The Impact of Vacuum-Assisted Venous Drainage and Miniaturized Bypass Circuits on Blood Transfusion in Pediatric Cardiac Surgery

Although blood transfusion is essential in pediatric surgery, it is associated with increased morbidity. The goal of this study is to assess the efficiency of downsized bypass circuits and vacuum-assisted venous return in decreasing the need for blood transfusion. This study was performed on 150 patients weighing 2.3-10 kg. The bypass circuit was composed of a Kids D100 oxygenator and 3/16 in. lines, with a 120-ml prime volume. The objective was to maintain a hemoglobin level of at least 8 g/dl during the procedure. Venous drainage was both gravity-dependent and vacuum-assisted. The level and tolerance of hemodilution were estimated based on hemoglobin and serum lactate dosages and on the time to extubation. Venous drainage varied from 500 to 1200 ml/min. All patients weighing <6.4 kg were transfused and 55% of the patients weighing 6.4-10 kg had bloodless surgery, none had platelet infusion. In bloodless surgery, the median hemoglobin level was 11.4 g/dl before surgery, 8.7 g/dl during bypass, and 10.6 g/dl postoperatively, median serum lactate levels were always under 2 mmol/L and the median time to extubation was 3 hours. Compared to gravity-dependent venous drainage, vacuum-assisted venous return is efficient for further reducing allogeneic blood transfusion.