Objectives: In paediatric cardiac surgery, body weight-adjusted miniaturized cardiopulmonary bypass (CPB) circuits within a comprehensive blood-sparing approach can reduce transfusion requirements. Haemodilution resulting from mixing the patient's blood with a CPB crystalloid solution may be reduced to the extent that asanguineous priming becomes possible. Therefore, we adopted asanguineous priming in our clinical routine. Our goal was to report the effects of asanguineous priming on transfusion requirements, clinical features associated with transfusion and effects on in-hospital morbidity.
Methods: Data of all paediatric patients with body weights up to 15 kg treated within a 2-year period between May 2013 and May 2015 were retrospectively analysed. The incidence of transfusions was analysed and periprocedural haemoglobin concentrations were evaluated. Predictors associated with transfusion requirements, duration of ventilation or length of stay in the intensive care unit were evaluated by multivariable analyses.
Results: Data from 579 patients with body weights up to 15 kg were analysed. The ability to avoid transfusion depended on body weight: in patients <3 kg, the rate (95% confidence interval) of transfusion during CPB was 0.53 (0.37-0.69), and in patients >8 kg, the rate was 0.14 (0.10-0.19). The respective rates of transfusions throughout the hospital stay were 1.00 (0.90-1.00) and 0.67 (0.60-0.73). Body weight, preoperative haemoglobin concentration, duration of CPB and palliative surgery were independently associated with transfusion during CPB. Transfusion, particularly transfusion during CPB, was independently associated with longer mechanical ventilation time (hazard ratio 3.52, confidence interval 2.66-4.65) and length of stay in the intensive care unit (hazard ratio 2.52, confidence interval 1.91-3.32).
Conclusions: Asanguineous priming is feasible using miniaturized CPB circuits. It may help to avoid blood transfusions in patients on CPB and reduce transfusion requirements and transfusion-related morbidity.