The association of diabetes and glucose control with surgical-site infections among cardiothoracic surgery patients

OBJECTIVE: To assess the importance of diabetes, diabetes control, hyperglycemia, and previously undiagnosed diabetes in the development of surgical-site infections (SSIs): among cardiothoracic surgery patients. SETTING: A 540-bed tertiary-care university-affiliated hospital. DESIGN: Prospective cohort and case-control studies. PATIENTS: All patients having cardiothoracic surgery between November 1998 and September 1999 were eligible: for participation. One thousand patients had preoperative hemoglobin Alc determinations. Seventy-four patients with SSIs were identified. RESULTS: Diabetes (odd ratio [OR], 2.76; P < .001) and postoperative hyperglycemia (OR, 2.02; P=.007) were independently associated with development of SSIs. Among known diabetics, elevated hemoglobin Alc values were not associated with a statistically significantly increased risk of infection; the mean Alc value was 8.44% among those with infections compared with 7.80% for those, without (P=6.09). Forty-two (6%) of 700 patients without prior diabetes history had evidence of undiagnosed diabetes; their infection rate was comparable to that of known diabetics (3/42 [7%] vs 17/300 [6%]; P=.72). An additional 30% of nondiabetics had elevated hemoglobin Alc determinations or perioperative hyperglycemia. CONCLUSIONS: Postoperative hyperglycemia and previously undiagnosed diabetes are associated with development of SSIs among cardiothoracic surgery patients. Screening for diabetes and hyperglycemia. among patients having cardiothoracic may be warranted to prevent postoperative and chronic complications of this metabolic abnormality.