[Risk factors for acute kidney injury after pediatric congenital heart surgery]

Objective: To investigate the clinical characteristics and risk factors of acute kidney injury (AKI) after pediatric congenital heart surgery among children aged<4 years old. Methods: A total of 410 children<4 years old with congenital heart disease who underwent cardiac pulmonary bypass (CPB) surgery from Guizhou Provincial People's Hospital between January 2017 and December 2018 were analyzed retrospectively. The patients were divided into two groups:AKI group (n=42) and non-AKI group (n=368) according to whether AKI occurred after surgery. The clinical data of patients was compared between two groups, including demographic data(sex, age, weight), preoperative, intraoperative and postoperative clinical data, the length of mechanical ventilation, hospitalization, intensive care unit (ICU) stay, hospital costs and death in hospital. Logistic regression analysis was used to screen the risk factors of postoperative AKI. Results: Compared with non-AKI group, children in AKI group had lower weight [(8.2±3.3) kg vs (9.9±2.6) kg,P=0.023] and mean arterial pressure (MAP) [(101.3±18.1) mmHg vs (118.2±15.6) mmHg,P<0.001], but longer duration of surgery [(210.3±74.8) min vs (149.1±52.2) min, P<0.001], CPB [(107.2±49.9) min vs (60.2±29.2) min,P<0.001],aortic clamping [62.0(50.0,88.0) min vs 34.5(18.3,52.3) min,P<0.001],mechanical ventilation duration, ICU stay, hospital stay, and higher mortality. Multivariate logistic regression analysis showed that lower weight (OR=0.489, 95%CI:0.298-0.802, P=0.005), lower MAP (OR=0.929, 95%CI: 0.891-0.969, P=0.001), longer duration of surgery (OR=1.035, 95%CI: 1.016-1.054, P<0.001) were the independent risk factors for AKI. Conclusion: Children with lower weight, longer duration of surgery, lower MAP are at higher risk of getting AKI after congenital heart surgery.