Wounds can be caused by many different problems, with diabetes being one of the common causes of wounds that are not healing. The term ‘chronic wound’ may be used – in medical terms this means a wound has been a persistent, long-term wound.
Problem wounds have not progressed through the different stages of wound healing. Often these wounds are low in oxygen. This means the body’s ability to heal or fight infection are affected. White blood cells, which fight infection, need oxygen to be able to kill bacteria. Some of the processes which re-build tissue, need oxygen to be able to progress.
During HBO, the area surrounding a chronic wound has high levels of oxygen, whilst the wound itself is low in oxygen. This difference in oxygen levels encourages growth of small blood vessels into the wound. This in turn increases oxygen levels which helps the body’s own functions to fight infection and to re-build damaged tissue.
These processes all take time. A person having HBO to help heal a problem wound will usually have 20-40 HBO sessions, once per day, five days per week. Not much difference will be obvious for the first two weeks of treatment. Good wound care, proper foot wear and other factors such as good control of diabetes are also important in helping a wound heal.
We routinely treat selected patients here with problematic poor healing wounds. This is currently NHS funded with consultant referral.
Oxygen plays a key role in many of the steps throughout wound healing.
- During the initial inflammatory phase of wound healing oxygen is essential for platelet aggregation.
- During the proliferative phase high levels of oxygen are required for angiogenesis to occur.
- Finally, during the remodelling phase it is essential for collagen formation and to aid the strengthening of the extracellular matrix.
Wounds that do not heal with standard medical and surgical therapy are often underperfused with resultant poor oxygen tensions within the tissue. They may also be chronically infected. This infection may be the cause of hypo-perfusion (by interrupting wound healing) or may perpetuate the chronic wound hypoxia.
Hyperbaric Oxygen Therapy (HBOT) increases the diffusion gradient of oxygen in subcutaneous tissue by about 10-20 fold to allow hyperoxygenation of ischaemic tissue thus:
- Reducing inflammatory cytokines
- Stimulating growth factors
- Enhancing antibacterial activity, including production of oxygen free radicals
- Reducing non-specific activation of inflammatory cells
- Promoting transmigration of stem cells to infected wound tissue
- Altering leukocyte-endothelial adhesion
- Promote collagen formation
This is based on numerous animal and clinical studies.(Eggleton,2015)
However, it is important to assess each wound as some chronic wounds will not respond to HBOT. Each wound is assessed with TCOM (Transcutaneous Oxygen Monitoring). Each probe detects the baseline oxygen tension in the skin, which is used as a marker of perfusion. A rise in oxygen tension should be seen as the patient is exposed to increased oxygen levels.
Diabetic Foot Ulcers
We routinely treat diabetic foot ulcers in patients who have failed to respond to treatment with standard multidisciplinary foot clinic input, in particular to try and avoid surgical intervention if at all possible.
HBOT should be used in conjunction with gold standard wound care and in these circumstances evidence suggests that HBO will improve healing. There is also evidence with some studies where long term follow up occurred that a continued benefit was seen. (Eggleton,2015)
Further information regarding the Referral and Funding process can be found here.
In summary there are some key papers:
Doctor et al 1995 – Thirty patients were randomised to receive HBOT or conventional treatment alone. The HBOT was an unconventional treatment protocol. However, there was a significant reduction in amputation above the ankle joint in the HBOT group compared with the control.
Faglia et al 1996 – A significant reduction of major amputations in patients with diabetic foot ulcers was seen in the HBOT group.
Abidia 2001 – Investigated the therapeutic effect of HBOT on diabetic foot ulcers in patients with peripheral arterial disease. At 1 year follow up the majority of patients in the HBOT group remained healed, whereas no healed wounds were present in the control group. However, this was a very small trial with only 16 patients.
Kalani et al 2002 – Compared outcomes of patients with diabetic foot ulcers treated with or without HBOT at 3 years. Those in the HBOT group had better outcomes – healed wounds, less amputations and no deaths.
Treatment entails up to 40 sessions of HBO over a 8 week period subject to response to treatment.
Eggleton P, Bishop A, Smerdon G
“Safety and efficacy of hyperbaric oxygen therapy in chronic wound management:current evidence”
Due for publication
Please email firstname.lastname@example.org to request from authors
Doctor N, Pandya S, Supe
“Hyperbaric oxygen therapy in diabetic foo
J Postgrad Med
Faglia E, Favales F, Aldeghi A, et al
“Adjunctive systemic hyperbaric oxygen therapy in treatment of severe prevalently ischemic diabetic foot ulcer. A randomised study “
Abidia A, Laden G, Kuhan G et al
“The role of hyperbaric oxygen therapy in ischemic diabetic lower extremity ulcers:a double-blind randomised-controlled trial”
Eur J Vasc Endovasc Surg
Kalani M, Jorneskog G, Naderi N, Lind F, Brismar K.
“Hyperbaric oxygen (HBO)therapy in treatment of diabetic foot ulcers. Long-term follow”
J Diabetes Complications
UHMS Hyperbaric Oxygen Therapy Indications 13th Edition