Multicentre, Adaptive, Double-Blind, Three-Arm, Placebo-Controlled, Noninferiority Trial Examining Antimicrobial Prophylaxis Duration in Cardiac Surgery: CALIPSO Trial

Administration of antibiotics before incision ("surgical antimicrobial prophylaxis") is a critical infection prevention strategy in cardiac surgery. Extending doses of prophylaxis into the postoperative period is common practice in cardiac surgery; however, the benefit has not been clearly established and may drive emergence of antimicrobial resistance and lead to patient harm. Recent World Health Organization guidelines have recommended that prophylaxis be limited to the intraoperative period only for all surgical procedures, but potential benefits with extending prophylaxis postoperatively in cardiac surgery were noted. The efficacy, safety, and microbiome impact of differing durations of surgical antimicrobial prophylaxis in cardiac surgery have not been established.