Can an oximeter give a false positive reading?

Hello All,

I joined up because my fiance and I are both getting aggravated over a potential sleep apnea issue...so I hope I can get some good insight here!

I had gone to my sleep doctor twice in the past:

The first time was to investigate the possibility of having sleep apnea because I frequently woke up during the night and was tired during the day. I never went for an official sleep test that time because we both determined that a combination of environmental factors was keeping me awake: my brother would come home at 2am-3am and make noise in the kitchen, my bed was too soft, etc.

The second time I went, I was much heavier and my fiance was complaining that I would stop breathing at night and/or be choking. I always found this interesting because I was under the impression she was asleep long before me, but I decided to go again for the hell of it. There was definitely some quality of life to be desired in terms of feeling awake during the day and having energy.

My doctor examined me and said based on a physical examination of my airway and neck size, and the fact that my father has sleep apnea, I would be a decent candidate for the test. We decided on a take-home test because it was easy and cheaper than going to an "official" sleep study as an inpatient.

The night that I ran this test, I was up all night tossing and turning. I just couldn't fall asleep. I think I finally fell asleep somewhere in the ~3am-330am range and woke up around 6am-630am. I was pissed because I knew the machine was only set to acquire data for one day and it was probably not the best data...but I sent it in anyway. When I went to the doctor's office to get the results, I was kind of amazed on the conclusions that were drawn. He said that I had a lot of partial events and some full apnea events as well. I told him about my concern for the validity of the test since I remember being awake but he said "well it says here that you slept for about 6 hours". I couldn't believe it. He assured me that the device generally does not provide a false positive answer, so I said, OK, now what? We decided that I would lost a "significant amount" of weight and re-test.

I briefly tried using a CPAP machine because my fiance was bugging the crap out of me to just get one. So I got one from the office that was pre-programmed for me (not based on any tests though) and I thought even if I didn't use it, it would be good to have. I tried it a dozen or so times but could not fall asleep (I'm a very picky sleeper) and eventually I returned it because of the way my insurance worked; they were going to charge me the full price if I didn't use it for 4 hours every day.

Onward...

Since this test I have lost 23lbs (from 260 to 237), started working out again, feel less stressed and less tired during the day. Most nights I sleep through the night and most nights I am able to fall asleep quickly too. The only symptom that still lingers is as follows (I find it complicated): sometimes I will get random anxiety attacks and kind of prop myself up and start to regulate my breathing by taking deep breaths. My fiance will hear this and think that I am choking. When the attacks come, I am conscious...I don't know how to describe how I feel...it's just weird. But the major debate is whether or not sleep apnea is causing a lack of breathing and the feeling of choking and bringing the attack on.

Based on all of this, I don't know what to do other than 1) ask for some opinions, understanding that they are opinions and 2) go for an official sleep test. I will continue to exercise and lose weight regardless.

Any help is appreciated in advance!

-Chris

you ask a question in the title and never go back to it.

and, unless it's faulty, the answer to the title question is "no".

though i don't know what you're thinking of as being "false".

palerider wrote:you ask a question in the title and never go back to it.

and, unless it's faulty, the answer to the title question is "no".

though i don't know what you're thinking of as being "false".

Good question, and my apologies! Yes, as the title states, I was wondering if the the diagnosis of sleep apnea based on the data from the take-home oximeter test could be false or skewed if the data was skewed.

I have read some anecdotes that talk about how patient movement could throw the data off and there was another article I read where the author said that you could fool the oximeter by lying still, staring at the ceiling all night.

The fact that the oximeter "thought" that I was asleep for 6 hours really had me dumbfounded.

C&C wrote:

palerider wrote:you ask a question in the title and never go back to it.

and, unless it's faulty, the answer to the title question is "no".

though i don't know what you're thinking of as being "false".

Good question, and my apologies! Yes, as the title states, I was wondering if the the diagnosis of sleep apnea based on the data from the take-home oximeter test could be false or skewed if the data was skewed.

there's no test that's just an oximeter, an oximeter may be *part* of the test, but only a piece of it.

C&C wrote: I have read some anecdotes that talk about how patient movement could throw the data off and there was another article I read where the author said that you could fool the oximeter by lying still, staring at the ceiling all night.

The fact that the oximeter "thought" that I was asleep for 6 hours really had me dumbfounded.

the sleep testing machines are better at determining whether you're asleep than you are.

before I started cpap, I'd watch tv, and I'd be told "you were snoring" and yet I'd swear that I never went to sleep.... of course, watching that tv show again, there'd be big chunks of it that I didn't remember..

the point is, your brain is really good at lying to you about things like that.

conversely, people with apnea spend the night choking and gasping and being aroused dozens of times an hour, sometimes multiple times per MINUTE... and yet, they *think* they slept soundly all night long.

thanks for the response and information...sounds like i should just re-test to confirm and go from there based on what you are saying

What kind of "in home sleep test did you have?" Did it just clip on your finger or what?

We can work you through the details, but the final answer is almost certainly that you have sleep apnea and need to decide whether you want to do CPAP or do you want to die slowly by degrees?

Read the Useful LInks in my signature line at the bottom of this post to get forwarned about dealing with the DME (CPAP salesman) without getting screwed with a bad CPAP machine. The most important part of CPAP is getting a good, data capable CPAP machine.

Btw, if you're a 'back sleeper' (which provokes more apneas in most people, especially if you're not on Cpap), make every effort to not do so at least until you have a better idea of what's happening even if it means putting pillows etc. behind you to keep it from happening overnight, and see if you feel any better. And if you sleep sitting up (recliner?) and your head falls forward, it can block your airway, so wearing a soft cervical collar can help with that as well - makes a big difference to some people. Also stay away from alcohol anywhere at all near bedtime, plus coffee anywhere after noon ('silent' GERD - acid reflux) can really mess up your sleep even if you're not aware of it.

archangle wrote:What kind of "in home sleep test did you have?" Did it just clip on your finger or what?

We can work you through the details, but the final answer is almost certainly that you have sleep apnea and need to decide whether you want to do CPAP or do you want to die slowly by degrees?

Read the Useful LInks in my signature line at the bottom of this post to get forwarned about dealing with the DME (CPAP salesman) without getting screwed with a bad CPAP machine. The most important part of CPAP is getting a good, data capable CPAP machine.

It was a device that wrapped around my wrist and my finger went inside what I think was the oximeter...

Julie wrote:Btw, if you're a 'back sleeper' (which provokes more apneas in most people, especially if you're not on Cpap), make every effort to not do so at least until you have a better idea of what's happening even if it means putting pillows etc. behind you to keep it from happening overnight, and see if you feel any better. And if you sleep sitting up (recliner?) and your head falls forward, it can block your airway, so wearing a soft cervical collar can help with that as well - makes a big difference to some people. Also stay away from alcohol anywhere at all near bedtime, plus coffee anywhere after noon ('silent' GERD - acid reflux) can really mess up your sleep even if you're not aware of it.

Thanks Julie. I always sleep on my stomach (kind of to either side). I pretty much can't fall asleep on my back but I HAVE caught myself starting to doze on my back before and that's the only time I will snore slightly.

Also I avoid alcohol largely because I know it will screw up my sleep. Coffee in the evening: same thing. Never heard of silent GERD being a possible cause though...interesting.

Oh, it's not a cause, but can certainly affect things as it can arouse (tho' not waken) you, or just irritate you below being conscious of it, and you don't want any of that on top of OSA.

Have your wife listen to this youtube video and ask her if you sound like that: https://www.youtube.com/watch?v=9bFTcmREtqQ

yaconsult wrote:Have your wife listen to this youtube video and ask her if you sound like that: https://www.youtube.com/watch?v=9bFTcmREtqQ

Wow that's bad! No as far as I know from what she tells me, she doesn't hear anything unless I wake up and I am consciously trying to control my own breathing (deep inhales and exhales) after the anxious state...

C&C wrote:

yaconsult wrote:Have your wife listen to this youtube video and ask her if you sound like that: https://www.youtube.com/watch?v=9bFTcmREtqQ

Wow that's bad! No as far as I know from what she tells me, she doesn't hear anything unless I wake up and I am consciously trying to control my own breathing (deep inhales and exhales) after the anxious state...

Have her listen to it - it's very educational. Once you know what to listen for, you can recognize apnea in people. And don't be distracted by the snoring - that doesn't matter. It's the cessation of breathing that is the problem. It's just more obvious in loud snorers when they stop breathing. But plenty of people who don't snore at all have apnea too.

C&C wrote:

archangle wrote:What kind of "in home sleep test did you have?" Did it just clip on your finger or what?

We can work you through the details, but the final answer is almost certainly that you have sleep apnea and need to decide whether you want to do CPAP or do you want to die slowly by degrees?

Read the Useful LInks in my signature line at the bottom of this post to get forwarned about dealing with the DME (CPAP salesman) without getting screwed with a bad CPAP machine. The most important part of CPAP is getting a good, data capable CPAP machine.

It was a device that wrapped around my wrist and my finger went inside what I think was the oximeter...

does the term "watchpat" mean anything to you?

if so, it's a lot more than an oximeter.

palerider wrote:

C&C wrote:

archangle wrote:What kind of "in home sleep test did you have?" Did it just clip on your finger or what?

We can work you through the details, but the final answer is almost certainly that you have sleep apnea and need to decide whether you want to do CPAP or do you want to die slowly by degrees?

Read the Useful LInks in my signature line at the bottom of this post to get forwarned about dealing with the DME (CPAP salesman) without getting screwed with a bad CPAP machine. The most important part of CPAP is getting a good, data capable CPAP machine.

It was a device that wrapped around my wrist and my finger went inside what I think was the oximeter...

does the term "watchpat" mean anything to you?

if so, it's a lot more than an oximeter.

I had to google it but yes that is exactly what it was