Home oxymeter study

[Gary_UT]

On Feb 27 my sleep doctor had me do a take home oximeter study. They emailed me the results today. Below is the graph from the report, along with my sleepyhead screen for that night. Should I be concerned about the drops in the o2 levels?





Gary

[Pugsy]

Some of those look like loss of contact artifacts to me. I don't see 1 little CA or OA causing that desat unless it was massive long and sure wouldn't explain the later in the night drops as nothing happened. Did you look at those 2 events to see how long they lasted? The extremely sharp fast drops might be loss of contact. The others I am not so sure as they are gradual which points to the real deal.

What did your doctor say about the results?

[Bitman]

I'm on oxygen 24/7, and use a CPAP machine.
Your oxygen level should be in the mid to upper 90's. Not running 90 to 92 as they show on the graph.
Any time your saturation levels drop below 90%, you are going to be causing damage to internal organs, heart and brain.
I'm no doctor, but I'd think you should be on 2LPM while sleeping to keep O2 levels in the mid 90's.

[Pugsy]

Do you live in the mountains at altitude?

[Gary_UT]

Those look like loss of contact artifacts to me. I don't see 1 little CA or OA causing that desat unless it was massive long and sure wouldn't explain the later in the night drops as nothing happened. Did you look at those 2 events to see how long they lasted?

What did your doctor say about the results?

If I am reading the charts correctly the events last less then 30 seconds.



The Dr. says that it is REM desaturation and wants to do another sleep study using BIPAP and see if I need to get a BIPAP machine, or he suggests using oxygen at night. I don't see how he can tell it is a problem with REM sleep just by the oximeter results, I know I was awake for the last desaturation just before I shut off the recorder and the CPAP.

GAry

[Gary_UT]

Do you live in the mountains at altitude?

In the foothills at 4400 feet

Gary

[Pugsy]

Actually the time frame of the drops in oxygen coincide with where we would expect to see REM stage sleep so your doctor has a good idea there.
30 seconds wouldn't cause that much of a desat anyway. You can hold your breathe longer than that and not see any desat.
REM stage sleep comes in fairly predictable stages and time frames.
http://en.wikipedia.org/wiki/Sleep

So while he can't actually see REM stage sleep....he does have a good idea when it happens.

At 4400 feet your baseline oxygen levels might be a bit lower than normal just because of altitude. While not horribly high...it is high enough for the air to thin out a bit. That might explain the slightly lower than usual baseline O2.

[HoseCrusher]

Gary, you need to match up the pulse rate recording with the O2 saturation.

Looking at your data and making a guess I would say that the first desaturation occurred at around 00:30, the next one at around 02:45, the next one at around 04:15, and the last one at around 05:15. You can compare your sleep report and zoom in at around those times.

The summary data should give a value for artifacts and that can play a part in this, however it is interesting to notice from the pattern of your Resp. Rate that you were at the lower end of that at each desaturation immediately followed by a rapid increase in Resp. Rate.

If your pulse recording shows something similar to your Resp. Rate then there may be cause for concern.

[Kennerly]

Gary in a thread awhile back someone posted that if a big desaturation is followed by or concurrent with a jump in your pulse rate it provides some support for the idea that the desat is genuine and not just noise from the oximeter slipping around. Since reading that I've gone back and looked over some of my old graphs and it seems to hold true when the desat lasts for awhile.

Does your report also have the graph for your pulse rate and if so does your pulse spike with that big dip in the middle? It looks to me like that one runs for 30+ minutes before it is resolved. Is there a timeline on the graphs to verify that that page really contains the data from the full night and not just a portion of the night?

[Gary_UT]

The oxymeter study did not show any pulse rate data.

I had the sleep center email me copies of my two overnight sleep studies. Neither overnight sleep study showed a drop in heart rate during REM sleep, they show a slight increase in average pulse rate during REM sleep.

My first overnight sleep study was a split study that showed an AHI of 28, with 0 centrals, with no CPAP. The second overnight study included a couple of hours of BIPAP. It showed 2 centrals. Both studies showed desaturation in REM sleep. The doctors notes included "It is doubtful but not proven that bilevel-PAP therapy may address hypoxia in REM sleep." I cant understand the sudden interest in having me try BIPAP when the doctor has already noted that it is doubtfull that it will help. The other recommendation is 2 LPM of supplemental oxygen.

My AHI has averaged .74 for the 79 days that I have been using my CPAP. Apparently my apnea is under control, but I still have desaturation during REM.

Looks like I need to go shopping for an oxygen concentrator, anyone know a good place online to purchase one? (My DME is a rip off, and I wont use them again.)

Gary

[HoseCrusher]

What you are looking for is a spike in pulse rate during a desaturation. When your body notices that you are running out of O2, it startles the heart into beating faster. The chemicals released during this "fight or flight" response are what causes the cardiovascular decline from sleep apnea.

[Kennerly]

Since your situation is somewhat unique you might find it worthwhile to get your own oximeter. A low end one that is servicable and can produce overnight reports runs about $50-60.

[Gary_UT]

What you are looking for is a spike in pulse rate during a desaturation. When your body notices that you are running out of O2, it startles the heart into beating faster. The chemicals released during this "fight or flight" response are what causes the cardiovascular decline from sleep apnea.

Unfortunately none of the reports I have show a pulse rate graph. The only mention of pulse rate is in the technicians notes: "Average heart rate (bpm) during REM sleep was 88.4 and during non-REM was 84.0." So it looks like my pulse rate is not spiking up during the desaturation events.

I am thinking that the best course to follow is to use the doctors suggested 2LPM of supplemental oxygen, and to get my own pulse oxymeter.

Gary

[HoseCrusher]

Sounds like a good plan to me.