can an APAP approximate a biPAP for a trial period?

[uphill]

Dear friends,

Thank you so much for this forum. It is indispensable.

Here's my background info: I'm two years into using my machine. It's a PR System One 60 Series Heated Tube Humidifier with Heated Tube. I use the P10 nasal mask with it.

ISSUE: Cripplingly exhausted despite getting my AHI down below one almost every night, sometimes even below .5.

Per my reading here and elsewhere, the look of my breathing is classic for UARS, with choppy plateaus for every breath. I've been experimenting with raising the pressure, trying to approximate a Dr. Krakow experience. I'm up now to 14 max, 10 min. But my breathing is no less choppy, and I feel horrible still. I do not have insomnia or any lung issues that I know of. I fall asleep prepared for a good night's sleep every night (the beauty of denial!) but have many arousals. Definitely a low arousal threshold.

I see that biPAP could be better for UARS, but I can't run out and buy a machine without getting a sense of whether it might help. I do not presently have a sleep doctor worthy of those words.

So my question is (at last--thanks for your patience): Can I approximate a biPAP experience by setting, say, the exhalation relief to the lowest setting and moving the max and min air pressures up in tandem on my System One aPAP?

Would I be better off trying it as a straight CPAP so that the exhalation fall-off is less? I can tolerate about 11 on that. Have only tried it for an hour so far, just thought of it.

MANY THANKS in advance for any thoughts.

[OkyDoky]

With your Respironics machine flex options is more of a flow shaping than actual pressure decrease on exhale. Even with the Aflex setting at 3 the most decrease you can get is 2cm/H20.
ResMed Auto machines have EPR (Exhalation Pressure relief) which can provide 3cm/H20 decrease at expiration.
Bilevel machines provide larger decreases in exhale pressures.

If you want to monitor with software, here is a link to help you. https://sleep.tnet.com/resources/sleepyhead

[PoolQ]

I started with APAP with EPR set to 3 and changed to BiLevel (VPAP) and set exhale relief to 4 and this was all I needed to tolerate the machine, until I found out that I also had COPD

[uphill]

Hi, many thanks to OkyDoky and PoolQ. I am monitoring on Sleepyhead (crazy grateful for that).

I just switched to CPAP after two years, as in switched for a single hour of sleep time this morning, and the crazy breath-flow variations are calmer. Is this expected and might it result in fewer RERAs and FLs?

I wonder if others with UARS have found CPAP better than APAP. (And then, maybe they have found biPAP better than both.)

[OkyDoky]

I started with APAP with EPR set to 3 and changed to BiLevel (VPAP) and set exhale relief to 4 and this was all I needed to tolerate the machine, until I found out that I also had COPD

PoolQ, The OP has a Respironics machine and doesn't have EPR. They only have flex settings which will only produce a decrease of appx. 2cm/H2O

We really need to see data to see if there is anything there that might point to why you are having arousals. Before APAP did you have problems staying asleep?
Your question here "Would I be better off trying it as a straight CPAP so that the exhalation fall-off is less?" Is backwards of how a Bipap works. Bilevel machines have greater exhalation decreases. A more narrow range between your minimum and maximum pressures or CPAP could be beneficial as long as your AHI is low. Especially if you are sensitive to the pressure changes.
Check out your medications to see if they interfere with sleep.

[djhall]

So my question is (at last--thanks for your patience): Can I approximate a biPAP experience by setting, say, the exhalation relief to the lowest setting and moving the max and min air pressures up in tandem on my System One aPAP?

No. A biPAP can function a bit like power assist for your breathing. As you begin to breathe in the pressure rises and if the inhale/exhale difference (pressure support) is set high enough the machine is practically pushing the air into your lungs. Once you stop inhaling the machine drops the pressure and all that high pressure air in your lungs wants to go rushing back out. For basic obstructive apneas this isn't particularly helpful other than moderate pressure support making exhaling against high pressures feel much more natural and comfortable. Pressure support can have interesting effects on other kinds of breathing disorders, but a CPAP will never give you enough sustained pressure support to replicate the effects.

[uphill]

Thank you, djhall and OkyDoky, for helping to clarify. I'm only taking melatonin and tryptophan at night. Recent sleep study showed no apnea or hypopnea with CPAP treatment during study AND no stage three sleep! I'm going to try straight CPAP for a few nights and compare it to a few nights of using the aPAP with the min and max very close.

It may simply be that I can't get the pressure up high enough on inspiration without a biPAP. Thanks to a brother who used to put a pillow over my face and suffocate me when I snored, I get claustrophobic very easily and can't deal with high expiration pressure.

I found this useful post from Dr. Krakow, too, in case anyone is interested. wiki/index.php/UARS

Also a very interesting 2015 article from Sleep Science advocating the development of machines able to detect and address inspiratory flow limitations. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688581/

[djhall]

Thank you, djhall and OkyDoky, for helping to clarify. I'm only taking melatonin and tryptophan at night. Recent sleep study showed no apnea or hypopnea with CPAP treatment during study AND no stage three sleep! I'm going to try straight CPAP for a few nights and compare it to a few nights of using the aPAP with the min and max very close.

It may simply be that I can't get the pressure up high enough on inspiration without a biPAP. Thanks to a brother who used to put a pillow over my face and suffocate me when I snored, I get claustrophobic very easily and can't deal with high expiration pressure.

I found this useful post from Dr. Krakow, too, in case anyone is interested. wiki/index.php/UARS

Also a very interesting 2015 article from Sleep Science advocating the development of machines able to detect and address inspiratory flow limitations. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688581/

First, let me just say that the use of xPAP therapy to treat obstructive apnea is a fairly straightforward and well understood process. Treating UARS, FLs, RERAs, CAs, etc is a far less straightforward process and frequently ends up partially being a process of trial and error. There really won't be any way to predict what effect a bilevel machine will have for you short of actually getting your hands on one and trying it. I was lucky. I suspected I had sleep apnea, so when I saw an auto machine on craigslist for $100 I decided to buy it and test myself. That machine just happened to be an auto biPAP, and it wasn't until a few weeks later that I realized how much easier that made everything.

Unless you are one of the few people who are very sensitive to pressure changes I don't see CPAP vs APAP with a narrow min/max range making much difference. With CPAP the only tool you have at your disposal is adding more constant pressure to inflate your airway larger. If your sleep disruptions aren't caused by a narrow airway, adding constant pressure simply won't help. For disruptions caused by a narrow airway, at some point the effort of breathing against the increased incoming pressure causes more disruptions than it prevents (clinical guidelines are to switch to bipap at 15). If you hit either of those two conditions then you hit the limit of what you can do with a straight CPAP.

As I see it, your only real options are to condition yourself to higher constant pressures in the hope those will help, get a better sleep doctor, or find a way to get your hands on a biPAP to try.

[Julie]

You just said something important - melatonin is great for making you go to sleep, but even in small doses is also known (and I speak from experience) to waken you - or at least allow you to wake up - within hours of taking it... which is why it's so problematic for some people. There may be a way to take it (raising the dose a little, not a lot) that works better - I tend to take very little bits and if I do take a bit more, it seems to help.

[djhall]

Can I approximate a biPAP experience by setting, say, the exhalation relief to the lowest setting and moving the max and min air pressures up in tandem on my System One aPAP? ... Would I be better off trying it as a straight CPAP so that the exhalation fall-off is less?

It just occurred to me that you might have a misunderstanding about how these settings work. On a CPAP you only have one pressure. In straight CPAP that pressure never changes unless you change it. In auto CPAP the pressure starts at the minimum setting but the machine can adjust it up or down periodically during the night as long as it doesn't go below your minimum setting or above your maximum setting. Auto CPAP with 10 min and 14 max just means the machine starts at 10 but has your permission to change the setting to 11, 12, 13, or 14 on its own if it thinks one of those pressures will be better. None of that will have any effect on exhalation fall off or cause any change in the pressure delivered over the course of individual breaths.

Other than a little exhalation relief for comfort, there is no way to vary the pressure of a CPAP over the course of individual breaths.

[Jay Aitchsee]

Uphill, I recognize you've narrowed in on UARs as a possible cause of your poor sleep, but have you exhausted other possibilities? Do you follow the best sleep hygiene practices? Have you eliminated caffeine? Do you exercise daily? Have you taken a hard look at all prescription and OTC medications? Have you had a complete and thorough physical examination accompanied by other than routine blood tests which could reveal conditions known to contribute to poor sleep and fatigue?

[palerider]

I started with APAP with EPR set to 3 and changed to BiLevel (VPAP) and set exhale relief to 4 and this was all I needed to tolerate the machine, until I found out that I also had COPD

your comment is inapplicable to the OP's question.

[palerider]

So my question is (at last--thanks for your patience): Can I approximate a biPAP experience by setting, say, the exhalation relief to the lowest setting and moving the max and min air pressures up in tandem on my System One aPAP?

Would I be better off trying it as a straight CPAP so that the exhalation fall-off is less? I can tolerate about 11 on that. Have only tried it for an hour so far, just thought of it.

MANY THANKS in advance for any thoughts.

in a word, no.

a "biPAP" (more properly, bi-level, since ' BiPAP is a trademark of respironics) is a machine that gives you higher pressures on inhale and lower pressures on exhale. a bi-level setup may have inhale pressure at 12 and exhale at 7, or inhale at 18 and exhale at 10, or most any other combination. what you're talking about experimenting "exhalation fall-off is less" is the opposite of bi-level.

a resmed s9 or airsense 10 can act as a limited bi-level with their EPR setting, which reduces the exhale pressure up to 3cm, however respironics machines, such as yours, don't have this feature available. the *Flex setting, as OkyDoky said, is more of a pressure shaping routine, and while it does provide a little exhale relief, it is variable, and much less than resmed machines.

so, again, in short, no, it can't.