, Florida (1,207 square miles, population 468,000), used a load-distributing-band chest compression device (AutoPulse, ZOLL Circulation, A-CPR) and evaluated its impact on end tidal carbon dioxide (ETCO2) and patient survival to emergency department admission during out-of-hospital cardiac arrest. An intention to treat, concurrently controlled, retrospective review was undertaken to compare A-CPR to manual cardiopulmonary resuscitation (M-CPR). METHODS: A-CPR (n=269) was used by advanced life support certified paramedics until return of spontaneous circulation or until death was declared. Patient survival to emergency department admission with measurable blood pressure (short-term survival) was evaluated. All data were compiled from dispatch, patient care, and monitor/defibrillator records. The M-CPR comparison group (n=607) received the same treatment but without A-CPR. During the study period, cardiac arrest treatment protocols followed AHA Guidelines 2000. Routine capnographic monitoring yielded sequential ETCO2 values recorded following endotracheal intubation. Ventilation was achieved using a transport ventilator with fixed minute ventilation.
RESULTS: There were no differences between groups in patient characteristics or other factors typically associated with cardiac arrest survival. A-CPR increased short-term survival overall (M-CPR 18%, A-CPR 28%, OR 1.7, 95% CI 1.2–2.4, p=0.001). ETCO2 at four sequential time points following intubation was evaluated (M-CPR: 18±1, 18±1, 18±1, 18±2 mmHg; A-CPR: 23±1 23±1 24±2 27±3 mmHg; mean±SE, p<0.01 each M vs. A-CPR). Multifactor logistic regression showed sequential ETCO2 increases temporally with A-CPR (p<0.005) but not with M-CPR. The model showed short-term survival was correlated with ETCO2 levels in both arms, however there was a significant interaction between A-CPR and ETCO2 but not with M-CPR (p<0.01).
CONCLUSION: This study was limited by a lack of data on long-term survival and non-randomized design. Despite these limitations, treatment with AutoPulse CPR showed a significant increase in short-term survival and ETCO2 was higher at every time point compared to manual CPR.