Confused and frustrated...machines, AHI, etc.

[dannah00]

I am a newbie here but I'm not too new to cpap. I am a 32 year old woman. I was diagnosed 5 years ago and was compliant with treatment for about a year and a half. I never felt better with treatment and after multiple pressure changes and overnight oximetry tests with no improvement, I gave up. I used my cpap intermittently for the last 3 years and have been using it nightly for about the last 6 months. I still feel tired and have headaches daily. I don't notice any difference in my alertness or well being whether I use my cpap or not. I am desperate to feel better and I don't want to give up on treatment. I recently had an appointment with another sleep doctor who suggests having another sleep study and buying a new cpap machine. I don't feel like I can afford to go through with either of these options, let alone both.

My Dr. referred me to a local DME and I have had multiple experiences which I would categorize as horrible. I currently have a ResMed S8 Elite II which this DME told me was "broken" and tried to sell me another machine. They were able to pull data from my machine which said my AHI over the past several months was between 10 and 11. I know this is not ideal. This DME sent me home with a loaner - Respironics Mstar something or other. I used that for several weeks before I got into another DME which told me my S8 was working fine. This DME read the Respironics data card which puts my AHI around 4. The RT told me that was acceptable and when I asked about the differences in AHI between the machines and she didn't know.

I did two overnight oximetry tests last week using each machine. Both oximetries were nearly identical but the AHI's were significantly different. With my S8 the AHI was around 12 and with the Respironics it was around 2.

I would rather not pay for another sleep study or purchase a new cpap machine at this point in time. Not sure if the doc will go for that, but can anyone explain to me why there would be such a difference in AHI between the machines and give any suggestions for steps to take next.

[VikingGnome]

It is possible that your S8 is no longer blowing at the pressure it's programmed to blow. Hence, you are having more events with the lower pressure. You could ask your DME to test the pressure with the little manometer to confirm that it is indeed blowing at the correct pressure. As machines age, they gradually lose some their power and do not deliver the pressure they are supposed to blow.

[Foggy1]

Probably a silly question, but it never hurts to ask--The machines are both configured with the same pressure settings?

[dannah00]

The S8 was tested and it measures at the correct pressure. Both machines are set to a pressure of 13.

[Julie]

Have you ever tried a different mask, possibly a FF one that might short-circuit any mouth breathing that might be happening when you're asleep? Losing the Cpap air that way will not help your OSA if it's a factor.

[dannah00]

I struggle with mouth breathing and am currently using a chin strap. I asked my DME about a full face mask but she didn't think I needed to change masks. I am just so confused about why the AHIs are so different between the machines. All local DMEs here use Respironics machines only. None are familiar with ResMed machines at all. I have thought about looking for a DME farther away that may use/support ResMed.

[robysue]

Do you know the break down of the event recorded by the S8? Are they mostly Hs???? The S8 has the reputation of being very, very aggressive when it comes to scoring hypopneas. And that could explain part (or all) of the difference in AHI between the Repironics M-series and the Resmed S8 machine if the AI was similar on the two machines.

Are there any other sleep issues? What's your sleep schedule look like? How many times do you typically wake up during the night? How much sleep do you think you get on a typical night?

[Julie]

Chin straps can be less effective as you can still lose air through your lips.

[LSAT]

I have used the S8 and know that it definitely overstates HI. When I used the S8 my AHI was consistantly in the 4-5 range. Once I switched to the newer S9 my AHI dropped to 1.5 - 2.5. This was using the same pressure range. There are many posts discussing this. The S8 is an excellent machine and definitely will give you the therapy you need. Just be aware that it tends to overstate AHI compared to other machines. It's not defective in any way....it just uses a different algorithm for calculating AHI.

[dannah00]

I was looking at my data (on the machine since no local DME can read my data) and AHI has been between about 8 and 16 every night for the past month or so. When I look at the breakdown the AI is usually around 2 and the HI make up the rest. I understand that the machine reads high HI vs other machines. I just don't understand how to interpret my AHI. Does treatment get based on the reported AHI or the way I feel? I don't know where to go from here.

[jamiswolf]

Hi dannah00,
Sorry you are having all these difficulties. Some cpap users in your situation just abandon the MD/DME runaround and simply buy equipment, masks etc from the secondary market...like Craigslist sellers. I'm one of those people.

One comment on your pressure. Once you get up into that range and above, some people have difficulty exhaling against the pressure. That's when a BiPap or BiLevel machine comes in. The inhale pressure and exhale pressure are different making it easier to exhale. Has that been an issue with you?

I know it's frustrating but you have many years ahead of you so hopefully this can be resolved and get you back on track.
Hang in there,
Jamis

[robysue]

I was looking at my data (on the machine since no local DME can read my data) and AHI has been between about 8 and 16 every night for the past month or so. When I look at the breakdown the AI is usually around 2 and the HI make up the rest. I understand that the machine reads high HI vs other machines.

Are those numbers coming off the S8?? If so, that means that your real AHI is likely between 6 and 10 on many nights. And that is too high for therapy to be considered effective.

I just don't understand how to interpret my AHI. Does treatment get based on the reported AHI or the way I feel? I don't know where to go from here.

It's a combination of both. If you feel lousy AND the AHI is still too high, then undertreated OSA is the usual suspect for explaining the continuing fatigue and daytime sleepiness and tweaks to the PAP therapy are often recommended. An increase in pressure is the usual first suggestion --- if leaks are under control. If leaks are not under control, then getting them under control is the first step and then it's worth seeing if that fixes the problem before increasing the pressure.

If the AHI is consistently under 5, but the patient reports no improvement in terms of daytime functioning or how they feel during the day, things are much more problematic. Some patients never feel much different with CPAP than without it. (Figures commonly cited in the literature say about 10-15% of compliant PAPers never see much improvement; part-time PAPers are not likely to see much improvement because it takes time for PAPing to make a real difference in many people.) There's also a lot more to getting a genuinely good night's sleep for many people than simply fixing the OSA problem. Many PAPers continue to be plagued with fragmented sleep for other reasons and some PAPers have problems with the machine itself triggering additional arousals in a variety of ways.

And then there's also the fact that just because you have OSA doesn't mean you can't have other health problems that can manifest themselves with OSA-type symptoms of daytime fatigue, brain fog, and excessive daytime sleepiness.

[old dude]

I was looking at my data (on the machine since no local DME can read my data) and AHI has been between about 8 and 16 every night for the past month or so. When I look at the breakdown the AI is usually around 2 and the HI make up the rest. I understand that the machine reads high HI vs other machines.

Are those numbers coming off the S8?? If so, that means that your real AHI is likely between 6 and 10 on many nights. And that is too high for therapy to be considered effective.

I just don't understand how to interpret my AHI. Does treatment get based on the reported AHI or the way I feel? I don't know where to go from here.

It's a combination of both. If you feel lousy AND the AHI is still too high, then undertreated OSA is the usual suspect for explaining the continuing fatigue and daytime sleepiness and tweaks to the PAP therapy are often recommended. An increase in pressure is the usual first suggestion --- if leaks are under control. If leaks are not under control, then getting them under control is the first step and then it's worth seeing if that fixes the problem before increasing the pressure.

If the AHI is consistently under 5, but the patient reports no improvement in terms of daytime functioning or how they feel during the day, things are much more problematic. Some patients never feel much different with CPAP than without it. (Figures commonly cited in the literature say about 10-15% of compliant PAPers never see much improvement; part-time PAPers are not likely to see much improvement because it takes time for PAPing to make a real difference in many people.) There's also a lot more to getting a genuinely good night's sleep for many people than simply fixing the OSA problem. Many PAPers continue to be plagued with fragmented sleep for other reasons and some PAPers have problems with the machine itself triggering additional arousals in a variety of ways.

And then there's also the fact that just because you have OSA doesn't mean you can't have other health problems that can manifest themselves with OSA-type symptoms of daytime fatigue, brain fog, and excessive daytime sleepiness.

These are good things to remember robysue; thanks for reminding me of them and summing it up so nicely. It's easy to forget some of this if you've had a good night on the machine but don't feel perfect the next day!