Hyperbaric Oxygen Therapy for Chronic Ankle Wounds in Diabetic Patients
Consider hyperbaric oxygen therapy (HBOT) as an adjunctive treatment for this patient's chronic ankle wound, but only if the wound is ischemic (not purely neuropathic), has failed to respond to best standard care including appropriate offloading and debridement, and only after revascularization has been performed if peripheral arterial disease is present. 1, 2
Critical Prerequisites Before HBOT Consideration
Before even discussing HBOT, ensure the following foundation is in place:
Vascular assessment is mandatory: Measure ankle-brachial index (ABI) and toe pressures to determine if ischemia is present 1. HBOT is only recommended for ischemic or neuro-ischemic ulcers, not purely neuropathic wounds 1.
Revascularization must come first: If peripheral arterial disease is present, the American College of Cardiology explicitly states that HBOT should only be considered after successful revascularization has been performed 2. Never delay revascularization to pursue HBOT 2.
Best standard care must be optimized and failing: This includes sharp debridement of necrotic tissue and callus, appropriate pressure offloading, infection control, and glycemic optimization 1. HBOT is never a standalone treatment 2.
When HBOT May Be Appropriate
The International Working Group on the Diabetic Foot (IWGDF) provides specific guidance:
Consider HBOT for non-healing ischemic diabetic foot ulcers that have not responded despite best standard care (weak recommendation, moderate quality evidence) 1.
The wound should demonstrate inadequate healing response: One high-quality study excluded patients who had >30% wound area reduction during a 2-week period of good standard care, suggesting HBOT is reserved for truly refractory wounds 1.
Moderate ischemia parameters: Evidence supports use in wounds with ABI <0.9 or toe-brachial index <0.7 but toe pressure >50 mmHg 1.
Important Limitations and Contraindications
HBOT is NOT appropriate for:
Purely neuropathic ulcers without ischemia: Recent evidence shows no benefit in healing diabetic foot ulcers in the absence of ischemia 1.
Patients on hemodialysis: Research demonstrates HBOT is significantly less effective in diabetic patients requiring hemodialysis, with all "poor responders" in one study having both diabetes and hemodialysis 3.
Post-surgical wounds: The IWGDF recommends against using HBOT for non-surgical diabetic foot ulcers 1.
Evidence Quality and Realistic Expectations
The evidence base has significant limitations:
Recent high-quality trials have been negative: Two large outcome-blinded RCTs showed no additional benefit of HBOT above usual care, and both had methodological limitations including being underpowered 1.
Mixed historical evidence: While early studies showed benefit, a large retrospective cohort study of 83 U.S. centers concluded HBOT did not prevent amputation or improve healing likelihood 1.
Only one positive recent trial: The American Diabetes Association notes only one positive RCT in the last decade showing increased healing rates at 9 and 12 months 1.
Response rate is modest: Even in selected patients, 30-40% of Wagner Grade 3-4 diabetic foot ulcers treated with HBOT fail to heal by 24 weeks 4.
Practical Considerations
Logistical barriers include:
High cost without proven cost-effectiveness: Treatment courses run into tens of thousands of dollars 1, 4.
Time-intensive protocol: Requires daily sessions for 60-90 minutes at 2.5-2.8 atmospheres absolute pressure, 5 days per week, for 6-10 weeks 3, 5.
Limited availability: Requires specialized facilities and equipment, potentially requiring patient transfer 1, 6.
Potential oxidative stress: One study showed increased malondialdehyde and oxidative stress markers in ulcer tissue after 2 weeks of HBOT, which may offset long-term benefits 5.
Alternative to Systemic HBOT
Do not use topical oxygen therapy as a substitute for systemic HBOT in this patient 1. The IWGDF recommends against topical oxygen therapy for diabetic foot ulcers (weak recommendation, low quality evidence) 1. However, the American Diabetes Association notes that recent high-quality RCTs and systematic reviews support topical oxygen therapy efficacy at 12 weeks, with the advantage of home-based treatment 1.
Common Pitfalls to Avoid
Do not delay standard wound care including surgical debridement, infection control, and pressure offloading to pursue HBOT 2, 7.
Do not use HBOT as monotherapy for peripheral arterial disease or critical limb-threatening ischemia 2.
Do not continue indefinitely: Sessions should be continued until complete healing is observed or non-response is confirmed, typically assessed by 4 weeks of preliminary healing response 8, 4.
Recognize that normobaric oxygen is not equivalent to hyperbaric oxygen therapy 8.