Hyperbaric Oxygen Therapy (HBOT) is a long-established treatment for decompression sickness, a hazard for both scuba and deep-sea divers. However, it is also used occasionally in the treatment of medical conditions as diverse as burns, gangrene, carbon monoxide poisoning and severe anaemia.
The patient enters a pressure chamber where they breathe 100 per cent oxygen at higher than normal atmospheric pressure. This compares to the usual air that we breathe, which contains only around 21 per cent oxygen.
HBOT for CRPS
Despite understandable scepticism in many quarters, for a number of years HBOT has periodically been touted as a treatment for CRPS. Much of the limited research available in this regard has come from the University of Toronto. In a paper published in 2016, they presented the results of an isolated case:
“A 41-year-old male with one-year history of CRPS [Type 2] of left foot followed by left ankle fracture demonstrated less pain, decreased swelling, less allodynia, and improvement in skin color and range of motion of the lower limb after 3 weeks of HBOT. Patient was back to work for the first time in over a year. HBOT may be considered as a valuable therapeutic tool in the treatment of long-standing CRPS.”
More recently they have published the results of a study involving the use of HBOT in a single case of widespread and essentially therapy-resistent CRPS:
“We describe a case of long-standing CRPS with multi-limb spread and systemic autonomic features, controlled only with very high dose oral corticosteroids, which led to several complications. Multiple other treatment modalities failed or were insufficient to control the CRPS and allow tapering of the corticosteroids, but the patient had a dramatic response to hyperbaric oxygen therapy (HBOT), allowing a reduction in prednisone dose to just over the physiologic range. When symptoms started to increase several months later, a second course of HBOT treatments allowed reduction in prednisone dose into the physiologic range while still controlling CRPS symptoms. This case is unique in that it shows that HBOT can be effective in long-standing CRPS, both initially, and for subsequent flares, and adds to the evidence supporting HBOT as a potential treatment for this condition.”
How does it work?
The most commonly accepted theory seems to be that HBOT works by supersaturating body tissues that have been starved of oxygen as a result of swelling caused by the CRPS. HBOT also causes a modest constriction in vessels which reduces the swelling (oedema) caused by the CRPS.
As with so many aspects of CRPS, there is a considerable amount of anecdotal evidence available online concerning the efficacy of HBOT. Not unexpectedly, reported outcomes vary considerably, with some people experiencing either no, or very modest (and short term) improvement in levels of pain. Others, however, report longer term pain relief. The following comments illustrate that variability:
- “I had a total of 20 sessions in four weeks – which is a commonly prescribed schedule. Unfortunately, in my case, no significant improvement was experienced.”
- “Ultimately I cannot say the HBOT helped me, but I can’t say that I would not recommend it to others. It may very well have helped me, but other contributing factors that lead to less swelling and better range of motion need to be considered. My treatments occurred during the summer and I generally have lower pain levels and better range of motion during warmer weather.”
- “Probably within a half dozen dives, I noticed a difference. Even my friends said that I looked amazing.”
- “After about two months I went from being in a wheelchair for the most part, to walking and being able to lead a much better life.”
- “Sadly it didn’t work for me but I wouldn’t discourage others. What do you have to lose?”
- “My leg has not worsened since the treatment. It’s still painful, but I don’t use my wheelchair unless we go to places where we do a lot of walking.”
- “I was at a point in my life with the RSD and pain that I was ready to try anything, or I was ready to die, because I could not take the pain anymore. After the first few days I could feel the difference, I was feeling better, the pain was less, and I was taking less pain medication. After four weeks, I was pain free for the first time in eight or nine years. I slowly quit taking Oxycontin, Loratab, and Zanax. About two weeks later – six weeks after I began therapy – I was pain free and drug free. I could not believe it!”
- “Even though I am not cured of RSD, I feel like I got some of my old life back. I recommend HBOT for RSD. My doctor told me when you have chronic pain, it takes a lot of different modalities to keep the pain at a manageable level and I believe that.”
Where is HBOT available?
Clearly, before trying HBOT it is very important to discuss your intentions with those treating you.
The number of centres where HBOT is available continues to grow and the website of the Hyperbaric Oxygen Treatment Trust, a registered charity, has a useful search tool to identify your closest centre.