Randomized Pilot Trial of Acute Normovolemic Hemodilution in Pediatric Cardiac Surgery Patients

Abstract

Background: Due to the substantial improvement in survival among pediatric patients undergoing congenital heart surgery, reducing early and long-term morbidity is becoming the major focus of care. Blood transfusion is associated with worse postoperative outcomes after cardiac surgery. Acute normovolemic hemodilution (ANH) is a blood conservation strategy that aims to reduce allogenic blood transfusion during cardiac surgery. However, there are scant data regarding its efficacy for pediatric cardiac surgery patients. Methods: We designed a single-center, controlled, randomized, pilot trial in patients between 6 and 36 months old undergoing pediatric heart surgery. Patients were equally assigned to undergo ANH prior to initiation of cardiopulmonary bypass or to be managed per usual care. The primary end point was the amount of blood product transfused perioperatively. Secondary end points were markers of morbidity: postoperative bleeding, hematocrit, inotropic agents use, intensive care unit, and hospital stay. The analysis was by intention-to-treat. Estimates of differences between groups are presented with 95% CIs. Results: Twelve pediatric heart surgery patients were randomized to each group, ANH and usual care. Baseline characteristics were similar between groups. Acute normovolemic hemodilution implementation did not result in a reduction in the administration of blood product transfused (difference between ANH and usual care among patients transfused = −1.4 mL [−29.4 to 26.6], P = .92). Secondary end points were not different between groups. Conclusions: In this small trial of pediatric cardiac surgery patients, ANH as a strategy to reduce blood component therapy was safe; however, the study failed to show a reduction in perioperative transfusion or other postoperative outcomes.