Two questions, CPAP vs APAP and lowering pressure

Over the six years of using PAP machines I have tried CPAP and APAP. One DME, who was very good said after a few months to switch my APAP to CPAP (using S8 Autoset) mode at about 8cm.
His feelings were that the majority of my AHIs were controlled by the 8cm pressure, now I use an S9 Autoset in auto mode (pressure range 5-20cm).
First question is, with the newer S9s is it better to use auto mode or is there any reason just to use the fixed pressure of CPAP (say at 9cm). My 95% pressure is 8.4cm and my average pressure is 6.3cm, there are some peaks at 12cm. Read some articles but still not sure what is the reason reasons to go one way or the other.
Second question is, my sleep doctor still says to leave my auto mode pressure range at 5-20cm. He says because my peaks are not going that high (12cm), the APAP is not chasing high pressures and this will not cause any sleep disruption. It sounds logical because the pressure range is really only 5-12cm because I am needing any more, but not know how the electronics works in the APAP, is the machine still looking at the top pressure of 20cm or is it only looking as high as the required pressure (12cm) to control AHIs.
Because I am still having quite of lot of sleep disruption I am just trying to figure out the best method to control my sleep problems.

Thanks Dave

DJL wrote:Over the six years of using PAP machines I have tried CPAP and APAP. One DME, who was very good said after a few months to switch my APAP to CPAP (using S8 Autoset) mode at about 8cm.
His feelings were that the majority of my AHIs were controlled by the 8cm pressure, now I use an S9 Autoset in auto mode (pressure range 5-20cm).
First question is, with the newer S9s is it better to use auto mode or is there any reason just to use the fixed pressure of CPAP (say at 9cm). My 95% pressure is 8.4cm and my average pressure is 6.3cm, there are some peaks at 12cm. Read some articles but still not sure what is the reason reasons to go one way or the other.
Second question is, my sleep doctor still says to leave my auto mode pressure range at 5-20cm. He says because my peaks are not going that high (12cm), the APAP is not chasing high pressures and this will not cause any sleep disruption. It sounds logical because the pressure range is really only 5-12cm because I am needing any more, but not know how the electronics works in the APAP, is the machine still looking at the top pressure of 20cm or is it only looking as high as the required pressure (12cm) to control AHIs.
Because I am still having quite of lot of sleep disruption I am just trying to figure out the best method to control my sleep problems.

Thanks Dave

Are you using software to monitor your therapy? If not, I strongly recommend doing so. That will tell you what's going on.
From my eight years of observations on this forum and personal experience with using an APAP in a range of pressures, the pressure changes can wreck the user's sleep. The typical scenario is that as you enter deep sleep stages or REM, your breathing changes and the machine interprets that as a reason to respond and increase pressure.......the pressure increases can then bump you out of the much-needed sleep stages and leave you feeling unrested. They can even cause complete awakenings......then the user tries to get back to sleep.

I'd suggest setting the new machine to a single pressure (maybe 8 cm) and see how that works. (monitor it with software)


Den

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Some people are sensitive to even modest changes in pressure when using APAP mode. Some people can sleep right through going from 8 to 20. When someone is still complaining of sleep disruptions the first thing we might look at is APAP mode and the range of pressures. While it's true your machine may not be needing more than 12 (so that 20 cm is really a moot point) just the changes from your current 5 cm to the 12 cm it is doing could possibly be a factor in poor sleep quality.

If the minimum pressure is set optimally the pressure shouldn't need to bounce around all over the place and then there's less chance of pressure changes disrupting sleep. Meaning if your minimum pressure was set so that the airway was better stented open then the machine wouldn't have to be increasing the pressure as much or as often. Working more in preventive mode instead of fix it mode sort of.

See this thread for an example of what I mean about using optimal minimum pressure to stabilize the varying pressures and limit the movement of the pressure.
viewtopic.php?f=1&t=39869&st=0&sk=t&sd=a

If you want to use APAP mode...maybe consider a really tight range to start with to see if it helps with the sleep disruptions...on the chance that the pressure changes are a factor in your sleep quality.
Maybe consider a minimum in between your average and 95% pressure and maximum 2 cm above that just to see if the machine still wants to move upwards.

I assume that you have spent some time in cpap mode...did you still have sleep quality problems in cpap mode? At what pressure?
Can you put a finger on any possible cause of the sleep disruptions? How often?
Software? Evaluate the reports to see what might be going on.
Meds...take any meds that might impact sleep?

Check this:


wiki/index.php/APAP