Modified versus conventional ultrafiltration in pediatric cardiac surgery: a meta-analysis of randomized controlled trials comparing clinical outcome parameters.

Objective Although previous studies have demonstrated that modified ultrafiltration improves laboratory parameters in pediatric cardiac surgery, the clinical outcome data have been inconsistent. We performed a meta-analysis of randomized controlled trials comparing modified versus conventional ultrafiltration. Methods We conducted a comprehensive search of the literature to identify clinical trials that met our inclusion criteria. To be included, studies had to be prospective randomized trials that compared modified ultrafiltration and conventional ultrafiltration in pediatric cardiac surgery using cardiopulmonary bypass. We focused on the following outcome variables: hematocrit and mean arterial blood pressure after cardiopulmonary bypass, amount of chest tube drainage after surgery, time to extubation, and length of stay in the intensive care unit. The random effects model was used to determine the pooled effect estimates. The estimators of treatment effects were expressed as the weighted mean difference with 95% confidence intervals. The heterogeneity of collected data was also evaluated. Results We screened 54 studies, 8 of which satisfied our inclusion criteria. Combined analysis revealed that modified ultrafiltration resulted in significantly higher postbypass hematocrit and higher mean arterial blood pressure. Benefits in postoperative blood loss, ventilator time, and intensive care unit stay were not apparent. There was significant heterogeneity among the studies surveyed. Conclusions The advantage of modified ultrafiltration over conventional ultrafiltration consists of significant improvement of clinical conditions in the immediate postbypass period. The postoperative outcome parameters were not significantly influenced. We should also take into account possible clinical or methodologic variations in the currently available ultrafiltration studies.