A Multicenter Randomized Controlled Trial of Antimicrobial Prophylaxis to Prevent Urinary Tract Infections after...

Shockwave lithotripsy (SWL) carries a risk of postprocedural infection. Use of antibiotic prophylaxis by clinicians is variable and international guidelines provide conflicting recommendations, reflecting low-certainty evidence. We investigated whether antibiotic prophylaxis reduces bacteriuria and post-SWL urinary tract infections (UTIs).

APPEAL, an international multicenter, blinded trial, randomized adults undergoing SWL for urolithiasis to a single dose of ciprofloxacin or placebo. The primary outcome was the incidence of a composite of bacteriuria or symptomatic UTI after SWL. Other outcomes included the incidence of pyelonephritis or urosepsis.

Of the 1722 randomized patients, 28 underwent postrandomization exclusions (mainly nonvisualizable stones). Among the analysis population (n = 1694; median age 50 yr; 30% female), 74% had kidney stones and 26% had ureteral stones. Bacteriuria (without symptoms) or symptomatic UTI occurred in 20 patients (2.7%) in the ciprofloxacin arm and 30 (3.9%) in the placebo arm (risk ratio [RR] 0.68, 95% confidence interval [CI] 0.41-1.15). Symptomatic UTI occurred in ten patients (1.3%) in the ciprofloxacin arm and 21 (2.7%) in the placebo arm (RR 0.49, 95% CI 0.19-1.23). No patients in the ciprofloxacin arm and nine (1.2%) in the placebo arm developed pyelonephritis (RR 0.05, 95% CI 0.003-0.93). No patients developed urosepsis and no serious adverse events occurred.

A single dose of ciprofloxacin reduced the risk of post-SWL pyelonephritis, with a modest absolute benefit. The patient importance of this reduction depends on individual preferences in weighing a small absolute reduction in risk against the potential harms and resistance-related implications of antibiotic use. Results from the APPEAL trial will inform global practice and support evidence-based decision-making for patients undergoing SWL.