Comparison of defibrillation efficacy between two pads placements in a pediatric porcine model of cardiac arrest

Abstract

ObjectiveThe placement of defibrillation pads at ideal anatomical sites is one of the major determinants of transthoracic defibrillation success. However, the optimal pads position for ventricular defibrillation is still undetermined. In the present study, we compared the effects of two different pads positions on defibrillation success rate in a pediatric porcine model of cardiac arrest. MethodsEight domestic male pigs weighing 12–15kg were randomized to receive shocks using either the anterior–posterior (AP) or the anterior–lateral (AL) position with pediatric pads. Ventricular fibrillation (VF) was electrically induced and untreated for 30s. A sequence of randomized biphasic electrical shocks ranging from 10 to 100J was attempted. If the defibrillation failed to terminate VF, a 100J rescuer shock was then delivered. After a recovery interval of 5min, the sequence was repeated for a total of approximately 30 test shocks were attempted for each animal. The dose response curves were constructed and the defibrillation thresholds were compared between groups. ResultsThe aggregated success rate was 65.6% for AP placement and 43.0% for AL one (p=0.0005) when shock energy was between 10 and 70J. A significantly lower 50% defibrillation threshold was obtained for AP pads placement compared with traditional AL pads position (2.1±0.4J/kg vs. 3.6±0.9J/kg, p=0.041). ConclusionIn this pediatric porcine model of cardiac arrest, the anterior–posterior placement of pediatric pads yielded a higher success rate by lowering defibrillation threshold compared to the anterior–lateral position.