Antibiotic Microbial Prophylaxis for Spinal Surgery: Comparison between 48 and 72-Hour AMP Protocols

STUDY DESIGN This is a prospective randomized cohort study. PURPOSE We intended to evaluate the efficacy of a 48 hour antibiotic microbial prophylaxis (AMP) protocol as compared with a 72 hour AMP protocol. OVERVIEW OF LITERATURE The current guideline for the prevention of surgical site infection (SSI) suggests the AMP should not exceed 24 hours after clean surgery like spinal surgery. But there exist some confusion in real clinical practice about the duration of postoperative antibiotic administration because the evidence of the guideline was not robust. METHODS The subjects were 548 patients who underwent spinal surgery at our department from April 2007 to December 2008. The patients were classified into two groups according to the prophylaxis protocol: group A, for which AMP was employed for 72 hours postoperatively and group B, for which AMP was employed for 48 hours postoperatively. Five hundred two patients out of 548 patients were followed until 6 months postoperatively. The incidence of SSI in the two groups was analyzed. RESULTS The overall infection rate was 0.8%. There was no significant difference in infection rate between the two groups. The overall infection rate for the patients who underwent instrumented fusion was 0.9%. There was no significant difference in the infection rate between the patients of the two groups who underwent instrumented fusion. CONCLUSIONS AMP for 48 hours is as efficient as AMP for 72 hours.