General Principles for Prescribing Antibiotic Prophylaxis

  • Surgical prophylaxis aims to reduce surgical site and healthcare-associated infection so reducing surgical morbidity (and mortality)
  • Antimicrobial prophylaxis should only be prescribed for procedures that are “recommended” or “consider” in SIGN 104 guideline.
  • Antimicrobial Prophylaxis is usually a single dose given within 60 minutes prior to the start of the procedure/skin incision.  Repeat dosing may be required if the procedure lasts more than 4 hours or if there is intra-operative blood loss >1.5 litres.  See table below.
  • Restrict the use of agents with increased capacity for promoting C. difficile infection (cephalosporins, clindamycin, co-amoxiclav, quinolones) where possible considering the benefits and risks of use.
  • It is important to assess the nature of the reaction for those patients labeled with a penicillin allergy.  Consider de-labelling where indicated.
  • Patients with complex issue including multi-drug resistant carriage should be discussed with a Microbiologist pre-operatively.
  • For patients colonized with MRSA, decolonisation therapy following local policy should be used prior to surgery when possible.

General surgery

Antibiotic Dosing Table
Antibiotic Dose Administration Prolonged surgery >1.5L blood loss (redose after fluid replacement)
Amoxicillin 1g

IV bolus over   3-5 mins

If surgery >4 hours, Repeat original dose Repeat original dose
Gentamicin See below

Doses up to 300mg - IV bolus over 3-5 mins.

Doses above 300mg - IV infusion in 100ml of normal saline over 20-30 mins

If surgery lasts > 8 hrs AND eGFR >60ml/min, then redose with full original dose Give 50% of original dose
Metronidazole 500mg IV infusion over minimum of 20 mins

If surgery >8 hours,

Repeat original dose
Repeat original dose
Teicoplanin

<65kg - 400mg

≥65kg - 800mg

IV bolus over 3-5 mins No repeat dosing required Give 50% of original dose if ≥1.5L blood loss within the first hour of operation
Prophylactic Gentamicin Dosing

Avoid if eGFR <20:  seek advice on alternative from microbiology

In renal transplant patients avoid Gentamicin and seek advice from microbiology or renal team

Height (feet and inches) Height (cm) Gentamicin dosing (mg)
Males Females
4'8 - 4'10" 142 - 147 160 140
4'11" - 5'3" 148 - 160 180 160
5'4" - 5'10" 161 - 178 240 200
5'11" - 6'2" 179 - 188 300 260
≥ 6'3" ≥ 188 300 300
Procedures
Procedure

SIGN 104 and  NHS Fife Recommendation

Suggested antibiotic(s)
UPPER GI
Oesophageal Recommended Amoxicillin* + Gentamicin + Metronidazole
Stomach and duodenal Recommended
Gastric bypass Recommended
Small intestinal Recommended
HEPATOBILIARY
Bile duct Recommended

Amoxicillin* + Gentamicin + Metronidazole

~High risk: intra-op cholangiogram, bile spillage, conversion to laparotomy, acute cholecystitis/pancreatitis, jaundice, pregnancy, immunosuppression, insertion of prosthetic devices

Gall bladder surgery - open Recommended
Gall bladder surgery - laparoscopic Not recommended but should be considered in high risk patients~
LOWER GI
Appendicectomy Highly recommended Amoxicillin* + Gentamicin + Metronidazole
Colorectal surgery Highly recommended
ABDOMEN
Hernia repair groin, inguinal / femoral with or without mesh Not recommended  
Hernia repair groin, laparoscopic with or without mesh Not recommended
Hernia repair, incisional with or without mesh Not recommended
Open/laparoscopic surgery with mesh (e.g. gastric band or rectoplexy) Not recommended but should be considered in high risk patients

If necessary:

Amoxicillin* + Gentamicin + Metronidazole

Splenectomy Not recommended but should be considered in high risk patients

If necessary:

Amoxicillin* + Gentamicin + Metronidazole

High risk: immunosuppressed

Note, not carried out as an elective procedure in Fife. If undertaken would be as part of a procedure where suitable prophylaxis would already be given.

Clean-contaminated procedures where no specific evidence is available Recommended Amoxicillin* + Gentamicin + Metronidazole
  • *Patients who have a true allergy to penicillin or who are MRSA positive should be given teicoplanin instead of amoxicillin.
  • If a patient is on treatment and requires surgery the patient may not need additional prophylaxis if the antibiotic(s) they are on cover(s) the pathogens that would be expected to cause an SSI for that procedure.  However, it must be ensured that treatment antibiotics are not delayed/missed while the patient is in theatre.