Hey Maggi,
Give the folks at OxyTravel a call... It's run by the Linde Group of companies. Once they have a confirmation you have a valid Rx for oxygen therapy, they can arrange for oxygen to be delivered to your travel locations in most countries.
The Linde Group also includes BOA, AGA, PanGas and a few other companies who supply medical oxygen around the world.
The OxyTravel home pages for Iceland, UK and Hong Kong follow although only one call to the office in Reykjavik is all that's needed... You can have your Doctors office fax or email them your Rx. After that you can give them your travel itinerary and you're good to go.
I've used them all over the world and the oxygen is always at the hotel or my travel destination when I arrive.
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A second suggestion is to ask your doctor for the lab test for 25-Hydroxyvitamin D, a.k.a. 25(OH)D, the metabolite of vitamin D3 used to measure your vitamin D3 status.
I suspect you're vitamin D3 deficient and that deficiency has been contributing to your cluster headaches. Nearly all of episodic CH'ers with active CH who have gone in for this test have had their results come back less than 30 ng/mL, (75 nmol/L). Some chronic CH'ers have tested as high as 55 to 61 ng/mL.
The really interesting news is nearly all of the CH'ers who have gone pain free or had a significant reduction in the frequency and severity of their CH while on the anti-inflammatory regimen with 10,000 IU/day or more vitamin D3, have tested in a range of 60-110 ng/mL. A few have tested higher between 130 to 150 ng/mL.
So far the efficacy of this regimen with nearly 150 CH'ers participating is 75% and most have a favorable response in less than three weeks.
Most of the other 25% who have yet to respond to this regimen may have other medical conditions that prevents them from building 25(OH)D reserves high enough or metabolizing it further to 1,25(OH)2D3, the active metabolite.
The only note of caution is to use the vitamin D3 softgel capsules (5,000 IU are best), and not cod liver oil. Although cod liver oil will work, it has a high level of vitamin A and too much vitamin A can interfere with the benefits of vitamin D3.
The 5,000 IU liquid softgel vitamin D3 capsules can be hard to find in some countries... If you run into that problem, you can order them over the internet easily from several sources...
Please stop by Jimmy's Kitchen for me while in HK and have a bowl of their French Onion soup... It's the best I've had and one of my favorites.
Take care and please keep us posted.
V/R, Batch