Should I increase my pressure?

[loveoverbooks]

I have been on CPAP for two months now. I've seen some improvements in my symptoms (no more nocturia, headache, body aches, or trouble remembering nouns; more emotionally stable) but no difference in my energy levels (which may partially be because of having surgery a month ago). My sleep study came back with an AHI of 4, which my sleep dr refused to treat, but when I saw a neurologist who specializes in sleep medicine, he thought my symptoms could be caused by sleep apnea and wrote me a prescription for a CPAP machine. (More history in a previous post here.) My AHIs over the last two months have always been under 1. About 2/3 of the time spent in apnea are clear airway events, and the others are a mixture of the rest according to SleepyHead. I'm not sure how close CAs have to be in order to be a "cluster" so I don't know if I should be concerned about when two or three happen next to each other, about 4x/month. My pressure is currently set to 7-12 (changed from the 4-12 the neurologist originally set me at; I was never titrated). I have been having a lot of trouble finding a mask that will fit me because I have a very narrow chin and am currently trying the FitLife Total Face Mask. My DME let me borrow a small because the large won't be in stock till March, and I've had some trouble with leaking since it's too small.

Anyway, I have been looking at my data in SleepyHead and I have maxed out my pressure 9 out of the last 10 nights, and it's not happening when the mask is leaking. It looks like the pressure is responding to flow limitations. Should I Increase my max pressure to let the machine get as high as it needs to? Or should I increase my min pressure to try to get rid of the flow limitations?

Thanks!

[Pugsy]

I would increase the minimum pressure first and then evaluate the maximum. Often when the minimal pressure is more effective in preventing the Flow limitations in the first place then it won't need to go so high trying to fix them after they happened.
Also sometimes the pressure changes themselves can be a potential disruptive factor to our sleep quality so if we reduce the amount of variation then sleep quality can maybe improve.
Now not everyone will have problems with pressure variations (I don't) but some do and it's worth considering as a potential factor in how we feel during the day.

How much more minimum?....it's hard to judge when all we are seeing is mainly flow limitation as they can be stubborn little buggers to deal with. At least 8 minimum and maybe 9 minimum would be my guess but could be even a little more.

Ignore the Clear Airway/centrals...they could even be a post arousal central or a sleep onset central or just Sleep/wake/junk central and we have no way to know exactly what it is and even if they were 100% the real deal centrals you aren't having enough of them to worry about. It's normal to have a few "real" centrals anyway.

Given your symptoms and low AHI and a somewhat positive response to cpap therapy...and the way your pressure wants to deal with the flow limitations, it makes me wonder if you have some UARS going on here...Upper Airway Resistance Syndrome.
If that is the case the AHI isn't going to be of much use to you because it never was bad to start with. You are going to have to evaluate things more on how you feel in general and that's not an easy task.

[palerider]

How much more minimum?....it's hard to judge when all we are seeing is mainly flow limitation as they can be stubborn little buggers to deal with. At least 8 minimum and maybe 9 minimum would be my guess but could be even a little more.

I was going to say 9, but then I usually want to be a little more aggressive than you on pressure... if nine works, then they could try backing down a little and see if it still works.

[loveoverbooks]

Thanks for the replies, Pugsy and Palerider. UARS was what I asked my sleep dr about because I fit the symptoms much better than sleep apnea. He just brushed me off, said he didn't know what was wrong with me, and told me to go see a neurologist.

I increased the minimum pressure to 8 last night and really struggled with breathing all night long. I took a look at the data this afternoon and it doesn't look like the the flow limitations decreased at all. The pressure also maxed out at 12 again. Should I change my EPR to 2 or 3 while I get used to breathing at the higher pressure? Should I leave it at 8 for a week and see what happens before moving to a 9, or move to a 9 now?

Thanks! My neurologist didn't look at the graphs when I saw him last month, just evaluated my compliance and AHI, so I'm very grateful to have SleepyHead and the help on this forum to try to optimize things myself!

[palerider]

Should I change my EPR to 2 or 3 while I get used to breathing at the higher pressure? !

remember that increasing EPR has the effect of lowering your pressure by that amount.

if you increase EPR, I'd also increase your min pressure.

[loveoverbooks]

Good point. I'll leave it as it is then!

[palerider]

Good point. I'll leave it as it is then!

increasing the pressure differential between inhale and exhale might make it easier for you to breath... so you can try that... the higher pressure on inhale can make you not notice the exhale pressure as much.

I'd say, experiment with it some while awake and see what you think.

[loveoverbooks]

OK, last night I changed my min pressure to be 11, kept my max pressure at 12, and raised the EPR from 1 to 3 (which was MUCH more comfortable, thank you palerider). This is what the night looked like:



It looks like the amplitude of most of the flow limitations is smaller than the previous example night I posted (except for that one spike). Any more recommendations?

[palerider]

I'd give it a few nights and see how you feel, at this point.

[Slartybartfast]

remember that increasing EPR has the effect of lowering your pressure by that amount.

if you increase EPR, I'd also increase your min pressure.

I respectfully disagree. EPR, Expiratory Pressure Reduction, kicks in only after the machine senses that the patient is beginning to exhale. So the patient's lungs have taken in as much air as they are going to. The EPR feature lowers the pressure the sleeping patient must overcome during exhalation by 1, 2, or 3 cm H2O, then turns off when the patient begins to take the next breath. The pressure delivered during inspiration is unaffected by the EPR setting.

The effect of EPR is to reduce the amount of pressure present during exhalation, which mitigates a feeling many patients express as "feeling like I was blowing up balloons all night." It's a comfort feature, and doesn't affect the efficacy of the therapy, per se.

That said, it looks like you're pretty well dialed in. I think the upper setting is not very important anymore. The last couple of generations of APAP machines don't tend to run away with most people, so setting an upper limit shouldn't be necessary. Paying attention to the lower limit will net you the greatest benefit. It looks like between events your pressure comes down to just over 11 cm, then the machine senses some flow limitation, and jacks up the pressure. It might be that you need a little more pressure to keep the flow limitations from triggering the pressure increase. Maybe 0.5 cm. But I agree with Palerider. Give it some time and watch your data to see if a consistent pattern emerges. If you notice flow limitations are detected immediately before a pressure increase, absent any mask leaks, then your lower pressure needs to be raised a little.

[palerider]

remember that increasing EPR has the effect of lowering your pressure by that amount.
if you increase EPR, I'd also increase your min pressure.

I respectfully disagree. EPR, Expiratory Pressure Reduction, kicks in only after the machine senses that the patient is beginning to exhale. So the patient's lungs have taken in as much air as they are going to. The EPR feature lowers the pressure the sleeping patient must overcome during exhalation by 1, 2, or 3 cm H2O, then turns off when the patient begins to take the next breath. The pressure delivered during inspiration is unaffected by the EPR setting.

The effect of EPR is to reduce the amount of pressure present during exhalation, which mitigates a feeling many patients express as "feeling like I was blowing up balloons all night." It's a comfort feature, and doesn't affect the efficacy of the therapy, per se.

you're making a common mistake that's caused by the naming of the feature.

a breath cycle during sleep typically involves inhalation, exhalation, and a pause, then the cycle repeats. EPR reduces pressure *except* during the inhalation phase, so as soon as you start to exhale, and during the pause, you have a lower pressure. then when you start to inhale, the pressure ramps back up.

the *point* of that nitpicky distinction is that if you crank EPR to 3, you've reduced your non-inhalation pressure by 3, and if you are prone to getting apneas at that pressure, then you'll get more apneas, since the pressure, during the pause before inhalation may be too low to keep your airway open.

for example, if you've determined you need 9cm to avoid apneas, and so you have your pressure at 10, and then you set 3epr, you'll have apneas, because your pressure is 7, except when you inhale, and since you get an apnea, you can't inhale to trigger the higher pressure.

make sense?

[loveoverbooks]

It's been a week at the higher pressures and I am still not seeing an improvement in my energy levels. I've had aerophagia/gastric insufflation all week which hasn't been too fun either. This was last night's chart, which was typical of most days this week. Lots of maxing out. Should I stay at this pressure longer and see if I adapt to the aerophagia before increasing the minimum pressure again?

[Julie]

You've got more centrals than obstructive events and they won't respond to higher pressures. But hopefully Pugsy will give you more useful info about the results here... but I personally would lower my pressure a bit for now and you should get a little relief from aerophagia. You do need to look further into what's going on however... wait for Pugsy.

[Pugsy]

So you are trying to reduce the flow limitations...is that correct?
Your AHI doesn't need any work.

You are going to have to weigh the benefits of reducing the FLs (if there are any benefits) against the discomfort associated with the aerophagia.
The FLs aren't horrible though....and If trying to reduce them further causes a problem...don't swap one problem for another one.

[loveoverbooks]

Yes. My overall AHI during the sleep study was 4, so it's not like I can go much further down in terms of AHI since it's always less than 1 now. After being on CPAP for two months and not feeling any less tired, I thought trying to decrease the flow limitations might help in case I fell more under UARS than sleep apnea.