Local guidelines for empirical therapy combined with principles of antimicrobial prescribing are pivotal for the appropriateness of prescriptions.

Prescribers and hospital pharmacists should follow local guidelines (see chapter 4) and apply the principles of antimicrobial prescribing.

(1) For empirical prescribing: “Start Smart Then Focus”(BSAC)  

Start smart

Only start antibiotics if there is high clinical probability of bacterial infection

• Take a thorough drug allergy history to assess for patient hypersensitivity reactions and potential contraindications.
• Initiate prompt, effective antibiotic treatment within one hour of diagnosis (or as soon as possible) in patients with severe sepsis or life-threatening infection.
• Comply with local prescribing guidance
• Document on the drug chart and in the clinical notes: clinical indication, dose, and route as per severity/patient factors
• Include review/stop date or duration
• Ensure relevant microbiological specimens are taken!

Then focus

Focus therapy based on a clinical review including microbiology results and decide at 48-72 hours post initiation of therapy, whether to

• STOP antimicrobials?
  If no evidence of infection.
• Switch from IV to oral?
  If satisfactory clinical response and no infection- or patient-specific indications for continuing intravenous antibiotic therapy.
• Change antibiotics?
  From empirical to targeted therapy (guided by microbiology results).
• (If none of the above) continue?
  Consider referral to infectious diseases specialist).
• Outpatient parenteral antibiotic therapy (OPAT)?
  IV antibiotic treatment might be continued on an outpatient basis in patients who are clinically well and safe to do so. Check for regional OPAT services.

(2) For perioperative antibiotic prophylaxis: Swissnoso

General principles of perioperative (surgical) prophylaxis include:

• Clean surgery without the placement of a prosthesis or implant does not warrant perioperative prophylaxis
• Clean-contaminated or contaminated surgery, or surgery with placement of implants, require perioperative prophylaxis
• Perioperative prophylaxis is most effective if applied 0-60 min before knife to skin (vancomycin and fluoroquinolones 60-120 min).
• Single doses of antimicrobials should not be adapted to renal function.
• Redosing is required in interventions with a duration over two times the half-life of the used antibiotic agent.
• If penicillin allergy can be excluded, cephalosporin, instead of other less effective options, can be used in most cases.
• In general, prophylaxis over 24h is not associated with an additional benefit but might increase the risk of antimicrobial resistance selection and adverse events such as renal failure and CDI.

(3) Metrics

Monitoring trends in antimicrobial consumption and audit results can indicate whether prescribing has improved.
If there is no visible effect, ensure that local practice and the further development of ASP are discussed in relevant committees.

Swissnoso provides an exemplary guideline on perioperative prophylaxis.