Intraoperative albumin use and postoperative acute kidney injury in patients undergoing noncardiac surgery

The beneficial effects of albumin use have been suggested in various clinical settings including critically ill patients. However, the association between intraoperative albumin administration and acute kidney injury (AKI) after noncardiac surgery is unclear. This is a retrospective, hospital registry-based study including 39,336 adult patients who underwent intermediate to high risk noncardiac surgery between January 2011 and June 2019 at single tertiary hospital. The patients were divided into two groups based on exposure to 5% albumin during intraoperative period. The primary outcome was the incidence of AKI within seven days after surgery. Among 39,336 patients, 1725 (4.4%) patients were administered 5% albumin during the intraoperative period. The incidence of AKI was 3.4% (1285/37,611) in the albumin non-exposure group and 13.0% (225/1725) in the albumin exposure group. After 1:3 propensity score matching, 5221 patients (albumin non-exposures 3697; albumin exposures 1524) were included in the analysis. After propensity score matching and adjustment for residual confounders, albumin exposure was associated with higher risk of postoperative AKI (odds ratio = 1.82; 95% confidence interval, 1.41-2.34; p < 0.001). This association persisted in sensitivity analyses, including a subgroup with estimated blood loss < 500 mL (odds ratio = 2.40; 95% confidence interval, 1.76-3.28; p < 0.001), and in the entire cohort (odd ratio = 2.44; 95% confidence interval, 1.97-3.02; p < 0.001). Intraoperative 5% albumin use during noncardiac surgery was associated with increased risk of postoperative AKI. Our results should be verified in further studies to guide the optimal choice of fluid in noncardiac surgery.