General principles

The prophylactic antibiotic regimens recommended for specific procedures are directed against the organism(s) most likely to cause postoperative infection. Cefazolin is the preferred drug for the majority of procedures that require prophylaxis.

The antibiotic regimens may need to be modified according to patient factors (eg presence of infection, colonisation with multidrug-resistant bacteria) and environmental factors (eg organisms causing infection within the institution and their susceptibilities).

Most postoperative infections are caused by organisms that already colonise the patient; these may include multidrug-resistant bacteria when there has been prolonged hospitalisation, recent travel or repeated antibiotic use. See Preventing postoperative Staphylococcus aureus infections and Preventing postoperative infections caused by multidrug-resistant Gram-negative bacteria.

There is little evidence that patients colonised with vancomycin-resistant enterococci (VRE) require modified prophylaxis regimens and the recommendations in these guidelines are appropriate.

Avoid using broad-spectrum antibiotics, including broad-spectrum cephalosporins (eg cefotaxime, ceftriaxone), for surgical antibiotic prophylaxis.

For specific advice about the role of gentamicin in surgical antibiotic prophylaxis, see here. For specific advice about the role of vancomycin and teicoplanin in surgical antibiotic prophylaxis, see here.