Antibiotic prophylaxis for acute cholecystectomy: PEANUTS II multicentre randomized non-inferiority clinical trial.

Background: Guidelines recommending antibiotic prophylaxis at emergency cholecystectomy for cholecystitis were based on low-quality evidence. The aim of this trial was to demonstrate that omitting antibiotics is not inferior to their prophylactic use.

Methods: This multicentre, randomized, open-label, non-inferiority clinical trial randomly assigned adults with mild-to-moderate acute calculous cholecystitis (immediate cholecystectomy indicated) to 2 g cefazolin administered before incision or no antibiotic prophylaxis. The primary endpoint was a composite of all postoperative infectious complications in the first 30 days after surgery. Secondary endpoints included all individual components of the primary endpoint, other morbidity, and duration of hospital stay.

Results: Sixteen of 226 patients (7.1 per cent) in the single-dose prophylaxis group and 29 of 231 (12.6 per cent) in the no-prophylaxis group developed postoperative infectious complications (absolute difference 5.5 (95 per cent c.i. -0.4 to 11.3) per cent). With a non-inferiority margin of 10 per cent, non-inferiority of no prophylaxis was not proven. The number of surgical-site infections was significantly higher in the no-prophylaxis group (5.3 versus 12.1 per cent; P = 0.010). No differences were observed in the number of other complications, or duration of hospital stay.

Conclusion: Omitting antibiotic prophylaxis is not recommended.