Lousy results with new machine

I recently replaced my M series with a PR60. I am using the same settings for min and max pressure, no EPR (same as old machine). My AHI on the old M series was constantly below 3. With the PR60 is runs between 5-10. I did try a new mask recently and thought it could be that but the numbers are just as high with my Activa mask that I have used for years.

Also, I notice that the PR60 seems to blow a higher pressure puff of air at the end of exhalation and at the end of inhalation. I never felt that with my M series.

Last night I hooked up my M series again and boom... The number was back down: 1.7 AHI. Yesterday I felt horrible and groggy. This morning I feel great.

I did notice with the PR60 that most of my events are centrals. Don't have that with the M series.

Is this just a matter of getting used to the new machine, or is the PR60 that much different than the M series?

Is there something else that I might be doing wrong with the PR60 or something I am missing as this is my first new machine in five years?

hzjpmp wrote:I did notice with the PR60 that most of my events are centrals. Don't have that with the M series.

M series machines didn't flag centrals. So you have to back out the central index from your AHI to compare the obstructive index with what you saw on the M series machine...so subtract the clear airway index. You need the software to do this.
Do you have the software? I can't remember if I gave you that information or not. If I didn't..send me a private message.

Are you sleeping the same? Like number of hours of sleep??? Is your sleep with the PR S1 machine fragmented? Waking often during the night? Tossing and turning a lot during the night. Spend time awake while masked up?

I used M series APAP until I got a PR S1 APAP in Feb 2011. My AHI wasn't all that different from M series AHI...maybe a couple of centrals but overall no big change like yours.
To help determine if an event is open airway or closed airway the PR S1 machine sends out little pressure pulses..wonder if those are disturbing your sleep?

Could you please post an image of your detailed software reports (if you have it) so we can see where those events are occurring. It is possible that they might be related to awake or sleep stage transition.

I'll post a report when I have access to my Windows machine again. I use a Mac for real work.

If I recall when I looked subtracting the centrals would make the number a lot more reasonable.

If the pulse of air is bothersome when I am awake it could very well be the issue. That they would do this and not give a way to turn it off is very troublesome to me.

If that is the issue then I am out $600+ and may need to get a different machine. Does the ResMed S9 APAP also do this puff of air thing?

My insurance insists on renting first - so I won't be able to afford another machine for another several (6-9) months.

Will post a report either later today or sometime tomorrow.

hzjpmp wrote:If the pulse of air is bothersome when I am awake it could very well be the issue. That they would do this and not give a way to turn it off is very troublesome to me.

If that is the issue then I am out $600+ and may need to get a different machine. Does the ResMed S9 APAP also do this puff of air thing?

Those little pressure pulses are how the machine determines airway patency...to see if a perceived event is central in nature or obstructive and is a critical component to adjusting pressures...remember the machines won't increase pressure if it thinks a central is what is being sensed.

A few people do seem to find these little pulses disturbing..most people don't even notice them. If you find that they are waking you up..you very well could be one of those people.
ResMed S9 machines use what they call FOT (Forced Oscillation Technique) to do the same thing...distinguish between centrals and obstructives. Discussed a bit here viewtopic.php?f=1&t=78252&p=711867&hilit=FOT#p711867.

Again little pressure increases..whether they also would disturb you...have no way to know except if you try it.

Pugsy and I have differing opinions on how the M series reacts to centrals. I think that if you have centrals on an M series, the machine will detect them as an apnea, but it won't distinguish them from obstructive apneas.

Whichever one of us is right, even if the treatment is the same, different machines (or even different human sleep techs) may give different AHI scores. Even on manual CPAP pressure, different machines will give different AHI ratings if you have a lot of "borderline" apneas.

Look at the airflow waveforms if possible. Are your apneas short enough or mild enough in terms of air volume that they might be considered "borderline?" i.e. something the machine might reasonably have a short time making a decision about?

H, what pressure range do you use? What levels do the two machines end up running at? Different machines may be more "aggressive" in pressure adjustment.

H, are the "pulses" you're talking about on each breath, not just when you're having an apnea? The PRS1 machine should only be doing the "central detection" pressure pulse when it thinks you're having an apnea, not on each breath. i.e. you should not be seeing those pulses more often than 10 times an hour or so if it thinks your AHI is 10. You should not be seeing them at times when you aren't having apneas.

I have noticed that there is a bit of a "pulse" on some CPAPs at the beginning and end of each breath, especially if I do something abrupt like swallow or exhale quickly. I assume this is the machine adjusting the fan speed up and down to keep the pressure constant, and taking a little time to get the adjustment right.

Do you have a full size or narrow hose? Be sure your hose type is set correctly on your machine. If it's the heated hose, I think it is always small (15) and the machine automatically sets the hose size.

archangle wrote:Pugsy and I have differing opinions on how the M series reacts to centrals. I think that if you have centrals on an M series, the machine will detect them as an apnea, but it won't distinguish them from obstructive apneas.

This is why I said it doesn't flag centrals meaning it doesn't differentiate if any events are centrals or not.
I have amended what I say to encompass your thoughts.
It still doesn't flag a central...at least as a central.
Given that a M series report (in this OP instance) has a quite acceptable low AHI...and a PR S1 machine report has an elevated AHI predominately central in nature..leads me to believe that the M series just doesn't flag centrals even as obstructives. If AHI was the same...it might be calling centrals obstructives.

When I say it doesn't flag centrals..I am meaning there is no special central or clear airway event being flagged.

Pugsy wrote:This is why I said...

It's confusing enough to figure what apnea, obstructive, and central "really" mean. I am sure that different machines don't score apneas the same even with the same airflow/pressure data, so it's doubly confusing. Even with the same patient, different machines may give slightly different treatment in subtle ways so it's triply confusing.

Comparing one machine vs. another is very iffy if you're talking about low AHI numbers.

archangle wrote: Comparing one machine vs. another is very iffy if you're talking about low AHI numbers.

Yes. It certainly is.
All we have to go on is what we see reported.
M series machines don't say clear airway...they say obstructive...do they lump clear airways in with obstructives?
You think they do, I think they don't.
The reports say obstructive apneas and hyponeas...they don't say obstructive and clear airway. No where is CA mentioned in the reports.
I think that if they did...the M series AHI would likely be pretty much near what the PR S1 AHI is when more clear airway events are flagged.

So we are back to we don't know what or if anything the M series (and older) machines does with any potential clear airway events, at least with any certainty.
We do know that the reports don't flag them as clear airway because there is no such category.
Since there is no such category...they aren't identified as clear airway because we can't count something that isn't flagged.
So the statement that M series do not flag clear airway events like the PR S1 machine does...is correct. There is no such category on a M series report.

There is a non responsive category though. I used to have a few NRs on my M series reports...wonder if those were clear airway events? For all we know that could be what Respironics does with any potential clear airway events.

A M series report and a PR S1 report is an apples and oranges comparison. They don't report the same thing...they can't because the categories aren't the same. We are pretty much limited to what the reports show. They don't report centrals...at least not as centrals so all I can say is that they don't report them.

In the case of this OP problem with the pressure pulses and a slightly elevated AHI that is predominately central in nature my first suspect would be that the sleep stages are disturbed by the pressure pulses causing little mini arousals and possibly sleep stage transition "centrals". He wakes up to feel the pulses...I have heard of a few others who find the pressure pulses very disturbing. Just last week a woman in England has decided to buy a ResMed S8 machine because of it.
She had been using a S7 machine...got time to upgrade...tried the S9 and the FOT bugged her...so she got a PR S1 machine and those pressure pulses bugged her...so she decided to get a S8 machine and is very happy.

I really don't want to get into another pissing contest here. Neither one of us can prove what we think to the others satisfaction and to be honest..it doesn't really matter because we have to deal with what is going on now...We treat it just like the M series data didn't ever exist. We treat it just like that data was from a S8 machine.
We address the known situation and not the unknown. Heck, this stuff is hard enough to sort through without adding in a bunch of maybe unknowns.

The known factors...pressure pulses are causing OP to wake up and sense them. They disturb his sleep architecture.
The elevated AHI with predominance of clear airway events could possibly be explained by sleep stage transition events.
The sleep disturbances...they need to be addressed whether clear airway events are present anyway. Even if the AHI was less than 1...the sleep is disturbed and he feels lousy. It needs to be fixed some how. Gotta get good uninterrupted sleep before we can evaluate any clear airway events. Fix the known problem somehow...and maybe fix a potential secondary problem...if it doesn't then take the time to investigate the presence of clear airway events.

I'm not looking for a fight. Just pointing out not to put too much faith in the numbers, especially not in comparisons between different machines, especially current models and out of production models.

Well, I figured it out. I had the A-Flex set at 3. I could have sworn I had it turned off. Had a great night last night. Had 0 centrals on report this morning, AHI of 1.2.

Sorry for the stir. My bad. (Still don't like the pressure pulses - sure wish I could turn them off.