Antibiotic Prophylaxis Before Shock Wave Lithotripsy
We are currently conducting an international multicenter randomized controlled trial (RCT) of antibiotic prophylaxis before shock wave lithotripsy (SWL), the APPEAL trial. The APPEAL trial is a large, two arm, blinded placebo controlled trial that will recruit over 1,400 patients. Our primary outcome is a composite of positive post-SWL urine culture (≥ 105 CFU/ ml), with symptoms of cystitis (defined as new onset burning sensation or pain with voiding, frequency, urgency), or pyelonephritis or urosepsis (hospital admission with fever ≥38.5 C) within 2 weeks of SWL. Secondary analyses include individual components of our primary outcome and a pre-defined exploratory analysis to identify pre-operative characteristics that predict infection. We have recruited approximately 400 patients in Canada and over 200 patients in Finland thus far. Recruitment is also underway in Denmark, and will begin in Saudi Arabia and Brazil shortly.
The results of our RCT, whether positive or negative, will contribute significantly to the existing literature. If the study results show a benefit to antibiotic use the expected impact on patient care will be to reduce rates of infectious complications. Conversely, a null study will provide the strongest evidence against routine prophylaxis in the literature to date and potentially decrease the unnecessary use of antibiotics among patients undergoing SWL. Consequently, this would represent a cost savings to the healthcare system and may reduce the risk antibiotic resistant bacteria.
