Apap Auto Range

Yoga · Post by **Yoga** » Fri Apr 01, 2005 10:14 pm

Just received encore pro software today and my husband set it up for my Remstar auto w/cflex. The machine is set for a pressure of 7-16. My recorded range for the past week has been been between 7 - 10. I can't stand it below 7. Should I leave the top setting at 16 or lower it and, if so, what would be the advantage?

I was titrated at a pressure of 7 but still snored and the sleep doc said to up it to 9. However, I still felt at times that was not enough pressure.

The long term trend average snore index is 3.4. Is that in a good range?

My AHI over a period of 4 days fluctuated between 2.8 to 13.5.

Thank you Derek, Rested Gal, Harper, and others who provided information on how to use the software. Respironics should definitely hire you.

Any other advice would be greatly appreciated.

rested gal · Post by **rested gal** » Sat Apr 02, 2005 2:15 am

Yoga, what mask are you using? If it's not a full face mask, do you think you might be breathing through your mouth sometimes during your sleep...or leaking air through your mouth?

derek · Post by **derek** » Sat Apr 02, 2005 7:12 am

I wouldn't worry about the maximum pressure setting too much, since you are apparently not hitting the limit. In my case I find that my nightly AHI is affected by the minimum setting. I have written software that gleans additional info from the Encore Pro database - it shows me the following:

Min Press. 7cm - Average AHI 1.9
Min Press. 8cm - Average AHI 1.3
Min Press, 9cm - Average AHI 0.6

The trend is statistically significant. My conjecture is that at low AHI levels the REMStar Auto does not react to the isolated events, and so the APAP is really acting more like a CPAP - therefore the minimum pressure becomes more important in the treatment. This may not apply to you.

wading thru the muck! · Post by **wading thru the muck!** » Sat Apr 02, 2005 9:03 am

Yoga,

As I think rested gal was getting at, I would like to know what your leak graph looked like. Those AHI numbers are higher than they should be. You should get AHI results between about 1 and 3. It's been my supposition that auto machines can miss "events" when the leak level is high. Get back to us on the leak data. I think if leaks are the culptret, if you get them under control my guess is your AHI will be more in line. As far a the top end of the range, derek's data analysis is very valuable and indicative of how you should approach setting your pressure range.

Thomas · Post by **Thomas** » Sat Apr 02, 2005 9:30 am

I've been having high and variable AHI numbers as well, and leaks are clearly not a part of the problem. Surely they would be if they were there, but for me, it's something else, yet to be determined. My mask fit rating on my machine is always at a five star excellent rating. The leak numbers are extremely low, often 0. So there are other variables to consider other than leaks. In fact, sometimes when there were more leaks using different masks, AHI was lower than when leaks were 0 (usually with pillows). Doesn't make a whole lot of sense, but I'm determined to figure this out. So far, I'm having better results with masks, which I don't like, than with nasal pillows, which I prefer. Each person is different. I seem to be the MOST different

Tom

Mikesus · Post by **Mikesus** » Sat Apr 02, 2005 10:11 am

Thomas wrote:I've been having high and variable AHI numbers as well, and leaks are clearly not a part of the problem. Surely they would be if they were there, but for me, it's something else, yet to be determined. My mask fit rating on my machine is always at a five star excellent rating. The leak numbers are extremely low, often 0. So there are other variables to consider other than leaks. In fact, sometimes when there were more leaks using different masks, AHI was lower than when leaks were 0 (usually with pillows). Doesn't make a whole lot of sense, but I'm determined to figure this out. So far, I'm having better results with masks, which I don't like, than with nasal pillows, which I prefer. Each person is different. I seem to be the MOST different

Tom

What machine are you using?

wading thru the muck! · Post by **wading thru the muck!** » Sat Apr 02, 2005 10:28 am

Thomas,

I'm not familiar with a "star" rating system for mask leaks. Can you fill us in on what is is and where it is from. Also it is not possible to have "0" leaks. There is a certain amount of leak built in to any mask to clear out the CO2.

rested gal · Post by **rested gal** » Sat Apr 02, 2005 4:21 pm

I think Thomas has the ResMed Autoset Spirit. You have to select a mask type on the machine. It also lets you test how the mask fit is ("poor" to "excellent") leakwise. I had a Spirit for a little over a week. Nice machine. The Humidaire 2 heated humidifier that you can get with the Spirit is a pain to deal with. One of the handiest features of the Spirit is being able to push a few buttons on top and see the AI, HI, and AHI in the little display window the next morning.

Thomas · Post by **Thomas** » Sat Apr 02, 2005 5:49 pm

RG is correct. The Spirit has one to five stars (*) on the display to help define mask fit. It has always shown five so far. I have had 12 nights of zero leaks shown on the display out of the last 23 nights. The highest leak number was 0.3. During that time period of 23 nights the AHI reading has measured from 7.1 to 43.5.

Tom

wading thru the muck! · Post by **wading thru the muck!** » Sat Apr 02, 2005 7:24 pm

Thomas,

Are you looking at a leak graph or just a readout number on the screen. If you AHI variation is not leak driven, I would guess the Spirit algorithm is not very good at anticipating your "events."

Thomas · Post by **Thomas** » Sat Apr 02, 2005 9:36 pm

These are readouts on the screen. The strange thing is that I used a Spirit machine from the sleep lab last summer for a two week study to re-determine what pressure my cpap should be set at. My AHI average from that time was 5.5. The technicians at the lab were baffled.

Tom

Yoga · Post by **Yoga** » Sat Apr 02, 2005 10:26 pm

Rested Gal,

During my daily sleeping hours, half of the time I use the F&P Flexfit 405 and the other half the Swift with adaptations - one of which is to make it a snugger fit as I posted some time ago using a chin strap.

I have never been a mouth breather to my knowledge and my husband has confirmed this at night.

Muck,

The leak ranges for a period of approximately one week are:

20 - 80 LPM
45 - 60 LPM
45 - 70 LPM
50 - 70 LPM
45 - 50 LPM
40 - 75 LPM
45 - 60 LPM

Thank you both for you interest.

Yoga

rested gal · Post by **rested gal** » Sat Apr 02, 2005 11:51 pm

Yoga, I guess I'd probably try upping the lower pressure some more. But I really don't know what's best in that case. Since you have the software, you could give that a try for a night or two.

Thomas · Post by **Thomas** » Mon Apr 04, 2005 7:21 am

If the algorithm is the problem, would increasing the minimum pressure counter-act the algorithm and correct the problem? I've tried increasing it to 10 for a few days awhile ago, and had no difference. 95th centile pressure has varied from 8.6 to 12 in the last week. AHI has also been better, below 20, in the last week. I've read a few times about raising the minimum until the problem is resolved, and I figured 10 would resolve it since that was my median pressure last summer when tested. But it didn't work. Any more thoughts anyone?

(didn't mean to steal Yoga's thread)

Tom

Yoga · Post by **Yoga** » Tue Apr 05, 2005 3:48 pm

Rested Gal,

I increased the minimum pressure from 7 to 8.5 as you suggested. My highest leak rate with the Swift was 64.7 lpm - with the F&P 405 was 50.6 lpm at a minimum pressure setting of 7. My highest leak rate with the Swift was 56.7 lpm - with the F&P 405 was 43.75 lpm at a minimum pressure setting of 8.5. Therefore, it did make a difference as you suggested. Is this considered a significant leak rate?

However, the biggest surprise is that my AHI is significantly lower using the F&P 405 than the Swift. At a minimum pressure setting of 7 cm my AHI was 4.5 with the F&P 405 and 9.8 with the Swift.

At a minimum pressure of 8.5 cm with the Swift mask my AHI was 6.8 and with the F&P 405 it was 1.4.

However, I feel more refreshed after using the Swift.