The impact of hypoalbuminemia on postoperative outcomes after outpatient surgery: a national analysis of the NSQIP database.

PURPOSE: Hypoalbuminemia has been described as a modifiable factor to optimize postoperative outcomes after major inpatient surgeries. Nevertheless, the role of hypoalbuminemia on outpatient procedures is not well defined. The purpose of this study was to examine the impact of hypoalbuminemia on postoperative outcomes of patients undergoing low-risk outpatient surgery.

METHODS

Patients were extracted from the American College of Surgeons National Surgical Quality Improvement Program database who had outpatient surgery from 2018 and recorded preoperative albumin levels. The primary outcome was a composite of any major complications including: 1) unplanned intubation, 2) pulmonary embolism, 3) ventilator use > 48 hr, 4) progressive renal failure, 5) acute renal failure, 6) stroke/cerebrovascular accident, 7) cardiac arrest, 8) myocardial infarction, 9) sepsis, 10) septic shock, 11) deep venous thrombosis, and 12) transfusion. Death, any infection, and readmissions were secondary outcomes.

RESULTS

A total of 65,192 (21%) surgical outpatients had albumin collected preoperatively and 3,704 (1.2%) patients had levels below 3.5 g⋅dL-1. In the albumin cohort, 394/65,192 (0.6%) patients had a major medical complication and 68/65,192 (0.1%) patients died within 30 days after surgery. Albumin values < 3.5 g⋅dL-1 were associated with major complications (adjusted odds ratio [aOR], 1.92; 95% confidence interval [CI], 1.44 to 2.57; P < 0.001; death-adjusted OR, 3.03; 95% CI, 1.72 to 5.34; P < 0.001); any infection (aOR, 1.49; 95% CI, 1.23 to 1.82; P < 0.001); and readmissions (aOR, 1.82; 95% CI, 1.56 to 2.14; P < 0.001). In addition, when evaluated as a continuous variable in a multivariate analysis, for each increase in albumin of 0.10 g⋅dL-1, there was an associated reduction of major complications (aOR, 0.94; 95% CI, 0.92 to 0.96; P < 0.001).

CONCLUSIONS

Hypoalbuminemia is associated with major complications and death in outpatient surgery. Since hypoalbuminemia is a potential modifiable intervention, future clinical trials to evaluate the impact of optimizing preoperative albumin levels before outpatient surgery are warranted.