home testing as good, and cheaper than sleep lab testing.

[bwexler]

I use my pulse OX periodicaly. Especially the week befor a doctor visit, so I can bury him in paper work.
And occaisionaly I get a meaningful coment.

[archangle]

While a pulse oxymeter can be a great way to first gauge if there is something to look at, it gives no information other than you are desaturating - how and why are not disclosed by the device - for that you need a far more thorough test, so it is only of use to eliminate the possibility that you have Apnoea, not to confirm it and determine type, cause and therapeutic approach.

In short - no desats = no Apnoea, look at other causes of your problem; desats = maybe Apnoea, certainly something that needs to be looked into further.

I think quite a few apneacs get an arousal and end their apnea event with no desats at all. They still suffer from the effects of not getting good sleep and stress.

I also think the patterns of desats plus pulse rate recorded overnight can give a really good indication of apnea vs. other problems in some patients.

i.e. I think a pulseox test done right and evaluated right has a low false positive rate but a fairly high false negative rate. It's probably worth having a followup sleep test if you decide the pulseox showed apnea, or at least closely monitoring the results from a CPAP machine, probably with a pulseox during CPAP.

[DocWils]

Archangle, the problem is that by definition, Apnoea must be accompanied by a deprivation of O2, so while there may be some sort of atypical or asymptomatic Apnoea, we wouldn't first define it as such until further testing. But yes, I think there would be a high false negative testing, especially given the amount of noise most home pulse-ox's generate - if you don't know how to read it and what to look for, you will not get a clear reading.

That said, I would not advocate using a pulse-ox as a method of first line screening. If you have one and it shows desats, you know you need further testing. If it doesn't, and you feel rotten after your sleep, you still need further testing. In the end, my point is that a pulse-ox is not a reliable method of testing for Apnoea and while cheaper than a proper sleep test, is simply not revealing enough to be of any real diagnostic use. If you have a bed partner, and that partner complains of strange snoring or breathing patterns when you sleep, it is probably a more reliable and cheaper first diagnostic tool than buying a recording pulse-ox. The best first line tool is - do you feel like a dog's dinner after you get up? Do you fall asleep in the early afternoon? Are you cranky, fuzzy or otherwise rotten? Is your health declining? Do you have a sore or dry throat in the morning? Any of these will tell you to head of to get a test, and again, will save the money of buying a pulse-ox.

[archangle]

Archangle, the problem is that by definition, Apnoea must be accompanied by a deprivation of O2, so while there may be some sort of atypical or asymptomatic Apnoea, we wouldn't first define it as such until further testing.

I know there may be conflicting standards, but isn't "apnea" usually scored as 10 seconds of not breathing? I thought only "hypopnea" required O2 desat or EEG arousal.

"1. Score a respiratory event as an apnea when BOTH of the following criteria are met:...
a. There is a drop in the peak signal excursion by ≥90% of pre-event baseline using an oronasal thermal sensor (diagnostic study), PAP device flow (titration study) or an alternative apnea sensor (diagnostic study).
b. The duration of the ≥90% drop in sensor signal is ≥10 seconds.
...
Note 1. Identification of an apnea does not require a minimum desaturation criterion."

http://www.aasmnet.org/scoringmanual/v2....pneas.html

Or am I misunderstanding your point?

[surferdude2]

As a side note here, I self diagnosed my sleep problem using a $29 (Walmart item) small digital audio recorder taped to the upper area of my tee shirt while sleeping. It was scary to hear that I was getting restricted airways and failing to breathe for periods lasting >30 seconds. They terminated with a loud gasp for air and sounds that indicated I had moved slightly. Once that started, it repeated on regular intervals of approximately 5 minutes.

FYI, I had just underwent a sleep lab session a week earlier and the results didn't show that I could meet the Medicare criteria for getting coverage for sleep apnea treatment or equipment. Frankly I don't see how they determined anything from the test since I slept less than 30 minutes.

I have since bought and paid for my S9 AutoSet and am currently getting positive results from using it. The ResMed software graphs certainly show the need for treatment. The fact that I'm now resting better and feeling better is evidence enough for me.

When I subsequently mentioned my test method to my pulmanologist/board certified sleep doctor, he made no comment. He did however agree to write me a script for a CPAP machine.

[herbm]

Surfie, you are pretty much correct.

Without desaturation events, OSA would be pretty meaningless.

With desaturation events, OSA is the cause some 99% of the time.

(But let's pretend it is only 75% of the time or some other suitably conservative figure.)

Stick an APAP on everyone with "tentative OSA" based on desaturation events and those that respond are pretty much covered leaving the others to be diagnosed by other means.

It's not rocket science, and pretty much all of us who monitor our own data (including the sleep docs) accept our machine's report of our AHI even without the pulse ox measurement.

It's only when someone gets "good numbers" with the machine and still gets LOUSY SLEEP that the docs typically look deeper.

[DocWils]

Archangel,

You are correct in one way, but not in another - there are several steps to a diagnosis of any illness, starting from suspected/preliminary to primary to confirmed. In order to provide guidelines for practitioners to arrive at list of possible illnesses for a given set of symptoms, we have a general description of various sorts of illnesses, often based on the Latin or Greek root name for the observed problem.

Apnoea means cessation in breathing (and there are tons of different apnoeas, not every one related to sleep and not every one an illness - deep free diving for instance is a type of apnoea sport) and in sleep apnoea is usually accompanied by some sort of hypopnoea. Almost any cessation in breathing, no matter how short, will cause some desaturation of the O2 levels (actually, it is a build up of CO2, but we measure it from the O2 saturation in the blood). So our preliminary diagnosis is based on the O2 desaturation levels OR on the observed cessations of breathing. From there we see via further testing if the patient meets the necessary criteria for the clinical definition. In short, a visible number of sO2sat desaturations over a given night would indicate to any examiner that the patient should be tested for a suspected sleep apnoea, providing there are no other visible circumstances to deny the preliminary diagnosis. However, it does not constitute a final diagnosis, and certainly not a clinical diagnosis and treatment method.

Your mistake in in your definition of hypopnoea. In my medical dictionary on my desk (admittedly it is the Swiss standard version, not the US) the definition is a sustained period of overly shallow breathing or an abnormally low respiratory rate. There is no included definition of O2 desaturation within it, but it is assumed that such would be the case anyway.

That is a round about way of saying that yes, I think you missed my point a bit, by sticking to your dictionary definition of the overall term for Apnoea, rather than general medical usage for sleep apnoea, wherein a cessation of breathing is assumed, simply by the prolonged cessation of breath, to raise the CO2 saturation in the blood stream and show a lowered O2sat readout on an oxymeter. Because of that assumption, the actual sO2sat levels are not considered clinically significant in meeting the definition, however, a series of desats would push any doctor to write in the referral "suspected sleep apnoea". While I know of no GP who gives out recording pulse-oxymeters to patients to do a first line test at home, on more than one occasion in the hospital I have encountered interns who, after looking at the overnights of patients with oxymeters on their fingers (or ear lobes - we have that type as well) as part of their monitoring for whatever (heart attacks, surgery, various illnesses, you name it) have flagged the number of desats and started a referral for SA testing.

My actual point was that while I thought that home testing is a good method of starting out diagnosis procedure, simply relying on your own recording pulse-ox to provide you with enough material to get a doctor to write a referral, as one poster suggested, is not a good idea - alone it is not reliable, and as a part of the definitions of clinical SA it is only a small part of the story and most of all, buying one because you think you might have SA instead of going to a lab and requesting a home test is a waste of money. On its own, these devices don't provide clinically significant information besides that you have a pattern of desaturation. We need more than that before we write you out a scrip for a CPAP machine. Once you have a CPAP, however, it is a very good way to accompany the data produced by the PAP device in order to monitor the progress of the treatment. Just don't think that because you come into my office with a PO readout and say you have SA that I will be impressed and send you home with a PAP machine. The most I would do is refer you to a sleep specialist, and your will have wasted 150 smackers for nothing. If you came to me complaining of feeling tired all the time, needing a nap at 4 in the afternoon each day even while still at work, showing a weight gain and a blood pressure rise, etc, yet showing a normal EKG, I would probably send you to the sleep lab anyway and have them do a work up on you, including testing all the other possibilities, like thyroid problems, etc.

[bwexler]

My new GP when I started on Medicare, first visit did an EKG and attemted to scare me to death with a diagnosis of AFib. He told me I had to go imediately to the ER, because he didn't wnt me dying in his office. On the follow up visit he said he thought i also had sleep apnea and ordered an overnight puls ox test, which he said was required prior to ordering a sleep study. He did order the sleep study and since my AHI was only 83 I was able to get an S9 Autoset.
My average AHI since I got my ASV machine last Oct is 1.7.

[herbm]

AFib is serious but generally not THAT BAD, in and off itself. (It can cause or contribute to OTHER really serious problems and can sooner or later be VERY VERY BAD if left untreated. Conversely VFib kills right now or soon if you don't get immediately treatment, e.g., shock paddles.)

My doc was very worried when he found AFib and immediately referred me to a cardiologist but that took a couple of days and she let me go a couple of MONTHS while testing. We did an echo (25% ejection fraction which is less than half of what it SHOULD be at about 55%), then a cardiac stress test, then scheduled and did a cardiac catheterization (which was negative for any blockages).

After all that, she gave me an antiarythmic pill which converted my AFib in about 1-3 days (could have done that to start with if you ask me.)

Likely I had the AFib for a year based on looking back at the symptoms, maybe longer.

I had it one more time when we completely stopped the antiarythmic (I now take a half pill a day for maintenance until we try to stop it again.) This likely lasted for a week or so without any real excitement.

BTW: My ejection fraction was treated (strengthening my heart) with carvedilol (correg) and the amiodarone (the antiarythmic) and is now back at 55% or better where it belongs.

The antiarythmic drugs are generally pretty toxic but I tolerate it with NO ISSUES at all, same for the high does of carvedilol.


FYI: My dentist caught my OSA, and offered an inexpensive (< $200) pulse ox for 2 nights which pretty much convinced me -- went to the sleep doc and did the sleep lab because it was required but if I had no insurance and know what I know now it would have been a no brainer to just buy a machine on the grey market.

[archangle]

I think of a pulseox test as being like asking someone if they snore. If they snore, it increases the likelihood of having apnea. If they don't snore, it isn't a really strong indication that they don't have apnea.

A bad pulseox result, especially if read by an experienced person may give a very good indication of apnea. It would be dangerous to assume that a good pulseox test (or no snoring) means no apnea.