The Experiment...

In an earlier thread "Home Sleep Study Using RemStar Auto???"
viewtopic.php?t=1357&sid=5bca8b9c6e0025 ... 800b8f5022
I asked about doing an informal sleep study using a Remstar Auto. The goal was to resolve questions about my diagnosis (34 apneas/hr) and titration (12cm H2O) that were called into question my the Encore Pro reports.

Here's the "experiment" we set up: I showed my wife how to set the Auto up to be either:
1) AutoPAP at 5.5 - 14 cm, and
2) Straight CPAP at 5.5 cm.
Each night for 10 nights she was to randomly choose one of these and set the machine up without telling me. I would then spend the night without knowing which one, and in the morning record how the night went, and download the data into Encore Pro. At the end of the experiment I would do some statistical analyses to determine whether there was any difference.

The rationale was that 1) the CPAP mode was well below any treatment for me, and would thus simply record my untreated sleep behavior, and 2) that I would not be able to tell the difference between the two as I went to sleep.

Well that's the theory Didn't quite work out that way

Night 1: Had a wonderful night's sleep. Woke once to drag myself to the bathroom and went straight back to sleep.
Compliance: 8.3 hours (almost entirely sleeping)
Apneas: 0
Hyponeas: 7
AHI: 0.8
Snores: Spread thinly across the night
90 percentile pressure: 7.1 cm
Average pressure: 6.3 in
This was an APAP night.

Night 2 (last night): A disaster. Went straight to sleep. Woke at 12:30am with heart pounding, stomach in a knot, feeling extremely anxious (frightened?, panicky?). Lay awake with mask on for more than an hour, trying to relax and get back to sleep. Got up for 90 mins, trying to get rid of the anxious feeling. Went back to bed at about 2:45am, and couldn't get back to sleep (mask on). Dozed on and off until 6:00am.
This is exactly a repetition of my nightly performance before I started CPAP, and is what sent me to the Sleep Lab (diagnosis apnea, restless legs, general insomnia). At that time the anxious feeling was being treated with Lorazepam (Ativan) which helped me get back to sleep.
This morning's Encore Pro report:
Apneas: 1 (about one hour after I first fell asleep)(First ever recorded since starting APAP last week)
Hyponeas: 23
Compliance: 7.8 hours (but a great deal of that was awake)
Reported AHI: 3.1 (obviously higher because I was awake for several hours)
Snores: Heavy band across times when I was asleep
Pressure: 5.5 cm
This was a CPAP night.

I don't want another night like that, so I am canning the experiment, and going back to AutoPAP

BUT it still raises the question: what is happening? The AHI last night is still way lower than my diagnosis. The CPAP pressure used is way less than the titrated pressure. What woke me? There were no hyponeas around the time of my waking - just snores. Maybe I just have a severe snoring problem???

As I said this is the same pattern as I had nightly in the pre CPAP days. I had written off the anxiety feelings to being induced by apneas, but I'm not having apneas (at least as reported by Encore Pro).

Obviously CPAP/APAP is helping me sleep. The question now is how? I don't see it as AHI reduction. Is it simply reducing my snoring? Is the RemStar data to be trusted?

I'm seeing the sleep doc next week. We have a lot to talk about.
derek

Derek, very interesting experiment.

I'm not a doctor, but my guess about the discrepancy between your AHI from the sleep study and the AHI from your machine on the "low pressure" test night is this:

Even though 5.5 cmwp is treating your collapsible throat sub-optimally, it still is providing a fair amount of assistance in keeping your throat open. Depending on the exact nature of your throat's collapsibility, 5.5 might be providing quite a bit of preventive force against complete closure, compared to what was happening with no cpap at all during the diagnosis phase of the sleep study.

Also, I don't know this for a fact, but perhaps the machine is using a slightly different definition for what degree of limited air flow it has to sense before the machine calls it an apnea, hypopnea, etc....compared to the different machinery/sensors/definitions at the sleep clinic. Perhaps there was also a difference in the sleep positions you were in at home vs at the clinic.

Obviously from the way you felt, 5.5 was not giving you "good" treatment, but was giving you "some" treatment. Just my guess. I don't blame you for deciding one night was enough of that.

Hi,
The flaw in your data is this. When we sleep without our machine we have 0 cmwc forcing open our airway . You were set at 5.5 . So you were being treated at 5.5 cmwc to some degree. This proves that IS working. Your challange now is to find that perfect pressure for your low side. Just enough to prevent those hypopneas without being overtreated "most " of the time.

Thats the problem with us mechanotechno heads. We have a hard time just letting this simple looking machine do its job. We try to psychoanalyze it . Its just a dumb machine that keeps asking the same questions over and over until it gets an unnexpected answer, then it reacts until it gets the expected answer again. (Very simplified I know)

Hey , I'm not any type of guru at anything. Some things are best left to themselves to do what they were designed to do. Your job in this instance is to determine the lowest setting that will still prevent the onset of hypopneas.

Its like a backyard mechanic wanting to tweak his new car for more power. 500 phd designers somehow got it wrong so he is going to change XYZ to make it better. LOL

Sometimes the more we know the more dangerous we can be.
I know. I've messed up my share of perfectly good toys .

Cheers,

Chris

Sorry for the mess guys. Everytime I type [url=https://www.cpap.com/cpap-compare-chart/CPAP]cpap[/url] it puts in the web site. Does anyone know why ?

Rested and Chrisp,
I understand this argument of partial assistance from the 5.5 cmwp. Of course it's true. This is not a definitive experiment - never pretended to be. Just me trying to understand and resolve some puzzling observations on APAP.

Lets assume that my untreated AHI is 34. Then last night shows that CPAP 5.5cm has reduced it down below 5. Yet I was titrated at 12 cm, and I had my classic pre-CPAP behavior last night. I haven't had a night like that since last November. My conclusion was that the 5.5cm wasn't doing much to alleviate the behavioral symptoms.

As I said, I'll talk to the sleep doc next week.
derek

whoops - can't see how to delete.

I recently visited 2 sleep docs to try to tweak a few things. I have a Spirit. This is what they said . .

I adjusted my lower pressure slightly each night or so until the HI was as low as I could get it. Its still a AHI 10-15

Then I used my wifes PB420 and it went to AHI .4 And I feel better.

Good luck with your Doc.

Chris

Ok Johnny, This link to any product on your site is very frustrating. IE [url=https://www.cpap.com/productSearch.php?query=resmed]resmed[/url] , pb420e [url=https://www.cpap.com/cpap-compare-chart/CPAP]cpap[/url]

derek,

You have to get away from that "CPAP" 12cm mindset. Engrave in your mind that the 12cm is the worst case pressure. You may have most of your hypopnias and 90% of your apneas treated with the 5.5cm. The residual 5% of the OSA events are the most severe and the most disturbing of your sleep. For arguments sake if there was a machine that would treat only the severe events and leave the lesser events, you would probably sleep OK. At the risk of sounding (again) like "mister apap", your circumstance is living proof of the beauty of the apap. These wonderful machines use only the pressure necessary to treat each event, resulting in lower pressures and less pressure related problems.

If I read between the lines, I think you are still trying to disprove your diagnoses. Am I correct?

Your study was better and more brilliant than any sleep lab? Can you patent this and make some $ off it?

derek wrote:In an earlier thread "Home Sleep Study Using RemStar Auto???"
viewtopic.php?t=1357&sid=5bca8b9c6e0025 ... 800b8f5022
I asked about doing an informal sleep study using a Remstar Auto. The goal was to resolve questions about my diagnosis (34 apneas/hr) and titration (12cm H2O) that were called into question my the Encore Pro reports.

Here's the "experiment" we set up: I showed my wife how to set the Auto up to be either:
1) AutoPAP at 5.5 - 14 cm, and
2) Straight CPAP at 5.5 cm.
Each night for 10 nights she was to randomly choose one of these and set the machine up without telling me. I would then spend the night without knowing which one, and in the morning record how the night went, and download the data into Encore Pro. At the end of the experiment I would do some statistical analyses to determine whether there was any difference.

The rationale was that 1) the CPAP mode was well below any treatment for me, and would thus simply record my untreated sleep behavior, and 2) that I would not be able to tell the difference between the two as I went to sleep.

Well that's the theory Didn't quite work out that way

Night 1: Had a wonderful night's sleep. Woke once to drag myself to the bathroom and went straight back to sleep.
Compliance: 8.3 hours (almost entirely sleeping)
Apneas: 0
Hyponeas: 7
AHI: 0.8
Snores: Spread thinly across the night
90 percentile pressure: 7.1 cm
Average pressure: 6.3 in
This was an APAP night.

Night 2 (last night): A disaster. Went straight to sleep. Woke at 12:30am with heart pounding, stomach in a knot, feeling extremely anxious (frightened?, panicky?). Lay awake with mask on for more than an hour, trying to relax and get back to sleep. Got up for 90 mins, trying to get rid of the anxious feeling. Went back to bed at about 2:45am, and couldn't get back to sleep (mask on). Dozed on and off until 6:00am.
This is exactly a repetition of my nightly performance before I started CPAP, and is what sent me to the Sleep Lab (diagnosis apnea, restless legs, general insomnia). At that time the anxious feeling was being treated with Lorazepam (Ativan) which helped me get back to sleep.
This morning's Encore Pro report:
Apneas: 1 (about one hour after I first fell asleep)(First ever recorded since starting APAP last week)
Hyponeas: 23
Compliance: 7.8 hours (but a great deal of that was awake)
Reported AHI: 3.1 (obviously higher because I was awake for several hours)
Snores: Heavy band across times when I was asleep
Pressure: 5.5 cm
This was a CPAP night.

I don't want another night like that, so I am canning the experiment, and going back to AutoPAP

BUT it still raises the question: what is happening? The AHI last night is still way lower than my diagnosis. The CPAP pressure used is way less than the titrated pressure. What woke me? There were no hyponeas around the time of my waking - just snores. Maybe I just have a severe snoring problem???

As I said this is the same pattern as I had nightly in the pre CPAP days. I had written off the anxiety feelings to being induced by apneas, but I'm not having apneas (at least as reported by Encore Pro).

Obviously CPAP/APAP is helping me sleep. The question now is how? I don't see it as AHI reduction. Is it simply reducing my snoring? Is the RemStar data to be trusted?

I'm seeing the sleep doc next week. We have a lot to talk about.
derek

Wader,
No, not at all. I fully accept that I have a sleep disorder, and that I have found profound relief through CPAP/APAP. Furthermore like you I am thoroughly convinced of the benefits of APAP. I fully accept that Otto Papp and I are going to become lifelong friends.
My signature really is a tongue-in-cheek "denial". That's all.
From our previous email contact (re RemStar manuals) I think you know what my profession is. My lifetime endeavors lie very, very close to this field. I am just a very curious person who likes to understand what is happenning, especially when it comes to my health.

That said, wouldn't it be wonderful if we all could toss these machines over a high cliff

derek

derek,

Glad to see you are using your expertice to better understand your cpap therapy. I'm sure we will all benefit from it. I'm also glad to hear your tougue in cheek denial is just that. I think your questions regarding the discrepency between your lab titrated pressure and what seems to be required to treat your OSA is the reason many of us ar so enthusiastic about the apap (there I go again). As a scientist I'm sure you can appreciate the wonder of finding a solution that rethinks the whole approach to determining appropriate OSA therapy.

Maybe your newfound therapy will start a whole new branch of your career.

We'll all be waiting for the "D"-pap!