General Principles of Prescribing Antibiotics for Surgical Prophylaxis

 

  1. 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. MRSA – See intranet for MRSA infection control policy on de-colonization prior to surgery.

Antimicrobial Recommendations

Procedure Recommended

Penicillin allergy

Penicillin allergy + MRSA

Liver Transplant

At induction:

amoxicillin 1g IV

and 

gentamicin IV dosing (as per chart below) 

and 

metronidazole 500 mg IV

At induction:

ciprofloxacin 400 mg IV 

and 

vancomycin 1g IV

and 

metronidazole 500 mg IV

 

Gentamicin dosing

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

IV antibiotic administration and re-dosing guidance

Antibiotic

Administration

Re-dosing advice prolonged surgery

>1.5 L blood loss

(After giving fluids replacements)

Amoxicillin IV

Infuse 1g over 30 minutes

Repeat original dose after 4 hours and if needed after 8 hours (again)

after initial dose

Repeat original dose

Ciprofloxacin IV

Infuse 400mg over 60 minutes

Repeat original dose at 12 hours after initial dose

Not required

Gentamicin IV

Bolus over 3 to 5 minutes

Repeat original dose 8 hours after initial dose

if eGFR > 60ml/min

Give 50% original dose

Metronidazole IV

Infuse over 20minutes

Repeat original dose 8 hours after initial dose

Repeat original dose

Vancomycin IV

Infuse 1g over 100-120 minutes

Repeat original dose 12 hours after initial dose

Repeat half original dose (e.g. 500mg)