CPAPtalk.com

If someone is into the AHI Olympics (let's see if I can get my AHI reports even lower)

To the cynical it might look like an AHI olympics but to me it's about getting the best treatment possible. What basis does a person have to determine if they are getting the best treatment possible....two ways....the numbers and how one feels. Will lower AHI numbers make one feel better? How do you know unless you achieve those numbers? Maybe feeling ok is really feeling poorly to how one could feel if they achieve lower numbers. When does one stop striving to feel better and get better treatment...ie....lower their AHI numbers? Does one just accept the status quo of their treatment and quit trying

track wrote:When does one stop striving to feel better and get better treatment...ie....lower their AHI numbers?

You are assuming that a "better" number below an AHI of 5 means "better" treatment, but there is no published evidence that I am aware of to support that proposition.

Cheers,

Bill

You are assuming that a "better" number below an AHI of 5 means "better" treatment, but there is no published evidence that I am aware of to support that proposition.

I am not aware of any either....but plenty of people on this forum that claim that is the case. If people of the forum are to be believed...lower is better... in terms of how one feels. I am all labout feeling as good as I can when I get up in the morning and during the entire day. I don't want 45 second AI nor to I want 1.5 AI if I can get .5 AI....same with HI.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): AHI

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): AHI

Again, with my ResMed S8, my 4-month average AHI was about 2.5 and my 4-month average AI was 0.1 (so HI=2.4).

With my Remstar machines my 11-month average AHI has been about 0.4 and my AI has been 0.1 (so HI=0.3). Also, my 11-month average flow limitation index (FLI) is 1.3.

As was mentioned earlier, the Remstar machines measure flow limitations and ResMed does not. I think maybe ResMed may be lumping flow limitations with hypopneas but I don't know enough about these machines to know if that is indeed the case. I felt just as good with both machine brands ... perhaps because my AI was maintained at 0.1 for both machine brands ... thus the difference in HI measured made no difference (at least for me).

Nevertheless, even when I have a "rare" bad night (AHI > 4 ... I don't think I have ever had an AHI over 5 since starting my treatment) there is very little difference in the way I feel. When I do feel tired, it is usually because I stayed up too late and/or woke up too early (ie. just not enough sleep). I did have one bad week of sleep when I was experimenting with melatonin earlier this summer but it did not affect my AHI numbers. I appearantly do not respond well to melatonin supplements.

Also, the ResMed and Remstar algorithms are different. The ResMed APAP machines are more aggressive in ramping up pressure to prevent obstructive apneas and this quick rise in pressure may arouse (wake) light sleepers. The Remstar APAP machines are more gentle and less likely to arouse light sleepers, however the slower response may not prevent the onset of all obstructive apneas in time. As a fairly heavy sleeper, this difference made no difference for me.

As Bill said, don't approach it as an AHI Olympics competition. Instead I think you should approach it as optimizing your treatment for YOU (irrelevant to the AHI averages of others ... everyone is different). To otimize your treatment: 1) make certain you have leaks under control as a first prioity; 2) then analyze data by plotting efficacy data against pressure (a sensitivity analysis); and 3) don't make changes to machine settings unless you have one to two weeks of average efficacy data to base that change on.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): resmed, AHI

Thanks dreamstalker....trust me I am not in any olympic competition....except as it relates to optimizing the treatment....a goal I would think everyone would have.

As far as " then analyze data by plotting efficacy data against pressure (a sensitivity analysis);"....I don't have a clue what that is. I have software but there is no "efficacy" data provided that I know of. I look at the numbers and so far have not been able to pinpoint any specific causes to apnea or hypoapnea events other than what position I am sleeping in. No doubt sleeping on my back is bad news. To get the pressure necessary to deal with the apnea on my back I would have severe stomach bloating when I got on my side....so the obvious solution seems to be to not sleep on the back...even if that causes some sleeping discomfort and less sleep due to that discomfort.

Efficacy data is the info that appears in the LCD screen that provides the 95th percentile of pressure and leak that night, AHI, AI and HI. The Usage data is also available from that same initial Efficacy Data menu by pressing the Down button instead of the Left button.

Efficacy data include the observation values of AHI, AI, and HI measured by your machine.

Sensitivity analysis is a way of determining how a parameter such as pressure affects a dependent variable such as an efficacy value. How sensistive is AHI for example to changes in pressure.



Note how in this chart the various indicies relate to various machine pressures observed over 552 hours of data. The AHI curve is the cumlative of HI + OAI (or AI for ResMed). My OAI or AI is minimized with 11 cm of pressure while my HI is minimized with a pressure of about 10.2 cm of pressure. My optimum pressure setting is therefore between 10.2 and 11 cm and since I have an APAP I currently have my machine set at a min pressure of 10 and a max pressure of 13. That hump around 12 cm of pressure probably represents my time sleeping in supine and requires a little more pressure to minimize my AHI. However, my 90% pressure is 12 cm (not shown in this chart) and only about 10% of the time is more than that needed.

With ResMed software you should be able to export/import your data into Excel and make a similar plot of efficacy data values against pressure.

My findings from having used the Resmed S8 for over a year and the Respironics M Series Bipap Auto for over a year are that the Respironics algorithm treats MY sleep apnea condition in a more favorable way.

Most importantly, I no longer require daily naps with the Respironics, which to me means I'm getting more restorative sleep. The Resmed still left me foggy and tired. I sleep longer on a daily basis, in no small part due to the comfort of Bi-flex. As you would suspect, My HI and AHI numbers are also much lower with the Respironics.

I'm not a brand name bigot and think both machines have advantages, but the Respironics treats my particular condition much more effectively.

[quote="Paul B"]My findings from having used the Resmed S8 for over a year and the Respironics M Series Bipap Auto for over a year are that the Respironics algorithm treats MY sleep apnea condition in a more favorable way.

Most importantly, I no longer require daily naps with the Respironics, which to me means I'm getting more restorative sleep. The Resmed still left me foggy and tired. I sleep longer on a daily basis, in no small part due to the comfort of Bi-flex. As you would suspect, My HI and AHI numbers are also much lower with the Respironics.

I'm not a brand name bigot and think both machines have advantages, but the Respironics treats my particular condition much more effectively.

What I'm really trying to compare is efficacy of treatment, irrespective of technology. Might I have achieved similar results on a Resmed bi-level? Perhaps. Anecdotally, I feel much better with the Respironics treatment; I sleep a lot longer; and it is a more comfortable experience for me.

I tried EPR with the S8 but I couldn't adequately synchronize my breathing pattern without it being a distraction, so I went back to APAP at 12.0. My M Series Bipap is set at 10.0 through 16.5 and I usually end up at 10.0 and 14.0.

I'm not trying to advocate one machine over the other. I am however, much happier with the Respironics.

[quote="Paul B"]What I'm really trying to compare is efficacy of treatment, irrespective of technology. Might I have achieved similar results on a Resmed bi-level? Perhaps. Anecdotally, I feel much better with the Respironics treatment; I sleep a lot longer; and it is a more comfortable experience for me.

I tried EPR with the S8 but I couldn't adequately synchronize my breathing pattern without it being a distraction, so I went back to APAP at 12.0. My M Series Bipap is set at 10.0 through 16.5 and I usually end up at 10.0 and 14.0.

I'm not trying to advocate one machine over the other. I am however, much happier with the Respironics.

billbolton wrote:

track wrote:When does one stop striving to feel better and get better treatment...ie....lower their AHI numbers?

You are assuming that a "better" number below an AHI of 5 means "better" treatment, but there is no published evidence that I am aware of to support that proposition.

Cheers,

Bill

I agree with Bill. There are no studies or published evidence I'm aware of either to support the idea that AHI less than 5.0 would mean "better" treatment.

Sleep labs and insurance companies that go by Medicare requirements consider AHI under 5.0 as normal. "Normal" people (in a PSG sleep study) who score less than 5 are not diagnosed as having OSA.

In other words, it's considered "normal" to have some events -- apneas and hypopneas -- during the night. Everyone can have some apneas and hypopneas every night, and still get sufficient restful sleep. They don't need CPAP.

For "normal" people with a sleep study AHI under 5 (unless they have UARS -- Upper Airway Resistance Syndrome) it could be very counterproductive to prescribe CPAP. You'd be trading the slight number -- "normal" number -- of sleep disruptions from just a few events for what could be many sleep disruptions from equipment issues -- mainly mask issues.

I think that if a person diagnosed with OSA and using CPAP is feeling well rested and is functioning "normally" in their daily life, THAT's the sign that the treatment is working well. Not what AHI their machines are reporting.

There can be so many other underlying health factors besides OSA affecting how a person feels even when CPAP is doing its job fine. If the treated AHI is under 5 I'd figure the OSA was being well treated. I'd not be concerned at all about getting it down lower.

If I felt sleepy, fatigued, or not fully "awake" during the day with an AHI under 5, I'd look to other possible health reasons...thyroid, GERD, hormones, nutrition, etc. I'd not think, "Would I feel better if my AHI was zero or .3 instead of 3 or 4?" First and foremost I'd look at my sleep hygiene...am I even getting enough hours of sleep? Is my mattress comfortable? Is everything about my sleeping environment conducive to getting good sleep?

Even if I did not feel sleepy, etc., I would not wonder, "Would I feel BETTER if I got my 3.0 AHI down to zero?" If I wanted to see if something could make me feel better, I'd concentrate first on sleep hygiene and nutrition.

Regarding whether: a "better" number below an AHI of 5 means "better" treatment

track wrote:plenty of people on this forum that claim that is the case. If people of the forum are to be believed...lower is better... in terms of how one feels.

Personally, I've always taken that with a grain of salt. I would venture a guess that if people kept a diary for a month, noting how they felt each day and did NOT check their machine numbers that entire month, they might be surprised at how little correlation there was between how they felt and whether their AHI was 0.4 or 4.0 from day to day.

I feel equally well rested after an AHI 4.0 night or an AHI 0.0 night.

Thanks rested gal.....You make a lot of sense. I assumed I would feel better when I started sleeping on my side versus my back. My AI was 1.2 average for 6 months when I didn't worry about what position I slept. I am able to get it to averaging less than .5 when I limit myself to side sleeping.

I was concerned and a little freaked when I had a night of clusters on my back. I had an AI that lasted for 60 seconds and about 5 events in 5 minutes.. That's when I started sleeping on my side. I actually feel less rested when I limit myself to my side and I sleep about an hour less. It seems as though I miss that deep sleep early in the morning when I get on my back and have all the events. IT's sort of a damned if you do and damned if you don't.