Sierra

A CPAP makes the air more dense, so it contains more oxygen per unit of volume. The volume flow goes down as does the air velocity. No more complicated than that.

I think there is a bit of a misconception about CPAP's "blasting" air into the lungs. The amount of air one needs is basically determined by the amount of oxygen one needs. The required oxygen does not increase due to using a CPAP, and compared to during the day we use less oxygen at night. It is also frequently said that when a CPAP or BiPap uses a higher pressure that it is harder on the nose and the throat. Actually it is the reverse. Because the oxygen requirement does not increase but the pressure does increase, the volume of air required actually decreases. So the air flow velocity actually goes down with a CPAP, and the higher the pressure, the more it goes down.

I would like to help you, but I failed on full face masks. I tried the Mirage Quattro, and the AirFit F20, and could not make either one seal for me at only 15 cm. I have seen some good reports about the F&P Simplus, but have no experience with it. Perhaps Bonjour or others will check in and give you more suggestions...

The headgear on the Swift FX is very good and is adjustable. However the mask itself and specifically the design of the purge venting is terrible. It does not diffuse the air flow and is kind of like sleeping with a jet engine.

I am overweight and my standard practice is to take two tums right before putting my mask on to sleep. I also find getting to sleep is much easier if I avoid naps during the day and try to keep my sleep period to about 7 hours, and 8 max.

If you search around this site you will find others with similar symptoms and some that have in the low mild range of AHI that have done the CPAP. I'm not sure to what degree these symptoms have been addressed. In general CPAP can improve sleep, and reduce the number of arousals during the night due to apnea events. In the UK mild apnea is not treated under their healthcare system (NHS) with a CPAP. I guess they don't consider it serious enough. However in North America it is commonly treated with a CPAP. A dental appliance is the other option for mild apnea, and some use it with success.

One thing to check into before you make a decision is the type of apnea you are having. Most apnea is obstructive and is readily treated with a CPAP. If that is what you have an Auto CPAP could bring the AHI to less than 1, although it varies from individual to individual. However if a significant portion of your AHI is due to central apnea where the airway is open and not obstructed, then a CPAP really does not help, and can even make it worse.

This design of mask with the tubes going up the side of the face results in quite a bit of dead space in the mask. If it is not purged with fresh air, CO2 can build up and cause issues. That must be why they purge it in two places. Most masks only have one area of purge exit, normally close to where the hose meets the mask.

You might find this thread on reasonable replacement frequency I initiated some time ago of interest. My conclusion is that there is lobbying going on by the industry and over compliant politicians setting regulations for Medicaid. Would be interesting to dig into it deeper to actually follow the money, but I pay my own way, and can't be bothered.

There are three silicone seals to check for damage. One seals the top and bottom half of the reservoir. The other two are inside and seal two air ports into and out of the reservoir. See page 24 in the clinical manual at this link.

There are some fairly rare situations where EPR may reduce centrals. The basic problem is that it forces the pressure up higher. For most using the AutoSet program setting it to 3 but in Ramp Only mode is the best. It makes it more comfortable to get to sleep, and then does not reduce effectiveness when you are asleep.