Of sleep studies, respirologists, and skipping a night

[BML]

I've been on CPAP for a year+. I was seen at a private clinic (paid for home study) and was sold a Respironics M series auto BPAP. Was on BPAP 4-8 when I started. moved up my numbers with your help to 12-16. Saw the respirologist first time last fall, he changed me from BPAP to CPAP at a presure of 14. I recently had my first titration study at the hospital. The next morning the tech said: 'wow, your respirologist is good, he guessed the right pressure without a titration tudy!'Sigh.. he guessed using my machine which he thought was overkill and the reports it produces which he said were unecessary..... right. I'm glad i have my machine. That being said moving me to CPAP made all the difference... with BPAP all I was doing was chasing the apneas.

Last thing, and I know, I know, never ever "not use" the machine BUT.... I have cheated a few times to spend a night in the woods backpacking. I LOVE backpacking and miss it terribly - used to go out for 4-10 nights. I mentionned to the tech that I had survived those trips fairly well but that recently and quite accidently, I had spent a better part of a night at home without my CPAP and the next day felt like I had been hit over the head with a baseball bat. I asked if this was the case because we get so used to the therapy that a night without it gets increasingly difficult. And here is the interesting part, she said when patients lose weight and can/hope to stop using CPAP, they come in for another study and they are asked to wait 4 days after having stopped using CPAP to eliminate "residual effects" (uh?).. so according to her, I could go out to camp for a few nights and not be worse off for it. Well, I have cheated but I don't think I buy that. Has anyone heard of this, residual effects????? What's up with that?

Bernard

[elena88]

thats a very good question!


I dont know that after therapy, that we are more sensitive to events when we miss the therapy.. it might seem that way..

I was mouth breathing the other night, I KNOW because I woke up and asked my husband if we were having an earthquake.. because I felt
the bed trembling.. he said "no, go back to sleep!"

I realized it was my heart beating into the mattress...

That was pretty typical before cpap for me, and I guess if Im not getting therapy it stil happens, but it just SEEMS like I notice it a little bit more..
there is more of a contrast now..

I think that is wonderful if people can get off it, my doctor told me no matter what I would be on it the rest of my life..

IM glad you enjoyed your time out in the woods, must have been grand!

[slapmeawake]

I am one who has lost weight and my pressure needs are all the way down to 5. My doc wants me to try to go without the machine and see how I do. This residual effect is interesting to me because I tried but never for more than 3 nights. I seem to sleep better with the machine but 5 is such a low number. I think I will try to go a week and see what I come up with. I sleep so poorly anyway, its not the apnea waking me anymore, who knows what it is. All I know is since I lost weight my therapy is not keeping me asleep. I wake up at least twice a night, like every 2 or 3 hrs. I'm very depressed to think this is what I have to look forward to for the rest of my life. Anyway, don't have answer to all of this. Keep in mind my apnea was mild to begin with so the weight loss really helped me. Someone with severe apnea will need the machine always but I do want to get off if I can. Just don't know if that little bit of pressure is really helping. The Doc thinks it might actually be disturbing my sleep but when I tried to go without my machine it seemed I slept a little worse. I'll try longer and report back. Maybe after 3 years of CPAP I can't just stop but need to wean.

[Slinky]

And, MAYBE, despite the weight loss 5 cm is just plain NOT ENOUGH pressure for you.

[kteague]

slapmeawake - I'm with Slinky. How was it determined that your pressure need is now 5? Is your data showing you have no events at 5? Just wondering, there's got to be a point where minimum effective pressure crosses the line into too low to breathe. Unless you have good data to substantiate that reduction to 5, I'd be suspect. Are you using it in straight cpap mode? I see you have an auto listed. If you used it in a range, say from 5-10, just picking a number out of the sky, and your pressure increases during the night, you'll know that 5 is inadequate, and you do indeed still NEED cpap. If it stays at 5, you'll know that being too low is not the issue.

BML - I don't have a link to the old thread, but this has been discussed and there was an old article on PubMed about there maybe was a 1 night residual effect, but the study was too small to be impressive. I would suggest maybe you had trouble not because it was a bipap, but because of the auto feature. While it's not an end-all answer, maybe you should sleep a night with an oximeter and at least how that looks when you're out in the woods.

[Rebecca R]

My doc asked me to discontinue CPAP for three nights before my next PSG in order to avoid "residual effects" interfering with the results. I haven't looked it up yet, but have been meaning to.

I somehow suspect that sleep docs don't recommend relying on residual effects as a treatment alternative

I agree with Slinky and Kteague about a pressure of 5. I can't breathe at five or even six, and certainly wouldn't be able to sleep at all, but you may be different.


r

[SleepingUgly]

Borrowed from another thread I wrote: I read something to suggest that AHI level may remain decreased after 1 night without CPAP (Sahlman et al., 2007, "Evolution of Mild Obstructive Sleep Apnea after Different Treatments"). They cite these folks as the source of that info: Sforza & Lugaresi (1995), "Daytime Sleepiness and Nasal Continuous Positive Airway Pressure therapy in Obstructive Sleep Apnea Syndrome Patients: Effects of Chronic Treatment and 1-night therapy Withdrawal" AND Kribbs, et al. (1993), "Effects of one night without nasal CPAP treatment on sleep and sleepiness in patients with obstructive sleep apnea".

I don't remember the details of this (and I don't think I read the original articles), so I don't know how compelling the data was that there are residual effects for one night. I haven't seen anything to suggest that there can be effects for more than 1 night, and frankly, I don't know by what mechanism there would be any for one night, let alone more.

[slapmeawake]

My settings on my auto are 4 - 9. The 90% pressure reports from machine are 4.8-5.2. I have no problem breathing at a setting of 4. It sounds like I must be one of the few that can as most people need higher pressure. This is why my doc suggests I should try without the machine. I might actually be spending most nights at a pressure of 4. My AHI is always .4 or under. Leak is fine also. I slept without machine last night and woke up a lot but I wake up a lot with the machine. My sleep is just fractured all the time anyway. I really don't know what else to do at this point.

[BML]

I am one who has lost weight and my pressure needs are all the way down to 5. My doc wants me to try to go without the machine and see how I do. This residual effect is interesting to me because I tried but never for more than 3 nights. I seem to sleep better with the machine but 5 is such a low number. I think I will try to go a week and see what I come up with. I sleep so poorly anyway, its not the apnea waking me anymore, who knows what it is. All I know is since I lost weight my therapy is not keeping me asleep. I wake up at least twice a night, like every 2 or 3 hrs. I'm very depressed to think this is what I have to look forward to for the rest of my life. Anyway, don't have answer to all of this. Keep in mind my apnea was mild to begin with so the weight loss really helped me. Someone with severe apnea will need the machine always but I do want to get off if I can. Just don't know if that little bit of pressure is really helping. The Doc thinks it might actually be disturbing my sleep but when I tried to go without my machine it seemed I slept a little worse. I'll try longer and report back. Maybe after 3 years of CPAP I can't just stop but need to wean.

You know, I weigh 175lbs most of the time, it was even a bit less when I started therapy. MY AHI when diagnosed was close to 70. Weight is not always the issue and by the way at 180lbs today my pressure is 14. So 5 may not be enough for you, or maybe you are so used to the therapy, you need to adjust physically and psychologically to not having it to support you at night.

[BML]

slapmeawake - I'm with Slinky. How was it determined that your pressure need is now 5? Is your data showing you have no events at 5? Just wondering, there's got to be a point where minimum effective pressure crosses the line into too low to breathe. Unless you have good data to substantiate that reduction to 5, I'd be suspect. Are you using it in straight cpap mode? I see you have an auto listed. If you used it in a range, say from 5-10, just picking a number out of the sky, and your pressure increases during the night, you'll know that 5 is inadequate, and you do indeed still NEED cpap. If it stays at 5, you'll know that being too low is not the issue.

BML - I don't have a link to the old thread, but this has been discussed and there was an old article on PubMed about there maybe was a 1 night residual effect, but the study was too small to be impressive. I would suggest maybe you had trouble not because it was a bipap, but because of the auto feature. While it's not an end-all answer, maybe you should sleep a night with an oximeter and at least how that looks when you're out in the woods.

Actually, the most recent night where I took mask off (and didn't notice!) I was on CPAP 14, still felt like I got a baseball bat over the head in the morning. I thought of the oxymeter, its a good idea, would give me a sense of how I compromise my health when off CPAP. Just need to find the $$$ to pay for it.

[BML]

I don't remember the details of this (and I don't think I read the original articles), so I don't know how compelling the data was that there are residual effects for one night. I haven't seen anything to suggest that there can be effects for more than 1 night, and frankly, I don't know by what mechanism there would be any for one night, let alone more.

I know, I mean if you need the machine then you need the machine, right? I know when I skip when I spend a night in the woods, I am compromising my night's sleep/health. I don't get that its ok ever, residual effect? If your airway collapses because of 'mechanical' reasons then with no CPAP support, it should collapse and cause problems. Interesting that some of you have heard of these 'residual effects'.

[slapmeawake]

I don't understand what is meant by 5 might not be enough for you. If I have my Auto set at pressures 4-9 and in 8 hrs of sleep it only goes up to 4.8 or 5 why would I require more pressure? Wouldn't my auto adjust for that since I have it set at 9 for the upper limit,which by the way was my titrated number when I was 60 lbs heavier? Am I missing something here? Just curious what others think about this residual effect thing and maybe that is what my problem also.

[pat200]

Not sure if I understand. Your doctor wants to see if you still need it since you now need such a low pressure? If you only needed 4-5 pressure at the beginning would you have been given CPAP as a treatment? Maybe one of those dental devises?

My understanding was that the severity of the apnea was not related to the amount of pressure needed to prevent the apneas. (Just beginning the learning process)

[slapmeawake]

This has taken on a life of its own lol, didn't mean to hijack the thread. I was originally titrated at 9, think this was in my previous message. Since I have lost weight my pressure need has dropped to 5 and the Doc says since my apnea was mild to begin with I might not need the machine since the pressure is barely moving at all on my auto most nights. Now I don't know if I really need the machine or I'm just so used to sleeping with it that it seems like I don't sleep quite as well without it. Anyone else out there who has a really low pressure like me and can give me some insight. I was curious about the residual effects of CPAP and thought maybe that was going on with me also.