Sample Unna Boot Prescription for Venous Stasis Ulcer
For a venous stasis ulcer, prescribe a zinc-oxide impregnated Unna boot (4-inch wide, 10-yard roll, non-sterile) with 30-40 mmHg compression, changed weekly, after confirming ankle-brachial index >0.9 to exclude arterial disease. 1, 2
Patient Demographics and Diagnosis
- Patient: Adult (age ≥55 years typical for venous ulcers) 3
- Gender: Male or Female
- Diagnosis: Venous stasis ulcer, lower leg (ICD-10: I83.90) 4, 3
Pre-Application Requirements
Measure ankle-brachial index (ABI) before any compression application: 1, 2
- ABI >0.9: Proceed with full compression at 30-40 mmHg 1, 2
- ABI 0.6-0.9: Reduce compression to 20-30 mmHg 1, 2
- ABI <0.6: Compression contraindicated; arterial revascularization required first 1, 2, 5
Critical caveat: Approximately 16% of venous ulcer patients have unrecognized arterial disease, making ABI assessment mandatory. 1, 2
Prescription Details
Rx: Zinc-Oxide Impregnated Unna Boot
- Product: Zinc-oxide paste bandage, 4-inch width, 10-yard roll, non-sterile
- Quantity: Dispense 12 rolls (3-month supply at weekly changes)
- Refills: 3 refills (1-year total supply)
Application Instructions
Compression level: 30-40 mmHg inelastic compression 1, 2
Application technique - negative graduated compression (higher pressure at calf than ankle): 1, 2, 6
- Start at base of toes (open-heel technique allows normal footwear and ankle mobility) 7
- Wrap in spiral fashion from toes to just below knee
- Apply 50% overlap with each turn
- Achieve higher compression at calf (30-40 mmHg) than at ankle - this negative graduated technique produces superior venous ejection fraction compared to traditional graduated compression 1, 2, 6
- Leave heel exposed to monitor skin condition and maintain ankle mobility 7
- Cover with elastic outer wrap for additional support
Dressing Change Interval
Change weekly (every 7 days): 8
- Weekly changes are the standard for long-term Unna boot treatment in venous ulcers 8
- More frequent changes only if excessive drainage, infection suspected, or patient discomfort 8
Concurrent Wound Care
- Maintain moist wound environment with protective topical dressing 2, 6
- Perform surgical debridement if necrotic tissue present (gold standard for wound bed preparation) 2
- Control periwound dermatitis 2, 6
- Treat infection aggressively with systemic antibiotics if cellulitis, >1×10⁶ CFU, or difficult-to-eradicate bacteria present 2
Adjunctive Therapy
Add pentoxifylline 400 mg orally three times daily: 2, 6, 5
- Pentoxifylline plus compression yields 1.56 times higher healing rate versus compression alone 2, 6
- Counsel patient about gastrointestinal side effects (nausea, indigestion, diarrhea; RR 1.56) 2, 6
Patient Instructions
Leg elevation: Elevate legs above heart level when resting 6
Exercise: Perform ankle-pump exercises even when boot is in place to activate calf muscle pump 7
Ambulation: Continue normal walking - the open-heel design maintains ankle mobility and prevents "frozen ankle" 7
Footwear: Normal shoes can be worn with open-heel technique 7
Avoid: Prolonged standing 6
Monitoring and Reassessment
If ulcer fails to show ≥50% reduction after 4-6 weeks: 2, 5
- Perform duplex ultrasound to document venous reflux ≥500 ms 1, 6
- Consider endovenous ablation if reflux confirmed at saphenofemoral/saphenopopliteal junction and target vein ≥4.5 mm 6
- Consider advanced therapies: split-thickness skin grafting, bioengineered cellular therapy, or negative pressure wound therapy 2, 5
Long-Term Prevention
After healing, transition to compression stockings (30-40 mmHg) worn indefinitely to prevent recurrence, as venous ulcers recur in 20-28% of patients within 5 years despite successful treatment. 6, 8