Should the duration of Antibiotics Prophylaxis be Prolonged in Diabetes patients with Isolated Coronary Artery Bypass Grafting?

Objective: To compare the outcome of short-term (<24 hours) versus longer-term (>24 hours) antibiotic prophylaxis (ABP) in Diabetic patients undergoing coronary artery bypass graft (CABG) surgery and its impact on in-hospital incidence of deep Sternal Wound Infection (DSWI) / Mediastinitis. Patients and method: We performed a cross sectional comparative study in 160 Diabetic patients undergoing CABG from October 2010 through April 2012. Comparison was made between 80 diabetic patients receiving less than 24 hours of prophylactic antibiotics with another 80 diabetic patients receiving more than 24 hours of prophylactic antibiotics undergoing isolated CABG. Surgical Site infection (SSI) was assessed on a daily basis during the patient's stay in the Department of Cardiac Surgery, Mayo Hospital/KEMU, Lahore. Diagnosis of identified SSI were based on fever, pain, redness, secretion, purulent drainage, positive cultures, clear dehiscence of the sternotomy wound. Results: In-hospital incidence of Deep Sternal Wound Infection (DSWI)/Mediastinitis was 7.50% in the group <24h of ABP and 1.25% in the group receiving >24 h of ABP therapy, and the difference was statistically significant (P=0.042).The proportion of patients with deep-organ-space involvement (mediastinitis) and sepsis requiring rewiring were 7 patients (8.75%) for <24 hours and 1 patients (1.25%) in >24 hours of ABP (P=0.030). Similar results were observed in terms of mortality (8.75% Vs 1.25%). However, the microorganisms isolated showed a similar distribution in both groups. Morbidity, infections and the composite outcomes occurred more commonly in diabetic patients. Conclusions: Diabetes mellitus is an important risk factor for mortality and morbidity among those undergoing CABG. This study documents the higher incidence of deep Sternal Wound Infection (DSWI) / Mediastinitis associated with less than 24h of ABP therapy, suggesting the need for prolonged ABP in Diabetic patients undergoing CABG.