Surgical Prophylactic Antimicrobials
General principles
Surgical prophylaxis aims to reduce surgical site and healthcare associated infection so reducing surgical morbidity (and mortality). Growing evidence indicates that aspects of prescribing practice are also associated with healthcare associated infections, notably Clostridium difficile infection with cephalosporin use. SIGN 104, published July 2008, outlines which surgical procedures require prophylactic antibiotics and how and when these should be administered. In conjunction with surgical specialists and consultant microbiologists, the Antimicrobial Management Team (AMT) have formulated a local prophylaxis policy for use in NHS Ayrshire & Arran.
N.B. These guidelines refer to prophylaxis only. In patients with surgical infection, please follow treatment guidelines.
- Indication and duration of prophylaxis including when antibiotics should be recommended or considered should comply with SIGN 104.
- Timing of antibiotic(s):
- Optimum timing is ≤30 minutes prior to skin incision (usually in anaesthetic room at induction of anaesthesia)
- Sub-optimal if >1 hour prior to skin incision or post-skin incision.
- Recording of antibiotic administration: In “once only” section of drug prescription form or the anaesthetic record where appropriate.
- Choice of agent:
- Use the IV route unless otherwise specified in the text
- Avoid cephalosporins and use appropriate narrow spectrum agent(s) when possible
- Provision of alternatives when patient is beta-lactam allergic.
- Frequency of administration: Usually single dose. 2nd dose only if:
- >1.5 litre intra-operative blood loss. Re-dose following fluid replacement giving same dose for all agents EXCEPT gentamicin (give half dose, see below) and teicoplanin (do not re-dose). In head and neck procedures, do not re-dose gentamicin.
- Operation prolonged:
- >4 hours, re-dose flucloxacillin
- >8 hours re-dose flucloxacillin, co-amoxiclav, metronidazole and, if eGFR >60ml/min gentamicin (at full dose, see point 10 below)
- Do not re-dose teicoplanin or clarithromycin
- In head and neck procedures, do not re-dose gentamicin.
- Document reason for antibiotic administration beyond first dose (as above).
- De-colonisation therapy prior to surgery when MRSA positive.
- Complex individual prophylaxis issues should be discussed with microbiology pre-operatively.
- Post-operative infection. Follow infection management guidelines. If gentamicin required, please follow treatment guidelines using dosing calculator. Administer the first treatment dose 8-12 hours after the prophylactic dose was given, checking concentrations 6-14 hours post treatment dose.
- Prophylactic gentamicin dosing is based on patient height and approximates to 3mg/kg ideal body weight, capped at 300mg. This allows bolus administration in the anaesthetic room. The dosing table below should be used to calculate dosing for all prophylaxis indications.
Specific procedures
Guideline reviewed |
March 2024 |
Page updated |
September 2024 |