Ricardo,

Harper's observations and more importantly his conclusions are apples and oranges when it comes to using oxygen therapy to abort a cluster headache.  His main point centered on using oxygen to treat a child who is either not breathing spontaneously or who is unconscious. A person suffering from a CH attack is neither of the above.

Moreover, he assumes because his neuroimaging indicated less blood flow in the brain while breathing oxygen that there is less actual oxygen perfusion in the brain tissue.  I don't think that is a correct conclusion as there are several studies that monitored venous blood flow coming from the brain during hyperoxia and the oxygen content of the venous blood indicated the brain tissues were receiving more oxygen than breathing normal air with no indications of ishemia noted using similar neuroimaging techniques.

The bottom line here is simple.  If you're going to cite a study relevant to CH, it's best to do just that and don't try to editorialize too much.

For the new folks reading this link, oxygen therapy is very safe, very effective if used properly at high enough flow rates ≥15 liters/minute, and it has no real side effects.  That cannot be said for verapamil, depakote, or sumatriptan succinate. 

Over 150,000 Navy and Marine Corps pilots have been breathing 100% oxygen on every flight from takeoff to landing since 1941 with an average mission length of 2 hours.  They continue to do this today flying the F/A-18s and they'll continue to do this when they start flying the Joint Strike Fighter.  Our Astronauts have been breathing 100% oxygen every time they suit up since Alan Shepard made the first US manned space flight in 1961.

I've 3000 hours in Navy fighters and all of that flight time was spent breathing 100% oxygen at flow rates up to 50 liters/minute.  I've also used oxygen therapy at flow rates that support hyperventilation since 2005.  I'm still here at age 67 and in great health.

Moreover, all military pilots must pass an annual flight physical to remain on flight status and astronauts get one before every space flight.  If there was a problem associated with breathing 100% oxygen... we would have known about it back in the early 1940's.

Finally, you might want to ask yourself...  Would the Navy or NASA make us breathe 100% oxygen for several hours at a crack if it was harmful?

Take care,

V/R, Batch

Good People of Clusterville,

Hmm, Hmm, Hmm!  I was waiting for just that kind of reaction to my last post on this thread. 

It just so happens that I reviewed the study by Macy, Woo, and Harper titled "Hyperoxic Brain Effects Are Normalized by Addition of CO2" in 2008 while Royce Fishman, Michael Berger and I were developing the patent for the demand valve method of oxygen therapy.  This study is located at the following link:

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

Read it for yourself.

I found the opening paragraph in the discussion section of this study to be centered on a statement that was not substantiated by any observations or measurements taken in study nor in the reference study cited, [6] "Hyperoxia-induced hypocapnia: an underappreciated risk", as that study appeared to be just as flakey in its overly dramatic assertions. 

The discussion section of the Macy, Woo, and Harper study starts out with the following:

"We found that a number of brain areas responded to a hyperoxic challenge, especially neural regions that mediate autonomic and hormonal systems. However, addition of 5% CO2 to the hyperoxic mixture substantially reduced reactions of these neural structures. The perfusion and hormonal changes to 100% O2 could initiate a cascade of central and peripheral injuries through oxidative stress processes commonly reported with high oxygen ventilation.

Since the structures recruited in hyperoxia control output of hypothalamic sympathetic and hormonal regulatory areas, the reduced responses of those structures with the addition of CO2 may diminish injury to central and peripheral organs following hyperoxia alone, a possibility suggested by others [6]."

Pardon me folks, but in my opinion based my understanding of the basic logic used in the scientific method, this smacks of pseudoscience and some kind of agenda against the use of 100% oxygen.  Making a statement with the conditionals "could" and "may" does not constitute a scientific method of proof!

Where are the biochemical measurements and observations (read medical evidence) to substantiate this "cascade of central and peripheral injuries"?  What injuries?  How were these central and peripheral injuries detected? What is the extent of these central and peripheral injuries?

If the study authors can't substantiate the nature and extent of these injuries, then how can they make any claim as to the efficacy of adding CO2 in diminishing them? 

I don't doubt they observed a change in the functional neuroimaging after adding 5% CO2, but that’s where the science ended…  The rest with respect to central and peripheral injuries is little more than subjective fluff and a clear indication, at least to me, that they have an agenda.

The authors of this study also claimed that 100% oxygen caused cerebral ischemia yet they provided no evidence as proof to back up their neuroimaging. 

You might want to read the study by B.F. Matta et. al reported in the Canadian Journal of Anesthesia titled "The influence of arterial oxygenation on cerebral venous oxygen saturation during hyperventilation."  You can download a pdf copy at the following link.  It totally debunks and refutes the assertions made by Macy, Woo, and Harper about ischemia caused by breathing 100% oxygen…  and Matta has the medical evidence on his side.

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

While we're at it, "Oxidative Stress" is also a code word for an agenda with a highly probable mission statement that reads: (we've got to restrict the use of 100% oxygen).  A related code for this same agenda is "Reactive Oxygen Species."  Now that's a real spooky phrase, but what does it mean and how do you characterize it?

What is the real impact of Oxidative Stress and Reactive Oxygen Species (ROS) on the human body?  Is it bigger than a breadbox and smaller than a house?  Is the health hazard of ROS greater than or less than the common cold?  What is the real health risk?

Having a degree in Chemistry I do know that ROS refers to a single atom of oxygen or the larger molecule, O3 (ozone) as it breaks down into a molecule of oxygen (O2) and a single atom of oxygen.  Although both of these ROS are chemically active and will bind with other atoms or molecules very rapidly, neither of them is present in medical oxygen in any measurable quantity. 

You'll get a thousand times more ozone walking down the street of any large city in five minutes than you would ever get from breathing the entire contents of a K-size cylinder of compressed 100% oxygen.

Now if you think I'm paranoid about an agenda to restrict the use of 100% oxygen, please consider the following: 

The Centers for Medicare and Medicaid Services (CMS) ruled in October of 2010 that Medicare beneficiaries suffering from cluster headache WILL NOT RECEIVE COVERAGE for medical oxygen as an abortive for this disorder as there is not sufficient medical proof of its efficacy… 

The bureaucrats at CMS basically basically told the Presidents of the American Headache Association and American Association of Neurologists to get stuffed when they asked for a new coverage determination on the use of oxygen therapy as an acute treatment and abortive for cluster headache…  but it backfired and they had to do some "careful reconsideration" after pressure from Speaker Boehner turned up the heat.  Home Oxygen Therapy is NOW COVERED for Medicare beneficiaries suffering from cluster headache. 

I misspoke... but this update makes my concerns even more valid...  Oxygen therapy is only covered for Medicare beneficiaries suffering from cluster headache if they are taking part in a CMS sanctioned study of oxygen therapy...  See the following link:

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

CMS has also developed a spend plan that will cut a tad less than $1 Billion in funding for home oxygen therapy for Medicare beneficiaries suffering from COPD.  Here's a copy of their spend plan:

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

CMS also mandated a bidding process to hold down the cost of compressed oxygen and it has had the not so unintended consequence of driving most of the Mom & Pop home oxygen providers out of business as they can't compete. 

What's even worse is the cost of home oxygen therapy has actually gone up even with lower oxygen costs because of the increased delivery charges to locations previously serviced by the smaller home oxygen providers.

All for now.  Brew, please move this thread to where you think it belongs.

Take care, and when you read the results of medical studies related to cluster headache...  be critical.

V/R, Batch

Edited to correct the nature of the CMS action on non-coverage for Medicare beneficiaries suffering from cluster headache.