Thanks to all who have contributed to this discussion.
Some points in reply:
1
Hard-hat divers were protected from re-breathing by an over-supply of air i.e. though a flushing action of a helmet.
I believe this should be the same in a system where there is no non-return valve and has been noted about the volumes of air produced by the CPAP machines.
2
Twin-hose SCUBA systems were engineered out because they relied on a full, deep evacuation of the lungs to blow out as much as possible of the CO2 from the hoses and then take in enough fresh air to for the diver to survive. Shallow breathing would result in CO2 poisoning.
3
The sleep disturbance I have experienced is all subconscious. Regardless of the mask I use, I fall straight to sleep within minutes of lying down. When I get any disturbance during the night I usually go straight back to sleep after attending to the problem. As this is happening continuously though the night I suspect that I am not achieving little, if any deep sleep?
This has been resulting in the daytime fatigue, cognitive function symptoms and so inability to work.
Dr. Stasha Gominak states “We all know that you can make someone “crazy” by sleep depriving them, we’ve seen it used as a form of torture”
http://drgominak.com/sleep/
and Discusses:-
Sleep and Vitamin D (All Parts Combined)
https://www.youtube.com/watch?v=xF24xmJQK1k
4
So, with SleepyHead reporting the AHI down to between 2 and 2.5 (was 24 at the Sleep Study) and the Obstructive Index between 0.86 and 1.22, I thought it probable that the debilitating fatigue I was experiencing was due to the actual mechanics of the CPAP equipment and my subconscious acclimatisation to having to wear this equipment.
So, a week ago I changed to a RESMED AirFit F20:
a.
There was a huge improvement in my waking state, I felt fitter and alert.
b.
Each day it this has improved.
c.
There are longer periods of undisturbed sleep.
d.
There is continual flow though the mask and the air always feels fresh.
e.
I note there is a ‘non-return’ valve in the nose-piece. While it does not seal against a seat it does provide a resistance against exhaust. Note when washing it the water runs one-way easily but the other way it runs out the vents.
f.
I feel relaxed and confident in this mask. I think this is largely due to my BA and Dive Training.
g.
The tension on the straps is critical to balance between ‘blowout’ prevention and impingement of the hard-plastic mask on my face.
h.
As the CPAP pressure changes this balance is lost so the seal unrolls and I have to re-tuck it or adjust the tension on the head gear. (I suppose something like what happens on hovercraft to keep the skirt inflated and the bottom of the hovercraft airborne?)
i.
I am keen to try the RESMED AIRTOUCH F20 to see it solves the leakage problems. My CPAP supplier has advised it is not available yet.
j.
I believe there is still a lot of fine tuning that can be done so I am looking forward to my next visit to the Sleep Physician.
5
I find Dr. Stasha Gominak’s talks interesting, as, through her link between sleep and headaches, she makes the distinction between the management (of which CPAP is one tool) and the causes of sleep apnoea.
6
This leads to the question of solving the cause of Sleep Apnoea? Is Dr. Stasha Gominak’s correct that Vitamin D, being a hormone is pivotal in maintaining the correct level of paralysis?