Maximizing the proportion of time spent performing chest compressions during cardiopulmonary resuscitation (CPR) substantially improves survival in patients who suffer cardiac arrest outside a hospital setting, according to a multicenter clinical study that included UT Southwestern Medical Center.
The findings, available in September 29, 2009 issue of Circulation, come from the largest clinical investigation to evaluate the association between chest compressions by emergency medical service (EMS) providers before the first attempted defibrillation and survival to hospital discharge. Out-of-hospital cardiac arrest is a leading cause of premature death worldwide, and survival is often less than 5%.
One of the most important aspects of quality CPR is the proportion of time spent performing chest compressions, but EMS providers typically perform chest compressions only 50% of the total time spent on resuscitative efforts.
Dallas-area paramedics and firefighters are being trained to begin CPR immediately and to administer uninterrupted chest compressions for two minutes before re-checking the heart rhythm or using a defibrillator to shock the heart. UT Southwestern’s emergency medicine program provides medical oversight for EMS providers in more than a dozen Dallas-area cities.
In this study, researchers studied data from patients in the Resuscitation Outcomes Consortium (ROC) who had suffered from cardiac arrest with a heart rhythm indicating ventricular fibrillation or ventricular tachychardia. The researchers focused on the effect of the number of chest compressions paramedics administered per minute before they shocked the heart.
The data for this study was collected from the ROC, which is comprised of 11 regional clinical centers funded by the National Institutes of Health and several US and Canadian agencies to test lifesaving interventions for critical trauma and sudden cardiac arrest.