Intraoperative Use of Albumin in Major Noncardiac Surgery: Incidence, Variability, and Association With Outcomes

Abstract

Background: The impact of albumin use during major surgery is unknown, and a dearth of evidence governing its use in major noncardiac surgery has long precluded its standardization in clinical guidelines.

Objective: In this study, we investigate institutional variation in albumin use among medical centers in the United States during major noncardiac surgery and explore the association of intraoperative albumin administration with important postoperative outcomes.

Methods: The study is an observational retrospective cohort analysis performed among 54 U.S. hospitals in the Multicenter Perioperative Outcomes Group and includes adult patients who underwent major noncardiac surgery under general anesthesia between January 2014 and June 2020. The primary endpoint was the incidence of albumin administration. Secondary endpoints are acute kidney injury (AKI), net-positive fluid balance, pulmonary complications, and 30-day mortality. Albumin-exposed and albumin-unexposed cases were compared within a propensity score-matched cohort to evaluate associations of albumin use with outcomes.

Results: Among 614,215 major surgeries, predominantly iso-oncotic albumin was administered in 15.3% of cases and featured significant inter-institutional variability in use patterns. Cases receiving intraoperative albumin involved patients of higher American Society of Anesthesiologists physical status and featured larger infused crystalloid volumes, greater blood loss, and vasopressor use. Overall, albumin was most often administered at high-volume surgery centers with academic affiliation, and within a propensity score-matched cohort (n=153,218), the use of albumin was associated with AKI (aOR 1.24, 95% CI 1.20-1.28, P <0.001), severe AKI (aOR 1.45, 95% CI 1.34-1.56, P <0.001), net-positive fluid balance (aOR 1.18, 95% CI 1.16-1.20, P <0.001), pulmonary complications (aOR 1.56, 95% CI 1.30-1.86, P <0.001), and 30-day all-cause mortality (aOR 1.37, 95% CI 1.26-1.49, P <0.001).

Conclusions: Intravenous albumin is commonly administered among noncardiac surgeries with significant inter-institutional variability in use in the United States. Albumin administration was associated with an increased risk of postoperative complications.

FIGURE 1

Albumin use over time. This graph depicts albumin use over the course of the 6-year retrospective period plotted by institutional use quartile. Cases were stratified by institution, with surgery centers divided into albumin use quartiles according to the proportion of cases at each center using any amount of albumin, thereby grouping cases by location at minimal-use, low-use, medium-use, or high-use centers.

FIGURE 2

Secondary clinical endpoints in propensity score-matched cohort based on albumin exposure. These include AKI, severe AKI, net-positive fluid balance, pulmonary complications, and 30-day all-cause mortality, graphically depicted in odds ratios and 95% confidence intervals (CI). AKI indicates acute kidney injury.

FIGURE 3

Incidences of secondary endpoints. Incidence of acute kidney injury (A), respiratory complications (B), volume of crystalloids received (C), and duration of hypotension (D) in the propensity score-matched cohort stratified by albumin exposure.