Sleep study inaccurate

[Sanjay1976]

Hello.
I just had a home sleep study with Resmed link Air apparatus. I have not gotten the results from my physician yet - so I don't know what was found.
However reading this forum for the past couple of days has alerted me to a possible problem.

My wife tells me that I sleep with my mouth open, sometimes wide and sometimes just a little bit. So I'd have to admit to being a mouth breather sometimes.

I've gathered that measuring the flow of air is critical to accurate sleep study results. Does the sleep study measure all the air that I take with each breath?
Is it supposed to?
Does it need to measure all the air that I inhales including through my mouth?
Do I need to tell my doctor that the air flow measures may be incorrect?

(I think I've figured out that having air dirverted probably wont affect apneas, but it would certainly affect hypopneas. )

Thanks for any guidance.
Sanjay

[Miss Emerita]

Welcome to the forum! It won’t matter whether you slept with mouth open or closed. We could provide a little more detail if you could describe what the test kit contained.

[Sanjay1976]

Thank you
As I said, the apparatus was Resmed Apnea Airlink, which uses a nasal cannula, a pulse odometer, and two body belts.
Thank you for helping me understand.

[chunkyfrog]

If your sleep test included a pulse odometer, I'd wager you picked it up
from Advanced Auto Parts.
Please say you didn't do that.

[Sanjay1976]

If your sleep test included a pulse odometer, I'd wager you picked it up
from Advanced Auto Parts.
Please say you didn't do that.

Hello and thank you

Auto correct does strange things. I typed oximeter but it was changed to odometer.

Thank you

[chunkyfrog]

It does that to me all the time.
I was able to shut it off on my work computer,
because I did a lot of technical writing.
Sadly, autoINcorrect has a small vocabulary--
but a HUGE ego.

[Sanjay1976]

Welcome to the forum! It won’t matter whether you slept with mouth open or closed. We could provide a little more detail if you could describe what the test kit contained.

Thank you for your welcome,
As best as I can tell the measurement of the air flow is done by this:

honda_002.jpg (49.21 KiB) Viewed 3425 times

Thanking you for your kind concern and advice,
Sanjay

[Miss Emerita]

It's my understanding that unless your nasal passages are completely blocked, the prongs will help to detect events even when you are mouth breathing. But I hope the forum experts will weigh in on this question.

[Miss Emerita]

Sanjay, I conferred with a couple of the forum's experts. While they can't say for sure whether mouth breathing affects the results of a sleep test that relies in part on data from nasal prongs, they stress that this might not matter even if it were true. As long as you have an AHI that is high enough to warrant treatment, you'll get treatment. And if your AHI is not high enough, you can talk with your doctor about the mouth-breathing issue to see whether a different kind of test could be performed.

[Sanjay1976]

@ Miss E,
Thank you for conferring with the other experts on my behalf.
I'm not understanding why air flow that is improperly measured would not make any difference.
If it would make no difference, then why measure it at all?

I called the doctors office today to see if they would give me any results, but they said that I have to wait for a face visit with the doctor - some weeks away.

So now that scares me, I see others on this forum suggest that a person could die.

Again, thank you for taking your time to consult with the team of experts.

Sanjay

[ChicagoGranny]

alerted me to a possible problem

Is there a word for this? Maybe "pre-worrying". Your test results may be accurate, and you have worried for nothing.

I assume you have some symptoms of sleep apnea that led you to be tested. Let's wait to see the results of your study.

BTW, it's hard to breathe through the mouth and not have some flow through the nostrils unless you have a severe nasal blockage.

What are the symptoms that led you to a sleep study?

[ChicagoGranny]

I called the doctors office today to see if they would give me any results, but they said that I have to wait for a face visit with the doctor - some weeks away.

Oh, I forgot to mention, while waiting, don't sleep on your back. Sleep on your sides or stomach. Sleep-disordered breathing is often worse on the back where gravity directly pulls your tongue and soft palate into the airway. In the other positions, gravity is not working so directly.

[Miss Emerita]

I'm not understanding why air flow that is improperly measured would not make any difference.
If it would make no difference, then why measure it at all?

The idea was that your AHI for the whole night may be over the threshold for treatment whether there's a sub-optimal measurement during mouth breathing or not. If it is over the threshold, then great; you'll get a machine. If it isn't, then you can discuss the mouth-breathing question with your doctor.

I'm really sorry you'll have to wait for so long to get any news. I wonder whether the office would put you on a waiting list in case a cancellation opens up an earlier opportunity.

It is wildly, WILDLY unlikely you would die of apnea in the meantime. People with really high levels of apnea sleep miserably and fall asleep repeatedly during the day, but that doesn't mean they die at night from apnea events. They just wake up over and over and over again, and as the years go by, their general risks of heart disease (and possibly stroke) go up from the stress and strain.

The wake-ups can be brief enough so that they aren't remembered, but the body is still doing its job of waking people up from apnea events so they can breathe.

[Sanjay1976]

@ Miss E,
Thank you, I was alarmed because others on this form keep saying if you don't use your Cpap you could die. You have relievd my fears.

i started question with the idea that it was important to have accurate flow numbers. From what little I've been understanding is that the AHI is based on the flow data. So why is accurate flow values not important - that's what my mind keeps coming back to.
Help me understand why the flow data not important.
Thanking you so much for helping me.
Sanjay

[ChicagoGranny]

Help me understand why the flow data not important.

1. What's the worst that could happen in your sleep study? That would be a false negative - the test shows no sleep apnea, but you actually have sleep apnea.

2. Let's take the case you are worried about which is an unlikely case: you breathe through your mouth and there is no flow through your nose. The device will record you are not breathing. You get diagnosed with sleep apnea.

You are overthinking this and worrying needlessly. That is actually a symptom of sleep apnea - emotional instability.