Could CPAP be better than APAP??

[Reznik]

Hi everyone,

I'm newly diagnosed with OSA and just starting my therapy with an Automatic CPAP ("APAP") machine.  I was diagnosed based upon a home sleep test and was given an APAP in lieu of a sleep study.  I'm tracking my sleep using ResScan and SleepyHead.  Right now, I'm using it in Automatic mode with a range of 5.0-8.0.  I'm having difficulty adjusting to the APAP.  When I use the machine, I feel much more tired the next day than when I do not, and if the pressure gets up above about 8.5 it wakes me up, which is why I set the machine to 8.0 as the upper limit.  With the 5.0 to 8.0 limits, I get an AHI of about 3.8, which is obviously good.

In looking at the charts in ResScan, I've noticed an interesting pattern.  Throughout the night, whenever I have an apnea, the machine bumps up the pressure to or just under 8.0, and holds it there for a very short period of time.  The apnea clears, usually right at 10 seconds.  Then the machine starts to decrease the pressure, usually to about 7.0 to 7.4.  After some period of time with the pressure decreasing, another apnea occurs and the cycle repeats itself.

Now, most people would say that the machine is doing exactly what it should do.  I start to have another apnea, and the machine ramps up to stop it.  However, I always like to consider the other possibilities, and so I can't help but wonder if it was the decrease in pressure from about 8.0 to about 7.2 that caused the airway to collapse and the next apnea to occur.  In other words, if I just set the machine on CPAP mode, with a continuous pressure, would many of those apneas stop happening altogether.  And more importantly, would it be just as effective at a lower pressure than the APAP is using??

In other words, is a continuous pressure more effective than a changing pressure range that has lower and upper limits than are higher than the continuous pressure?  e.g., is it possible that a CPAP set at 6.0 might be more effective than an APAP that is set to 6.0 to 8.0? 

Has anyone had any experience with using an APAP machine and then switching to CPAP mode at a lower pressure than what the APAP was doing?

Thank you in advance for your input!

[jaswilliams]

Post your charts so we can take a look, but maybe rather than Cpap just increase the lower pressure to 6 as 5 is quite a low value so the machine does not have to go so far to resolve the apnea.


Jason

[Walla Walla]

For some people fixed pressure is better. But you need to know what that pressure is. What's the highest the pressure has gone and for how long? I see you capped it at 8 cm but have you ever started at say 8cm and seen how high your pressure rises to? It could very well be you need higher settings with a narrow range to prevent pressure spikes.

[Reznik]

Hi guys,

Thanks for responding.

I'm not asking for personalized advice based upon my pressures or charts.

I'm asking if anyone here has experience going from APAP mode to CPAP mode, and found that the CPAP pressure that they needed was lower than the typical pressure the APAP produced for them.

Thanks again!

[Walla Walla]

No problem. Good luck.

[TASmart]

find that CPAP works better for me than APAP. My pressure is 10.6 with CPAP.

[Reznik]

Hi TASmart!

Thanks for responding.  When you were on APAP, what were your pressures?

[Hojo]

After 2 months of CPAP therapy I went and got the actual results of my sleep studies and was surprised that while they said I needed 10 of CPAP to 'clear my OA', I did NOT have a single OA episode during the study.  It seems that for insurance reasons, many of us need to start with CPAP to see how it goes, then change parameter and/or machines.

Hence, what you were told may not be the actual treatment you need, IMHO.

[Sleeprider]

Reznik, we often find fixed pressure or a narrow range is superior in providing treatment to many people. The APAP depends on detecting pre-apnea events like flow limitation, snores or volume-flow changes to increase pressure before an actual apnea occurs. In some people, these warning events do not occur. Your description is accurate that this can cause a cycle where it takes an apnea to occur to bring pressure to therapeutic level, but the machine drops pressure after that event, causing a persistent cycle. In addition, we have had to limit maximum pressure in some people that do not appear to benefit from higher pressure, but may have persistent flow limits or snores that would cause the APAP to increase pressure to uncomfortable levels unnecessary for therapeutic efficacy.

Everyone seems to have their own individual response to CPAP and it's very hard to make generalized recommendations. What works for one (wide-open APAP), may be very disruptive to another. Even comfort features like EPR/Flex, Humidity and Ramp can make or break it. The best part about APAP is you can tune it to whatever your needs are within limits.

[Reznik]

Hi SleepRider,

Thanks for responding.  

I've always been a very light sleeper.  I tried using my Auto CPAP with the prescription recommended by my doctor (5-20) but just couldn't tolerate when the machine bumped me up to 10+ especially in the very last few hours of sleep.  I woke up constantly during the night, couldn't get back to sleep because of the pressure, and spent the next day feeling terrible.  I've found that I can tolerate an automatic range from 5-8, that it reduces my AHI to 3.8, that it knocks out Apneas after 10 seconds, but I still feel awful the next day, i.e. like I didn't get a good night's sleep.  I'm guessing that the pressure adjustments are disrupting my sleep.  I finally had to take three days off of the machine to recover.

I think that, for now, I'm going to start in CPAP mode at a very conservative pressure that's comfortable for me (probably 6.0), and see what result it yields. My thinking is that this still more support than if I had no CPAP at all, but hopefully not enough to disrupt my sleep.  Once I can get my sleep quality to the same level as if I don't wear a CPAP, then I'll start moving the numbers up gradually until it brings down the AHI without making me feel terrible.

Do you see any flaws in my thinking here?

P.S.  Thanks to you and everyone who made the ResScan software available.  This gives a lot more information to work with in understanding what's happening to my body while I sleep.