I know that a lot of the replies have indicated that you need to rather significantly increase the min pressure and maximum pressure, with sbd even saying to increase it all the way to 9-14cm. I beg to differ with the idea that you need to significantly increase your minimum pressure and maximum pressures.
Here's why I would be very cautious about increasing your minimum
(04-13-2016, 03:57 PM)mikenz Wrote: During first month trial I was on 5-11.
The sleep specialist set my machine to 5-12.
i was getting uncomfortable wind in stomach, so adjusted down, helped a little bit with wind, but probably not sleep. rather have wind and sleep well than the other way around.
The air (wind) in your stomach is called aerophagia. And it's a pretty common problem. It's also a problem that can aggravated by increased pressure. If it's bad enough it can interfere with your ability to get to sleep and to stay asleep with the mask on your nose. And unfortunately general restlessness (caused by whatever reason) can increase the aerophagia.
I bring this up because in my humble opinion, raising the minimum pressure from 5 to 9 cm in a person who is already reporting problems with aerophagia can easily make the aerophagia problem get much, much worse. Likewise, increasing your max pressure will allow the machine to increase the pressure to levels where your stomach goes from "uncomfortable" to "unbearable"---as in you might just find yourself waking up feeling like you've swallowed a basketball or bowling ball.
As a side note, my own extremely difficult adjustment period was set off by an initial script for straight CPAP at 9cm with a doc who was unwilling to lower the pressure for the first two weeks. The aerophagia was extreme and it lead to a nasty, long term case of CPAP-induced insomnia, which took 6-12 months to bring under control.
In looking at your data, what I notice is this:
1) Half your treated AHI is made up of CAs.
And CAs are not treated by increasing the pressure. And pressure increases can make CAs worse under some circumstances. It's not uncommon for new PAPers to develop a bit of a problem with CAs right after starting PAP therapy. The usual thing sleep docs do with a CAI like yours, however, is to do some prudent watchful waiting: In most people who develop CAs after starting PAP, the CAs disappear by themselves after a few weeks. The hypothesis seems to be that it can take the body a few weeks to fully adjust to PAP therapy and one of the adjustments the body has to do is learning how to properly maintain the CO2 level in the presence of the pressurized air. As others have pointed out, the CO2 level is what provides the trigger for inhalations. But CAs can also be (mis)scored by the machine if you are in a very light sleep bouncing back and forth between real sleep and wake. The reason is that the control of breathing is handed off between the voluntary nervous system (wake breathing) and the autonomous nervous system (sleep breathing) when transitioning to sleep, and part of that handoff includes resetting the CO2 trigger level. In the lab this kind of breathing pause is NOT scored as a CA if it occurs when the EEG says you are awake. So an important question to consider when looking at the CAs scored by your machine is: How restless were you during the times they're being scored? If you were awake or mostly awake anyway, there is a pretty good chance they're not real.
At this point I'd recommend reporting the CAs to your sleep doc's office. If they're not yet worried about them, I'd be inclined to continue monitoring them without worrying too much about them yet.
2) There are NO dense clusters of repeated OAs and Hs in the one night's data you posted.
Yes, there are a fair number of obstructive events, but for the most part they're well separated in time--as in they happen with at least 2 minutes between them. That means that for the most part the pressure increases are not being triggered by OAs and Hs. Rather, the pressure increases are most likely being triggered by snoring or flow limitations. You didn't post those graphs, but they're far more useful than the AHI graph that you did post.
So another good question to be asking yourself is whether there's a lot of snoring going on or whether the pressure increases are mainly being caused by activity in the flow limitation graph.
If there's real evidence of snoring going on, then a modest 1 or 1.5 increase
in the minimum pressure may be enough to take care of most of it. (Personally, I'd leave the max pressure where it is given that you're fighting aerophagia.)
If there's a lot of activity in the flow limitation graph, you're going to need to tease out how "real" the flow limitations are and whether they respond to pressure increases. Not all things that result in the machine scoring a flow limitation are real flow limitations, and not all of them are fixed by more pressure. In my own case, I have to cap my max pressure and tolerate some flow limitations due to the aerophagia. Doing that allows me to actually sleep
with machine, and the ability to sleep
(as opposed to dozing lightly most of the night) is critical in feeling well the next day.
You also write:
Quote:I did have a good patch of 4-5 over a few days a week or so ago, but for the last week its been alternating between high 6s and 8s, been tired and grumpy and frustrated at not understanding why etc etc.
Some questions for you to consider:
1) Do you look at the data as soon as you get up in the morning? And if so, do you react badly to seeing an AHI that's in the high 6s or above? There is such a thing as letting the data control how you feel, and you don't want to do that. It may be better to look at the data at night or every couple of days instead of the first thing morning.
2) Have you considered tracking a couple of other potentially significant variables in terms of how you feel? In particular, I'd suggest tracking the discomfort caused by the aerophagia and whether your sleep feels
relatively uninterrupted by lots of wakes and restlessness. I suspect that one or both of these things may be more responsible for how you feel in the morning than just the fact that on some days the AHI is elevated due to CAs. In other words, I think you need to be asking yourself these questions:
- Is the aerophagia (wind in your stomach) worse on the nights where you feel bad the next day?
- Do you spend a lot more time tossing and turning and being awake in bed on the nights where you feel bad the next day?
If either of these are true, then the problem could be the aerophagia, and addressing the aerophagia may wind up being the solution.
To make it a bit clearer about what I'm suggesting as the root problem:
On a night where aerophagia is a problem, you may have a lot more restlessness and a lot more middle of the night wakes that may only last a minute or two (so you might not remember them all). The initial aerophagia drives the wakefulness and the wakefulness and mini-arousals caused by the aeorphagia causes you to swallow more air, which in turn, increases the aerophagia. Which leads to more restlessness and more aerophagia. (You can get trapped in a nasty feedback loop.) Because you're doing more dozing than usual, the machine winds up (mis)scoring a lot more sleep transition "central apneas" as CAs, and hence when you wake up in the morning and look at the data, the first thing that your brain notices is AHI > 6.5. And so you (quite naturally) associate the feeling bad the next day with the high AHI and not the fact that you were dealing with a bad night's sleep caused by the aerophagia in the first place.