comparison of the effectiveness of continuous versus intermittent cefazolin for the prevention of infection after off-pump coronary artery bypass graft

background: surgical site infection is known as a common complication after cardiac surgery, and cefazolin is the best prophylactic antibiotic to prevent this complication. the goal of this study was to evaluate the effect of continuous and intermittent cefazolin for the prevention of superficial surgical site infection following off-pump coronary artery bypass (opcab). methods: this prospective randomized clinical trial study was conducted on 141 patients candidated for opcab and divided into two groups. this study was performed between february 2011 and february 2012 in the iranian city of yazd. patients in both groups received 2 g of cefazolin as a starting dose and at 30 minutes before incision. definition of surgical site infections was according to the centers for disease control and prevention criteria (cdc-criteria). in the continuous infusion group (n = 74), 3 g of cefazolin was infused over a 24-hour period after surgery. in the intermittent group (n = 67),1 g of cefazolin was administered at 3, 11, and 19 hours after the starting dose. hyperlipidemia, diabetes, hypertension, smoking, history of heart disease, and incidences of superficial infection were compared between the two groups. duration of follow- up was 4 weeks. results: the mean age of the patients was 60.49 ± 10.63 years. the patients were 30.5% female and 69.5% male. there were no significant differences in age, body surface area, duration of operation, number of distal grafts, number of proximal grafts, and duration of hospital stay before heart surgery between two groups. the incidence of infection in intermittent group was (7.5%) and in continuous groups was (2.7%). there was no significant difference in the incidence of infection between the two groups (p value = 0.26). conclusion: our findings in this study showed no significant differences between continuous and intermittent cefazolin for the prevention of superficial surgical site infections after opcab.