The impact of poor post-operative glucose control on neurosurgical surgical site infections (SSI)

Abstract

Elevated HbA1c is associated with increased surgical site infections (SSI) in neurosurgical patients. How blood glucose control in the early post-operative period relates to SSI is incompletely understood. We hypothesized that poor early post-operative blood glucose control would be associated with SSI. Data from patients undergoing neurosurgical procedures at University of Missouri Hospital was retrospectively collected. Post-operative blood glucose for 72 h after surgery was assessed and categorized by levels of hyperglycemia; those with glucose ≥200 mg/dl were classified as poorly controlled. Patients with SSI were compared to patients without SSI using Chi-Square test with Fisher’s exact test when appropriate. Of 500 patients having surgery, 300 had at least one post-operative blood glucose measurement. Of those 300 patients, 19 (6.33%) developed SSI. Patients with SSI had significantly higher mean post-operative blood glucose levels (p = 0.0081) and a greater mean number of point-of-care glucose level measurements >150 mg/dL (p = 0.0434). Pre-operative HbA1c and SSI were not associated (p = 0.0867). SSI was associated with pre-operative glucocorticoid use (p = 0.03), longer operative procedure (p = 0.0072), and required use of post-operative insulin drip (p = 0.047). Incidence of other wound complications (cellulitis, deep infection, dehiscence) increased with increase in post-operative blood glucose levels to >225 mg/dL. Post-operative hyperglycemia is associated with SSI after neurosurgical procedures, emphasizing the importance addressing blood glucose control after surgery.