Relationship between intraoperative blood pressure variability and postoperative acute kidney injury in pediatric cardiac surgery

Background Cardiac surgery-associated acute kidney injury (CSA-AKI) is a notably common complication in pediatrics, with an incidence rate ranging from 15% to 64%. This rate is significantly higher than that observed in adults. Currently, there is a lack of substantial evidence regarding the association between intraoperative blood pressure variability (BPV) during cardiac surgery with cardiopulmonary bypass (CPB) and the development of AKI in pediatric patients. Methods This retrospective observational study encompassed children aged of 0 – 7 years undergoing cardiac surgery with CPB. Intraoperative BPV was calculated using coefficients of variation (CVs) and the area under the curve (AUC). Univariate and multivariate analyses were employed to identify risk factors associated with CSA-AKI. Results Among 570 patients (median age 1 year) reviewed. 36.1% developed CSA-AKI (68.9% risk stage, 22.8% injury stage, 8.3% failure stage). After adjusting for other variables, male gender (OR=2.044, 95%CI: 1.297-3.222, P=0.002), congenital heart surgery risk assessment grade (RACHS-1) classification ≥3 (OR=0.510, 95%CI: 0.307-0.846, P=0.009), longer CPB time (OR=1.022, 95%CI: 1.007-1.037, P=0.004) and higher peak value of intraoperative vasoactive inotropic score (VIS) (OR=1.072, 95%CI: 1.026-1.119, P=0.002) were identified as independent risk factors for CSA-AKI. ±30%AUCm was different in univariate analysis (P=0.014), however, not statistically different in multifactor analysis (P=0.610). Conclusion Greater BPV, specifically MAP variations exceeding 30%AUC during CPB, may be a potential risk factor for CSA-AKI in pediatric. Further large sample clinical studies are warranted to analyze the correlation between BPV and CSA-AKI.