Perioperative Laboratory Markers as Risk Factors for Surgical Site Infection After Elective Hand Surgery.

PURPOSE: The purpose of this study was to test the null hypothesis that there is no association between perioperative laboratory markers (serum albumin and hemoglobin A1c [HbA1c]) and incidence of surgical site infection (SSI) after soft tissue upper extremity surgery.

METHODS

We analyzed patient-level data from a large, insurance-based database containing supplemental laboratory results. We identified patients undergoing soft tissue upper extremity surgery (defined as carpal tunnel release, trigger finger release, wrist ganglion excision, cubital tunnel release, Dupuytren partial fasciectomy, or first dorsal compartment release) with serum albumin or HbA1c measurements within 90 days of surgery. We stratified patients into cohorts based on serum albumin concentration (<3.5 g/dL) and HbA1c (≥7%) thresholds. The primary outcome was incidence of SSI within 30 days following surgery. We constructed multivariable logistic regression models to adjust for patient demographics and baseline comorbidities using the Elixhauser comorbidity index.

RESULTS

Patients with hypoalbuminemia experienced an SSI incidence of 3.5% compared to 0.9% in patients with normal serum albumin. In multivariable analysis, the odds ratio of SSI with hypoalbuminemia was 3.32 (95% CI, 2.32-4.65). Patients with HbA1c ≥ 7% experienced an SSI incidence of 1.1% compared to 0.7% in patients with HbA1c < 7%. Multivariable analysis revealed odds ratios for SSI of 1.47 (95% CI, 1.02-2.11) in patients with HbA1c ≥ 7% compared to those with HbA1c < 7%.

CONCLUSIONS

Hypoalbuminemia and elevated HbA1c (in patients with diabetes) are risk factors for SSI within 30 days following soft tissue upper extremity surgery. Preoperative measurement of these laboratory markers may be a useful tool for risk stratification and identification of high-risk patients for nutritional or glycemic optimization.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.