No call for hyperbaric oxygen therapy in diabetic ulcers
medwireNews: Hyperbaric oxygen therapy (HBOT) does not significantly improve wound healing or reduce major amputation rates when added to usual care in patients with diabetes and ischemic lower extremity ulcers, Dutch study data show.
For the DAMO2CLES (Does Applying More Oxygen [O2] Cure Lower Extremity Sores?) trial, patients with type 1 or 2 diabetes with an ischemic wound to the lower extremities were randomly assigned to receive standard care with HBOT (n=60) or standard care alone (n=60) and were followed up for 12 months.
Standard care involved an open or endovascular revascularization, where applicable, and optimal conservative treatment with antibiotics, anticoagulants, and glycemic control, as well as local wound treatment, while HBOT comprised up to 40 sessions of 90 minutes in a multiplaced chamber, pressurized at 2.4 or 2.5 atmospheres absolute during which patients were breathing 100% oxygen, with three 5 minute breaks to prevent oxygen intoxication.
At the end of the follow-up period there were no significant differences between the patients assigned to HBOT and those assigned to standard care in the rates of limb salvage (88 vs 78%), complete wound healing (50 vs 47%), and amputation-free survival (AFS; 82 vs 68%). There was also no difference in the median time to complete healing of the index ulcer (202 vs 217 days).
Dirk Ubbink (Academic Medical Center, Amsterdam) and co-investigators note that 35% of patients assigned to HBOT were unable to complete the protocol as planned, that is, until complete wound closure or at least 30 sessions.
They say that this “possibly reflects the bad overall medical condition of patients with diabetic ulcers and [peripheral arterial occlusive disease].”
Indeed, the researchers add that daily visits to a HBOT centre were “too burdensome” for some patients. “As such, lack of ability to adhere to a strenuous HBOT regimen could mitigate the efficacy of HBOT in clinical practice, even if HBOT would improve clinical outcomes under optimal circumstances,” they write.
Nonetheless, a per-protocol analysis of patients who did complete HBOT showed that they had a significantly lower rate of major amputations (5 vs 22%) and a significantly higher rate of AFS (92 vs 67%) than patients who received standard care.
But Ubbink et al caution that per-protocol analyses are subject to selection bias and the findings could “merely be due to the selection of a subset of patients with a better general condition who might have had a favorable outcome even without HBOT.”
There were two HBOT-related serious adverse events: an oxygen-induced seizure and a barotraumatic perforation of the tympanic membrane. Both cases resolved without long-term complications.
The study findings are published in Diabetes Care.
By Laura Cowen
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