Oxygen Delivery During Cardiopulmonary Bypass in Pediatric Patients With Congenital Heart Disease: Association With Postoperative Acute Kidney Injury.

Objective: This study was designed to investigate the distribution of nadir oxygen delivery (DO), mean DO, and area under ideal DO (AUiDO) among categorized age groups of pediatric patients and their associations with postoperative cardiac surgery-associated (CSA) acute kidney injury (AKI) and clinical outcomes.

Design: Retrospective cohort study.

Setting: A tertiary teaching hospital.

Participants: Patients aged <15 years with congenital heart disease who underwent cardiac surgery between May 2018 and May 2022.

Interventions: None.

Measurements And Main Results: Nadir DO, mean DO, and AUiDO were defined as the lowest DO, average DO, and dose of decrement combining the intensity and duration of DO less than the calculated ideal DO, respectively. The primary outcome was CSA-AKI occurrence within 48 hours postoperatively. Secondary outcomes included maximum serum lactate levels (Lac) for the first 24 hours after pediatric cardiac intensive care unit admission. Of 479 patients, 147 (30.7%) developed AKI. Nadir DO and AUiDO were not significantly different between patients with CSA-AKI and those without CSA-AKI (p = 0.115 and p = 0.12, respectively). However, the mean DO was significantly higher in patients with CSA-AKI (p = 0.025). After adjusting for potential confounders, no significant differences were observed in the odds for CSA-AKI based on increments in nadir DO, mean DO, or AUiDO. In contrast, nadir DO and mean DO were significantly associated with Lac in both univariate and multivariable regression analyses.

Conclusion: DO-related values during cardiopulmonary bypass were not associated with CSA-AKI in pediatric patients with congenital heart disease. However, nadir DO and mean DO were significantly associated with postoperative serum lactate levels.