Abstract P173: A New Defibrillator Mode Reduces Chest Compression Interruptions for Lay Rescuers and BLS Providers
Introduction: Interruptions in chest compressions (CC), especially prior to a shock, adversely affect patient outcome from cardiac arrest. A new automated external defibrillator (AED) feature was designed for laypersons and basic life support providers to limit interruptions in CC by detecting shockable rhythms during CC and automatically charging if the underlying rhythm is shockable. We tested the hypothesis that use of the new mode of operation would reduce interruptions in CC compared with the standard AED mode of operation without impacting other measures of CC quality.
Methods: Twenty CPR certified rescuers (10 EMTs, 1 nurse, and 9 lay rescuers) worked in pairs to perform 2 simulated cardiac resuscitations on a mannequin, one with an E-series defibrillator (ZOLL Medical) operating in standard AED mode and the other using the same defibrillator in the new CPR Ready Charge (CRC) mode. The order of the trials was randomized and the subjects rested a minimum of 30 minutes between trials. Each trial consisted of 8 cycles of CC (1 cycle=2 min CC, analysis, and shock if necessary). The underlying rhythm for each cycle was randomly assigned with a total of 4 shockable and 4 non-shockable rhythms. Rescuers were instructed to follow the defibrillator prompts and for one rescuer to operate the defibrillator while the other rescuer performed continuous CC. Subjects switched roles after every 2 cycles of CC. Paired t-tests were used to compare CC quality between the CRC and standard AED trials.
Results: The percentage of time without CC (no-flow fraction) was considerably reduced with CRC (4.35±1.61% CRC vs. 10.39±1.65% AED, p<0.0001). Interruptions in CC prior to a shock were substantially reduced with CRC compared with AED (1.7±0.5 sec CRC vs. 11.3±0.8 sec AED, p<0.0001). There was no difference in delay to resuming CC after a shock (5.8±2.0 sec CRC vs. 4.9±2.0 sec AED, p=0.3). There were no differences in other measures of CC quality such as mean depth (1.56±0.34 in CRC vs. 1.57±0.26 in AED, p=0.9) and mean rate (123±11 CC/min CRC vs. 125±15 CC/min AED, p=0.5).
Conclusions: A new defibrillator mode, CPR Ready Charge, can be utilized to effectively reduce interruptions in CC and reduce no flow time during CPR without affecting depth or rate of CC.