Anecdotally I've heard that oxygen is toxic at higher-than-atmospheric pressure. Your link does mention oxygen toxicity, but I didn't notice any discussion of the antidote.
After posting that I figured out how the antidote for oxygen toxicity got memory-holed. It was in the 1950's, and ... there was a little protest, circa 1959, saying the new guidelines weren't so great for carbon monoxide poisoning.
My email address is in my profile, drop a line with a link to this comment and I'll provide more references.
I have no idea and wouldn't claim this is true for you in your situation though. My partner has brain cancer and I wish I'd tried this earlier.