Newly Diagnosed With Question

[ronsch00]

I recently had my first sleep study and was tested with CPAP and Bi-Level machines (see attached results). After about two hours on the CPAP machine I could not tolerate it any more and they switched me to a Bi-Level. Apparently the Central Apneas continued on the Bi-Level and they have me coming back for an ASV test.

To my uninformed eye it appears that the apneas increased on the bi-Level compared to the base CPAP. Is this normal? I had no REM sleep during the test and oxygen levels ranged from 94 to 89%.

I would appreciate any advice from the experts.

Thanks, Ron

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[PaulaO2]

It would appear the best setting was a CPAP pressure of 14.

Do you have a lung condition? That would be why they switched to the bilevel. Otherwise, if you were "simply" feeling overwhelmed by the pressure, that is easily fixed by just getting used to it over time, starting out slightly less than what you need then slowly increasing. Or using APAP.

xPAP pressures can cause central apnea events and they typically go away with treatment. The user starts out at a lower than optimum pressure then slowly increases it. Or just waits it out. An APAP can often assist with the problem as the pressure only increases as needed.

Some people can have "mixed" or "complex apnea" but it doesn't really look that that is your case. The central events are barely worth noting until the bilevel is used.

[justMongo]

Our Expert is at their night job at McDonalds. But, I'll give it a shot.
Bilevel permits a split between inhalation (IPAP) and exhalation pressure (EPAP.)
A reduced exhalation pressure (EPAP) makes it easier to breathe.

They had you at a split of 4 cm-water. That makes it easier to breathe out; but...
You also blow off more CO₂ at the reduced EPAP. CO₂ is a primary central ventilation driver while asleep.
Hence, bilevel can increase Central Apnea (CA.)

[ronsch00]

Thanks for the reply. I do not have any known lung or heart problems, they switched during the test because I felt that I was smothered using the CPAP device. The report also said that periodic breathing persisted and central events continued at the bi-level settings and a Cheyne Stokes pattern developed.

The earlier home sleep study using SNAP (with no CPAP device) showed an RDI(AHI) of 78 and a central index of 16. If the bi-level or ASV device is more comfortable and ultimately controls the apnea levels, is going to bi-level or ASV ultimately going to make the condition worse compared to using a simple CPAP? We have great insurance at the moment so cost is not a major factor.

Thanks, Ron

[richb]

One option to try is using Ramp when starting your therapy. The machine starts at lower pressures and raises them over time (up to 45 minutes). This is another way to get used to the pressures.

Rich

[trish6hundred]

Hi ronsch00,
WELCOME! to the forum.!
I wish you much success as you start your CPAP journey, hang in there for more responses to your post.

[Sleepster]

If the bi-level or ASV device is more comfortable and ultimately controls the apnea levels, is going to bi-level or ASV ultimately going to make the condition worse compared to using a simple CPAP?

As others have said, bi-level gives two levels of pressure. The higher IPAP pressure when you inhale, and the lower EPAP pressure when you exhale. The difference between the two levels is called the pressure support. Having too high of a pressure, or too high of a pressure support, can lower the carbon dioxide level in your blood. It's the high carbon dioxide level that triggers the brain to call for a breath, so without this trigger the body doesn't breathe. When this happens for at least 10 seconds, a central apnea is scored. The central apnea index is the average number of central apneas per hour.

It appears you have central apnea, how much of it is there naturally and how much of it is caused by the CPAP or the bi-level therapy, is unknown. Most people get adapted to the therapy and the central apnea index drops on its own. If it doesn't then you need a machine that will initiate breathing on it's own. Bi-level CPAP machines can be set in a mode that allows them to do this, but ASV machines have more flexibility in the way they can be adjusted to do this. Of course, the greater flexibility means it's also more difficult to get the adjustment right.

This is where a good doctor comes in. Usually insurance companies direct the doctor to try the lower priced machines first, and when they don't work then you're switched to the more expensive and harder to adjust ASV machines.

If I had to guess, I'd say they'll start you out on a bi-level machine, and if it doesn't work you'll be switched to the ASV machine. If that's the case, I highly recommend that you push for an auto-adjusting bi-level machine. For example, the ResMed AirCurve 10 VAuto.

[ronsch00]

Thanks for all the good advice. I am scheduled for a echo cardiogram and the follow-up sleep study in about a week. I can't wait to start therapy and sleep better...

Thanks, Ron

[srlevine1]

Thanks for all the good advice. I am scheduled for a echo cardiogram and the follow-up sleep study in about a week. I can't wait to start therapy and sleep better...

Thanks, Ron

I would be interested in the results of the echocardiogram and if they found you had CHF, pulmonary edema, or were retaining fluid -- all potential causes of Cheyne-Stokes (Periodic Breathing) symptoms. My CSR appears to be linked to my salt-intake and fluid balance.

Best of luck with the test and the road to better sleep.

[ronsch00]

The tests were all normal and I started with an ASV device 2 months ago. My AHI went from 70 to less than 1. I feel much better. I had no fluid balance or salt level issues. Good luck with your therapy.

Ron