Oxygen therapy, really?!

[TheComrade]

Four or five years ago I had a sleep study, and as it turns out I had some mild sleep apnea. I was told that my saturation didn't go that low but that I would probably sleep better with a CPAP, so I got one and used it.

Had a couple more follow-up appointments, where they downloaded information from the memory card. They were satisfied therapy was working.

Fast forward to now.

I decide to consult with a doc about whether I still need to use the CPAP, since it was mild to begin with and I'm in much better shape than I was when I started the therapy. I do a good amount of strength training and cardio and have been for the last year. I was never "very" fat but now I'm basically athletic with a bit of a gut still but according to docs I am 'in shape'.

I have been sporadically using the CPAP, as it feels that I've been sleeping worse with it on lately. The tube and mask is now different than what it was 4 years ago. Years ago the sensation was that when I started using the machine, it was difficult to breathe through the mask, like I was mildly fighting against suction, but the feeling abated, and I would wake up taking deep, slow breaths with the machine, and felt very calm. It was a great sensation. But nowadays it feels more like the machine makes me feel worse. I wake up taking shallow breaths, but I would not call it rapid breathing. It's like, I'm too lazy to fully inhale, or something.

data point: I am on a small dose of beta blockers for BP and anxiety, though I will probably get off of it as it's primarily white coat related.

So I was sent home with a home sleep study device, that mounts on the head and has nasal cannules. You use this without the CPAP and it records a bunch of data. Results of this were that I had something like 10 events per hour on my back and 2 events per hour on my side. The advice was that I should probably still use the machine, but it's kind of on the line. More like "use it if you sleep on your back, but if you sleep on your side you probably don't need to keep using it." They also said I had some variable in pulse rate, from a low of 36 to a high of 78, and a mean of 46. Normally, because of the beta blocker or some other reason, my resting HR is around 60 during the day. They became far less concerned when they learned I was on the BB.

As a follow up to this, I wore my CPAP with a pulse oximeter. Two weeks after this, I was called by a medical supply company who told me that they had received an order for oxygen. I told them there must be some mistake because I had not discussed anything like this with a doctor. I declined this until my next appointment which is in about a month.

I was told the pulse oximeter ranged from 89% to 94% saturation and on at least one point there were 11 desat events in 3 minutes... I am not sure what this means exactly.

My CPAP is an auto, and the AHI is normally < 1, anywhere from 0.4 to 0.9. Pressure is set to 6 and it tells me it ramps up to somewhere like 9 or 10 most nights.

While doing the pulse oximetry, I was not using a chin strap, and I, for some reason, have been mouth breathing lately with the machine.

So many questions!

- Do you think it is reasonable to order up oxygen based on a single overnight oximetry, without questioning whether the machine is calibrated, functioning, mouth breathing, etc?
- Is it possible the AHI is being misreported by the machine? How can I verify?
- Is it possible I am over beta-blocked and that is causing problems with sleeping respiration? I should note that I climb 210 floors on a stair climber in 30 minutes, but my HR never exceeds 130-140. And as I said my normal resting rate is 56-60.
- Can CPAP therapy not be working due to mouth breathing, and would that cause the oxy desats that are being reported? In other words, if the chin strap works, could it have an effect of raising the O2 to normal levels?
- If the CPAP is ineffective because of mouth breathing, would that not, in fact, cause a spike in AHI, or is it possible the machine does not detect the mouth breathing is going on, so doesn't think there's a problem?

I am 37 years old, the beta blocker is 5mg bystolic.

Basically, I'm trying to wrap my brain around this concept that I've been ordered up O2 without consultation, and trying to square this with AHI that I understand is perfect or close to. How does one go from "if you sleep on your side you probably don't need the CPAP anymore" to "you need the CPAP plus an oxygen supply". It feels like there's something missing from the equation.

I have ordered my own oximeter and will see what I can glean from that, now that I'm using the chin strap.

Any advice on any of the above would be appreciated.

Thank you-

[BlackSpinner]

You have a data capable machine. Download sleepyhead software and see how your nights go.

[JDS74]

Call the doc's office and get a copy of the sleep at home study and also the oximetry report.
Those two should tell you what is going on.
Just because you have a low AHI doesn't mean that you are breathing enough oxygen in at night.

Some folks just need oxygen supplementation and don't have any sleep apnea issues.

[TheComrade]

I apparently don't have the machine I think I have... Sleephead tells me I have a brick. Apparently I have the cheapy ResMed.

[greatunclebill]

if insurance pays for o2, you need it. the doc can order all he wants, but if the numbers aren't there, insurance will reject it. so if they pay for it, you need it because the numbers are there. you can always ask for a second opinion.

[JScottEvans]

An o2 sat of 89 should not qualify you for oxygen therapy. It's right on the border though.

[Julie]

Sounds fishy to me... I'd want to hear a lot more about why, in detail, from a pulmonologist, before just going along with it.

[SleepyToo2]

The order for O2 is definitely odd. My 02 went down to the low 70s during my sleep study, but was back to normal during the titration study. I asked my sleep doc about the need for monitoring/02 in addition to the CPAP, and he told me that almost always (I think his word may have been just the "always" but I have to question that as well!) O2 levels are normalized by CPAP. I have done a couple of oximeter checks since then and found them to be normal, so I have not worried about it. My AHI was 31, but with the CPAP is now down below 1 most nights (0.85 over the last 3 months!). Sounds like you need to ask some searching questions.

[oldie]

Your machine doesn't know that you're mouth-breathing, so a 'good' AHI is meaningless. Solve the mouth-breathing problem.

[bwexler]

Can you tell us the exact model of your Resmed machine, and which mansk you are using?
Which pulse oximeter did you order? Will it record over night results?

My starting point was much different than yours. Test was AHI of 84 and with pap I am usually below 1.0. Even had a zero recently.

I agree you need to get copies of all your detail reports, so you can see what's going on. There are plenty of knowledgeable folks here who can help you understand them.

[TheComrade]

It's the cheap Resmed Escape Auto. I just recently switched to a full face mask, so we'll see how that goes. With the FFM I am sleeping with my mouth wide open now, which I don't do with the nasal mask, but I understand that doesn't make much difference with the FFM. I'll also wake up sometimes with my cheeks puffed out with air and drool being forced out from between my lips. Amusing. It seems like I'm waking up a few times a night ... so maybe I'm just not used to the mask yet and that's interrupting my sleep.

I've got an appointment with the Mayo clinic in three weeks so I'll soldier on until then and see what the doc there says after reviewing all of these things.

[TheComrade]

I wanted to post a followup regarding how this turned out:

I went to see a pulmonologist at the Mayo Clinic about all this and he started laughing when I told him the sequence of events. The pulse oximetry did show a dip but his interpretation was: The device fell off your finger. There is no way that is physiologically possible, for it to drop that fast. And indeed, I do remember waking up and having to readjust the clip; and that was the only strangeness on the graph.

After looking at all my records, he determined that I may not even need the CPAP at all, but may be able to just use a dental device. This doctor has been in practice for 30 years and has his name on multiple research papers, so I trust this more than the 15-minute shoe you in-and-out-the-door pulmonologist at the cheapy center.

So if I had just gone along with the original rec, I would have cost the insurance company/medical system overall thousands of dollars for oxygen. My suspicion is that the O2 was ordered based on a written summary, and not by someone actually looking at the graph. Medicine by numbers.

I suppose I am just relaying thing in case it can help someone else- If you hear something that doesn't feel like it makes much sense, it is possible someone made a mistake.

[tortoisegirl]

Thanks for the update! I'm glad you got it sorted out and had the sense to question things.

Did the doctor discuss positional apnea? If you can comfortably sleep on your side all night, there are various tricks to remind yourself to stay on your side, such as sewing a tennis ball into a pouch on the back of a shirt or a bolster pillow. If I had your results, if I could sleep on my side, I would do that rather than use a dental appliance or CPAP (unless you found your sleep quality better with CPAP). My results were also a bit borderline, AHI=9, but with lots of daytime symptoms which we're unsure of how much is caused by my meds, and I have medical issues that would make sleeping on my side or wearing a dental device difficult, so we went for CPAP. I'm glad I did as I have some peace of mind that I'm having less apnea events, plus I'm disturbing my hubby less now during the night. I see little noticeable difference in my daytime function though.

I had something kinda similar happen...my sleep study report mentioned a low oxygen reading of 81%, yet 0% of the time was below 89%, etc. I asked my doctor and she was able to look at the graph I assume and say that no, the low was in the low 90s, and that was an artifact of some sort. Then why wasn't the real number published on the report lol? Best wishes.

[TheComrade]

In my case I apparently snore so loudly that it actually disrupts my sleep. My AHI is something like 10 on my back, but there was some other number in the high 50s, 4-letter acronym I'm not remembering, that indicated snoring. So the take away is I still want to deal with the snoring, but other than that no treatment is really indicated.

You'd think the insurance companies would really be on top of oxygen being incorrectly prescribed given that it is really expensive, but hey, obviously I'm missing something. Maybe the money they would spend trying to catch errors is greater than the money they'd save by throwing up the flags.

[kteague]

Glad to read you're getting things sorted out. One time I saw some things in my detailed report that weren't in the summary report. My sleep doc said that she looks at the details and makes a judgement about the information's validity for inclusion in the calculations. A low oxygen reading could be one of those types of situations. Yes, it happened, but it may not have met criteria to be be considered valid or relevant, as when the finger clip comes loose.

I would encourage you to make any decisions fully informed. Look at your reports and be sure those times of side sleeping with a low AHI include some time in REM sleep. It's common for events to be worse in REM, so it's important that you are not making treatment decisions based on incomplete information. Also, a sleep study is one night and may or may not be reflective of your typical sleep patterns. Another question is what was the duration of those side sleeping events and the corresponding oxygen levels? And does your snoring disrupt your sleep cycles and cause daytime symptoms? If all the information available to you gives you confidence that the side sleeping events are insignificant and you don't otherwise feel a need for CPAP, I think I'd rig my bed to make back sleeping impossible and enjoy the freedom. Let us know how this pans out for you.