How to Administer a Vancomycin Retention Enema
For vancomycin retention enema administration, use 500 mg vancomycin diluted in 100 mL normal saline, administered every 6 hours via a Foley catheter with the balloon inflated to retain the solution for at least 60 minutes. 1
Preparation and Dosing
Standard Dosing Protocol
- Dose: 500 mg vancomycin 1
- Volume: 100 mL normal saline (per IDSA/SHEA guidelines) 1
- Frequency: Every 6 hours 1
- Alternative volume: Some evidence suggests 500 mL may be more effective than 100 mL, though this contradicts current guideline recommendations 2
When to Use Retention Enema
Vancomycin retention enema is indicated specifically for: 1
- Fulminant C. difficile infection with ileus present
- Patients unable to take oral medications
- Conditions where oral vancomycin cannot reach the colon (Hartmann's pouch, ileostomies, colon diversions) 3
Always combine with IV metronidazole 500 mg every 8 hours when treating fulminant CDI, particularly if ileus is present. 1
Administration Technique
Equipment Needed
- 18 French Foley catheter with 30 cc balloon 2
- 500 mg vancomycin powder
- 100 mL normal saline (or 500 mL based on emerging evidence) 1, 2
- Syringe for balloon inflation
- Clamp for catheter
Step-by-Step Procedure
Patient positioning: Place patient in left lateral position to facilitate retention 4
Catheter insertion: Insert 18F Foley catheter into the rectum 2
Balloon inflation: Inflate the balloon with 30 cc to create a seal and prevent leakage 2, 5
Solution instillation: Slowly instill the vancomycin solution (500 mg in 100 mL normal saline) through the catheter 1
Retention period: Clamp the catheter and retain the solution for at least 60 minutes 2
Removal: After retention period, deflate balloon and remove catheter
Critical Clinical Considerations
Combination Therapy Requirements
Never use vancomycin enema as monotherapy in fulminant CDI. 1 The regimen must include:
- Vancomycin 500 mg rectally every 6 hours 1
- Plus IV metronidazole 500 mg every 8 hours 1
- Consider oral/NG vancomycin 500 mg four times daily if any oral route is feasible 1
Important Caveats
Volume controversy: While IDSA/SHEA guidelines recommend 100 mL 1, observational data suggests higher volumes (500 mL) with retention technique may be more effective 2. Lower volumes (100 mL) with lower doses (125-250 mg) showed no efficacy in some case series 2. However, follow the guideline recommendation of 100 mL unless institutional protocols specify otherwise.
Limited colonic distribution: It remains unclear whether sufficient vancomycin reaches beyond the left colon with rectal administration 1. This is why combination with IV metronidazole is essential in fulminant disease 1.
Systemic absorption risk: High-dose vancomycin with prolonged exposure, renal failure, or disrupted intestinal integrity can lead to measurable serum concentrations 1. Monitor trough serum vancomycin levels in these circumstances to rule out drug accumulation 1.
Monitoring Parameters
- Clinical response (typically requires 3-5 days) 6
- Rising WBC count (≥25,000) or lactate (≥5 mmol/L) suggests treatment failure and potential need for surgery 1
- Serum vancomycin levels if renal impairment or prolonged therapy 1
Alternative Routes When Enema Fails
If retention enema cannot be administered or is ineffective: 1