Abstract: Objective This study is to investigatethe relationship between erythrocyte storage duration and acute kidney injury (AKI) after pediatric cardiac surgery with cardiopulmonary bypass (CPB). Methods A total of 346 consecutive pediatric patients from January 2019 to December 2022 who received cardiac surgery by CPB in Beijing Children's Hospital were retrospectively analysed. They were divided into fresher blood group (≤14 d, n=163) and older blood group (15~35 d, n=183) according to the erythrocyte storage duration. The incidence and severity of postoperative AKI were compared between two groups. Results A total of 346 subjects were included in the study. Among them, 93 cases developed AKI after surgery, and the incidence rate was 26.88%. There were 163 children in the newer blood group, and 47 (28.83%) had AKI after surgery, including 28 cases (59.57%) in AKI stage 1, 15 cases (31.92%) in AKI stage 2, and 4 cases (8.51%) in AKI stage 3. There were 183 childrenin the older blood group, and 46 cases (25.14%) developed AKI after surgery, including 28 cases (60.87%) in AKI stage 1, 16 cases (34.78%) in AKI stage 2, and 2 cases (4.35%) in AKI stage 3. The results showed that there was no significant difference in the incidence and severity of AKI between the two groups (incidence rate χ²=0.600, P=0.439; severity χ²=0.699, P=0.797). Conclusion AKI is a common complication following cardiac surgery with CPB in children, the incidence rate was 26.88%. But the duration of blood storage had no effect on the incidence of acute kidney injury after pediatric cardiac surgery with CPB.

Key words: Erythrocyte storage duration, Acute kidney injury, Pediatric Cardiopulmonary bypass, Cardiac surgery