Question about fixed vs auto settings

So, I'm relatively new to using a cpap and, because I'm a huge geek, I was able to find the sleepyhead software and view my data. My AHI is hovering around 9 or 10 most nights and I'm sure I can do better. The CPAP machine I was given/bought is an F&P Auto meaning it can be set up as an APAP. My question is this: Why wouldn't the Dr. who diagnosed me just automatically set it to auto if that feature is better? Are there any downsides to using it in auto mode? Can it hurt me, etc? I am not seeing my Dr. for another 45 days and if I can adjust it myself, why wouldn't I?

Any guidance would be helpful! Thanks!

No downsides unless you're one of a few people who when using Apap finds that the pressure changes are responsible for frequent wake-ups, something that you learn when tracking your sleep with software. Doctors don't prescribe them because they're ignorant - they may know what apnea is in terms of how it affects you (airway closure, etc.) but doofuses re equipment. You need to ask assertively for what you want, get a script that spells out which machine, and not let them (or the DME's who lie about everything) keep you from optimal therapy. Sad... Apaps can be used in Cpap mode but not vice versa.

The APAP can respond to flow limitations and snores to intercept obstructive apneas by increasing pressure. A CPAP on the other hand will hold the same positive air pressure at all times. It's interesting that we vest so much faith in a single titration study that doctors will issue fixed pressure CPAPs when for just a few dollars more the patient could be issued an APAP.

Anyway, your treated AHI is pretty bad, and you do need to make some changes. Most likely you either have severe leaks, or the pressure is too low to prevent airway collapse. Kind of hard to know without seeing the types of events and other data. A good approach would be to put the unit in Auto mode using your current CPAP pressure as a minimum, and see how the machine responds. If you'd like to share the data you have and get some additional feedback, this tutorial should help you post images on the forum. https://sleep.tnet.com/reference/tips/imgur

Papbabypap wrote:So, I'm relatively new to using a cpap and, because I'm a huge geek, I was able to find the sleepyhead software and view my data. My AHI is hovering around 9 or 10 most nights and I'm sure I can do better. The CPAP machine I was given/bought is an F&P Auto meaning it can be set up as an APAP. My question is this: Why wouldn't the Dr. who diagnosed me just automatically set it to auto if that feature is better? Are there any downsides to using it in auto mode? Can it hurt me, etc? I am not seeing my Dr. for another 45 days and if I can adjust it myself, why wouldn't I?

Any guidance would be helpful! Thanks!

What ARE your machine settings?
Just because it's "auto", doesn't make it "better". They respond to breathing events (mostly snores and flow limitations) to increase pressures. But if those events aren't present, it won't increase pressure to head off apneas. And, too wide of a range of pressures can take too long to get to where the pressure needs to be. And, many people are disturbed by the pressure changes. As you enter a deep or REM sleep stage your breathing can change and that may trigger the machine to increase pressure......which MAY bump you out of that needed sleep stage and into a lighter one.......leaving you feel unrested.

Ranges or pressures work for some people but they're not for everyone. The individual users have to decide for themselves.


Den

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I'm currently set at 10. The ironic part of this is that I'm seeing a high level of FL events as well as hypopnea events. It sounds like the APAP setting might actually bring these back to normal.

Papbabypap wrote:I'm currently set at 10. The ironic part of this is that I'm seeing a high level of FL events as well as hypopnea events. It sounds like the APAP setting might actually bring these back to normal.

I would recommend increasing your pressure one or two centimeters over about a week and see if that helps your AHI. Flow limitations aren't counted in the AHI numbers, but could present a problem with increasing pressures if more pressure doesn't resolve them. There are some folks who have that problem. And, the human subconscious reflex reaction to pressure increases MAY cause a person's breathing to generate even more Flow Limitations. You need to analyze WHAT you're trying to fix and whether the "cure" may be worse than the perceived problem.


Den

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At least the OP is thinking of how to fix the issue from early on. you can TRY APAP for however long. If you find after a couple hours that it bugs you, and want straight pressure back, have at it. APAP is a way to find what the minimum pressure is to maintain an open airway. Just another option that works better for some than Den.

I think a lot of doctors are rather clueless about CPAP machines and think the only way to use an APAP is with the pressure set to the full range of pressure, usually 4-20.

Most people will do better with an APAP that starts at a pressure closer to what they need. Too wide a pressure range can be uncomfortable, and can cause mask leaks as the pressure changes. If the pressure starts too low, you rebreathe some of your exhaled air and may feel like you're suffocating until the pressure ramps up. You may also have some apnea until the machine adjusts.

Sometimes, a machine will not find the "right" pressure and will "run away" to a pressure that is too high. It may not be needed, or it may simply be too uncomfortable.

All of these problems can be fixed by setting the APAP to a narrower pressure range. You can even set the pressure range down to zero, making it a manual CPAP machine.

Some people may simply do better on a single pressure.

The doctor may also find it easier to figure the treatment out if it's a single pressure.

I suspect that a lot of doctors subconsciously choose manual CPAP because of the medical mafia's bias to do expensive $leep te$t$. If it costs more money and employs medical professionals, it must be better, right.