Second Sleep Study, oh oh...

[SnuffySleeper]

Pressure induced central apneas aren't uncommon. Thats one of the reasons they spend so much effort on proper titration.

They aren't? All the reading I done online and it still caught me by surprise when the doctor said that was the results. Not many people talk about it on forums and such. Even on other forums *cough cough* they didn't want to believe it and even some suggesting that it's not true, which is very dangerous.

Anyways, I have more reading to do as my doctor didn't really want to give up too much information on this, I could tell he didn't want to get into the details of it and just wanted me to accept 9 as the pressure and go home.

[3porpoise]

Hi SnuffySleeper,
Sorry to hear about the complications. I've also found HCP's can clam up when the going gets tough. You know , cough cough,rather sweep it under the rug. They also have a name for it, complex apnea, so ...it must have happened often enough to recognize and label it.
Did you get a copy of your titration study that's about 6 pages of results? Lot's of interesting info in them.
3

[SnuffySleeper]

Yeah, I have a "report" my doctor gave me that he sends to my family doctor with a summary of the study, but as far as the wavforms and graphs he was much more coy and said he would have to get those to me later and just left it at that....

I found that odd as my first sleep study he was more than happy to show my the wavforms and graphs.

[robysue]

Pressure induced central apneas aren't uncommon. Thats one of the reasons they spend so much effort on proper titration.

They aren't? All the reading I done online and it still caught me by surprise when the doctor said that was the results. Not many people talk about it on forums and such. Even on other forums *cough cough* they didn't want to believe it and even some suggesting that it's not true, which is very dangerous.

It's all in the definition of "not uncommon". Most of the things I've read indicate that 10-15% of new PAPers wind up having serious problems with pressure induced central apneas. And for many of those people, there is a threshold pressure that seems to start inducing them---from a central point of view, things are fine as long as the pressure is below n cm, but once the pressure is increased beyond that point, all hell can break loose as far as the centrals are concerned.

In general, if the pressure needed to control the obstructive events is below the threshold pressure for triggering the centrals, straight CPAP or APAP with the max pressure capped low enough to not trigger the centrals will work fine for treating the OSA.

Problems occur when the pressure needed to control the obstructive events is higher than the threshold for triggering central apneas. And in that case, things get murky pretty quickly. In an ideal situation, the sleep doc has the data from the home machine that shows both:

• The OSA is NOT controlled at pressures of less than n.
  
• The ComSA centrals continue to be a problem at pressures of n cm or greater----or there's a quality titration study that demonstrates CompSA sets in at or around n cm of pressure.

And at that point, the discussion about what to do should involve a possible (likely) switch of machines. In the US the patient's insurance company may insist on a trial on bi-level (which might work if the patient is lucky) and after "failing at bilevel" the insurance company will (often reluctantly) then approve a bilevel-ST titration or (even better) an ASV titration.

So: In your case, how does the data look when you have your Elite set to 9cm of pressure?

[SnuffySleeper]

I have read the opinion that it only happens in "new" cpap users over and over on forums but that's not true. It might go away for some but that's the reason we wait 5 months for the second sleep study. It's a different form of Apnea, that does not go away over time.

A couple articles:

http://www.sciencedaily.com/releases/200...161349.htm
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2576323/

My case the 9cm is pretty much the same as 8cm. AHI ranges from .8 to 1.8 which seems fine to me, but the sleep study scored much higher than the cpap machine. So 9 treats my OSA fine, without inducing CA's, which I guess makes me lucky.

[robysue]

I have read the opinion that it only happens in "new" cpap users over and over on forums but that's not true. It might go away for some but that's the reason we wait 5 months for the second sleep study. It's a different form of Apnea, that does not go away over time.

My point about new PAPers is that the problem with centrals usually emerges as PAP therapy is started. In other words, for folks with CompSA, there were no centrals present on the diagnostic study (without PAP), but there were lots of obstructive events. But shortly after PAP therapy was started (or when the pressure was increased past the person's particular threshold), the central apneas started to happen in clinically significant numbers.

But you are correct: If you're in the unlucky subset of PAPers who develop CompSA once PAP therapy is started, the centrals are not going to magically go away over time. And if the pressure needed to control the OSA is high enough to trigger the centrals, then long term CPAP/APAP therapy is not likely to be very effective. And the question becomes: How many hoops is the health care system going to make you jump through before someone somewhere wakes up enough to say, "This person needs an ASV and an ASV titration."

My case the 9cm is pretty much the same as 8cm. AHI ranges from .8 to 1.8 which seems fine to me, but the sleep study scored much higher than the cpap machine. So 9 treats my OSA fine, without inducing CA's, which I guess makes me lucky.

Not quite sure what you mean by "the sleep study scored much higher than the cpap machine". Do you mean that your AHI was much higher on your diagnostic study? Or do you mean it was much higher on the last titration study when the tech had you at pressures between 10 and 15 cm and you were having scads of centrals scored??

Have you ever had a titration study where the tech did NOT go above 9cm of pressure? If so, how was the AHI at 9cm on that study?

In general, a treated AHI of .8 to 1.8 is considered EXCELLENT. And long term if 9cm keeps your OSA this well in control without triggering the centrals, then you are lucky and there's no real need to do anything different.

And so the big question right NOT How should I tweak PAP therapy to make it more effective?

The real big question is: How do you feel?

And if you're still not feeling well or sleeping well, it may be time to look at the whole picture and consider things beyond the OSA/CompSA to explain why you continue to not feel very well.

If at some point 8-9cm of pressure no longer controls your OSA, you and your doc will need to do some serious work in figuring out whether and when to switch you to an ASV. But as long as 8-9cm controls the OSA without causing the centrals, there's no real point in switching machines.

[vsheline]

My point about new PAPers is that the problem with centrals usually emerges as PAP therapy is started. In other words, for folks with CompSA, there were no centrals present on the diagnostic study (without PAP), but there were lots of obstructive events. But shortly after PAP therapy was started (or when the pressure was increased past the person's particular threshold), the central apneas started to happen in clinically significant numbers.

But you are correct: If you're in the unlucky subset of PAPers who develop CompSA once PAP therapy is started, the centrals are not going to magically go away over time. And if the pressure needed to control the OSA is high enough to trigger the centrals, then long term CPAP/APAP therapy is not likely to be very effective. And the question becomes: How many hoops is the health care system going to make you jump through before someone somewhere wakes up enough to say, "This person needs an ASV and an ASV titration."

One of the things mentioned in the articles SnuffySleeper posted links for, is that of 13 patients studied who had CompSA, about half showed central events (in addition to mostly obstructive events) during their diagnostic overnight study (when not being treated with CPAP).

Another thing mentioned was that of 13 CompSA patients studied, that after months of adherence to CPAP treatment the frequency of central events had very significantly decreased -- so that (even without bi-level ST or ASV treatment) their AHI with CPAP had lowered from a median of 26 to a median of 7, which is a factor of nearly 4.

I think this may indicate that the pressure threshold (above which CompSA would begin) rises as we become more accustomed to CPAP therapy.

In SnuffySleeper's case, for example, I think there is hope that if in future his pressure needs were to increase to 10 or 12, perhaps by that time his threshold at which CompSA would begin will be higher than 10 or 12, so ASV may still not be needed.

In about half of the 13 CompSA patients studied the AHI remained high even after months of CPAP treatment. I think this may indicate that about half of new PAPers who initially display CompSA will be shown to need ASV because the CompSA will not have gone away on its own within a few weeks or months of starting CPAP therapy.


Below is an excerpt from the second article SnuffySleeper posted a link to, discussing how often CompSA is transient (goes away on its own):

BEGIN EXCERPT FROM ARTICLE:
A most pertinent issue in this debate is how many of these CompSA events are transient and whether patients can quickly use CPAP treatment successfully. Here there are conflicting results. Recently, a retrospective search was done of patients with 2 PSGs between 2003 and 2005 with CompSA evident on the first PSG and a subsequent therapeutic PSG using CPAP. There were 13 such patients with a median follow-up of 195 (49–562) days. The residual AHI on CPAP decreased from 26 (23–40) on the first PSG to 7 (3–21.5) on the follow-up PSG. There were 7 patients who reached AHI <10 and were regarded as “CPAP responders.” There were 6 “CPAP non-responders” with AHI ≥10 at follow-up. The latter were sleepier by Epworth Sleepiness Score (p = 0.03) and trended toward a lower body mass index (p = 0.06), but both groups showed similar adherence to CPAP therapy. The authors concluded that over time in CompSA patients treated with CPAP, the AHI tends to improve. However, nearly half maintained a persistently elevated AHI and remained symptomatic or had abnormal oximetry.
END EXCERPT FROM ARTICLE.

[SnuffySleeper]

Not quite sure what you mean by "the sleep study scored much higher than the cpap machine".

My sleep study scored an AHI of 8.7 at a pressure of 8 (the majority being hypopneas) the s9 scores my average ahi at 1.8 at a pressure of 8 (with the majority being CA events), so the sleep study scores significantly higher with different "types" of events..

Without Cpap my AHI is 48 (scored on my first sleep study), the majority hypopneas. But what my second sleep study discovered that AFTER 5 MONTHS ON CPAP WITHOUT A DAY MISSED that soon as the pressure goes over 10 my AHI increased with the majority being Central apneas.

I am getting the polysomnogram today, but what the report shows is that my AHI increases over a pressure of 10 and the tech stopped at a pressure of 14 as my AHI was higher than that without Cpap with the majority being all Central Apenas, which is dangerous. Basically if I had an Apap with a wide open range up to 24, i would go into cardiac arrest and stop breathing, not good.

Anyways, I can go back to my doctor for a sleep test every 6 months or he said whenever I feel like it.

I want to bring this to light in the Cpap communities, as it's dangerous to just have apap's with wide open settings. It might be hurting people like Sleep apnea without cpap and they would never know it. I even read stories about people who set their own pressure settings and left the max pressure to 16 and now they have kidney damage, which it was a forum post on another forum, so it can't be verified, but I choose to believe it.

[SnuffySleeper]

A most pertinent issue in this debate is how many of these CompSA events are transient and whether patients can quickly use CPAP treatment successfully.

I don't really think there is a debate. The average forum poster who reads about cpap won't hear of it because it does happen to a minority, which the way the internet works and forums in general is to drown out minorities and get the majority opinion simply by posting over and over or not relating to the situation so just ignore it.

It's real and is always diagnosed with sleep studies (in fact it's the main reason for titration tests). Sleep Study labs everywhere know of this, that's why doctors don't just prescribe everyone Apap's and set the pressure settings to whatever.

If COMPSA WAS NOT AN ISSUE, then doctors could just up Cpap pressure to whatever is comfortable for the patient and call it a day. Luckily Data capable machines would catch this (not totally accurately) but it would show your AHI rising and which would be a warning to see your doctor.

[SleepWrangler]

I want to bring this to light in the Cpap communities, as it's dangerous to just have apap's with wide open settings. It might be hurting people like Sleep apnea without cpap and they would never know it. I even read stories about people who set their own pressure settings and left the max pressure to 16 and now they have kidney damage, which it was a forum post on another forum, so it can't be verified, but I choose to believe it.

Looks like things are working out for you! Excellent!

The CA issue has been reported quite often in this forum and the other one. Fixed pressure is a possible solution for those who have persistent centrals. If CPAP doesn't work then BiPAP at fixed pressures and then ASV.

The first two weeks I had peak AHI of 60, mostly CA, and long episodes of periodic breathing and hypopnea, and almost no obstructions. After 2 1/2 months my AHI is often less than 2, mostly centrals, and long episodes of irregular breathing (not flagged by S9). I am very sensitive to changes in pressure ... even mask leaks. So ya, getting past the first two weeks was hell. Even so, strangely enough, I felt less tired than no treatment but my eyes were still swollen, pinkish, and marbled with red lines.

For myself, auto titration, or any change in pressure, can result in centrals. The most consistent problems occur on the initial pressure ramp. I am currently experimenting with different EPR levels.

I agree that self treating without a sleep study as reference is a mistake. Maybe a stroke causing fatal one.