Effects of Intra-Operative Glucose Control on the Development of Surgical Site Infection in Cardiac Surgery Patients

Abstract

OBJECTIVE: To assess the effects of timing and glucose control on the development of post-operative surgical site infections in cardiac surgery patients. METHODS: The cardiothoracic team at Rochester General Hospital instituted a program to standardize cardiac care by initiation of a standardized intra-operative insulin protocol. The objective was to maintain glucose levels below 200mg/dL. A distinct data-collection tool was designed to measure and record glucose levels pre-, intra-, and post-operatively. Blood glucose readings were determined by a Chiron ABG chemistry analyzer and obtained via an indwelling arterial catheter and documented at 30-minute intervals. Glucose levels were recorded on all patients regardless of diabetic history. RESULTS: A total of 1880 patients from 2000 to 2002 were entered into the database. In the univariate analysis, pre-operative and early intra-operative glucose levels of 200 or more were not associated with an increased risk of infection. However, of the 61 patients who developed a surgical-site infection (chest or leg), 38 had glucose levels above 200 after bypass. Of the 1819 non-infected patients, 566 had glucose levels above 200 during the same timeframe. A Fisher's Exact test was performed to evaluate the association of elevated blood sugars in the post bypass and late surgical phase and the development of a surgical site infection. This relationship was statistically significant (p=0.0001). CONCLUSIONS: Although further evaluation is necessary, preliminary results suggest that tight glucose control is especially critical during the latter part of surgery and in the early recovery phase of cardiac surgery.