Effects of Arterial Oxygen Pressure Values During Cardiopulmonary Bypass on Postoperative Outcomes in Pediatric Patients

Objective: To investigate the effects of supraphysiological arterial oxygen pressure (PaO2) levels during cardiopulmonary bypass (CPB) on clinical outcomes in children undergoing open heart surgery. Methods: Intraoperative and postoperative data of patients aged 16 years and younger undergoing open heart surgery were retrospectively reviewed. Patients were divided into three groups according to maximum PaO2 values determined by blood gas analysis during CPB. Group I was defined as maximum PaO2 = 100-199 mmHg during CPB; group II, PaO2 = 200-299 mmHg; and group III, PaO2 ≥ 300 mmHg. Results: The maximum PaO2 values achieved during CPB increased with increasing duration of CPB and cross-clamp duration (p=0.001, p=0.028). In the postoperative period, no significant difference was found between the groups in terms of maximum PaO2 levels achieved during CPB, duration of mechanical ventilation, hospital and intensive care unit (ICU) stay and complications (p = 0.307). There was no difference between systemic inflammatory response syndrome and PaO2 levels assessed at 6, 24 and 48 hours postoperatively in the ICU (p = 0.706, p = 0.926, p = 0.876). An increase in the maximum PaO2 achieved during CPB was associated with an increase in mortality (p = 0.039). When analysing the subgroup of cyanotic patients, ICU length of stay ≤ 10 days was associated with high oxygen levels (p = 0.028). Conclusion: The results of our study indicate that supraphysiological oxygen levels used during CPB cause an increase in mortality.