Home Sleep Study Using RemStar Auto???

[derek]

So here's the deal: I was diagnosed with an AI of 35, and titrated at 12 cm. I was compliant (> 8hrs/night) for three months on RemStar Plus. Hated it.

Got the Auto last weekend. Love it. But, after four nights at min/max of 6 - 14 cm, Encore reports no apneas at all, a handful of hyponeas for a mean AHI of 0.3, a few snores and the occasional flow limitation. Last night the 90 percentile pressure was 7.5 cm, mean pressure 6.6cm - way below my sleep lab titrated pressure. Sure is comfortable with the C-Flex.

The question really is whether I really am being treated at these lower pressures, I have changed over the three months, or there is something wrong with the original diagnosis/titration. I am proposing to do a crude home sleep study by setting the min/max apap pressures low (say 5-5.5 cm) and spending the night that way, then looking at the Encore Pro data for events. Then if I can trust Respironic's data collection, I should get some (crude) idea of my untreated AHI. The conjecture is that the low pressure will not affect me Any comments?

derek

[Poisson]

Hi Derek,

I'm no doctor, but it sounds like a reasonable experiment.

I've considered doing something similar except that my 420e (min 4, max 20) spends too much time at my minimum pressure setting of 4 even though I was titrated at 8. (Last night I spent 94% of the time at 4.)

I'm guessing that the difference in my case between the titrated pressure and the pressures I'm seeing are due to losing a few pounds and re-training myself to sleep on my side. OTOH, I feel so much better that I'm sure the apap is doing a lot for me even though the apap rarely ever reaches pressures as high as my titrated pressure.

--Bob

So here's the deal: I was diagnosed with an AI of 35, and titrated at 12 cm. <snip>
Got the Auto last weekend. Love it. But, after four nights at min/max of 6 - 14 cm, Encore reports no apneas at all, a handful of hyponeas for a mean AHI of 0.3, a few snores and the occasional flow limitation. Last night the 90 percentile pressure was 7.5 cm, mean pressure 6.6cm - way below my sleep lab titrated pressure. <snip>

The question really is whether I really am being treated at these lower pressures, I have changed over the three months, or there is something wrong with the original diagnosis/titration. I am proposing to do a crude home sleep study by setting the min/max apap pressures low (say 5-5.5 cm) and spending the night that way, then looking at the Encore Pro data for events. Then if I can trust Respironic's data collection, I should get some (crude) idea of my untreated AHI. The conjecture is that the low pressure will not affect me Any comments?

derek

[rested gal]

Derek, out of curiosity I did what you're planning to do. I set the pressure range of the 420E auto I had, at 4 for both the high and the low. Slept 6 hours with it like that. It tallied up almost 2,000 snores in that time, and a handful more apneas, hypopneas and limited flows than usual.

The next morning I was back to the same groggy, slow-to-get-going feeling that I had always experienced before ever getting on cpap. Needed a nap that afternoon (back on the machine, of course!)

Two things about that little experiment keep it from being a true picture of what kind of events we have during sleep. One is that we are getting at least some pressure into the airway. 4 isn't much, but it's more than nothing, to help hold the throat open. The other thing is - depending on the mask being used, the wash-out of carbon dioxide might not be very good at a pressure of only 4. I don't know if a possible increase in breathing C02 would cause more mini-wakups that might cause a person to stay in lighter, less "apnea prone" stages of sleep.

Anyway, you already know that it would be just a crude "study" to set the machine that way. Interesting to do, even though a pressure of 4 or 5 is considerably more than none at all.

As for the discrepancy between the full PSG study finding 12 cmwp and your data at home on the auto showing a mean of 7.5, that's one of the many benefits of having an autopap instead of a straight cpap. In the sleep study, perhaps they had you stay on your back as much as possible... looking for the worst case scenario? Perhaps at home you sleep more often on your side, which usually results in less obstructive events? Whatever the reason, what you've found in being able to sleep at lower pressures than the sleep clinic's titrated pressure is what so many autopap users get to enjoy!

Let us know how your little home test turns out.

[wading thru the muck!]

Derek,

I have read posts from people who were sent home with a fixed pressure machine at 4cm for a week to see if the Docs suspicions were right. If so, they were given an auto to then provide the appropriate therapy. For those of us with mild to moderate apnea and no complications, this method is a much more efficient and less expensive way to get diagnosed.

As far as I'm concerned I think the week at 4cm is not necessary. The data from the software is showing that it is anticipating/responding to SDB events. That is your confirmation that you have OSA.

One sure way to confirm your diagnosis is to get a copy of the full data from your sleep study. It will show how the tech tried each pressure and the events at each pressure. They keep bumping up the pressure until it is resolving most or all of your events. It is possible that factors on the night of your sleep study varied enough from your usual night's sleep that it could cause this discrepency.

[Mikesus]

If you read the manual There is a description of the ramp feature when on Auto. You can set it to hours instead of minutes to allow a split night test. While ramped, it will stay on the lowest pressure and only record the events. After the ramp period runs out, it works as a normal apap. Might want to do this vs going a whole night with bad sleep...

[derek]

MuckWader,
What I don't understand is how the machine might be proactively preventing events if the indicated pressure is basically straight-lined at a low-level for much of the night. Maybe the Encore charts don't have enough time resolution to plot short-term pressure fluctuations???

If I truly have an AHI of around 35 I would have expected to see either a constant higher pressure (around my titrated pressure) to suppress apneas, or some sort of record of up and down pressures as the system detects a pre-apneac breathing pattern.

As it is, the machine had a stretch of about 4 hours last night at 6cm (the minimum) with occasional blips to 6.5 cm (every half hour or so). Is it doing proactive things that aren't shown in the pressure trace, or are the 0.5cm blips helping? That's what I want to find out.

BTW - I am a back and both sides sleeper.

derek
A great believer in the saying "a little knowledge is a dangerous thing"

[derek]

Mikesus,
Thanks for the suggestion - I knew that, just didn't register. My wife suggests that I just try going cold-turkey and see how I feel the next morning. If it is really bad through the night I can always put the mask on I wonder however whether the "shock" of not having the mask on after several months would itself disrupt sleep patterns - especially since part of my diagnosis was general insomnia.

There is no doubt that I am getting much more, and better quality, sleep since starting on the CPAP/APAP. Wifey says I lie absolutely still in bed instead of tossing and turning all night. So something is definitely happening.

derek

[snoozin']

Derek,
Do you have your complete sleep study? I got a copy of mine, and was very surprised at the numbers. I was titrated at a pressure of 16, which I felt was too high for me most of the time. Which is why I got an autopap a couple of weeks ago.
Anyway, my sleep study showed no real decrease in AHI below 8. A slight drop at 8. Then AHI was halved at 10. More than halved again at 12, down to 8 AHI per hour. But the tech kept upping the pressure until it got below 5 AHI, which took a pressure of 16. So, I needed pressure of 10-12 for about 55 minutes per hour, and a pressure of 15-16 for about 4-5 minutes. Since they set me up with a cpap, which only runs at one pressure, they set the pressure to 16, in order to make sure the AHI was under 5.
With my new autopap, I find I'm using a pressure of 10-12 the majority of the night, with an occasional increase to around 15. From my sleep study, this sounds about right, and the constant pressure of 16 really was too high for me. Everyone is different, so your numbers might vary, but the sleep tech may have titrated you at a higher number than you need for most of the night.
Debbie

[-SWS]

Did you see the link I provided in one of your previous posts showing pictures of "untreated snoring"? My take is that you could very well have had a swollen airway from untreated snoring that yielded your anpeas and hypopneas during your PSG----but that CPAP treatment has allowed your swollen airway to heal (at the expense of blindly running "over-pressure" and thus also experiencing dyspnea). Unrecognized and untreated acid reflux disease can yield similar airway dysfunction as well----and CPAP is thought to bring that condition in check as well. Yes, your physiology could have improved for the better. You might not have been suffering from "classic apnea" all along.

Your Remstar Auto has what is called "split night study mode". You set the ramp at 2 hours or higher to achieve a "split night" study. If you set the ramp at 4 hours, for instance, it would run at 4 cm straight for four hours, then at the beginning of the 5th hour it would again function in AutoPAP mode. So yes, your proposed experiment is feasible according to the Remstar Auto "split night study" feature design. You could run several nights in "split study" mode, comparing "before" and "after" data. If you decided to dispense with xPAP altogether based on these short term data results, you may run the risk of gradually achieving your original dysfunctional airway that just might have gradually improved via xPAP therapy.

[SleepyGuy]

Thanks, SWS. I've had trouble using my mask for more than two or three hours. I started acid reflux treatment just before starting CPAP and I'm careful to sleep on my side now and not my back.

I really feel I'm getting better despite not being able to use the CPAP all the time. Your message might explain it. I'm sure my esophagus is healing. (The endoscope showed scarring there.) I used to occasionally wake up in mid-snore. That's only happened once lately and I was on my back when I woke up. That's rare. I'm almost always on my side now.

I've tried backing my dose of Prilosec from two tablets down to one, but if it's that important, I'll stick with two.

Thanks.

[-SWS]

SleepyGuy, that's good news! I flagged that case as a possibility for Derek, yet I have absolutely no idea what the medical liklihood might be since I am not a medical professional. The swollen esophagus itself might not obstruct the airway so much as acid-reflux related swelling in the main pharyngeal portion of the airway could. The other acid reflux link to apnea is believed to be acid-induced vocal chord spasms, which in turn completely obstruct the airway. To the best of my knowledge the vocal chord spasm theory is just that.

I wonder if either a retitration or AutoPAP might not be a good idea for you as well? If your swollen airway is now less obstructive because of successful acid reflux treatment, your PSG titrated value might be too high. That potentially excessive pressure might be why you're having such a tough time using CPAP.

[derek]

SWS,
I think we can count out acid reflux in my case. I don't ever recall having indigestion, heartburn, or reflux.
derek

[Mikesus]

SleepyGuy, that's good news! I flagged that case as a possibility for Derek, yet I have absolutely no idea what the medical liklihood might be since I am not a medical professional. The swollen esophagus itself might not obstruct the airway so much as acid-reflux related swelling in the main pharyngeal portion of the airway could. The other acid reflux link to apnea is believed to be acid-induced vocal chord spasms, which in turn completely obstruct the airway. To the best of my knowledge the vocal chord spasm theory is just that.

I wonder if either a retitration or AutoPAP might not be a good idea for you as well? If your swollen airway is now less obstructive because of successful acid reflux treatment, your PSG titrated value might be too high. That potentially excessive pressure might be why you're having such a tough time using CPAP.

The Vocal cord theory is actually Fact. It is called Vocal Cord Dysfunction or VCD for short. I have it. The place that knows the most about it is National Jewish in Denver. I had the problem of the acid irritating the vocal cords which would then trigger an asthma attack. My solution was something called Enteryx (a polymer that is injected into the lower esophogeal sphincter (no not that sphincter!)Link Here, causes are bout 3 paragraphs down.

[-SWS]

I am aware of vocal chord dysfunction---often triggered by emotional stress. This normally manifests by day. Didn't know that the VCD physiological mechanism was pinned down as the exact apnea-linked etiology, however. Admittedly both scenarios entail spasms.

Derek, I didn't have a hint that I had acid reflux disease until I went to the ER with lobster tail hopelessly caught in my esophagus a few years back. Maybe untreated snoring caused pharangeal swelling that is now kept in check? Also, nocturnal asthma can mimick hypopnea/apnea events during a PSG I've read. Who knows exactly what might have factored in when you were titrated at 12?

[Mikesus]

I am aware of vocal chord dysfunction---often triggered by emotional stress. This normally manifests by day. Didn't know that the VCD physiological mechanism was pinned down as the exact apnea-linked etiology, however. Admittedly both scenarios entail spasms.

Derek, I didn't have a hint that I had acid reflux disease until I went to the ER with lobster tail hopelessly caught in my esophagus a few years back. Maybe untreated snoring caused pharangeal swelling that is now kept in check? Also, nocturnal asthma can mimick hypopnea/apnea events during a PSG I've read. Who knows exactly what might have factored in when you were titrated at 12?

Actually emotional stress is only one of MANY reasons... Quoted from National Jewish...

What can trigger VCD symptoms?

Possible triggers of VCD are often similar to asthma triggers. Triggers may include upper respiratory infections, air pollution, strong chemical fumes and odors, cigarette smoke, singing, laughing, emotional upset, post-nasal drip, gastroesophageal reflux disease, cold air and exercise. Sometimes the trigger is not known.