NEW YORK (Reuters Health) – During cardiopulmonary resuscitation, it is safe to continue chest compressions while a defibrillator is charging prior to shock administration, and this strategy shortens the hands-off time in the crucial seconds before defibrillation.

That finding is reported in an online issue of Resuscitation by Dr. Dana Peres Edelson at the University of Chicago, Illinois and colleagues. As they note, the American Heart Association recommends charging the defibrillator during chest compressions in order to minimize pauses in chest compressions, which correlate with poor outcomes. However, in simulation studies, participants stated they felt unsafe with this strategy.

“We hope that this study will help convince rescuers that charging during compressions can be accomplished safely,” Dr. Edelson commented in an email to Reuters Health.

To see how the AHA protocol is being adopted, the researchers analyzed recordings from CPR-sensing monitor/defibrillators used in three academic teaching hospitals. “A total of 680 charge-cycles from 244 in-hospital cardiac arrests involving 225 distinct patients were examined,” according to the report.

The investigators found that chest compressions were ongoing during defibrillator charging in 65.9% of all charge-cycles, but with wide variation between facilities.

“After adjusting for potential confounders, including clustering at the level of the patient, charging during chest compressions was associated with a 13.1 s decrease in pre-shock pause and 5.1 s decrease in total hands-off time in the 30 s preceding defibrillation,” the researchers report.

There was one instance of a rescuer being inadvertently shocked during the process, which was not even noticed, and the 20% rate of inappropriate shocks to patients was the same whether defibrillator charging occurred during compressions or not.

“Distinguishing quickly between shockable and non-shockable rhythms is important,” Dr. Edelson pointed out in explaining the inappropriate shocks. “However, cardiac rhythms read on a defibrillator during an actual resuscitation can look different than the textbook versions rescuers study, due to noise in the signal and time pressures. Since outcomes for shockable rhythms tend to be better, when in doubt, most rescuers would opt to err on the side of shocking a non-shockable rhythm than withholding or delaying a shock when one is indicated.”

The investigators conclude that defibrillator charging during compressions is underutilized in clinical practice.

“Resuscitation is a team sport, not unlike racing,” Dr. Edelson added. “If a pit crew can change tires, refuel and have a race car back on track in only a few seconds, surely we can check a rhythm, defibrillate, and rotate compressors. It just requires coordination between rescuers. Charging during compressions is a simple and safe strategy to cut the required time down.”

Resuscitation 2010.