better understanding of why hypopneas remain uncorrected

[RMinOntario]

Rosemary, my questions regarding your titration study are:

1. 12.4 AHI is nowhere near the "normal" 5.0. Why did they stop the titration before getting you at least close to a normal AHI? Do you know what your average and lowest oxy sat was during the titration?
2. Seeing as that 12.4 is during a titration study, it should accurately represent the true events. When we see 12.4 AHI on a ResMed machine, it's really only useful when considered as part of a trend.

I think we can assume high HI on a ResMed machine *may* be caused by erratic or shallow breathing. I don't think we can assume the same during an actual sleep study where we're hooked up to additional machinery. Have you been able to ask your doc or sleep clinic why they stopped the titration when you AHI was so high?

Does that imply that shallow or erratic breathing does not factor into the sleep study 'final' results at all? I guess when I reviewed my results earlier, I didn't understand enough to question the final AHI of 12.4. Now, as I am a bit more educated, I see that 12.4 as a final AHI at sleep study, is maybe not all that good.

I put my O2 stats in the previous post.

[twokatmew]

twokatmew,
My %SaO2 awake was 90.0 - 100% with a mean of 94.8%
NREM was 87.0 - 97.0% with a mean of 92.9%
REM was 89.0 - 96.0% with a mean of 93.2%
TRT (not sure what that is) 87.0 - 100% with a mean of 93.9%

%Duration SaO2 in Range
100 - 90% Awake 95.7, NREM 96.9, REM 98.6, and TST (not sure what that is) 97.4
90 - 80% Awake 0.3, NREM 2.7, REM 1.4, and TST (not sure what that is) 2.3

Nothing lower was reported.

I don't really know the significance of the above numbers. Maybe you can explain.

I don't know what TRT or TST are, nor do I claim to be an expert by any means. But ... your mean and high oxy sats look very good. Your lowest oxy sats of 87% and 89% are not horrendously low, but they're low enough to do damage and prevent you from getting a good night's sleep.

I'm still interested in knowing why they stopped titrating you when they did. Perhaps you can get an answer to that when you see the doc next?

[twokatmew]

Does that imply that shallow or erratic breathing does not factor into the sleep study 'final' results at all? I guess when I reviewed my results earlier, I didn't understand enough to question the final AHI of 12.4. Now, as I am a bit more educated, I see that 12.4 as a final AHI at sleep study, is maybe not all that good.

I don't believe erratic or shallow breathing is noted in sleep study results. Erratic or shallow breathing doesn't necessarily indicate anything (other than perhaps not the greatest sleep) unless it's accompanied by arousals and/or oxy desats. They're concerned with limiting oxygen desaturation levels and events. As 12.4 AHI is at the higher end of mild OSA, I'm curious as to why they didn't continue the titration to better control OSA. Perhaps they had a good reason that's not readily apparent in your study results, or perhaps they just botched the titration!

Incidentally, AHI 5.0 and below is considered "normal." AHI 15.0 and above is considered "moderate." IIRC, AHI over 30.0 is "severe." So that AHI of 12.4 is still mild OSA. IMNSHO, your titrated pressure is very likely to be quite insufficient if your sleep study AHI is 12.4. (That is, if your diagnostic study showed an AHI of 12.4, your diagnosis would be mild OSA, and they'd have prescribed a titration study with CPAP. Looks to me that PSG tech quit before the job was done.)

Of course, I suppose it's possible those events occurred earlier in your titration, and they watched you go through yet another complete sleep cycle with no (or very few) events.

Remember, I'm only a three-month "veteran," and I'm learning, learning, learning! I'm sure curious to hear what the doc or sleep study has to say about why they titrated you as they did.

[twokatmew]

twokatmew,
My %SaO2 awake was 90.0 - 100% with a mean of 94.8%
NREM was 87.0 - 97.0% with a mean of 92.9%
REM was 89.0 - 96.0% with a mean of 93.2%
TRT (not sure what that is) 87.0 - 100% with a mean of 93.9%

%Duration SaO2 in Range
100 - 90% Awake 95.7, NREM 96.9, REM 98.6, and TST (not sure what that is) 97.4
90 - 80% Awake 0.3, NREM 2.7, REM 1.4, and TST (not sure what that is) 2.3

Nothing lower was reported.

I don't really know the significance of the above numbers. Maybe you can explain.

OK, I bet TST is "total sleep time." In your second paragraph, this would mean your O2 saturation remained between 90 & 100% for 97.4% of total sleep time, and between 80 and 90% for 2.3% of total sleep time. These are pretty good numbers, especially considering the number of events you were having.

[RMinOntario]

Good to hear that those numbers (O2) look good.

I am going to follow-up with the sleep lab to see if they can explain why they only got me down to an AHI of 12.4. I wonder if 'everyone' normally gets to a titrated AHI of <5. If that's the case, then that means we all S/B able to reach an equivalent therapy level, altho' many of us don't seem to get there.

I keep a spreadsheet of all my daily results, for July, August & Sept. I highlight all AIs < 1.0 and < 1.5 (different colours), HIs < 7.0 (because I'm a Resmed person) and AHIs < 7.0 (picked arbitrarily). Each month there are more highlighted numbers. After the last 2 week APAP trial, I moved up from pressure 12.0 ---> 12.4. I wouldn't have thought that the .4 would help that much, but it is showing better numbers. On the spreadsheet, I also have a comment field to remind me of things, such as going on a tour of 3 wineries one day this week .

I am consciously working to improve my sleep hygiene as well as it definitely needs work. I just ordered a book carbonman was writing about by Barry Krakow (?sp) from Amazon.

[twokatmew]

I added this to my previous message as an edit, so you may not have seen it. What I said, is that it's entirely possible you had your events early on in your titration study before they got your pressure up to better control events.

Your spreadsheet is an excellent idea. I've been wishing I could easily look at, for example, all the days where my AI or AHI was in a certain range, so I can see what the predominant pressure & leak were. I've been contemplating a spreadsheet but haven't got my design down yet.

I saw something about Barry Krakow earlier. Perhaps I'll check Amazon, too.

I'm glad to see you're beginning to get those numbers under control, Rosemary. I've been sharing many of your frustrations in my own therapy, and I'm starting to see trends and slightly better numbers. I think last night I may have had my best sleep yet on CPAP. So there's hope for us all, I think!

[dkdc]

From what I read here and on a similar thread on apneasupport forum, seems like the bottom line is -

try to get low leaks and use the cpap every night - but if your HI doesn't come down to under 5 - don't worry too much? Tell the doctor, but you might be one of those folks with shallow or irregular breathing and so you may get an HI that is higher than it should be on certain machines. Or you may just be a slow responder. Just hang in there and wait a month or six months and see if you feel better.

Does that sound about right?

[RMinOntario]

From what others tried to explain to me in another thread, if your pressure is below 10 (with an APAP) the machine will try to chase the hypopneas. Over 10cm pressure it will not try to eliminate them unless there is a flow limitation (airway restriction) or snoring, because it could trigger central hypops and apneas. That explanation was what I was confused about in the earlier thread, but I think along with the Resmed reps explanation in the first post, it's making better sense. Then again, maybe someone else may correct me, because I still haven't 'got it'.

[twokatmew]

From what I read here and on a similar thread on apneasupport forum, seems like the bottom line is -

try to get low leaks and use the cpap every night - but if your HI doesn't come down to under 5 - don't worry too much? Tell the doctor, but you might be one of those folks with shallow or irregular breathing and so you may get an HI that is higher than it should be on certain machines. Or you may just be a slow responder. Just hang in there and wait a month or six months and see if you feel better.

Does that sound about right?

Yes, as long as AI is relatively low.

BTW, you have a very cute cat!!

[mray300]

This is a very interesting thread. I use an Intellipap Auto set on the CPAP mode. I've been very depressed that my AHI is usually between 8 and 10. I finally got the smartlink software and can see that the AHI is made up of mostly hypopneas and a very few apneas so maybe I'm doing better than I think. My point is other machines give similar results.

[twokatmew]

That's one reason I started the ResMed AHI poll, mray. I sure was feeling depressed when I continually read reports of users with AHIs of 2.00 or less and sometimes less than 1.0, even when those users were Respironics users. Although that thread helped me a bit, this thread has been even more helpful to me. When I hear of other users with similar struggles, I start to feel less like CPAP may not be going to work for me. It also helps to have an occasional night with an AHI barely more than 5.0. Of course, it's offset by nights where my AHI is mid-teens or worse. But ... it helps to know I'm not alone nonetheless.

[robertmarilyn]

That's one reason I started the ResMed AHI poll, mray. I sure was feeling depressed when I continually read reports of users with AHIs of 2.00 or less and sometimes less than 1.0, even when those users were Respironics users. Although that thread helped me a bit, this thread has been even more helpful to me. When I hear of other users with similar struggles, I start to feel less like CPAP may not be going to work for me. It also helps to have an occasional night with an AHI barely more than 5.0. Of course, it's offset by nights where my AHI is mid-teens or worse. But ... it helps to know I'm not alone nonetheless.

If it will help you guys feel better I will report my AHI every morning.

It was 19+ two and three nights ago but I got it down to 11+ last night.

mar (working towards a better sleep future)

[dkdc]

Yes, as long as AI is relatively low.

BTW, you have a very cute cat!!

AI is usually around 1-3. My first sleep study it was 0.5 - without cpap. So, that is encouraging. I will aim for under 5.0 AHI but can be happy with 10-13

Maybe my cat and yours are relatives? He thanks you for the compliment!

[billbolton]

While the numbers reported by data capable xPAP systems are useful, at the end of the day you need to keep in mind that they are scoring on a limited set of parameters compared to those available from a properly conducted PSG.

It is easy to get caught up in an xPAP Olympics.....chasing after numbers achieved by other OSA sufferers undergoing xPAP treatement for no particular good reason other than they are perceived as better than whatever numbers you personally get.

Also, xPAP therapy does not directly treat all sleep disordered breathing problems (let alone, all sleep problems). It only directly treats OSA. So there may be other things which are effecting sleep (and in turn the AHI score to some degree) which will simply not be impacted much, if at all, by xPAP therapy.

The pragmatic test for effectiveness of xPAP treatment on an individual basis, in the home, is going to be more along the lines on "do I feel noticeably more rested than I did before commencing xPAP treatmentl?", and "what, if anything kept me from experiencing good sleep last night?"

My nightly AHI score moves around quite a bit over the course of a year, depending on a whole variety of factors. I have come to realise, after having collected over two years worth of scored data (plus general recollection of several previous years on unscored CPAP usage), that in general my lowest scores tend to occur on the nights when I go to be bed absolutely bone-weary from whatever I have been doing during the day. Conversely, in general my highest scores (typically about double the lowest scores) tend to occur on the days when I have been relaxing and not doing much at all.

So, the biggest influence, in general, on my AHI scores is what I do while I am awake, much more than what happens when I am asleep at night

This is not to say that there aren't things on the more average nights than wont impact my AHI score (for example controlling maks leaks etc), but it is saying that the answer to the question "what, if anything kept me from experiencing good sleep last night?" may lie in areas of overall sleep hygene/architecture which have nothing much to do with xPAP therapy.... therefore sweating on the minutiae of XPAP therapy is not necessarily of great benefit in terms of longitudinal outcomes, once you have got into an acceptable range of being able to consistently answer yes to the "do I feel noticeably more rested than I did before commencing xPAP treatmentl?" question.

Hence the advice often offered here by longer term xPAP users that machine scored data is best applied to looking at trends, rather than becoming hung up on individual, nightly, specific numeric values

Cheers,

Bill

[dkdc]

The pragmatic test for effectiveness of xPAP treatment on an individual basis, in the home, is going to be more along the lines on "do I feel noticeably more rested than I did before commencing xPAP treatmentl?", and "what, if anything kept me from experiencing good sleep last night?"

My nightly AHI score moves around quite a bit over the course of a year, depending on a whole variety of factors. I have come to realise, after having collected over two years worth of scored data (plus general recollection of several previous years on unscored CPAP usage), that in general my lowest scores tend to occur on the nights when I go to be bed absolutely bone-weary from whatever I have been doing during the day. Conversely, in general my highest scores (typically about double the lowest scores) tend to occur on the days when I have been relaxing and not doing much at all.

That quote is worth putting on my wall. Thanks - this seemed pretty conclusive and clear to a fog brain like myself (at times).

Though, the data can be a helpful guide while you are waiting those 3 months to feel better. As long as you realize you don't need perfect data.