del Nido versus St. Thomas Cardioplegia Solutions: A Single-Center Retrospective Analysis of Post Cross-Clamp Defibrillation Rates

Abstract

There are many cardioplegia solutions currently in use for pediatric cardiopulmonary bypass (CPB). The most common being del Nido solution. Another common cardioplegia solution used for pediatric CPB is St. Thomas. In October 2014, Children's Mercy Kansas City changed from the use of modified St. Thomas to del Nido. This study compared rates of post cross-clamp fibrillation requiring defibrillation between del Nido solution and modified St. Thomas solution stratified by weight at Children's Mercy Kansas City. This retrospective study consisted of 394 patients who underwent cardiac surgery requiring cardioplegia between January 1, 2014 and July 31, 2015. The outcome measured was defibrillation upon cross-clamp removal. Statistical significance was determined using Fishers exact test with a two-sided significance level of .05. Incidence of defibrillation post cross-clamp removal was 4.4% in the del Nido group and 26.8% in the St. Thomas group (p< .0001). Analysis by weight stratifications displays a reduction in post cross-clamp defibrillation rates in groups using the del Nido solution. The 0- to 6-kg category had an incidence of fibrillation of 1.23% in the del Nido group and 17.5% in the St. Thomas group (p< .0003). The 6- to 15-kg category had an incidence of defibrillation of 1.82% in the del Nido group and 14% in the St. Thomas group (p< .0198). The 15- to 60-kg category had an incidence of defibrillation of 8.9% in the del Nido group and 61% in the St. Thomas group (p< .0001). The >60-kg category had an incidence of defibrillation of 16.7% in the del Nido group and 63% in the St. Thomas group (p< .0623). This study demonstrates a 6-fold decrease in the overall rate of defibrillation post cross-clamp removal between St. Thomas and del Nido cardioplegia solutions. Analyses of weight stratifications demonstrate a decrease in the rate of defibrillation post cross-clamp removal in all categories within the del Nido group.