Intraoperative 20% albumin infusion and acute kidney injury in on-pump cardiac surgery: a focus on preoperative albumin levels.

BACKGROUND

Albumin is widely used for volume replacement therapy during cardiopulmonary bypass (CPB) including priming fluid, despite significant controversy over its benefits. This study aimed to examine how 20% exogenous albumin affects kidney function in patients with varying preoperative albumin levels.

METHODS

We conducted this single-center, retrospective study in 28,298 adult patients undergoing on-pump cardiac surgery between 2018 and 2023. Patients were stratified according to preoperative albumin values (g/L): ≤35 ( = 1,525), 35.1-37.5 ( = 4,115), 37.6-40 ( = 7,894), and >40 ( = 14,764). Multivariate logistic regression, propensity score matching (PSM), and an inverse probability-weighting (IPW) model were applied to evaluated the impact of 20% albumin infusion on cardiac surgery-associated acute kidney injury (CSA-AKI).

RESULTS

A total of 2,541 pairs were created after PSM: ≤ 35 g/L (307 pairs), 35.1-37.5 g/L (518 pairs), 37.6-40 g/L (743 pairs), and > 40 g/L (973 pairs). Patients with intraoperative 20% albumin infusion had a statistically higher risk of CSA-AKI in the group with preoperative albumin above 40 g/L (OR, 1.29; 95% CI, 1.07-1.57;  = 0.007) in the PSM model. This result remained significant after adjusting for the effects of potential confounding variables (OR, 1.38; 95% CI, 1.19-1.61;  < 0.001 for multivariate logistic regression; OR, 1.63; 95% CI, 1.55-1.72;  < 0.001 for IPW model). However, there was no significant association with Stage 2 and 3 CSA-AKI both for multivariable logistic regression and PSM.

CONCLUSIONS

This analysis highlights that 20% albumin infusion during on-pump cardiac surgery may increase the risk of all stages CSA-AKI in patients with preoperative albumin above 40 g/L.