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Home Sleep Study - Low AHI but significant desat - ArcherNeedsSleep - 04-08-2021

Hello.  I’ve been reading through the archives on this forum and am amazed at how knowledgeable and helpful everyone is!  I’ve found some questions similar to mine in the archives, but not quite the same, so I figured I would just start a post and ask for some thoughts.

TL;DR: I have a history of signs and symptoms of sleep apnea.  At-home sleep study shows AHI 3.8 with significant oxygen desat to 67% with 107 minutes under 88%.  I’m assuming that insurance won’t cover a machine with the low AHI.  Looking for advice – should I wait for an in-lab sleep study to rule out other sleep-related issues or assume I’ll eventually end up with a PAP anyway and try to convince my primary care doc to write a prescription and self-titrate.

Here’s the longer version:
I’m a 48yo woman.  I’m overweight but not obese.  I’m active with hiking and archery, although I’m not as fit as I was in college, for sure.
I’ve snored since I was a kid – enough that I was often the but of jokes at sleepovers, and all of my college roommates complained about my snoring more than once.  My husband knows better than to complain Cool  but he definitely “hints strongly” that I snore.  My teenagers aren’t so polite about it – they complain openly that I snore a lot.  

For most of my adult life I’ve woken up with headaches that fade after about an hour.  I don’t drink often and I don’t do any drugs or take any crazy prescription medicine, so it’s not caused by an external factor that I know of.  Lately, I’ve even been waking up with headaches in the middle of the night and fighting to go back to sleep.  I’m tired and fuzzy-headed all day long and it’s impacting my job.  It’s high time to fix this issue.

So, I finally gave in and asked my doctor to schedule a sleep study.  It was a home study since she figured it would be the fastest way to get some answers during the COVID backlog.  The study came back with a low AHI but significant hypoxemia.  Being an inquisitive engineer, I spent hours searching for causes and cures for hypoxemia, I bought a Wellue ring to see what was going on, and now I have more questions than I had before…

Results of the sleep study (summary only – I’m still fighting with them to get a detailed report):

Diagnosis: Nocturnal Hypoxemia.

Impressions:
- No significant OSA with an overall AHI of 3.8 events per hour and lowest oxygen saturation of 67%.
- No significant central sleep apnea
- No snoring was audible during the study.  (side note: my kids told me I clearly did the test wrong because I always snore, and it should have been obvious to the sensors.)   Rolleyes

Respiratory Parameters:
- 1 apnea (obstructive)
- 28 hypopneas
- AHI 3.8 
- Oxygen desat to 67%
- Mean oxygen saturation 89%
- Cumulative time spent under 88%: 107.2 minutes
- Mean heart rate 59.6 bpm

The O2 desats kind of concerned me, so I sprung for the Wellue ring and have been wearing it at night.  I’ve attached a couple of sample nights.  My O2 doesn’t go down to 67% on any of these charts (thankfully), but it does consistently drop through the night.  Even considering that I live at an altitude of 7300 ft, it seems like it’s too low.  I’ve checked my daytime O2 and I stay in the 94-97% range, so there’s plenty of oxygen here for me to breathe.

[attachment=31365]
[attachment=31366]

I don’t have any significant health issues that would cause this.  I do have some autoimmune history that’s well treated with Synthroid. I have mitral valve prolapse, but I’ve passed every heart function test with flying colors, so I don’t think that’s the cause.  I’ve had two shoulder surgeries and do end up sleeping on my back more than I would like since side-sleeping too long gets painful.  I suspect that’s part of the issue, but not something that I can fix at this point since it will take a shoulder replacement to repair the rest of the damage there.

Whew!  Thank you to anyone with the fortitude to read through this mini-novel and get to my questions.  Here they are:

1)     I can’t find any examples of “normal” SpO2 charts at a similar altitude, so I’m not even certain that mine is bad.  Does anyone have insight to whether these charts are abnormal, or if I’m just over-reacting? 

2)     If the charts are abnormal, do they indicate RERAs?  That’s how I see it, anyway.  My O2 drops, I respond with increased heartrate and/or moving around, and then go back to sleep, only to have it happen again.  Most of the time I don’t remember waking up, but if I do fully awaken, it’s usually based on someone or something in my dream telling me I “must” wake up, and I’m panting and sweating with effort.  That seems like RERA to me, but I’m still trying to understand. 

3)     If this does look like an apnea type of thing, do you recommend that I go back and get an in-lab study to see if my AHI goes up enough for insurance coverage, or just accept that it’s not full-blown OSA and that I’ll be on my own for treatment?

4)     I have an appointment with my primary care doc in two weeks to go over the sleep study results.  I anticipate that she will agree to ordering an in-person study, but I’ve been warned that it will take months to get in due to the COVID backlog.  Should I just ask her to write a prescription for equipment?  I’m willing to buy my own equipment if the standard S10 Autoset is likely to work.  But if this is a UARS thing where I might end up on the VAuto after already spending a bunch on the Autoset, I’m a bit leery of jumping into a purchase without knowing more.
 
I’ll take any and all input on this.  I’m hoping to have a coherent plan of action when I go to my appointment. And after reading through years of posts on this board, I’m convinced that I’ll get good advice here.
 
Thank you!


RE: Home Sleep Study - Low AHI but significant desat - Gideon - 04-08-2021

A CPAP will help with the desats. Your desats are significant. My guess is your home test did not check for RERAs, so UARS cannot be determined. Having mostly hypopneas you could have the RERAs and thus the flow limits of UARS.

The Autoset will help with both your snoring and your desats.

Look at Supplier#2, call them about pricing for new and used (ask about hours) on both Autoset and Vauto.
Ask a couple of DME's what your price will be for both machines. You may see that buying outright is cheaper.

Discussion with your doctor.
1. Desats must be resolved. you understand that either PAP or nighttime oxygen will do this. Are there any other options?
2. CPAP/BiLevel will resolve snores and the very mild AHI of 3.8 which you know is below the normal threshold of 5.

What are your (your doctors) thoughts on this.

Give him your thoughts on treatment and ask her for her thoughts on the two options.


RE: Home Sleep Study - Low AHI but significant desat - ArcherNeedsSleep - 04-08-2021

Gideon - thank you for the insight and things to talk to the doc about.  

You are correct about the home sleep study - it didn't capture any RERAs and I knew it wouldn't recognize UARS even if that's what I'm dealing with.  Plus, I'm not sure it would matter since UARS isn't covered by insurance - I would be on my own for treatment anyway.

I've been pricing the two machines online to get an idea of how much money to set aside, but your recommendation to call DMEs and compare pricing is good and I'll do that before I talk to the doc and come up with a plan.

I've honestly been trying to avoid the thought of nighttime oxygen, so hopefully the concept of PAP resonates with the doc and I can give it a try first.


RE: Home Sleep Study - Low AHI but significant desat - Sleeprider - 04-09-2021

To add to the above, your results show you need supplemental oxygen at night. I suspect a more detailed polysomnogram test is in your future. Your test offers no insights on tidal volume, minute vent, respiratory rate and other critical respiratory parameters, and with an AHI of 3.8 and the comorbidities, you are actually close to qualifying on sleep apnea. In addition to resolving sleep apnea, CPAP increased your "positive end expiratory pressure" (PEEP), and this is critical to recruiting lung volume and promoting oxygen exchange at the alveolar level. Bilevel PAP can increase ventilation promoting inspiratory volume in addition to providing PEEP, so positive air pressure therapy has applications well beyond just treating sleep apnea, however insurance companies take a rather narrow view of the value of CPAP for reimbursement purposes. Unfortunately, many sleep specialists have forgotten anything about their medical training, and practice to conform with the easy path to insurance approval.

Well that covers a lot of territory. I think your next step must be to point out to your primary doctor that your test results and 02 ring appear to point to an urgent need for a solution. That solution may be supplemental O2 and/or PAP therapy. If you feel this is going to take a long time, and your health is at risk, we can help point your to a used CPAP or BPAP, and even without further study, your doctor could easily justify prescribing CPAP to see if it helps as confirmed by your recording oximeter. Something needs done sooner than later, and the available information IS sufficient for your doctor to prescribe remedies without delay, however that prescription may not qualify for insurance reimbursement. The current cost for a very good auto CPAP (Resmed Airsense 10 Autoset) is $539 from Supplier #2. All you need is for your doctor to agree, and it can be at your door early next week. At some point, sleep studies and insurance will catch up to your needs, but for now, you should not hesitate to take matters into your own hands and insist on a solution today. Call your doctor! Ask for the CPAP prescription, then Call Supplier #2. The whole matter can be concluded by phone in an hour. For a mask, the Resmed Airfit P10 is excellent as a minimal nasal pillows, and while my experience with full face masks is limited, the Amara View seems to be a good solution. If you can pull this off, we can help you to get it setup for your needs. Alternatively, your sleep study and oximetry show supplemental oxygen is certainly warranted with or without CPAP. Your doctor could prescribe and order that today. Why not?


RE: Home Sleep Study - Low AHI but significant desat - ArcherNeedsSleep - 04-09-2021

(04-09-2021, 08:28 AM)Sleeprider Wrote:  In addition to resolving sleep apnea, CPAP increased your "positive end expiratory pressure" (PEEP), and this is critical to recruiting lung volume and promoting oxygen exchange at the alveolar level. 

This is a great point.  Thank you.  I will use it when I communicate with my doc.

I'm packaging up some notes and the O2ring info and posting it to the portal for the doc.  Maybe I can get some movement before the appointment. 
(The good and bad news is that I'm traveling for work next week, so I wouldn't be here to start treatment for a few more days anyway.  The good part of that is that I'm traveling to sea level and I always sleep and feel better with the abundance of oxygen.) 

My current plan is shaping up to be:
- Try to get a PAP prescription asap and buy an Autoset (and probably the P10 pillows) out of pocket to get treatment started quickly (with the amazing help from the folks on this board...you are definitely a blessing!).
- Go to my scheduled appointment and discuss supplemental nighttime oxygen and a follow-on in-lab sleep study with the doc.
- Hope that insurance eventually gets on board   Rolleyes


RE: Home Sleep Study - Low AHI but significant desat - srlevine1 - 04-09-2021

Might I suggest you first need to ask a cardiologist for an echocardiogram to rule out pulmonary hypertension. All of the external things you may be trying to do are secondary to a potentially serious underlying issue. Also, a blood test to check oxygen-iron binding and to rule out polycythemia.


RE: Home Sleep Study - Low AHI but significant desat - ArcherNeedsSleep - 04-10-2021

(04-09-2021, 09:57 PM)srlevine1 Wrote: Might I suggest you first need to ask a cardiologist for an echocardiogram to rule out pulmonary hypertension. All of the external things you may be trying to do are secondary to a potentially serious underlying issue. Also, a blood test to check oxygen-iron binding and to rule out polycythemia.

Thanks for these recommendations.  

Thankfully, I've had a recent echo and holter monitor and my heart looks fine other than mitral valve prolapse, which I was born with but that doesn't seem to cause any real issues. 

I've never heard of polycythemia before, but I'll add it to the list of ??s for the doc.


RE: Home Sleep Study - Low AHI but significant desat - Sleeprider - 04-10-2021

Polycythemia is excess red blood cells or hemocrit and is the opposite of anemia. If you have had a complete blood count test (CBC) the answer is already in your records.


RE: Home Sleep Study - Low AHI but significant desat - ArcherNeedsSleep - 04-10-2021

Aha.  Makes sense. Then I'm clear for that, too.  CBC within the past month and all was good.  Thanks!


RE: Home Sleep Study - Low AHI but significant desat - srlevine1 - 04-10-2021

When I was de-sating, my body compensated by making more red blood cells to transport oxygen. "Long-term exposure to low oxygen levels causes secondary polycythemia. A lack of oxygen over a long period can cause your body to make more of the hormone erythropoietin (EPO). High levels of EPO can prompt your body to make more red blood cells than normal." The treatment is removing a pint of blood on a regular schedule to prevent clumping which may cause a heart attack.