Postoperative hypoalbuminemia is an independent risk factor for acute kidney injury after cardiac surgery under cardiopulmonary bypass / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the effect of postoperative hypoalbuminemia on acute kidney injury (AKI) after cardiac surgery under cardiopulmonary bypass (CPB).Methods:The clinical data of adult patients undergoing cardiac surgery under CPB were retrospectively analyzed. The difference between preoperative and postoperative serum albumin level was compared. The patients were divided into hypoalbuminemia group (≤35 g/L) and non-hypoalbuminemia group (>35 g/L) according to the lowest serum albumin concentration within 48 hours after surgery. The incidence and severity of postoperative AKI were compared between the two groups. Univariate analysis and binary logistic regression analysis were used to evaluate the effect of postoperative hypoalbuminemia on the incidence of postoperative AKI.Results:Among the 749 patients, the serum albumin level after cardiac surgery was significantly lower than that before surgery ( Z=-15.739, P<0.001), and the proportion of patients with hypoalbuminemia increased from 9.6% to 27.6% ( χ2=83.516, P<0.001). Postoperative AKI occurred in 273 patients, including 109 cases (52.7%) in hypoalbuminemia group and 164 cases (30.3%) in non-hypoalbuminemia group. The incidence of AKI in hypoalbuminemia group was significantly higher than that in non-hypoalbuminemia group ( χ2=32.443, P<0.001), and the severity of AKI in hypoalbuminemia group increased than that in non-hypoalbuminemia group ( Z=-2.098, P=0.036), and the time of hospital stay extended ( Z=-2.442, P=0.015). After adjusted by gender, age, preoperative hypoalbuminemia, comorbidities (hypertension, hyperuricemia, diabetes mellitus, cerebrovascular disease), renal insufficiency, preoperative heart function, coronary angiography, CPB time, aorta blocking time, type of heart surgery and postoperative hypotension, binary logistic regression analysis revealed that postoperative hypoalbuminemia was an independent risk factor for CPB-associated AKI ( OR=2.319, 95% CI 1.586-3.392, P<0.001). Conclusions:AKI is a common complication following cardiac surgery under CPB. Serum albumin after CBP is significantly lower than that before CBP, and postoperative hypoalbuminemia within 48 hours after surgery is an independent risk factor for AKI.