Strange results from sleep study- EXPLAINED biPAP

[SleepOly]

I just had a new sleep study last night, the first one since my initial sleep study in 2002. My original prescription was a straight pressure setting of 10. I had reset my apap to 9.5 to 14. Sleepyhead shows I have an ahi average that is normally under 2, and average pressure just under 10 with a peak of 13.5. I have not slept great for some time now, waking up frequently, and thought I may be having centrals, or strange breathing. I also have a nasty work schedule 1 AM to 11 AM Wednesdays and Thursdays, Fridays 9 AM to 7 PM, and Saturday 8 AM to 6 PM.

I thought I didn't sleep much during the study, but when I did I had some intense dreams. I asked the sleep tech if I really slept during the study, and he said I slept great. I asked him if I was in the 10 to 14 range. He told me I was sleeping best at 18. I am confused as to why the pressure is drastically different. Has anyone experienced anything like this? I will be seeing the sleep doctor/ neurologist Monday to go over results, and I am trying to wrap my head around why the pressure is so much higher, when technically I should sleeping well at the 10 cm setting.

[LSAT]

I don't think the tech was right in sharing that with you. If you have continually slept with a pressure of 10/14 with an AHI of <2, the pressure of 18 sounds unrealistic. Personally I would keep the pressure where it was until I discussed it with the doctor....(assuming it is a qualified sleep doctor). Have you been using Sleepyhead Software?

[SleepOly]

I occasionally check with sleepyhead, but can go months without checking. I knew my pressure was higher, after so many years with more or less the same setting. I was surprised that the pressure was left up. I actually adjusted a strap myself due to leaking at the higher pressure. I was also using a nasal mask instead of pillows. I also remember having several apneas when I dosed at the beginning of the study.
I normally have several arousals while sleeping, and not much dreaming. Could it be that I need the extra pressure to achieve REM sleep? I know I am jumping the gun, and may have a better understanding when the doctor goes over the data on Monday.

[palerider]

I thought I didn't sleep much during the study, ... I am confused as to why the pressure is drastically different. ... when technically I should be sleeping well at the 10 cm setting.

rather than type it over, I'll point to these thoughts:
viewtopic.php?f=1&t=111625&p=1072266&hi ... h#p1072266

[Mudrock63]

I wouldn't get wrapped around the axle with the sleep study, until you talk to your doctor. Also agree with PR's link. A sleep study is a snapshot of a small period of your overall sleep in an artificial environment. To me, it's a great tool for diagnosis. Optimal treatment, OTOH, is a different story. That is best achieved, IMO, by the patient learning about the condition, using the available software, and tweaking their own settings. But that is just me, and I am sure some will disagree. My original prescription settings were a third of the pressure I really needed to get my condition properly treated.

[dhoppe]

I thought I didn't sleep much during the study, ... I am confused as to why the pressure is drastically different. ... when technically I should be sleeping well at the 10 cm setting.

rather than type it over, I'll point to these thoughts:
viewtopic.php?f=1&t=111625&p=1072266&hi ... h#p1072266

+1

[SleepOly]

Just returned from follow up with doctor about sleep study, and I was prescribed bi-pap. Thanks for all the input. Now I am going to studybi-paps quick before going to my DME to request a new machine. Equipment suggestions welcomed>

[robysue]

Just returned from follow up with doctor about sleep study, and I was prescribed bi-pap. Thanks for all the input. Now I am going to studybi-paps quick before going to my DME to request a new machine. Equipment suggestions welcomed>

The leading bilevel machines on the market right now are the Resmed Aircurve 10 VPAP and VPAP Auto and the PR DreamStation BiPAP Pro and BiPAP Auto. All four record full efficacy data. Try for an Auto if you can; they're a bit more flexible.

The biggest differences between the Resmed and PR bilevels boil down to (1) BiFlex and how the machines transition between IPAP and EPAP and (2) how the auto algorithms handle PS = IPAP - EPAP.

The Resmed AirCurve VPAPs don't have "EPR" since EPR is strongly based on the way Resmed VPAPs transition between IPAP and EPAP; a PS = 1, 2, or 3 on an AirCurve VPAP with EasyBreathe set to ON feels pretty close to an AutoSet with EPR = 1, 2, or 3. But the PS can be set to 4 or more on the VPAP. If EasyBreathe is turned off, the transitions between IPAP and EPAP are sharper and more sudden.

The PR BiPAP Pro has BiFlex available. BiFlex provides a bit of extra exhalation relief that goes beyond that provided by the drop from IPAP to EPAP. In other words, if IPAP = 18 and EPAP = 14 and BiFlex is turned on, then when you start to exhale the pressure will actually drop to something between 12 and 14cm at the beginning of the exhalation and it will increase back to 14 during the second half of the exhalation. The exact amount the pressure will drop below EPAP depends on both the flex setting and the strength of the exhalation itself. Even with BiFlex turned on, the transitions between EPAP and IPAP are sharper and more sudden on the PR bilevels than they are on the Resmeds when EasyBreathe is turned on.

Some people (including me) find the more sudden transitions more natural to breathe with than the EasyBreathe pressure curve on the Resmed VPAPs. Others prefer the smoother transition created by EasyBreathe on the Resmeds.


The auto algorithms on each of the Auto bilevels are closely related to the auto CPAP algorithms of the APAPs from the same manufacturer. The Resmed machines increase EPAP and IPAP by exactly the same amount at the same time---in other words, the PS is constant. The PR machines increase IPAP for flow limitations, RERAs, and hypopneas and they increase EPAP for snoring and obstructive apneas. Hence the PS is allowed to vary. How much the PS can vary depends on the min PS and max PS settings.

[VVV]

I have not slept great for some time now, waking up frequently,

I also have a nasty work schedule 1 AM to 11 AM Wednesdays and Thursdays, Fridays 9 AM to 7 PM, and Saturday 8 AM to 6 PM.

Do you think one of those things might be the cause of the other and not have anything at all to do with the CPAP therapy you were getting? Just maybe?

[palerider]

Just returned from follow up with doctor about sleep study, and I was prescribed bi-pap. Thanks for all the input. Now I am going to studybi-paps quick before going to my DME to request a new machine. Equipment suggestions welcomed>

The leading bilevel machines on the market right now are the Resmed Aircurve 10 VPAP and VPAP Auto

that's the resmed aircurve 10 S and the aircurve 10 vauto.

If EasyBreathe is turned off, the transitions between IPAP and EPAP are sharper and more sudden.

easybreath is always on, and can't be turned off, in vauto mode, it's optional in S mode.

Some people (including me) find the more sudden transitions more natural to breathe with than the EasyBreathe pressure curve on the Resmed VPAPs. Others prefer the smoother transition created by EasyBreathe on the Resmeds.

I'm one that REALLY dislikes the sudden transitions...

[SleepOly]

I picked up my aircurve V auto this afternoon, actually had choice between this and the dreamstation. My DME only stocks the full data models. My machine was prescribed for 14/18. I have had a lot of running around today, so have been unable to check on the easybreath or other settings. Do the different settings determine the time of inhale and exhale? I never really paid much attention to biPAP. Something new to learn!

[palerider]

Do the different settings determine the time of inhale and exhale? I never really paid much attention to biPAP. Something new to learn!

there are settings that can tune the length of time that the machine remains at ipap, but I don't advise messing with them until you've figured out everything about how bilevel works.

[Chevie]

Sleepyhead shows I have an ahi average that is normally under 2, and average pressure just under 10 with a peak of 13.5.

I don't understand why you went for another sleep study. It seems obvious that your first problem is your work schedule.

[Chevie]

I have not slept great for some time now, waking up frequently,

I also have a nasty work schedule 1 AM to 11 AM Wednesdays and Thursdays, Fridays 9 AM to 7 PM, and Saturday 8 AM to 6 PM.

Do you think one of those things might be the cause of the other and not have anything at all to do with the CPAP therapy you were getting? Just maybe?

Yes! She is right in describing that as "a nasty work schedule".