The influence of bypass temperature on the systemic inflammatory response and organ injury after pediatric open surgery: A randomized trial

Abstract

Systemic cooling for cardiopulmonary bypass is widely used to attenuate the systemic inflammatory response syndrome and organ injury in children after open surgery. We compared the effects of moderate (24 °C) and mild (34 °C) hypothermia during bypass on markers of the systemic inflammatory response syndrome and organ injury, and on clinical outcome after corrective surgery for congenital heart disease. Sixty-six children (mean age, 6.8 ± 5.7 months; mean weight, 6.2 ± 2.3 kg) were randomized to 24 °C or 34 °C bypass temperature during cardiac surgery. Perfusion strategies were otherwise strictly identical. Clinical data and blood samples were collected before bypass, 5 minutes after aortic crossclamp release, and 4, 24, and 48 hours after bypass. Patients were followed up until discharge from the hospital. In the 54 children with outcome data, bypass temperature did not influence the duration of mechanical ventilation between the 24 °C group and the 34 °C group (median [interquartile range] 22 [13-40] hours vs 14 [8-40] hours, P = .14), intensive care unit stay (43 [24-49] hours vs 29 [23-47] hours, P = .79), blood loss (29 [20-38] mL/kg vs 23 [13-38] mL/kg, P = .36), or incidence of postoperative infection (9% vs 11%, P = 1.0). There was no evidence of an influence of bypass temperature on the markers of acute inflammation, innate immune response, organ injury, coagulation, or hemodynamics. There is no evidence that the systemic inflammatory response syndrome and organ injury after pediatric open surgery are influenced by bypass temperature. The routine use of hypothermic bypass may not be warranted in the pediatric population.