Effects of a comprehensive blood-sparing approach using body weight-adjusted miniaturized cardiopulmonary bypass circuits on transfusion requirements in pediatric cardiac surgery

Objectives: Transfusion-free pediatric cardiac surgery remains a challenge, mainly owing to the mismatch between the cardiopulmonary bypass (CPB) priming volume and the infants' blood volume. Within a comprehensive blood-sparing approach, we developed body weight-adjusted miniaturized CPB circuits with priming volumes of 95, 110, and 200 mL for, respectively, infants weighing less than 3 kg, 3 to 5 kg and 5 to 16 kg. We analyzed the effects of this approach on transfusion requirements and risk factors predisposing for blood transfusion. Methods: A total of 288 children with body weights between 1.7 and 15.9 kg were included and divided into 3 groups: No transfusion, postoperative transfusion only, and intraoperative and postoperative transfusion. Groups were compared by analysis of variance or analysis of variance on ranks. Risk factors predisposing for transfusion were identified by multivariate logistic regression. Results: Of the infants, 24.7% required no transfusion, 23.6% received postoperative transfusion only and 51.7% received intraoperative and postoperative transfusion. Groups differed by age, body weight, and size and by duration of surgery, CPB, and aortic crossclamp (P < .00001). Body weight (P < .00001), CPB duration (P < .00001), and persisting cyanosis (P = .03) were predictors of intraoperative and postoperative transfusion, whereas body weight (P = .00095), reoperations (P = .0051), and cyanotic heart defects (P = .035) were associated with postoperative transfusion only. Conclusions: Our blood-sparing approach allows for transfusion-free surgery in a substantial number of infants. The strongest predictors of transfusion requirement, body weight and complexity of surgery as reflected by CPB duration, are not amenable to further improvements. Better preservation of the coagulatory system might allow for reduction of postoperative transfusion requirements. (J Thorac Cardiovasc Surg 2012;144:493-9)