Predictors of Acute Kidney Injury Associated with Cardiopulmonary Bypass.

OBJECTIVES: To study the incidence of acute kidney injury (AKI) in the postoperative period of cardiac surgery in patients without preoperative renal insufficiency who underwent cardiac surgery with cardiopulmonary bypass (CPB), and to explore the association between the incidence of AKI and predictors related to CPB.

METHODS: Observational, cross-sectional study. Participants were divided in two groups, those who developed AKI in the postoperative period and those who did not develop AKI. Kidney Disease: Improving Global Outcomes - Clinical Practice Guideline for Acute Kidney Injury (KDIGO) classification was used to characterize AKI. The analysis included preoperative variables (anthropometric data, cardiovascular risk factors and blood parameters), as well as the type of surgery, intraoperative variables related to CPB, and postoperative creatinine variation. Association between variables was studied with binary logistic regression.

RESULTS: We have included 329 patients, of which 62 (19%), developed AKI. There were statistically significant differences between the groups in age (p<0.001; OR (95%)-1.075 (1.037-1.114)), duration of CPB (p=0.011; 1.008 (1.002-1.014)), urine output during CPB (p=0.038; 0.998 (0.996-0.999)), mannitol and furosemide administration during CPB, (respectively, p=0.032; 2.293 (1.075-4.890) and p=0.013; 2.535 (1.214-5.296)).

CONCLUSIONS: A significant number of patients developed AKI in the postoperative period of cardiac surgery and this incidence was influenced by factors related to CPB, namely: age, duration of CPB, urine output during CPB, mannitol and furosemide administration during CPB.