The Perioperative Hyperchloremia Is Associated With Postoperative Acute Kidney Injury in Patients With off-Pump Coronary Artery Bypass Grafting: A Retrospective Study

Abstract

Background: The relationship between perioperative hyperchloremia and postoperative acute kidney injury (AKI) is not well established. Our study aimed to evaluate the association between perioperative hyperchloremia and acute kidney injury in patients undergoing off-pump coronary artery bypass grafting (CABG). Methods: Patients with coronary disease who underwent off-pump CABG between April 2017 and December 2019 were enrolled in this retrospective study. The patients with perioperative hyperchloremia were matched 1:1 to patients without perioperative hyperchloremia. The primary outcome was the postoperative acute kidney injury rate. The secondary outcomes included intensive care unit (ICU)-free days, postoperative hospitalization days, wound infection rate, and in-hospital mortality. Propensity score matching and univariate and multivariate logistic regression analyses were used in this study. Results: A total of 321 patients who underwent off-pump CABG were included in the analysis. Propensity score matching selected 83 pairs for the final comparison. The results showed that the postoperative AKI rate was significantly different between the hyperchloremia and no hyperchloremia groups (56.6% versus 15.7%; P < .001). The number of ICU-free days, postoperative hospitalization days, wound infection rate, and in-hospital mortality were similar between the two groups. In the multivariable, logistic regression analysis, hyperchloremia was independently associated with the development of postoperative AKI (odds ratio [OR] = 1.814, 95% confidence interval [CI]: 1.072-3.070, P = .026). Conclusions: Perioperative hyperchloremia is associated with an increase in the postoperative AKI rate among patients undergoing off-pump CABG.