Best practices for appropriate use of antibiotics in surgery

Antibiotic prophylaxis

  1. Antibiotics alone are unable to prevent surgical site infections. Strategies to prevent surgical site infections should always include attention to infection prevention and control strategies including correct and compliant hand hygiene practices, meticulous surgical techniques and minimization of tissue trauma, hospital and operating room environments, instrument sterilization processes, perioperative optimization of patient risk factors and appropriate management of surgical wounds.
  2. Antibiotic prophylaxis should be administered for operative procedures that have a high rate of postoperative surgical site infection, or when foreign materials are implanted.
  3. Antibiotic given as prophylaxis should be effective against the aerobic and anaerobic pathogens most likely to contaminate the surgical site i.e., Gram-positive skin commensals or normal flora colonizing the incised mucosae.
  4. Antibiotic prophylaxis should be administered within 120 minutes prior to the incision. However, administration of the first dose of antibiotics beginning within 30-60 minutes before surgical incision is recommended for most antibiotics (e.g. Cefazolin), to ensure adequate serum and tissue concentrations during the period of potential contamination. Obese patients ≥ 120 kg require higher doses of antibiotic.
  5. A single dose is generally sufficient. Additional antibiotic doses should be administered intraoperatively for procedures >2-4 hours (typically where duration exceeds 2 half-lives of the antibiotic) or with associated significant blood loss (>1.5L).
  6. There is no evidence to support the use of post-operative antibiotic prophylaxis.
  7. Each institution is encouraged to develop guidelines for the proper surgical prophylaxis.


Antibiotic therapy

  1. The source of infection should always be identified and controlled as soon as possible.
  2. Antibiotic empiric therapy should be initiated after a treatable surgical infection has been recognized, since microbiological data (culture and susceptibility results) may not be available for up to 48-72 hours to guide targeted therapy.
  3. In critically ill patients empiric broad-spectrum therapy to cover all likely pathogensshould be initiated as soon as possible after a surgical infection has been recognized. Empiric antimicrobial therapy should be narrowed once culture and susceptibility results are available and/or adequate clinical improvement is noted
  4. Empirical therapy should be chosen on the basis of local epidemiology, individual patient risk factors for MDR bacteria and Candida, clinical severity, and infection source.
  5. Specimens for microbiological evaluation from the site of infection are always recommended for patients with hospital-acquired or with community-acquired infections at risk for resistant pathogens (e.g. previous antimicrobial therapy, prior infection or colonization with a MDR, XDR and PDR pathogens) and in critically ill patients. Blood cultures should be performed beforethe administration of antibiotics in critically ill patients.
  6. Antibiotics dose should be optimized to ensure that PK-PD targets are achieved. This involves prescribing of an adequate dose, according to the most appropriate and right method and schedule to maximize the probability of target attainment.
  7. The appropriateness and need for antimicrobial treatment should be re-assessed daily.
  8. Once source control is established, short courses of antibiotic therapy are as effective as longer courses regardless of signs of inflammation.
  9. Failure of antibiotic therapy in patients having continued evidence of active infection may require a re-operation for a second source control intervention.
  10. Biomarkers such as procalcitonin may be useful to guide duration and/or cessation of antibiotic therapy in critically ill patients.