Oral antibiotics to prevent postoperative urinary tract infection: a randomized controlled trial.

OBJECTIVE To evaluate whether nitrofurantoin prophylaxis prevents postoperative urinary tract infection (UTI) in patients receiving transurethral catheterization after pelvic reconstructive surgery. METHODS In a randomized, double-blind, placebo-controlled trial, participants undergoing pelvic reconstructive surgery were randomized to 100 mg nitrofurantoin or placebo once daily during catheterization if they were: 1) discharged with a transurethral Foley or performing intermittent self-catheterization; or 2) hospitalized overnight with a transurethral Foley. Our primary outcome was treatment for clinically suspected or culture-proven UTI within 3 weeks of surgery. Statistical analysis was performed by χ2 and logistic regression. Assuming 80% power at a P value of .05, 156 participants were needed to demonstrate a two-thirds reduction in UTI. RESULTS Of 159 participants, 81 (51%) received nitrofurantoin and 78 (49%) received placebo. There were no significant differences in baseline demographics, intraoperative characteristics, duration and type of catheterization, or postoperative hospitalization, except a lower rate of hysterectomy in the nitrofurantoin group. Nitrofurantoin prophylaxis did not reduce the risk of UTI treatment within 3 weeks of surgery (22% UTI with nitrofurantoin compared with 13% UTI with placebo, relative risk 1.73, 95% confidence interval 0.85-3.52, P=.12). Urinary tract infection treatment was higher in premenopausal women, lower in diabetics, and increased with longer duration of catheterization. In logistic regression adjusting for menopause, diabetes, preoperative postvoid residual volume, creatinine clearance, hysterectomy, and duration of catheterization, there was still no difference in UTI with nitrofurantoin as compared with placebo. CONCLUSION Prophylaxis with daily nitrofurantoin during catheterization does not reduce the risk of postoperative UTI in patients receiving short-term transurethral catheterization after pelvic reconstructive surgery. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, www.clinicaltrials.gov, NCT01450800. LEVEL OF EVIDENCE I.