Hey Kevin,
Welcome to CH.com. I've traveled to the UK for business on many occasions and I'm partial to the South of England from Blandford Forum down to Poole and Bournmouth. I loved the area.
I'm also familiar with the integrated oxygen systems in use there in the UK and across most of Europe. You've a couple options to improve the effectiveness of oxygen therapy when limited to a flow rate of 15 liters/minute. Both options use the same breathing technique so lets start there.
This breathing technique is essentially hyperventilating at forced tidal volumes. You can practice this with room air. Start by standing to give your diaphragm full range of motion then exhale forcibly. When it feels like your lungs are empty... they're not.
Do an abdominal crunch like doing situps. Hold the crunch and chest squeeze until your exhaled breath makes a wheezing sound for a couple seconds. This will squeeze out an additional half to full liter of exhaled breath that has the highest concentration of CO2. Then without delay, inhale as rapidly and fully as possible. Keep repeating this sequence.
This breathing technique accomplishes two important things. It elevates arterial partial pressure of oxygen above normal, and it lowers the arterial partial pressure of CO2 below normal. Both conditions stimulate vasoconstriction.
You also need a non-rebreathing oxygen mask with a 3-liter reservoir bag in order to be able to inhale a lung full of oxygen without waiting for the regulator to fill the reservoir bag further. The $27.50 O2PTIMASK™ kit here at CH.com is ideal. I think BOC may carry them as well.
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You'll notice three things happening when using this breathing technique... even with room air.
The first is an uncontrollable urge to cough. It will start with the second or third full breath using this breathing technique and it will clear in 10 to 15 seconds.
The coughing is due to a condition called atelectasis where areas of the lung's alveoli collapse like a compressed sponge during the abdominal crunch and chest squeeze where you force out as much exhaled breath as possible.
The body's response to this condition is coughing... That re-inflates the affected alveoli and also stimulates the secretion of additional surfactants that make the lining of the alveoli less sticky.
The second thing you'll experience are the symptoms of paresthesia... a very slight tingling or prickling of the fingertips, lips and back of the neck. It's also frequently associated with a slight dizziness.
Lean against a wall when using this breathing technique and if you feel too dizzy, sit erect in a chair. The important thing if you sit is not to hunch over your knees in a fetal position. This compresses the diaphragm and prevents complete lung ventilation.
The third thing is you will get tired... This is hard work, but the payoff is well worth the effort.
Now for the first option using the integrated regulator and oxygen cylinder at 15 liters/minute. This procedure is simple. Take two breaths of room air using the above breathing technique hyperventilating at forced vital capacity and one from the oxygen mask with the same technique.
I inhale directly from the O2PTIMASK's green "T" manifold with the palm of my hand cupped over the exhaust port and exhale away from the "T" manifold into the room. I then place the inhalation port on the "T" manifold against my cheek to prevent oxygen from leaking out while the reservoir bag is filling. By the time I've done two breaths of room air, the reservoir bag will have filled with oxygen and is ready for the next breath.
Although you're only breathing a third the oxygen you would get using the same mask, a regulator delivering 45 liters/minute, and the same breathing technique, you're casting off at least two to three times the volume of CO2 than you would breathing oxygen continuously at a flow rate of 15 liters/minute with a properly functioning non-rebreathing oxygen mask.
This accomplishes three things that stimulate vasoconstriction and aids in aborting a CH much faster than the alternative of breathing oxygen continuously at a flow rate of 15 liters/minute.
These include lowering the arterial partial pressure of CO2 and elevating arterial pH (respiratory alkalosis). The third thing comes as a result of the first two... By elevating the arterial pH, you increase blood hemoglobin's affinity for oxygen thereby enabling each hemoglobin molecule to carry up to 10% more oxygen. This results in a superoxygenated flow of blood to the brain further stimulating vasoconstriction.
The second option is to build your own "redneck reservoir bag" out of a clean 40 gal contractor trash bag.
The complete MacGyver instructions to build and use this contraption are listed in post #4 of the following link:
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You'll need to pre-fill the Redneck Reservoir Bag system and seal it with a rubber band for a gas tight seal ahead of time. If you do the math, the volume of the redneck reservoir bag is 150 liters so filling it will take 10 minutes at a flow rate of 15 liters/minute.
The procedure for the "redneck reservoir bag" breathing contraption is also simple. Use the same breathing technique from above, inhale from the bag and exhale into the room. If you're using this breathing technique correctly... most of your aborts will be one baggers...
The other thing to do is see your PCP and ask for a lab test for 25(OH)D. This is a metabolite of vitamin D3 that's used to measure your status of this vitamin... The normal reference range for this lab test is 30 to 100 ng/mL. (75 to 200 nmol/L as measured by most of the medical diagnostic labs in the UK).
Nearly all CH'ers with active CH are vitamin D3 deficient. Moreover, 76% of the CH'ers who have gone on the anti-inflammatory regimen have experienced a significant reduction in the frequency and severity of their CH. Most of them go completely pain free.
You can find a complete list of the supplements used in this regimen along with doses and dosing strategy at the following link:
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Take care,
V/R, Batch