Hey John,
Oxygen therapy is just an abortive... not a preventative... That said you should get at least an hour or more relief after an abort with oxygen therapy... Try hyperventilating with room air for 30 seconds breathing at forced vital capacity tidal volumes, i.e., exhaling with an abdominal crunch at the end of each exhale cycle until your exhaled breath makes a wheezing sound then inhale rapidly and fully then repeat ten times (~30 seconds), then inhale a lungful of 100% oxygen and hold it for 30 seconds. Repeat this entire sequence until the CH pain is completely gone.
If you want a lasting pain free existence, you need to start the anti-inflammatory regimen with 10,000 IU/day vitamin D3 plus Omega-3 fish Oil and the vitamin D3 cofactors. You can download the latest version of the anti-inflammatory regimen CH preventative treatment protocol at the following link.
Be sure to share a copy with your PCP or neurologist. That way you're both singing from the same sheet music when you ask for the suggested lab test of your serum 25(OH)D, total calcium and PTH (Parethyroid Hormone).
http://www.vitamindwiki.com/tiki-download_wiki_attachment.php?attId=7708
You can also scan the following QR code with your smart phone and it will download a pdf copy of the treatment protocol to your phone as a ready reference. If you don't have the QR Code Reader App, it's free and It takes less than 10 seconds to download and install.
Take care and please keep us posted.
V/R, Batch