ASV: Hypopnea Index Remains High

[quote="BrianinTN.

So, for me as a 31 year old guy with nothing going on other than (medicine-controlled) hypertension, and my doc preferring to let things ride, can I get a hall pass here? .quote]


Sorry, not by me b/c you keep adding pieces of info such as hypertension, anti infections, etc.

What about the rest of the stuff as:


CAUSES OF CENTRAL APNEAS & COMPLEX SAS


•Central sleep apnea due to a medical condition: The patient has a history of an underlying disorder other than heart failure or renal failure. Patients with stroke can have either classic CSB-CSA or central apneas without a crescendo-decrescendo pattern.

◦Stroke
◦Diabetes mellitus
◦Hypothyroidism
◦Parkinson disease
◦Multiple system atrophy or Shy-Dragger syndrome
◦Familial dysautonomia
◦Postpolio syndrome
◦Damage to medullary respiratory centers by tumor, infarction, or infection
◦Arnold-Chiari malformation types I-III
◦Cervical cordotomy (we can cross this)
◦Muscular dystrophy
◦Myasthenia gravis
◦Prader-Willi syndrome
◦Idiopathic cardiomyopathy
◦Acromegaly
=> lower resting PaCO2 than normal
More:
Atrial fibrillation
Ejection (from the left ventricle) fraction 25% or less
Mitral Regurgitation

BTW, age of 31 is often too young to tell what's cooking.

I am hoping that none is coming!

Hypertension is a symptom of OSA. My docs and I both hope treating the apnea will help resolve the blood pressure and that, maybe, I'll be able to go over the BP meds once treated. I have no family history of hypertension fortunately, and my bloodwork and urinology are all within normal limits. As for my shoulder, that's probably years of bad form in lifting and pitching. Could be early arthritis too? Who knows. MRIs have been negative for tears.

Oh and thanks. I hope nothing new and more is coming too!

BrianinTN wrote:... So, for me as a 31 year old guy with nothing going on other than (medicine-controlled) hypertension, and my doc preferring to let things ride, can I get a hall pass here? ...

Exactly. Though I recommend keeping your doctor in the loop, you clearly understand how to use the numbers to better manage your situation, including:

BrianinTN wrote:... All of the above would point to the suggestion given by ozij that I experimentally increase EPAP. However, I have also noticed something a little paradoxical: my best nights quantitatively tend to be followed by worse days qualitatively. And, I certainly have a harder time falling asleep at higher pressures too. ...

Your concern is spot on. Quality of sleep is as important as the AHI values. If the AHI is excellent, but the quality is bad, then you've gained nothing.

I would suggest trying a ramp time to allow you to fall asleep. This will keep the pressure down, but allow higher pressure once you are asleep.

I would also suggest you reexamine this in a couple months. You will adjust to the pressure more than you think. I hardly notice my EPAP pressure of 10. My machine can ramp the pressure upto 30cm H2O. I hardly notice the increased pressure. It's amazing how much our bodies can become acclimated to the increased pressure.

Personally, I would aim for a midpoint, where I feel better than with the very low AHI but not as good as the higher AHI. That might be a good compromise as your body adjusts to sleeping with the increased pressure.

Best wishes on your efforts to get things under control!

JohnBFisher, thank you for taking the time to write your comments. Very helpful.

I had been set up with a 20 minute ramp and had been using it all along, up until last night as a matter of fact. I turned it off precisely because my starting pressures has been so low.

For tonight, I'm going to turn that ramp back on and use the suggestion from ozij that I raise EPAP (to 6). I'm going to leave everything else intact so we can have a relatively clear and sterile experiment. I'll try this for a couple of days, and will post notes when I have some data, interim conclusions, or questions.

BrianinTN wrote:... I had been set up with a 20 minute ramp and had been using it all along, up until last night as a matter of fact. I turned it off precisely because my starting pressures has been so low. ...

A low pressure is often an issue. Many people find that they do better (feel as if they can breathe easily) with a starting EPAP of 6 or more. So, that's a good call.

BrianinTN wrote:... For tonight, I'm going to turn that ramp back on and use the suggestion from ozij that I raise EPAP (to 6). I'm going to leave everything else intact so we can have a relatively clear and sterile experiment. I'll try this for a couple of days, and will post notes when I have some data, interim conclusions, or questions. ...

You clearly know your way around statistical analysis and how to vary an experiment to leave the data valid.

I used to work with a very large computer company. I was a Level 3 engineer, who helped other engineers and teams resolve very complex issues. All too often I would hear how folks would change three or more things at once and wonder what caused the bad interaction. Sigh! I'm good, but I did not have an Ouija board that was IT certified.

In fact, most of the time, I had to force a team back through their problem solving steps one step at a time. It's amazing how often folks jump a step or two during a crisis situation. I would estimate that about three times out of ten, we discovered the issue when we took all the steps.

Short of it, I sure hope you are able to lock in on some settings that help improve your sleep. We all understand the frustration of time slowly ticking by as you take a step at a time to get the settings "just right" for you. We will try to do all we can to help.

I've tried a few nights now at EPAP=6. I've been slow to post because the first two nights, I battled pretty large mask leak problems, which I know can obscure the true problem. Last night was pretty stable as leaks go, though, but you'll notice a LOT of periodic breathing. I wrote it off when I'd seen it the previous night due to the leaks, but in this case, now I have to wonder. FWIW, I've left PS min at 0, so it's free to vary. I'm not sure what to make of the PB -- comments?



In case anyone is interested, here are those preceding two nights in reverse chronological order.

How do you feel after last night? That's probably more important than what the numbers say.

As far as the numbers go, an AHI of 7 is not too bad. It's mostly made of hypopneas, which tend not to be as bad as apneas. At least that's my own experience. I feel horrible if the AI of the AHI side is high. I also saw my AHI values DECREASE as I became accustomed to my ASV unit. You might see the same thing happen.

I would not panic about the periodic breathing. See how things go over time. Beside which, this machine is the right one to help with that issue. If it continues, you should then discuss it with your doctor. It could be related to your problems that lead to the central apneas. But it might be due to another issue.

As for how I feel: Not bad but not great. I went to bed late last night, which is usually the way for me to rest better. I feel about like I do after a night of apparatus-less sleep.

BrianinTN wrote:FWIW, I've left PS min at 0, so it's free to vary.

And what does that seem to be doing for you? Have it you way, Brian. Good luck.

When running an experiment, you don't want to vary too many factors at once. If you're forced to look at data where many factors do vary because you can't control the experimental design, then there are methodological ways to deal with that, but you have much higher variability around estimates of your parameters. This is why -- in medical experiments in particular -- they are heavily controlled. PS=0 is the default, and with it I have a large amount of older data against which I can compare. If you recall, I had tried PS=2 as a minimum for three nights, with mixed results (no better and no worse than I got with PS=0). ozij made a compelling case for why raising EPAP might be the next best choice, so that's what I'm playing with now. Assuming a couple more nights of EPAP=6 don't show improvement, I'll move up to EPAP=8 as she suggested, and barring that, I'll try raising PS in combination with higher EPAP. That is, unless someone else chimes in with a better single variable to tweak before then.

Here's last night, where I bumped min EPAP to 9. As before, all other parameters are unchanged. Once again, there is a large band of periodic breathing at the start, which as I noted previously is odd -- I did see some PB from time to time on the CPAP, but never for such long periods, and I haven't seen it much since. Note how flat the pressures are throughout the night, too. And I do feel groggy today.

So as I see it, there are four options:
1) Continue with this for a few nights to see if it improves
2) Go back down to the min EPAP=4 but make the min PS 3, 4, or more
3) Continue with a min EPAP around here, but add a min PS
4) Go back down to the out-of-the-box settings

ozij, I'd especially be interested in hearing from you, since you had some theoretical logic behind the tinkering you were suggesting. But comments from anyone would be welcome. Thanks.

BrianinTN wrote: ozij, I'd especially be interested in hearing from you, since you had some theoretical logic behind the tinkering you were suggesting.

I guess I'll defer to Dr. Ozij.

BrianinTN, I guess I have a suggestion... You said in your BiPAP study you had a PS difference of 4 (20/16).
viewtopic/p599736/posting.php?mode=quote&f=1&p=584991
Now its my newbie understanding that in order to keep down central events, one wants the EPAP to be a low as possible and let the ASV algorithm take care of events as they show up. This, because many (most?) with complex sleep apnea develop progressively more central events as CPAP and BIPAP pressure are increased. So, you may be making a mistake by raising min EPAP higher and higher instead of letting the ASV do the work.

So, Looking at your recent 90% EPAP at 7 and average PS of 3 results. I wonder if you would get similar results by setting Min EPAP at 7 and min PS at 3 or EPAP min at 6 and min PS at 4. In other words set you min EPAP low enough that your unit is occasionally bumping the EPAP up and set you min PS to 3 or 4 to give you a comfortable bilevel range. I'm thinking your min EPAP should be low enough that you should see your machine bumping it just a bit throughout the night. If you have no bumps in the Min EPAP, then it may be too high.

Sounds reasonable. As you saw, EPAP barely budged last night. I'll try lowering EPAP and increasing the min PS tonight and see how I do. Thanks.

I can't believe it that this thread showing 4 Hypopneas out of 5 AHI still continues. Mind you that these are Hypopneas and not Central apneas which could be more important. Usually, Hypopneas don't cause a complete airway closure. So some flow does ventilate the lungs.

See here that in my case of two Hypopneas the Minute Ventilation continued to ventilate the lungs:

Re-edit: I could be wrong here because even if there was a higher pressure and a higher flow showing on ResScan graphs it does not mean that the lungs got air. To acertain that the lungs got ventilated I need to also look at the thoracic and abdominal signals which coresspond to increase in chest volume. Otherwise, it would be a pure Central Hypopnea with no ventilation.




p.s. Avi123, I agree. Thank you.