DO You Have Confidence Your Sleep Study Is Accurate?

[riverdreamer]

Jan, while my apnea is not as severe as yours (not as many events per hour), I am finding my type and number of apneas swing wildly with only occasional hints as to why. My studies showed everything from no apneas at all, to only centrals, to only obstructive. I do have multiple health issues, take varying amounts of medication that can suppress the central nervous system, and my respiratory system is highly reactive to all kinds of inhaled and ingested substances. Recently an exposure to paint stripper and new paint set me off on a period of highly erratic nights. With my equipment, I can't tell for sure, but I expect my central apneas were increased, as the apneas were showing up as much longer, and more frequent, and at a higher pressure, than I had previously seen. Now, as my reaction is fading, I am showing almost no apnea or hypopnea, at much lower pressure. Makes me REALLY grateful for my APAP, and the forum here for letting me know that s what I needed.

While I am sure that sleep labs vary as to how accurate they are, I would bet that the more complex your health is, the more difficult it is to get a representative snapshot in a single night. It also requires getting the long view on the effectiveness of your therapy, as any particular day may not be representative of normal, or average, for you. I find if I make too drastic of a change, I may overshoot what is needed when things calm back down. Only by watching longer trends have I gotten a clue as to which direction to go.

[JoyD.]

Yes, I do believe that both my sleep studies were as accurate as "one night" can be. No doubt, if it was done on various nights, it would vary somewhat. I am convinced from reading this forum, that the Sleep Tech makes a big contribution to "accuracy" and I believe I had a good Sleep Tech. (She was a young RT who also was on CPAP herself . . . and it was she who told me about cpaptalk.)

What is amazing to me is that I forgot to take my Ambien, and I only slept off and on for about 2 hours total (my Titration Sleep Night)! Yet my tech titrated me at 13 and believed it was reliable. Once I got my Auto M Series, and originally set it from 10-20 then to 11-15, now at 12-16 . . . my 90% pressure has always showed to be 13. So I am pleasantly surprised that even 2 hours of sleep during my titration seems to have been accurate

[Raj]

There are so many artificial conditions during a sleep study such as electrodes taped all over one's body, sleeping in an unfamiliar environment and on an unfamiliar mattress, knowing that you are under constant observation etc. that I think it's a minor miracle or at least largely good luck when any such studies prove even close to the money. That's not even considering the other variables listed by our comrades earlier in the thread, perhaps most importantly the time constraints involved: using a single night (and usually a second night at some point to determine titration) as the total basis for evaluation -- assuming one can sleep at all (I only got about an hour and a half during my initial study).

My short answer to your question is no.

[SaltLakeJan]

wrote:

I had a doc dismiss the accuracy of the results of one of my studies, saying that they're only as good as the tech performing them and reading them. I'm waiting for those more knowledgeable than I about these things to chime in.

from personal experience I know how limb movements that are from Periodic Limb Movement Disorder can complicate getting a complete picture of either the apnea or the limb movements, as they can vie for prominence. I'd be interested in knowing what your limb movements look like after getting the OSA treatment to be therapeutic. Maybe they really were just event related, but I can't help but wonder if the two were coming so rapid fire that they appeared connected. .

Kathy

I realize you have studied PLM's because of your personal involvment, but I had no idea the PLM's could affect the study. I will check with the National Institutes of Health. Several times, I have found answers to remote questions at their site. You always give me something to think about. Thanks for the information. Jan

[SaltLakeJan]

wrote:

That is why most on this board push for us to get a Auto machine. It will keep adjusting the pressure until the apneas go away. My sleep study got close. The pressure got me just under the 5.0 AHI mark although the sleep doc told me I could probubly go down a cm/h20 if I wanted to. With the Auto I found out that +2cm/h2o puts me in the 0.5 AHI range. Before my heart problems it had been running around 0.2. Still a lot better than if I had blindly gone with the one night stand.

Jerry

Jerry, I think you summed up my sleep studies with your comment - "The one night stand"I have learned far, far more on this forum that from the questions I asked the sleep doctors. I left as baffled as when I went into the Doctors' offices Jan

[Catnapper]

My first sleep study was not right, and my basic cpap machine was set too high. Those first few weeks were dreadful. I talked the doctor into prescribing a specific auto-pap and then I adjusted it to be more comfortable and effective.

Over time, I managed to get an auto bi-pap, and did my own tweaking. When I had my second sleep study, this time using bi-pap, the doctor was surprised that I had my machine set exactly as the sleep study bi-pap titration showed to be optimal. I think that study was right, since it matched what I had found worked well over months at home. However, if it had not matched, I would not have hesitated to adjust it as needed. As a matter of fact, since then, I have lowered the EPAP a bit so I breathe even more easily and my AHI is at 1 or less. Before I lowered it, I had AHI of 0 most of the time. I am satisfied at the new settings.

My doctor is very encouraging to patients who take control of the therapy, so that helps. The DME specializes in sleep and pulmonary equipment and is a small local company. Once I got past the RT who started with me and got to the owner for what I wanted, things have gone perfectly there. The RT lied and was not very helpful. Who needs that?!? The owner is very reasonable and smart as well. I have been very lucky, from what I read here.

[RipVW]

RipVW,

I still don;t know what all the machines do. Did you find that 12 was your correct number by self-titration? Or How?
Curious for myself. Thanks for your reply.

Jan

Yes, my M Series Auto found the right pressure for me. When set in auto mode, auto machines (APAP) automatically adjusts to your pressure needs (within preset uppper/lower limits).

[howkim]

No, I don't have any confidence that my last sleep study is in any way accurate. When I woke in the morning, I had to fight the MASSIVE leaking around the mask. The leak was not mentioned in the study report. Need a new sleep doc.

[SaltLakeJan]

Den,

Thank you for your reply and the list. I have some of the information, but not all. I have a series of folders I have labeled with the various topics. I read on CPaptalk.com. I copy posts with information that helps me do the best I can, and I read & reread them frequently.

You would be surprised how many "quotes" I have copied from your posts - and Slinky's. You belong to a group of Sleep Apnea Pros who "give back" to the ones just starting. You may give back more than you received initially - Cpaptalk.com has grown in information basics since its inception.

Cpap is not a natural subject for me - My body & mind have not "caught on" as easily and quickly as many others, so I feel an extra appreciation for people like you who help me get it through my thick skull and resistant body.

Some subjects have been "naturals" for me to learn - but CPAP has not. Thanks again.
Jan

[LouC]

In a word NO. I came out of my study with pressures recommended at 14cm , chin straps or full face mask, and dire predictions. Never got more than 3 hours without giving up.

After reading here, and fighting the DME & sweet talking the sleep doc, I got an automatic machine and Mirage Swift II. I reviewed my smart card with the doc last week. Typically using 9-10 cm, minimal leakage, avg 8.2 hrs a night, almost no mouth breathing. Doc said go away for a year before you come back. The veterans here are a h*ll of a lot smarter than the average sleep tech.

[Bob himself]

Many years ago (30-35), I worked in sleep research (as a non-medical collaborator), concentrating on the relationship between REM sleep and depression. Back then, we were just beginning to hear about sleep apnea, so I have no special knowledge about it, but I can tell you that sleep architecture data collected from a single night in the lab is pretty close to useless. Our standard practice was to throw out the first two nights of data before tabulating baseline data. So I don't put a lot of trust in these one-night studies. A single night in a sleep lab, wired up for the polygraph, is about as far from a representative night of sleep as a person is likely to get.

A REM latency of 306 minutes or 419 minutes with no REM would be very unusual. My first guess would be that the sleep scoring was inaccurate, for whatever reasons.

Bob

[SaltLakeJan]

Hi Gerald, I got a great laugh out of your descriptions of a sleep study, and a sleep center.

My first sleep study was "super crappy".......and the second one was just "moderately crappy". I was run through two "sleep center" mills......just like a cow......and I can now fully understand why most people fail when it comes to CPAP therapy.]

If a person didn't have a sense of humor regarding cpap -- life could get pretty grim.

And your concluding statement

[take charge of your own therapy.....it's the only way to go]
Gerald

Could be a fitting motto for CpapTalk.com.

Thanks Gerald
Jan

[SaltLakeJan]

Hi Riverdreamer;
Thanks for your post regarding your sleep study. Like you, I have multiple health issues - do you think there is any connection between them and untimately using cpap? I am not as sensitive to fumes as you are, but since childhood, my nose and throat semi-closes over if I am around airomatic things - scented candles, perfume or tobacco smoke - I get over it faster than you do, but I feel there is a connection between multiple allergies and cpap.

I was interested in you saying that sleep studies are so complex, a one night study, cannot possible diagnose how we act and react under different circumstances in our lives. You said as you were sorting things out that you are doing better using your APAP at a lower pressure. Along with you equipment you list 4-15, and nine - Is that the pressure you are using.

Cpap isn't working as well as I would like.I hope my doctor will help me change to a machine better suited to my situation. Your post was helpful to me. Thanks.

Jan

[kteague]

Jan, I'm a little slow on this, but I was just thinking how some of us got loaner apap machines to recheck our pressure needs. Wonder if you could get a loner of one of the data machines that report centrals, or maybe one that treats centrals would be better if it reports any that it treats. Or do you need one more sleep study? I just hate to see you continuing as if none of that second study was even there if there's a chance it could factor into your ongoing difficulties.

By the way, can I blame my late bedtime tonight on you? Figured I'd join you in reading some research on PLMD. That was over 2 hours ago.

Kathy
Who couldn't have gone to be earlier anyhow cause I ate dinner too late and now have to wait to take my bedtime meds.

[jda1000]

I think they're accurate - for the night they're done, under those conditions, in that season, with your physical and emotional condition at that time, with infinite wires routed all over the place....

After that, they're not. I don't think they can be.