Hi, my name is Monica, just wanted to tell you how sorry I am that you and Pepe are going through this. Sending love and prayers that he gets better. I didn't know anything about hyper baric pressure treatments, but I googled it for you, and this is some of the information I found on the subject. It involves breathing oxygen under increased air pressure,it, helps slow down the progression of diseases. Oxygen is the healing element in the atmosphere, and breathing 100% oxygen allows extra oxygen to be absorbed into the tissues, which repairs damaged tissues. It is used to treat multiple sclerosis, Alzheimer's , dementia, gangrene, burns, diabetes, liver disease, and many other diseases and ailments.
The oxygen saturates 98% of the oxygen carrying protein in our blood, the hemoglobin. The body is exposed to 100 to 300% oxygen, 15 times the amount in our air as the pressure is increased, all the remaining oxygen is dissolved in the liquid portion of the blood, which is then delivered to all the tissues in the body. This speeds up healing at any sites of injury, including bone, soft tissue, brain, spinal cord, heart and liver. It stops inflammation and swelling, infections, clears toxins, and regenerates tissues .
So as far as I can see it has a lot of benefits, and uses oxygen, which our bodies already use, so there is no danger of side effects from medications, or anything that is invasive to the body. The only cons I read were it could cause some ear damaged due to the pressure, and could cause a seizure in 10% of cases, if used for more than 30 min intervals. A 10 minute break breathing normal air should be taken after every 30 mins of breathing the oxygenated air. Hope this helps. You can Google it as well if you want more information. Good luck in whatever you choose. I think you are a great Bully parent to be considering alternative treatments and options, and I think it is a very cool treatment option. I learned something new looking up this information.