Risk factors for surgical site infections after colorectal resection in diabetic patients.

Background: Surgical site infections (SSIs) are a well known complication of gastrointestinal surgery and associated with an increased morbidity, mortality and overall cost. Diabetes mellitus (DM) is a risk factor for SSI. However, there is no clear consensus as to which other risk factors play a significant role. The goal of this study was to identify risk factors associated with SSI in patients with DM undergoing colorectal resection.

Study Design: A retrospective review was conducted of DM patients who underwent colorectal resection from June 2000 to June 2009 at Milton S Hershey Medical Center, Division of Colorectal Surgery. Individual measures were analyzed using chi-square, t-test, and Mann-Whitney U tests, and statistical significance was confirmed using a multiple logistical regression model.

Results: There were 183 DM patients included in the study, 28 (15%) of whom developed SSI. Glucose levels were significantly higher in the SSI group for each time interval, 0 to 6 hours (211 mg/dL, p = 0.03), 0 to 48 hours (176 mg/dL, p = 0.001), and 48 to 96 hours (167 mg/dL, p = 0.012) postoperatively. Other measures significantly associated with SSI included the use of drains (p = 0.05) and the use of prophylactic antibiotics for more than 24 hours (p = 0.02). Body mass index and stoma creation approached statistical significance (p = 0.08, 0.07, respectively). The type of hypoglycemic regimen, immunosuppression, and emergency surgery were not associated with an increased rate of SSI.

Conclusions: Higher than normal glucose control at all postoperative time intervals was associated with SSI. The majority of glucose levels were below the American Diabetes Association recommended level of 200 mg/dL, but patients still developed SSI. Type of perioperative glucose control did not affect the incidence of SSI. These data suggest that DM patients undergoing colectomy should have glucose tightly controlled, avoid placement of drains, and receive antibiotics for less than 24 hours.