A Randomized Control Trial of Preoperative Oral Antibiotics as Adjunct Therapy to Systemic Antibiotics for Preventing Surgical Site Infection in Clean Contaminated, Contaminated, and Dirty Type of Colorectal Surgeries

BACKGROUND: Preoperative bowel preparation with or without oral antibiotics is controversial in terms of postoperative surgical site infections. OBJECTIVE: This study aimed to evaluate the efficacy of oral antibiotics as adjunct therapy to systemic antibiotics with mechanical bowel preparation for preventing surgical site infections in clean contaminated, contaminated, and dirty colorectal procedures. DESIGN: This was a single-center, prospective randomized study. SETTING: This study was conducted at the General Surgery Department at Jinling Hospital, Nanjing University, China, from July 15, 2014 to January 20, 2016. PATIENTS: Patients aged >= 18 years scheduled for abdominal surgery with clean-contaminated, contaminated, and dirty wounds were selected. INTERVENTIONS: Patients were randomly assigned to receive preoperative mechanical bowel preparation or mechanical bowel preparation with oral antibiotics. MAIN OUTCOMES: The primary outcome was the rate of surgical site infections. The secondary outcomes were extra-abdominal complications, duration of postoperative ileus, and readmission rate. RESULTS: Ninety-five patients were allocated to each group. Eight and 26 surgical site infections (8.42% vs 27.3 %, p = 0.004) occurred in the mechanical bowel preparation with oral antibiotics and mechanical bowel preparation groups. Thirteen extra-abdominal complications were reported: 6 in the mechanical bowel preparation with oral antibiotics group and 7 in the mechanical bowel preparation group (6.3% vs 7.3%, p = 0.77). Postoperative ileus duration did not differ between groups (p = 0.23). There were 4 readmissions in the mechanical bowel preparation group and none in the mechanical bowel preparation with oral antibiotics group (p = 0.04). On multivariable analysis, blood loss >= 500 mL (OR, 5.1; 95% CI, 1.27-20.4; p = 0.02), ASA score >= 3 (OR, 3.9; 95% CI, 1.2-12.5; p = 0.01), contaminated types (OR, 3.6; 95% CI, 1.5-8.6; p = 0.01), and administration of preoperative oral antibiotics (OR, 0.20; 95% CI, 0.06-0.60; p = 0.005) independently affected the incidence of surgical site infections. LIMITATIONS: This was a single-center study. CONCLUSION: Preoperative oral antibiotics, as adjunct therapy to systemic antibiotics and mechanical bowel preparation, significantly reduced surgical site infections and minimized the readmission rates in clean contaminated, contaminated, and dirty types of colorectal surgery. See Video Abstract at http://links.lww.com/DCR/A437.