General Principles of Prescribing Antibiotics for Surgical Prophylaxis

  1. Timing. Antibiotics should be administered, or infusion completed within 60 minutes before the procedure or skin incision.
  2. Document doses in the “once only” section of the paper drug administration chart (the kardex) or as STAT orders on HEPMA.
  3. A single dose of antibiotic is recommended. Exceptions are outlined in individual protocols.
  4. No dose adjustment in renal or hepatic impairment is required unless indicated.
  5. Repeat dosing may be required if the operation is prolonged (see table below for re-dosing guidance for individual antibiotics): 
    • The repeat dose is given at the recommended interval from the time the initial dose was administered.
    • Intra-operative blood loss >1.5L. Re-dose following fluid replacement/blood transfusion.
  6. Discuss patients with medical microbiology at pre-op assessment for complex issues including:
    • Carriage of, or previous infection with resistant organisms, other than MRSA.
    • Where eGFR is <20ml/min

     7. MRSA – See intranet for MRSA infection control policy on decolonisation prior to surgery.

Antimicrobial recommendations

 

Procedure

Recommended

Penicillin allergy or MRSA
Lower limb amputation

Flucloxacillin 1g IV

AND

Gentamicin*3mg/kg IV

AND

Metronidazole 500 mg IV

Teicoplanin 800 mg IV 

(600mg IV if patient weight<60Kg)

AND

Gentamicin*3mg/kg IV

AND

Metronidazole 500mg IV 
Vascular Surgery (abdominal and lower limb arterial reconstruction)

Flucloxacillin 1g IV

AND

Gentamicin*3mg/kg IV

Teicoplanin 800 mg IV 

(600mg IV if patient weight<60Kg)

AND

Gentamicin*3mg/kg IV

*Higher dose of gentamicin (5mg/kg) could be considered if operation is of known infected site and treatment dose is needed rather than prophylaxis

Gentamicin dosing

 

Height is used to estimate ideal body weight, dosing equates to approximately 3mg/kg capped at 300mg.

* When height <5 foot or <152cm use actual body weight to calculate gentamicin dose.

FEMALE

Height (Feet/Inches)

Height (cm)

Gentamicin dose

<5’

<152

*3mg/kg (max 300mg)

5' - 5'3''

152 - 163

160 mg

>5'3'' - 5'8''

>163 - 175

200 mg

>5'8'' - 6'1''

>175 - 188

240 mg

>6'1'' - 6'4''

>188 - 193

280 mg

>6’4''

>193

300mg

MALE

Height (Feet/Inches)

Height (cm)

Gentamicin dose

<5’

<152

*3mg/kg (max 300mg)

5' - 5'1''

152 - 155

160 mg

>5'1'' - 5'6''

>155 - 168

200 mg

>5'6'' - 5'11''

>168 - 180

240 mg

>5'11'' - 6'4''

>180 - 193

280 mg

>6'4''

>193

300mg

 

*Higher dose of gentamicin (5mg/kg) could be considered if operation is of known infected site and treatment dose is needed rather than prophylaxis

 

Height is used to estimate ideal body weight, dosing equates to approximately 5mg/kg, capped at 400mg.

* When height <5 foot or <152cm use actual body weight to calculate gentamicin dose.

Avoid gentamicin if eGFR<20mls/min, seek advice on an alternative from microbiology

FEMALE

Height (Feet/Inches)

Height (cm)

Gentamicin dose

<5'

<152

5mg/kg* (max 400mg)

5' - 5'1''

152 - 155

240mg

>5'1'' - 5'6''

>155 - 168

280 mg

>5'6'' - 5'10''

>168 - 178

320 mg

>5'10'' - 6'2''

>178 - 188

360 mg

>6'2''

>188

400mg

MALE

Height (Feet/Inches)

Height (cm)

Gentamicin dose

<5'

<152

5mg/kg* (max 400mg)

5' - 5'4''

152 - 163

280mg

>5'4'' - 5'8''

>163 - 173

320 mg

>5'8'' - 6'1''

>173 - 185

360 mg

>6'1''

>185

400mg

IV antibiotic administration and re-dosing guidance

 

Antibiotic Administration During the procedure >1.5L blood loss
After 4 hours After 8 hours

Flucloxacillin IV

Bolus over 3-5 minutes

Repeat original dose

Repeat original dose

Repeat original dose

Gentamicin  5mg/kg IV

Bolus over 3-5 minutes

Not required

Not required

Give half original dose

Gentamicin 3mg/kg IV

Bolus over 3-5 minutes

Not required

Give half original dose if eGFR >60ml/min

Give half original dose

Metronidazole IV

Infuse over 20 minutes

Not required

Repeat original dose

Repeat original dose

Teicoplanin IV

Bolus over 3-5 minutes

Not required

Not required

Half original dose original dose), if >1.5L blood loss within first hour of operation