Doing my own sleep study - surprising results

[Jerry69]

the Remstar ProII has the ablity to record data that it sees, but I don't know for sure if that includes a pneumotach sensor like the autopap version, that would greatly increase it's sensitivity to read events. I suspect it does as it would seem cheaper for Respironics in the long run to make all the hardware the identical and then just change the firmware that gets loaded and silkscreen on the model on the outside.

But I wonder if by lowering the pressure to 4cm if that does not somehow impede the ability of the machine to record events accurately. if the machine is going to read events it first has to determine the volume of air in your breath. It has to also compensate for mask & exhaust leak.

your data could be accurate but 4cm is low as you can go, I'm surprised you can tolerate that low a pressure, I'd be starving for air to breath at that pressure. Then if you enabled the c-flex feature I bet it gets pretty stuffy.

Anonymous, you are right. I don't like 4 cm and will go back to 6 or 8 tonight. I don't feel like I'm getting enough air and my nostrils are not staying dilated as they were at 8 cm.

My AHI shot up to 3.2 last night, but still with no apneas.


Snores dropped a bit, lowering the Ave SI.


Daily AHI:


If I did another night at 4 cm, I suspect I'd see another high AHI, but who knows.

Perry, thanks for your very informative explanation. I've had my doubts about how the machines could define events well enough to respond and record with assurance.

Merry Christmas, friends,

Jerry

[rested gal]

What an interesting thread. Perry, thank you so much for that wonderful explanation about what autopaps in general try to do.

Makes me think of one of my favorite quotes.
-SWS once wrote:

"Perhaps the biggest fallacy I have seen repeatedly mentioned on these message boards is that when a patient's AutoPAP cannot successfully treat their SDB [sleep disordered breathing] events, then at least their overnight data is going to be accurate. Nothing could really be further from the truth."

[Jerry69]

Rested well last night. It's a good feeling, isn't it? My AHI was only 1.1 and snores were practically non-existent: 1.9. The Swift mask was comfortable, as always, and I'm getting used to the noise it makes...I guess.

Here are the My Encore charts, annotated with treatment pressure.




You can guesstimate the correlation:
AHI: Tends to be lower with higher pressure, but some discrepancies.
SI: Definitely lower with higher pressure

I'm getting more comfortable with the therapy. Feeling good after a good night. I realize that there will be good nights and bad, just like sleeping prior to starting the therapy.

I probably won't post any more charts (yea, you say). I'm satisfied with my 'sleep study'. Hope it has been helpful to some of you. Thanks for the excellent participation.

Jerry

[Ric]

From your SI vs. date, I can sort of mentally reconstruct your SI vs Pressure chart. THAT has got to be pretty significant and dramatic, snorically speaking. NICE WORK!

[Jerry69]

From your SI vs. date, I can sort of mentally reconstruct your SI vs Pressure chart. THAT has got to be pretty significant and dramatic, snorically speaking. NICE WORK!

Ric,

Yep, pretty dramatic...zzzzzzzzzzz.


Jerry

[Mikesus]

Perry,

Great Post!

Add to the mix that there is no definative study that correlates AHI to symptoms and it causes one to ponder, "why would I feel better when my AHI was reported as 4 (from software) then when my AHI was 1?"

Simply because the AHI report of a machine is its interpretation of events based on limited sensors. Sometimes the newer machines can be really accurate (if you fit the "model" the mfg based the software on) and other times it can be very misleading, because you don't fit their model.

On top of this that adds to the confusion factor is that there aren't any studies that link AHI severity to symptoms (in fact there are a few that show otherwise) and it leads one to the conclusion that we are measuring the wrong things.

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

[FL andy]

Anyone who wants to, please help!

I do not own an APAP but was thinking of getting one. Now I'm not so sure. I used to be only perplexed about APAP's, now I am bewildered and almost afraid!

Sometimes the newer machines can be really accurate (if you fit the "model" the mfg based the software on) and other times it can be very misleading, because you don't fit their model.

Of course, each person is different - and the key to how well any APAP works in auto mode (and the data collection in any mode) is how well the individuals personal breathing curve and personal event curves match what the machine is looking for. This can be great, good, fair, or bad....

One of the advantages to having different Mfr's is that most likely a person can be adequately treated by one of the machines (since they all are actually looking for something different, even if the event shares a common name, - and respond at different rates).

Note however, there are people who's breathing and event patterns are sufficiently removed from the ideals that APAP will not work for them. There are also a number of other health issues that can prevent APAP from working. Of course, there are also a number of other health problems that a properly functioning APAP helps with (compared to CPAP).

How do I know which manufacturer has the "model" that fits me the best? How do I know whether my "breathing pattern" fits which manufacturer?

For example, I have low-level asthma. Does one Mfg's APAP work better for me than another Mfg's?

Does anyone here think doctors would even bother to spend time thinking about this detail when their medical practice covers so many other problems? Where does one go for an answer? How about Christinequilts?

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CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, auto, APAP

[Wulfman]

Jerry,

My suggestion would be to bump up your pressure another point or two (9 or 10) and see what the graph looks like. At some (pressure) point it should keep most of the apneas away, most of the time. I'll be willing to bet that you'll see your AHI drip below 1.0 pretty consistently.

Best wishes,

Den

[Perry]

FL Andy Ask:

How do I know which manufacturer has the "model" that fits me the best? How do I know whether my "breathing pattern" fits which manufacturer?

For example, I have low-level asthma. Does one Mfg's APAP work better for me than another Mfg's?

Andy: In general, you don't know wich machine will or won't work for you if you do not have specific issues (for some people with specific issues - one machine may be known to work better with that issue).

For most people all of the machines will work fairly well (perhaps not the best - but enough to greatly improve life). Thus, their are two types of people getting good treatment with APAP. Those who's first machine works well (most people) - and those who have had to try various machines to find one that works. No way to tell up front which group you are in.

Concerning your asthma. A person with asthma can use APAP if they keep their asthma well controlled. I have fairly significant asthma. One of the reasons I had initial problems with APAP (in 1999) was because my asthma was faking out the machine. Getting my asthma under control allowed the machine to work (at which point I had to figure out other issues with it).

Are you measuring peak flows - and how well do you keep them in good range. What drugs/inhalers are you using?

Perry

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

[Guest]

Mikesus wrote:

Add to the mix that there is no definative study that correlates AHI to symptoms and it causes one to ponder, "why would I feel better when my AHI was reported as 4 (from software) then when my AHI was 1?"

Simply because the AHI report of a machine is its interpretation of events based on limited sensors. Sometimes the newer machines can be really accurate (if you fit the "model" the mfg based the software on) and other times it can be very misleading, because you don't fit their model.

On top of this that adds to the confusion factor is that there aren't any studies that link AHI severity to symptoms (in fact there are a few that show otherwise) and it leads one to the conclusion that we are measuring the wrong things.

In general that is true. There are studies that correlate Apnea index to sleep problems. But not Hypopnea index (except for people with OHA - Obstructive Hypopnea Apnea - where the arousals are caused on a hypopnea).

Now I have been out of the loop for a couple of years; but, unless something has changed in the last 2 years their is not even a medical definition of what a hypopnea is from a standpoint of how much flow reduction from normal for how long (and different Mfr's used to define it differently in their detection algorithms).

Apnea is medically defined as no flow for 10 seconds - but interestingly that is not the definitions that the APAPs use (best APAP definition is 10% normal flow for 10 seconds- but I have seen others with higher flows). So are the Apneas that the the machines record real apneas? Do they even cause an arousal? What about people who have an arousal on a 6-8 second event. Many APAP machines completely misses those.

Reested Gal Quotes SWS:

"Perhaps the biggest fallacy I have seen repeatedly mentioned on these message boards is that when a patient's AutoPAP cannot successfully treat their SDB [sleep disordered breathing] events, then at least their overnight data is going to be accurate. Nothing could really be further from the truth."

Precisely!

I am hoping that my work from 2000-2003 has eliminated another myth - that setting a APAP for 4-20 works.... (at least for anyone who needs a pressure greater than 8 or 9). Fact is - most APAPs work best when set in a 4 to 5 range (i.e., 4-9, or 8-12, or 16-20). The machine has to be going fast enough to be able to a) prevent most events, and b) be able to respond fast enough when you transition through the sleep stages and the event rate can massively change.


Perry

[FL andy]

Andy: In general, you don't know wich machine will or won't work for you if you do not have specific issues (for some people with specific issues - one machine may be known to work better with that issue)....

Concerning your asthma. A person with asthma can use APAP if they keep their asthma well controlled. I have fairly significant asthma. One of the reasons I had initial problems with APAP (in 1999) was because my asthma was faking out the machine. Getting my asthma under control allowed the machine to work (at which point I had to figure out other issues with it).

Are you measuring peak flows - and how well do you keep them in good range. What drugs/inhalers are you using?

Perry: I was diagnosed with asthma two months after I started on CPAP in Feb this year. Titrated pressure was 13 but had difficulty exhaling. Was switched to Respironics BiPap Pro 2 set at 16/11, HH set at 2, using an Activa but probably should be FF since I mouth breath and have dry mouth in AM.

AHI now always under 3.0 with greatly reduced snores - usually under 4. Sleep through the night for 8 hours with one potty break, but only after I started 3 mg Lunesta along with 10 mg Melatonin (Life Extension Foundation brand).

Pulmonologist does not have me measuring peak flows. I use Advair Diskus 100/50 twice a day. I use Maxair Autohaler 400 only two or three times a month at the most. Pulmonologist just changed me from quarterly visits to every 5 months. I feel good now that I use the sleep aids. Am well rested and generally healthy for a guy 6' 2" and 260 pounds at age 70.

The doctor's technician suggested I speak with the doc about possibly getting one of the new Respironics auto bi-levels. That is what prompted my questions. But my Pro 2 is only 11 months old and AHI's seem good to me. Don't think I really need a different machine.

Would an auto be an improvement? If so, why?

Thank you for you help,
Andy

[Jerry69]

Jerry,

My suggestion would be to bump up your pressure another point or two (9 or 10) and see what the graph looks like. At some (pressure) point it should keep most of the apneas away, most of the time. I'll be willing to bet that you'll see your AHI drip below 1.0 pretty consistently.

Best wishes,

Den

Going to 10, tonight. Thanks, friend. But, recent posts make me wonder if there is really any advantage.

Mikesus said,

Add to the mix that there is no definative study that correlates AHI to symptoms and it causes one to ponder, "why would I feel better when my AHI was reported as 4 (from software) then when my AHI was 1?"

Simply because the AHI report of a machine is its interpretation of events based on limited sensors. Sometimes the newer machines can be really accurate (if you fit the "model" the mfg based the software on) and other times it can be very misleading, because you don't fit their model.

On top of this that adds to the confusion factor is that there aren't any studies that link AHI severity to symptoms (in fact there are a few that show otherwise) and it leads one to the conclusion that we are measuring the wrong things

And, Guest said,

In general that is true. There are studies that correlate Apnea index to sleep problems. But not Hypopnea index (except for people with OHA - Obstructive Hypopnea Apnea - where the arousals are caused on a hypopnea).

Now I have been out of the loop for a couple of years; but, unless something has changed in the last 2 years their is not even a medical definition of what a hypopnea is from a standpoint of how much flow reduction from normal for how long (and different Mfr's used to define it differently in their detection algorithms).

Apnea is medically defined as no flow for 10 seconds - but interestingly that is not the definitions that the APAPs use (best APAP definition is 10% normal flow for 10 seconds- but I have seen others with higher flows). So are the Apneas that the the machines record real apneas? Do they even cause an arousal? What about people who have an arousal on a 6-8 second event. Many APAP machines completely misses those.

Darnit! Why can't things be simple? Here I am playing with the CPAP pressure to see what the machine tells me about how I ought to feel. My machine says I may not have one apnea a night, even at 4 cm, and Guest says, that the machine may not know what an apnea is and that my hypopneas may not cause arousals and besides there is no accepted definition of an hypopnea, anyway, and they may not be bad.... .

Thanks to Perry and Mikesus and Guest (truly sorry if I've missed another contributor) for some really scientific-sounding feedback. Again, I've wondered, as a novice, just how these machines can give reports that are truly meaningful, and these guys have the background to substantiate my reservations.

Jerry

[Perry]

Jerry:

The "guest" you refer to in is me (Perry). This forum is unusual in that it allows you to post or reply without logging in. If you look at the bottom of the post I belive that I signed it.

As to your question:

Again, I've wondered, as a novice, just how these machines can give reports that are truly meaningful, and these guys have the background to substantiate my reservations.

That is the key issue. IF the machine is reading you well - the reports can provide a lot of very good information; if not - the information may be of little benefit (except someone like me may be able to see evidence of other medical problems - depending on which machine and if I am really familiar with that machine - unfortunately, I have been out of the loop for several years and have not studied many of the current machines on the market - but I do know their predecessors - and most of the current machines are minor tweaks from those I am sure).

Best way to tell if the machine is reading you well is how well you feel (see my previous post). When a machine is reading you well, properly set-up for you, and you have no other medical issues (including having sufficient time to sleep) - then a PAP or APAP will return you to - or very close - to the "Mental Zest" stage in weeks or at worst a few months.

My base advice: What pressure were you told you needed. If you are using an APAP set your max at that, and set the minimum 4 below. Run that for a week or so and see how you feel - and what the graphs look like. If the nightly charts shows that the max is interfering with treatment - talk to your Dr about a new max (and I am talking about a chart that shows your pressures readings during the night - it should move up and down). If the chart shows no pressure movement and you are feeling great - then I'd lower the minimum pressure. If the chart shows that you are always at the max pressure and you feel great: I would worry about false readings and over-response. If you feel lousy - I'd question if the machine is working right (or other problems).

If you are working in CPAP mode - just sit for a while (4 days min) at a pressure and see how you feel - and see if that corresponds to the output data. I do not recommending changing settings sooner than that unless it is really obvious that the settings are way wrong.

I'd like to say it is easy. For a few it is. For some - some difficulty. For others - it can take years to figure everything out.

Best of luck.

Perry

[Jerry69]

Jerry:

The "guest" you refer to in is me (Perry). This forum is unusual in that it allows you to post or reply without logging in. If you look at the bottom of the post I belive that I signed it.

As to your question:

Again, I've wondered, as a novice, just how these machines can give reports that are truly meaningful, and these guys have the background to substantiate my reservations.

That is the key issue. IF the machine is reading you well - the reports can provide a lot of very good information; if not - the information may be of little benefit (except someone like me may be able to see evidence of other medical problems - depending on which machine and if I am really familiar with that machine - unfortunately, I have been out of the loop for several years and have not studied many of the current machines on the market - but I do know their predecessors - and most of the current machines are minor tweaks from those I am sure).

Best way to tell if the machine is reading you well is how well you feel (see my previous post). When a machine is reading you well, properly set-up for you, and you have no other medical issues (including having sufficient time to sleep) - then a PAP or APAP will return you to - or very close - to the "Mental Zest" stage in weeks or at worst a few months.

My base advice: What pressure were you told you needed. If you are using an APAP set your max at that, and set the minimum 4 below. Run that for a week or so and see how you feel - and what the graphs look like. If the nightly charts shows that the max is interfering with treatment - talk to your Dr about a new max (and I am talking about a chart that shows your pressures readings during the night - it should move up and down). If the chart shows no pressure movement and you are feeling great - then I'd lower the minimum pressure. If the chart shows that you are always at the max pressure and you feel great: I would worry about false readings and over-response. If you feel lousy - I'd question if the machine is working right (or other problems).

If you are working in CPAP mode - just sit for a while (4 days min) at a pressure and see how you feel - and see if that corresponds to the output data. I do not recommending changing settings sooner than that unless it is really obvious that the settings are way wrong.

I'd like to say it is easy. For a few it is. For some - some difficulty. For others - it can take years to figure everything out.

Best of luck.

Perry

Perry, my titration resulted in a prescription of 6 cm. Pretty low, huh? A pressure of 8 cm results in reduced AHI's, as the charts show. I'm going to try 10 to see what the numbers are and how I feel. But, assuming the machine is 'reading' me, am I likely to notice a difference in the way I feel going from an average AHI of 2.0 to !.0? Just depends, doesn't it on how well the machine is 'reading' me. But, practically, what is the advantage of reducing the disturbances by one per hour. Some of the forum members are reporting untreated AHI's of 30 or even 40 per hour. Am I 'splitting hairs'?

Jerry

[Perry]

Jerry Ask:

But, assuming the machine is 'reading' me, am I likely to notice a difference in the way I feel going from an average AHI of 2.0 to !.0? Just depends, doesn't it on how well the machine is 'reading' me. But, practically, what is the advantage of reducing the disturbances by one per hour. Some of the forum members are reporting untreated AHI's of 30 or even 40 per hour. Am I 'splitting hairs'?

Jerry: At that level you are splitting hairs. Those are phenominal numbers.

Most sleep labs will not prescribe PAP treatment at all for a real "sleep lab AHI" below 5.

Everyone has some events each night. The "apneas" that you machine may be reading might just be sleep transition events that a sleep lab would not count (when transitioning from awake to sleep it is not uncommon for a person to have an stoppage of breathing similar to an "apnea" - and the normal person does this transition several times a night. The sleep lab can see that your brain is in transition and does not count these events at all - your APAP cannot see that your brain is in transition - and counts and even potentially responds to the event).

There was some research done at the University of Wisconsin - Madison that did indicate that long term heart damage could be caused by as low of "sleep lab" AHI's as 4. I do not know if this has actually affected the clinical treatment of OSA yet - I do know that other sites were attempting to duplicate the studies a couple of years ago.

If it helps for comparison purposes: I average an AHI from my APAP of 4 to 8 each night. However, the Hypopnea detection is set at 35% flow for 8 seconds and the Apnea detection is set at 10% flow for 10 seconds (I am using a machine that allows a person to change these settings - It is no longer available, and I am hoping that it's successor kept the user definable events section).

Perry