Using a Miniaturized Circuit and an Asanguineous Prime to Reduce Neutrophil-Mediated Organ Dysfunction Following Infant Cardiopulmonary Bypass

Background Contemporary infant cardiopulmonary bypass circuits require a blood prime. Blood, especially when stored, generates an inflammatory response, and may contribute to organ dysfunction following cardiopulmonary bypass. We determined whether using a miniaturized circuit and an asanguineous prime attenuated the post-bypass inflammatory response, and improved right ventricular and pulmonary function. Methods Sixteen infant piglets were placed into 3 groups based on prime components: group I (fresh blood), group II (stored blood), and group III (miniaturized circuit and asanguineous prime). Piglets were placed on cardiopulmonary bypass (100 mL • kg−1 • min−1), cooled to 18°C, and underwent continuous perfusion (50 mL • kg−1 • min−1) for 30 minutes. They were rewarmed and separated from bypass. Serum tumor necrosis factor-α, right ventricular function, and pulmonary function were measured before and 30 minutes after bypass. Neutrophil priming activity in fresh and stored donor blood was also assessed. Results Animals in group III had significantly improved cardiopulmonary function than the groups receiving blood (right ventricular cardiac index [mL • kg−1 • min−1]: group I [18.8 ± 4.8], group II [21.5 ± 6.2], and group III [81.2 ± 11.4], p< 0.001; and pulmonary vascular resistance index [dynes • mL−1 • kg−1]: group I [1169 ± 409], group II [1610 ± 486], and group III [214 ± 63], p = 0.03). Tumor necrosis factor-α (pg • mL−1) was lower in group III (1465 ± 39) than in the groups receiving blood (3940 ± 777), p = 0.002. Neutrophil priming activity (nmol • min−1) was also higher in stored blood (3.7 ± 6) than in fresh blood (1.9 ± 0.2), p = 0.02. Conclusions We have devised a unique miniaturized circuit that allows an asanguineous prime without hemodilution in an infant swine model. The employment of this circuit attenuates the post-bypass inflammatory response and has salutary effects on cardiopulmonary function.