Surgical Antimicrobial Prophylaxis

Surgical antimicrobial prophylaxis is antibiotic administration before skin incision to reduce surgical infection risk. The Australian Therapeutic Guidelines recommend preoperative intravenous cefazolin within 60 minutes before skin incision and intraoperative redosing every 3-4 hours for prolonged operations. The benefit of continuing antibiotics after wound closure in cardiac surgery remains uncertain. All trial participants receive standard intraoperative antimicrobial prophylaxis. Longer antimicrobial exposure may increase harms including antimicrobial resistance, C. difficile infection, microbiome disruption, acute kidney injury, and costs.