Effects Of Postoperative Hypoalbuminemia On Acute Renal Injury After Extracorporeal Circulation

Objective:To study the effect of hypoalbuminemia on acute kidney injury after cardiac surgery with cardiopulmonary bypass.Method:A retrospective analysis was performed on 749 adult patients who underwent cardiac surgery with cardiopulmonary bypass in the First Affiliated Hospital of Guangxi Medical University from January 2016 to October 2017.Preoperative and postoperative serum albumin levels and the proportion of patients with hypoalbuminemia were compared.According to the lowest serum albumin concentration within 48 hours after surgery,the patients were divided into the group with hypoalbuminemia(?35g/L)and the group with non-hypoalbuminemia(>35g/L).The incidence of AKI after surgery in these two groups was statistically analyzed and the severity of AKI in these two groups was compared.Univariate analysis and binary Logistic regression analysis were used successively to evaluate the effect of hypoalbuminemia within 48 hours after surgery on the occurrence of AKI after cardiac surgery with cardiopulmonary bypass.Results:Among the 749 patients included,the postoperative serum albumin level was significantly lower than that before surgery(Z=-15.739,P<0.001),and the proportion of postoperative patients with hypoalbuminemia was higher than that before surgery.There were 273 patients(36.5%)developed AKI after cardiac surgery with cardiopulmonary bypass,including 109 patients(52.7%)in the hypoalbuminemia group and 164 patients(30.3%)in the non-hypoalbuminemia group.The incidence of AKI in the hypoalbuminemia group was higher than that in the non-hypoalbuminemia group,univariate analysis showed that the difference was statistically significant(?~2=32.443,P<0.001).The severity of AKI in the hypoalbuminemia group was higher than that in the non-hypoalbuminemia group(Z=-7.571,P<0.001),and the length of hospital stay was increased(Z=-2.442,P=0.015).In adjusted for gender,age,comorbidities,such as high blood pressure,high uric acid hematic disease,diabetes,cerebrovascular disease,anemia,renal insufficiency,preoperative heart function,coronary angiography,cardiopulmonary bypass time,aorta blocking time,type of heart surgery,postoperative hypotension,proteinuria and other influencing factors,using the binary classification Logistic regression analysis revealed that hypoalbuminemia is still the independent risk factor for AKI after cardiac surgery with cardiopulmonary bypass(OR=2.285,95%CI 1.580~3.306,P<0.001).Conclusions:1.After cardiac surgery with cardiopulmonary bypass,serum albumin level decreased,and the proportion of postoperative patients with hypoalbuminemia increased significantly.2.The incidence of AKI after cardiac surgery with cardiopulmonary bypass is high,and hypoalbuminemia within 48 hours after surgery is an independent risk factor for AKI.Hypoalbuminemia increases the risk of AKI by 1.285 times,while hypoalbuminemia increases the length of hospital stay.