Jason,
Understand... The way I see it they've set you up to fail the oxygen therapy test. If you do go in and have an attack while there, the lower flow rates (7 to 9 liters/minute) that most PCPs and neurologists prescribe are too low to be effective against cluster headaches above Kip-4 to 5. If you get a heavy hitter at Kip-6 or above, a flow rate this low will be ineffective in aborting your attack. This will result in an incorrect assessment regarding the effectiveness of oxygen therapy and give them the excuse they need to deny you a prescription for oxygen therapy.
There's a good way around this trap, but it will take a little initiative on your part... and that's to take control of the oxygen therapy demo to make sure you have a properly configured non-rebreathing oxygen mask and that you get a flow rate high enough to support hyperventilation.
How you do this is simple. First of all make sure they give you a non-rebreathing oxygen mask with both exhaust flapper valves. Ask to see the mask as soon as you get to the clinic/doctors office. It should look like the following photo:
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Please note that both exhaust check valves are present in the photo above... This is the right configuration for a non-rebreathing oxygen mask.
If one or both the silicone flappers are missing from the mask they give you, TELL THEM the mask is not configured properly and to bring you a second mask. You can remove the silicone disk from the second mask and install it easily on the first if it's only missing one check valve. If both disposable masks come without any exhaust check valves, TELL THEM any failure of oxygen therapy to abort you attacks will be due to an improperly configured non-rebreathing mask and therefore not a valid test.
Once you have a properly configured non-rebreathing mask, check out the wall mounted oxygen regulator they want you to use. Most medical facilities use a flowmeter type oxygen regulator like shown in the photo below with a clear lucite venturi tube calibrated to a maximum flow rate of 15 liters/minute and a needle valve to adjust the flow rate... Flow meter type regulators like this will deliver oxygen at flow rates well above 15 liters/minute.
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You'll need an oxygen flow rate of at least 25 liters/minute and preferably higher in order to support a respiration rate high enough to hyperventilate. To obtain this flow rate, twist the needle valve open until the pellet inside the clear venturi tube rises to the 15 liter/minute graduated level then twist the needle valve open further until you have a flow rate to sustain a respiration rate of 30...
The simple way to gauge this flow rate and respiration rate is to inhale for a "One Potato" count and exhale for a "One Potato" count. That should result in a complete respiration cycle in 2 second for a respiration rate of 30. You'll need to adjust the volume of oxygen you inhale at this rate to keep the reservoir bag from filling tightly an not so fast as to collapse it completely. If you get ahead of the oxygen flow rate the reservoir bag will be collapsed most of the time... If this happens, continue to twist needle valve open until you achieve a balance on the reservoir bag between fully inflated and completely collapsed...
Even if you don't have a cluster headache attack while there, ask to use the oxygen therapy anyway. Using the procedure above in front of nurses and doctors not up to speed with respiratory physiology will likely make them nervous. Stay cool and tell them you feel just fine...
You'll be properly prepared if you read my post on obtaining a prescription for oxygen therapy... Just click the link below:
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Make sure you print out the links at the end of this post to take along when you go in to try oxygen therapy...
If you've got any questions, please shoot me a PM.
Take care,
V/R, Batch