Perioperative antibiotic prophylaxis in the treatment of acute cholecystitis (PEANUTS II trial): study protocol for a randomized controlled trial

BACKGROUND The additional value of perioperative antibiotic prophylaxis in preventing infectious complications after emergency cholecystectomy for acute cholecystitis is a much-debated subject in the surgical community. Evidence-based guidelines are lacking, and consequently the use of antibiotic prophylaxis varies greatly among surgeons and hospitals. Recently, high-level evidence became available demonstrating that postoperative antibiotic prophylaxis in patients with acute cholecystitis does not reduce the risk of infectious complications. Preoperative antibiotic prophylaxis in relation to the risk of infectious complications, however, has never been studied. METHODS The PEANUTS II trial is a randomized, controlled, multicenter, open-label noninferiority trial whose aim is to determine the utility of preoperative antibiotic prophylaxis in patients undergoing emergency cholecystectomy for acute calculous cholecystitis. Patients with mild or moderate acute cholecystitis, as defined according the Tokyo Guidelines, will be randomly assigned to a single preoperative dose of antibiotic prophylaxis (2000 mg of first-generation cephalosporin delivered intravenously) or no antibiotic prophylaxis before emergency cholecystectomy. The primary endpoint is a composite endpoint consisting of all postoperative infectious complications occurring during the first 30 days after surgery. Secondary endpoints include all the individual components of the primary endpoint, all other complications, duration of hospital stay, and total costs. The hypothesis is that the absence of antibiotic prophylaxis is noninferior to the presence of antibiotic prophylaxis. A noninferiority margin of 10% is assumed. With a 1-sided risk of 2.5% and a power of 80%, a total of 454 subjects will have to be included. Analysis will be performed according to the intention-to-treat principle. DISCUSSION The PEANUTS II trial will provide evidence-based advice concerning the utility of antibiotic prophylaxis in patients undergoing emergency cholecystectomy for acute calculous cholecystitis. TRIAL REGISTRATION Netherlands Trial Register, NTR5802 . Registered on 4 June 2016.