Hypoalbuminemia as an Independent Risk Factor for Perioperative Complications Following Surgical Decompression of Spinal Metastases

Abstract

Study design: Retrospective cohort study.

Objective: Malnutrition has been shown to be a risk factor for poor perioperative outcomes in multiple surgical subspecialties, but few studies have specifically investigated the effect of hypoalbuminemia in patients undergoing operative treatment of metastatic spinal tumors. The aim of this study was to assess the role of hypoalbuminemia as an independent risk factor for 30-day perioperative mortality and morbidity after surgical decompression of metastatic spinal tumors using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2011 to 2014.

Methods: We identified 1498 adult patients in the ACS-NSQIP database who underwent laminectomy and excision of metastatic extradural spinal tumors. Patients were categorized into normoalbuminemic and hypoalbuminemic (ie, albumin level <3.5 g/dL) groups. Univariate and multivariate regression analyses were performed to examine the association between preoperative hypoalbuminemia and 30-day perioperative mortality and morbidity. Subgroup analysis was performed in the hypoalbuminemic group to assess the dose-dependent effect of albumin depletion.

Results: Hypoalbuminemia was associated with increased risk of perioperative mortality, any complication, sepsis, intra- or postoperative transfusion, prolonged hospitalization, and non-home discharge. However, albumin depletion was also associated with decreased risk of readmission. There was an albumin level-dependent effect of increasing mortality and complication rates with worsening albumin depletion.

Conclusions: Hypoalbuminemia is an independent risk factor for perioperative mortality and morbidity following surgical decompression of metastatic spinal tumors with a dose-dependent effect on mortality and complication rates. Therefore, it is important to address malnutrition and optimize nutritional status prior to surgery.

Keywords: hypoalbuminemia; malnutrition; perioperative complications; spinal metastasis; spinal tumor.

Figure 1.

Preoperative serum albumin levels of 1498 patients. The red line represents the cutoff for hypoalbuminemia (ie, albumin ≤3.5 g/dL). The mean albumin level was 3.66 g/dL with a standard deviation of 0.66 g/dL. Hypoalbuminemia was present in 34.2% (512/1498) of patients.

Figure 2.

Multivariate regression analysis of perioperative mortality and complications that were significantly associated with hypoalbuminemia. Adjusted odds ratios are illustrated with 95% confidence intervals. LOS, length of stay.

Figure 3.

Multivariate regression analysis of perioperative mortality and complications that were significantly associated with varying severities of hypoalbuminemia using mild hypoalbuminemia (ie, serum albumin level of 3.3-3.4 g/dL) as the reference group. Adjusted odds ratios are reported with 95% confidence intervals. Mild-moderate, moderate-severe, and severe hypoalbuminemia were defined as a serum albumin level of 3.1 to 3.2 g/dL, 2.8 to 3.0 g/dL, and 1.2 to 2.7 g/dL, respectively. VTE, venous thromboembolism; LOS, length of stay.