Hyperbaric oxygen therapy (HOT) is a possible treatment for inflammatory bowel disease. The allure of HOT is its simplicity: the patient only has to breathe in more oxygen to benefit, and the risks and side effects are slight. But does it work?
In hyperbaric oxygen therapy, the patient is put into a sealed chamber in which the air is replaced by 100% oxygen, and the air pressure inside is raised to be greater than sea level (air pressure gets higher the deeper you go). ‘Hyperbaric’ simply means ‘more pressure’. In a hyperbaric chamber, the patient breathes more oxygen, and the pressure helps more of it enter the blood stream.
If you have ever spent time in the mountains, then quickly traveled to sea level, you know how good more oxygen can feel. In fact, more oxygen can have positive effects on inflammation and other aspects of our health. A growing body of literature is looking at whether these effects can be used to treat Crohn’s and Ulcerative Colitis.
Hyperbaric chambers are most often used to treat decompression injuries in scuba divers — such as the ‘bends’, where nitrogen bubbles form in the bloodstream, sometimes leading to paralyses or brain injury. The combination of pressure and oxygen helps dissolve the bubbles and get the excess nitrogen out of the body.
HOT is also used to treat wounds that won’t heal: the higher oxygen content in the blood helps speed up the body’s innate healing processes. Some researchers reason that the same effect can be achieved for patients with IBD: the ulcers formed by Ulcerative Colitis and Crohn’s are more or less wounds inside the gut.
Experiments with animal models have shown promise: mice made to show colitis symptoms respond well to HOT. Case studies with limited numbers of patients have also shown positive results. A study of patients with Crohn’s saw good results in healing perineal lesions, especially when combined with surgery.
In a clever study, researchers took six Crohn’s patients to the Dead Sea , which sits in a depression below sea level and thus has an atmosphere about 5% heavier and 3-4% more oxygen rich than normal elevations. The patients saw an improvement in their health, including healing of fistulas. Two patients were able to stop taking prednisone. (As someone who grew up at sea level, I often feel my disease gets worse at higher altitudes.)
Two reviews of HOT research for IBD patients suggest it has a lot of potential, especially for patients who don’t respond to other treatments. The first found that 78% of Crohn’s patients and all UC patients in the reviewed studies showed improvement at pressures 2 times or more normal. However, all of the patients had failed to respond to medical treatment, and the studies were small and not controlled trials. These limitations mean the results may not apply to all IBD patients.
The more recent review identified studies with a total of 613 patients having either Crohn’s or UC; the total response rate was 85% for CD and 88% for UC. However, the full article is not available (ie. not free), so the studies likely had the same problems and limitations as those in the earlier review.
However, a recent randomized trial of HOT found no effect for patients with severe ulcerative colitis; more experiments like this are needed before we have any certainty that HOT works for us. You should also beware of fraudsters touting HOT therapy: the FDA cautions that many of the claimed uses of hyperbaric oxygen are not approved — which includes inflammatory bowel disease, except for experimental cases.
The other bad news is that HOT is time-consuming: patients in some studies had to spend two 15-minute sessions per day in the hyperbaric chamber. For wound-therapy regimens, patients can spend up to two hours in the chambers per day. People with claustrophobia may find hyperbaric chambers to be very uncomfortable. What’s more, there are only about 700 chambers in North America — not many hospitals have one.
More research is needed, but HOT clearly holds promise as a therapy for people with IBD, especially those who have not responded well to standard treatments.
Photo from Wikimedia Commons member James Heilman, MD by Creative Commons license