Antibiotic prophylaxis - Colorectal Surgery
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 consultant microbiologist pre-operatively for complex issues including:
• Carriage of or previous infection with resistant organisms, other than MRSA.
• Where eGFR is <20ml/min.
| Procedure | Recommended | Penicillin Allergy or MRSA |
| Colorectal surgery |
Gentamicin IV (dose as per table)
|
Gentamicin IV (dose as per table) + Metronidazole 500mg IV + Teicoplanin 400mg IV |
Gentamicin surgical prophylaxis dosing table:
Height is used to estimate ideal bosy weight, dosing equates to approximately 3mg/kg capped at 300mg
*When height <5 feet, use actual body weight to calculate gentamicin dose.
| FEMALE | ||
| Height (Feet /Inches) | Height (cm) | Gentamicin dose (mg) |
| <5' | <152cm | *3mg/kg(max 300mg) |
| 5' - 5'3'' | 152 - 163 | 160 |
| >5'3'' - 5'8'' | >163 - 175 | 200 |
| >5'8'' - 6'1'' | >175 - 188 | 240 |
| >6'1'' - 6'4'' | >188 - 193 | 280 |
| >6'4'' | > 193 | 300 |
| MALE | ||
| Height (Feet /Inches) | Height (cm) | Gentamicin dose (mg) |
| <5' | <152cm | *3mg/kg(max 300mg) |
| 5' - 5'1'' | 152 - 155 | 160 |
| >5'1'' - 5'6'' | >155 - 168 | 200 |
| >5'6'' - 5'11'' | >168 - 180 | 240 |
| >5'11'' - 6'4'' | >180 - 193 | 280 |
| >6'4'' | > 193 | 300 |
IV Antibiotic administration and re-dosing guidance
| Antibiotic | Administration | Re-dosing: prolonged surgery | Re-dosing: >1.5L blood loss |
| Amoxicillin | Bolus over 3-5 minutes | Repeat 1g after 4 hours of initial dose | Repeat 1g |
| Gentamicin | Bolus over 3-5 minutes | Repeat original dose 8 hours after initial dose if eGFR >60 | Give 50% of original dose |
| Metronidazole | Infuse over 20 minutes | Repeat original dose after 8 hours of initial dose | Repeat original dose |
| Teicoplanin | Bolus over 3-5 minutes | No redosing required | 200mg (50% original dose) if >1.5L within first hour of surgery |