How to determine my current no-CPAP AHI

[DancesWithCats]

From my "just another patient" perspective, I would think so, other than for very short ones. In my particular case they didn't seem to think the 4-20 AHI was that big of a deal, but the under 90% O2 I was getting from them (during the one-night at home study which ended up costing me north of $300 after insurance contributed a paltry amount) caused my provider to kick getting me onto APAP into high gear. My AHI in treatment has been always under 2 and mostly under 1, but springing for O2 monitoring was not in the cards insurance-wise, and I have yet to do it on my own, so I don't know how that's doing. Total time in apnea (with APAP, as reported by Oscar) averages 32 seconds, with a high of 2:16 so it's probably not terrible, given those total times are spread over multiple events. But I am curious.

[BoxcarPete]

Oxygen isn't everything. My original sleep study had me at an AHI of 5.8 and min O2 of 93. If you stopped looking there you might conclude that I was fine. If you look a little closer, you can see 25 events per hour in REM, including a 9-minute-long section where I was in apnea for 110s and hypopnea for another 110s. That's almost 50% of those minutes below 50% normal flow rate, and half of those were below 20% flow, with O2 never dropping below 95 at any point. It's the sleep fragmentation that's killing me here.

So, for me, monitoring oxygen isn't going to tell me anything, unless it's that I have a much bigger problem than I had at the time of diagnosis.

[DancesWithCats]

Again, I don't have data to look at, (no graph in my overpriced results) but I would guess that (regardless of level) an apnea will result in lower O2 - so if looking for "number of apneas without CPAP/APAP" as the OP is, counting the dips in the graph whether they be to 97, 95, 93, 90, 88 (and the claim is that the affordable monitors are not terribly precise anyway - but they do show relative results) should show something relating to that.

My home study (and only study) did not involve any sleep-state information, but I'm fairly sure I hadn't dreamed in some large number of years.

[UnicornRider]

To do it more correctly you would have to monitor O2 on a recording Oximeter, limb movement, eye movement and brain waves. 

My personal major concern is that my O2 drops like a rock when my therapy stops. Some people do not have the same issues.

Since I have had my BPAP machine stop during the night and my Oximeter recorded my O2 drop to 70% (it does not record below 70%) and stays there until my machine kicks back in. I would not have to worry about brain waves as an indicator I need my therapy. Give me back to back 12 second CA events and I can see my O2 drop well below 80%. Therefore my Oximeter and OSCAR Reports are reviewed daily and excursions of O2 & Pulse are noted with reactions recorded on OSCAR.

[Jay51]

Red (Crimson Nape) said that he didn't see any correlation between apnea and spo2 drops reviewing all his data.  

I have seen my spo2 drop significantly with large clusters of OA's (and not wearing a collar) - lowest I got was 78.  Not nearly as much of a drop with clusters of H's.  And on my polysomnography, a large CA cluster only dropped my Spo2 from about 95 to 90 or so.  

The duration of the apnea is important, too, IMO.  Single, average length apneas didn't do much to my spo2 levels (like Red found).  I have seen a rare few charts here with very long apneas (maybe at least 30 seconds or more - a few over a minute in length) that produced spo2 drops.  

Then there is the relatively rare situation where a person has a clean chart, but bad spo2 numbers from oxygen delivery problems in the lungs, etc.  V/Q mismatch would be an example. 

Then there are things like flow limitations, RERAS, and even UARS, etc. that disrupt sleep continuity and can cause fatigue; that probably wouldn't show up on SPo2.  

This is a good thread IMO.  Just before getting into therapy, I was waking up an average of 5 times per night (with an all time high of 10 wake ups once).  Waking up with significant chest pain finally pushed me into action.  Cardiologist found a small spot on my heart most likely from sleep apnea (I still have normal LVEF and rhythm though).  POTS was noted once on my heart monitor that I wore for a week.  Angiogram showed clean coronary arteries, so untreated sleep apnea was the most likely culprit.  I now take a beta blocker and anti- arrythmia medications daily, too.

[dataq1]

Be sure that the oximeter is a recording device preferably one that measures and records every second. Then make sure that the recording can be exported to a CSV file.

Also take note of the fact that an complete apnea will take several seconds - perhaps as much as 30-40 - before it shows up as a desaturation.  Oximeters are very useful to detect clustered hypopneas, not so much for the occasional unclustered hypopnea.

My favored device is EMAY Model EMO-80 that is going for 59 USD, but can be occasionally found on sale at 39 USD

[paulag1955]

Or it could just as easily represent an occasional good night. So, for example, just because your one-night, at-home study shows an AHI of 4, it doesn't mean that you don't have apnea, because your AHI for the last year may have averaged 15.

[robbob2112]

Look at my graphs - tell me the nearly hour long spo2 drops and pulse rates aren't related in some way....  - note -the time on the ring was offset a bit - it drifts unless I reset it weekly.  That is viatom O2 ring.

Now there are other nights I have signifigant events like this night and there isn't a waver in the Spo2 or pulse.  In fact, 99% of the time my O2 is fine when I am having issues.

My point of saying all this is that the O2 data is interesting and sometimes corelates to events and most of the other times they don't.  So at least for me there is little/no linkage to the apnea and O2 events most of the time.

What I do find is when I have no apnea events but my SpO2 is crap I feel like have been hit by a truck the next day.

Robert

[UnicornRider]

That looks to be a positional apnea event and in that case I would call it a real event that that you need to be aware of.

Are you normally a side sleeper? Could you have rolled over on your back, or on your side have tucked your chin in?

Do you wear a soft cervical collar?

I check my OSCAR Report daily and also my "Checkme O2 Max" Pulse/Oximeter report. I too have to check for clock drift in both the Checkme O2 Max and my ResMed Aircurve 10,  I will check configuration of the Oximeter and sync the clock to my computer at the same time, then will check the time on the ResMed to ensure it has not drifted.

This is something both your primary physician and your Sleep Doctor should be made aware of.