Questions about Sleepyhead and 90% pressure

Hello everyone!

I have severe obstructive sleep apnea (AHI of 115+).

I have spent two nights in the sleep clinic. 1st night was a straight test that resulted in the 115+ events an hour. On the night of the titration, they titrated me on a range of 5-12, only to realize that at 11, I still had an AHI of 35+.

So my sleep doctor has prescribed me a APAP rental (Resmed Airsense 10) on a scale of 8-20cm to see whether I qualify for a BiPAP/VPAP as I live in Ontario, Canada. I'm currently using Sleepyhead and I'm pretty well versed with it. However, I have a couple of questions about it that I hope you can help me with:

(1) Does 90% pressure normally equal the level that a CPAP should be set?
(2) I'm realizing that on the statistics tab, the 90% pressure only shows up for the last session. Is there a way to bring up the other days 90% pressure?
(3) If I have a 90% on the average between 19.5 - 20.0 and APAP and CPAP machines only go up to 20, is that an argument to get a BiPAP/VPAP?

Thanks in Advance!

1. Not necessarily but it could work out that way. 90% just means you were at or below that number for 90% of the night. People tend to forget the "or below" part of the definition. 90% numbers are easily skewed by relatively short periods at higher pressures so while they might be an indication of a general area for cpap pressures...it isn't something that is absolutely always spot on where a cpap setting would fall. I would prefer to look at overall average myself because I have seen 90% pressures easily skewed and misleading.

2. Go to the daily detailed report section and there's a statistic for the 90 % number (or 95 depending on SleepyHead parameters which can be changed if you wish).
If you don't have a daily detailed tab...there's a problem with SH.

3. Definitely. If you are seeing pressures over 14 or 15 on a consistent basis then a bilevel device would likely be very helpful. Not only because it can go higher than 20 cm if needed but because the added exhale relief available on bilevel devices would likely make things more comfortable in general.

The 90% pressure is of course the pressure you were at or below 90% of the time. It is frequently used in titration as the single pressure CPAP pressure, assuming the control of OA, H is acceptable. The 90% pressure may change from night to night on a APAP set wide open at 4-20 pressure, and will likely increase if a higher minimum pressure is selected.

The 90% pressure is usually calculated for the most recent session, 7-day, 30-day and if available, 6-month and annual periods. Sleepyhead will display all of these periods, sometimes in the absence of long-term data.

A 90% pressure above 14 is an argument for bilevel. A 90% pressure in the 19-20 range pretty much shows APAP is not suitable. For one thing, you will need some exhale pressure relieve at those pressures.

Take it a day at a time. The severity of diagnostic sleep apnea is not a good predictor of ultimate pressure requirement, but the fact you had unacceptably high AHI at a pressure of 12 suggests you will end up at a higher pressure. There is generally an improvement in AHI as you adapt to the therapy, so letting you try this for a period of time allows some of that to occur. Still seems strange to use auto-pressure of 5-12 to titrate rather than increasing CPAP pressure until apnea events were at acceptable levels. Was this a home test? Setting the trial at 8-20 seems like a good approach, but it is essentially self-titration as opposed to lab titration.

Edit: I see I posted at the same time as Pugsy... and we agree.

Thanks for your quick answer, Pugsy!

My average pressure over the past 12 days (that I've used the machine) is 14.97, so it's on the high end of the 14-15 scale.

Because I live in Toronto, in Ontario, Canada, they have pretty strict rules on what machine the public insurance covers (whether it be CPAP or BiPAP/VPAP). I'm assuming that if my average is 14.97 and my 90% is around 19.9, that the sleep doctor would recommend somewhere between those numbers, which would most likely put me in BiPAP/VPAP range.

Thanks for responding, Sleeprider.

In terms of the second test, it was in the sleep lab, but they only tested in the range of 5-12. I don't know why they tested so low, as I actually slept for 6+ hours, but I guess that's the way they do it here in Ontario when it's covered by the government.

Because Ontario only allows two sleep tests to be covered by the government in a year, the sleep doctor has to fill out a form for the government to allow me to have a third test. She suggested that I use an APAP now to get some relief versus waiting two more months for a BiPAP/VPAP titration.

That's pretty impressive pressure, and clearly would be an argument for bilevel. The machine is basically maxed out. What kind of treatment results are you getting so far?

One suggestion in discussing this with your doctor, you will help your case if you complain about the discomfort of that high pressure. One of the criteria for bilevel is failure on CPAP. I think it's great that you have stuck with this and seem to be doing pretty well, but don't let the doc know it's okay for you to be subjected to that kind of pressure....complain a bit.

Sleeprider wrote:That's pretty impressive pressure, and clearly would be an argument for bilevel. The machine is basically maxed out. What kind of treatment results are you getting so far?

One suggestion in discussing this with your doctor, you will help your case if you complain about the discomfort of that high pressure. One of the criteria for bilevel is failure on CPAP. I think it's great that you have stuck with this and seem to be doing pretty well, but don't let the doc know it's okay for you to be subjected to that kind of pressure....complain a bit.

I admit that the pressure isn't the easiest (Almost very night I've ripped my mask off for about an hour or two), but I diligently will put it back on when I realize that I have it off and finish the last couple of hours of sleep with it on. In addition, I've swallowed a ton of air and feel bloated pretty much 24/7.

However, even with the pressure issues, I was at an extreme stage with O2 saturation at less than 70% so even anytime under treatment I feel tons better.

I've been averaging 4:35 of use a night with an AHI of 4.3 according to Sleepyhead. I know 4.3 isn't perfect, but it's sure better than 115, or even 35.

That's what I'm talking about.

It is pretty clear the results will point to high pressure for you. A bilevel device can provide substantial relief by reducing EPAP pressure and still maintaining the airway. You will have your hands full coping with that anyway, but a single pressure or auto machine would not be appropriate with those pressures. Good luck!

I'm at 19 IPAP and 14.4 EPAP....

Resmed VPAP machine has been awesome for me for 3 years now!

Sleeprider wrote:That's what I'm talking about.

It is pretty clear the results will point to high pressure for you. A bilevel device can provide substantial relief by reducing EPAP pressure and still maintaining the airway. You will have your hands full coping with that anyway, but a single pressure or auto machine would not be appropriate with those pressures. Good luck!

Question for you if you know: Would an Auto VPAP be better than a VPAP?

Having an auto bilevel would come in handy because it could auto adjust as needed and for part of the night you might not need as much pressure as other parts of the night.
It's not unusual to need more pressure when supine sleeping or during REM stage sleep so having auto adjusting bilevel instead of fixed bilevel might come in handy should you happen to be one of those people whose pressure needs change throughout the night. Lets a person use lower pressures when they will work and only increases as needed. Otherwise a person has to use higher all night to cover those maybe higher pressure times.

Pugsy wrote:Having an auto bilevel would come in handy because it could auto adjust as needed and for part of the night you might not need as much pressure as other parts of the night.
It's not unusual to need more pressure when supine sleeping or during REM stage sleep so having auto adjusting bilevel instead of fixed bilevel might come in handy should you happen to be one of those people whose pressure needs change throughout the night. Let's a person use lower pressures when they will work and only increases as needed. Otherwise a person has to use higher all night to cover those maybe higher pressure times.

Thanks! I still have a month to go before my next appointment with the sleep doctor, but now that I know a whole lot more about my numbers. I can talk to her much easier - with me understanding what she's talking.

ramblingasian wrote:

Sleeprider wrote:That's what I'm talking about.

It is pretty clear the results will point to high pressure for you. A bilevel device can provide substantial relief by reducing EPAP pressure and still maintaining the airway. You will have your hands full coping with that anyway, but a single pressure or auto machine would not be appropriate with those pressures. Good luck!

Question for you if you know: Would an Auto VPAP be better than a VPAP?

as much better as a apap is vs a cpap.