Inflammatory response to hyperoxemic and normoxemic cardiopulmonary bypass in acyanotic pediatric patients

Abstract

Background: Hyperoxemic management during cardiopulmonary bypass (CPB) is still common, and there is no consensus about physiologic oxygen tension strategy (normoxemic management) during pediatric CPB. In this study, we compared the postoperative conditions and measures of inflammatory response among patients with acyanotic congenital heart disease subjected to either hyperoxemic or normoxemic management strategy during CPB.

Methods: We studied 22 patients with a ventricular septal defect and pulmonary artery hypertension. The patients were divided into two groups. Group I (n=9) received normoxemic management (PaO2=100-150 mm Hg) and group II (n=13) received hyperoxemic management (PaO2=200-300 mm Hg) during CPB. There was no difference between groups with regard to age, body weight, duration of CPB, and aorta clamping time or preoperative pulmonary hypertension (pulmonary pressure/systemic pressure [Pp/Ps]). In each group, the blood samples to measure the cytokine levels were collected before and after the CPB.

Results: Although we observed no statistically significant differences in postoperative intubation time, alveolar-arterial oxygen difference, creatine kinase MB level, and pulmonary hypertension (Pp/Ps) between group I (10.7±13.4 hours, 197±132 mm Hg, 148±58.6 IU/L, 42.8%±22.1%, respectively) and group II (27.8±36.5 hours, 227±150 mm Hg, 151±72.6 IU/L, 50.4%±16.0%, respectively), levels of median interleukin 6 and tumor necrosis factor α were lower in group I (129.8 and 17.0 pg/mL, respectively) than that in group II (487.8 and 22.5 pg/mL, respectively).

Conclusion: During the CPB in acyanotic pediatric patients, normoxemic management can minimize the systemic inflammatory response syndrome associated with CPB. We can apply this physiologic oxygen tension strategy to surgical advantage during heart surgeries in acyanotic pediatric patients.

Keywords: acyanotic pediatric patients; cardiopulmonary bypass; hyperoxemia; normoxemia.