My Toe O2 Oximeter readings are 3% higher than fingers in be

Hi, Some background. Have been thru 2 sleep studies. Have both obstructive and Central apnea according to tests.

A dental appliance has 90%+ cured the obstructive apnea. The Central is weird as if I hold my breathe for 30-40 secs O2 drops (have own oximeter) only 3% or so, like from 94% to 91%. Yet I can be awake in bed on my side and watch it drop to 86% while breathing, how can that be??? BTW have indexed my oximeter to sleep study center one and is accurate, even on hold the breathe test they both read about the same..

Suspected my arteries to arm get squeezed while lying on side. So put oximeter on big toe instead. Bingo goes from 94% to 97% consistently, when swap location, with the toes (tried both left and right) being the 97%. I just found this out. Live at 5,000' so 97% is very good.

Looked up some med studies and they say readings should be the same for fingers and toes. 3% is huge. Have not done full nite yet, but finger average is 91% with 10-20 mins average lately below 88% with normal low of 84-85%. If I am really 94% average with dips to 88% for 10-20 mins a nite, with dental appliance, I do not have Sleep Apnea. Am just about to order VPAP with servo, until found this out today.

Anyone else try their toes? For me it could really be arm circulation problem when lying on side.

Maybe this is of value to others. Very curious if other do both the toe test and the hold breathe for 30 seconds test to see what their oximeters say.

Some more info, have videoed my sleep with sound, and with dental appliance, am very quiet, never to point of what would be called snoring. Obstructive is 100% off the table with dental thing.

Maybe the O2 in your blood is heavier and is sinking to your feet.

If you come down with diabetes and don't treat it well, the resulting damage to your feet may correct the difference in readings. Jim

Reno, if you have concerns, mention them to your doctor. If there is a difference in blood pressure between your legs and arms, then you may have peripheral artery disease. Other than that, it's armchair doctoring and won't really do you much value.

SewTired wrote:Reno, if you have concerns, mention them to your doctor. If there is a difference in blood pressure between your legs and arms, then you may have peripheral artery disease. Other than that, it's armchair doctoring and won't really do you much value.

Sew, Just found this out today, will tell doc. And will use it full nite tonite.

But did read some med studies and they said use the highest O2 digit, whether finger or toe, as is most reliable. That after blood leaves heart it can not pick up O2 so a lower reading means something is lowering the O2. I tested finger o2 on back and on side and it appears that 2% is lost from being on side, it 2% higher on back.

The data points to reduced circulation when lying on side. It does make sense. Sometimes arms go to sleep from squeezed arteries.

Just wondering if anyone else has same situation, noticed a finger/toe variation.

Write down your observations, and take the list to your doctor.
Include all you have said here.

Just checked the report. Generally very good, but see significant difference between awake and asleep readings.

The good news, O2 was about 1% higher for 9 hour sleep test compared to avg finger test, at 92.1%. This is with no VPAP just dental appliance and oximeter on right big toe. Surprise is that having on toe is just as easy as finger, never came off. Was 4.7 mins out of 9 hours under 88%.

But most of that was in first 90 mins on left side. Next 7.5 hours on right side was only 37 seconds under 88% and maybe 92.3% avg (guessing looking at graph) Again I am at 5,000' so 92% is good.

So about a 1.2% improvement in avg O2 when sleeping (toe versus finger) and 3% improvement when awake. And about 0.7% better O2 sleeping on right side versus left side. So during sleep the differential drops both for toe and left side vs. right side.

Hope this is on value to others. Most interested in seeing if any of you see difference between toe and finger.

Reno, My husband is a hypo apnea person (gets mostly that with a few obstructive, no central).
Cpap shows the hypo events.

He routinely drops his O2 when he lies down and relaxes - not quite where he is drowsy, but very very relaxed. Drowsy, he drops more.
Awake, irregardless of sitting or lying and his O2 doesn't drop.
So rule is - lay down, cpap must be on.

We have added some O2 to him in the last year or so, it helps to bring him up several %. Enough that his low points do not drop below 90% where as before he could dip below 88% (yeah, not good, his sitting up wide awake is 95%). He drops low during one longer period - about an hour or two at night (stage 4 sleep? rem sleep? we know he can get worse in rem sleep from the sleep study). But with the added O2, he is at 95% most of the night, so a big improvement. As you said 3% can be a lot. It did take several DME O2 testing nights to catch a bad night where he dropped below 88% for more than 4 minutes (their magic number for insurance to cover an o2 machine), but we ended up finding one on craigslist for a very good price and have been using it (the one plus of living in state with a Lot of elderly people.

The body works in mysterious ways.
He was a premie baby, back in the days they didn't have the knowledge they do now, and very small & early.
So likely born with some condition and very very luckily was not a SID baby.
He has hypo breathed and stopped breathing since his early 20s, discovered by of course a spouse (sleeping partner), and likely has his entire life.

CpapWife wrote:Reno, My husband is a hypo apnea person (gets mostly that with a few obstructive, no central).
Cpap shows the hypo events.

He routinely drops his O2 when he lies down and relaxes - not quite where he is drowsy, but very very relaxed. Drowsy, he drops more.
Awake, irregardless of sitting or lying and his O2 doesn't drop.
So rule is - lay down, cpap must be on.

We have added some O2 to him in the last year or so, it helps to bring him up several %. Enough that his low points do not drop below 90% where as before he could dip below 88% (yeah, not good, his sitting up wide awake is 95%). He drops low during one longer period - about an hour or two at night (stage 4 sleep? rem sleep? we know he can get worse in rem sleep from the sleep study). But with the added O2, he is at 95% most of the night, so a big improvement. As you said 3% can be a lot. It did take several DME O2 testing nights to catch a bad night where he dropped below 88% for more than 4 minutes (their magic number for insurance to cover an o2 machine), but we ended up finding one on craigslist for a very good price and have been using it (the one plus of living in state with a Lot of elderly people.

The body works in mysterious ways.
He was a premie baby, back in the days they didn't have the knowledge they do now, and very small & early.
So likely born with some condition and very very luckily was not a SID baby.
He has hypo breathed and stopped breathing since his early 20s, discovered by of course a spouse (sleeping partner), and likely has his entire life.

CPAP Wife, thanks for that info. It does line up with some of my experiences. Both horizontal effect and sleepy effect. I have been aware of o2 issues only last 9 months.

The strangest thing which doctor and no one else can explain is that I can not force my o2 down. A therapist at sleep study place was curious about it and said she had never tried it. But I have held breathe for 30 secs, for even 45 secs and can not get down to 88%, Have breathed as little as can stand for 2.5 minutes, and can not drop to 88%. Yet have dropped into 70s even on reports, woken up with such readings and am not out of breath?? Yet at 30 secs without breathing on purpose have huge need to breathe, very much out of breathe. But oximeter says something like 91% and does not drop lower as I do breathe again.

Video shows I never go 30 secs without a breath when sleeping, about 10-15 secs is the worse and at 85% readings taking a breathe every 4 secs or so, not laboring. A great mystery.

Thanks again for your info.

Just woke up and downloaded the data. Slept 6.5 hours and only 1.9 mins under 88%, And avg was 92.7%. Using toe for 2nd nite. This is officially not sleep apnea and best readings ever in 9 months since started testing.

This is more in line with my expectations for switching to Toe from finger, based on awake readings. A full 2% O2 improvement over average finger readings during sleep. I awoke early and could not get back to sleep, possible sign got better rest.

This is quite encouraging, a 2% O2 improvement with no CPAP machine and officially (less than 5mins is cutoff) not sleep apnea.

Encourage others to try the toe, let is know if you see a difference. It should be same as toe, if not there may be another issue not related to breathing.

Would you be willing to do an experiment for me and report the results?
I have often wondered about what happens when we have apnea events back to back for several minutes and how it affects O2 levels.
I am not surprised that holding your breath for 30 seconds doesn't cause a drop in O2 levels if that's all you try...that 1 time. Could you maybe try an experiment where you hold your breath for 30 seconds every minute for maybe 5 or 10 minutes and see what happens?
I used to have a pulse ox but loaned it out before I ever thought to try this experiment and the person I loaned it to ended up buying it and I just don't want to buy another just for that experiment.

Pugsy wrote:Would you be willing to do an experiment for me and report the results?
I have often wondered about what happens when we have apnea events back to back for several minutes and how it affects O2 levels.
I am not surprised that holding your breath for 30 seconds doesn't cause a drop in O2 levels if that's all you try...that 1 time. Could you maybe try an experiment where you hold your breath for 30 seconds every minute for maybe 5 or 10 minutes and see what happens?
I used to have a pulse ox but loaned it out before I ever thought to try this experiment and the person I loaned it to ended up buying it and I just don't want to buy another just for that experiment.

Hi, I did that by breathing tiny breathes as far apart as possible for 2.5 minutes, and never got down to 88%. Yet commonly will drop from 93% to 87% in 50 secs while sleeping on report.

the 30 on off, will be less effective, i think, because O2 goes back to 95% after just 15-20 secs of catch up big breathes. But will likely try it anyway.

Just checked readings today. 7.8 mins under 88%, not too bad. But not near yesterdays good results (1.8 mins). Unlike yesterday switched side slept on. Left side seems quite worse.

Had one 5 minute section that it whipsawed on, 6 time up and down. Average high 94% avg low 87%. So when sleeping get big up and downs fast. And have seen that when awake, but generally just one up and down, yet when holding breath, much slower and less distance in swings.

I too noticed my toe was higher by about 3%. I've been really concerned about my o2 saturation, but of course when i bring it up at the Drs office, it's 96-97% and get treated like a hypochondriac.
I did read somewhere that during the night, some of the fibers (sorry I forgot their name) drop out and its normal to have a lower o2 reading during sleep. In fact it's not good for them to not drop out. So now I'm really confused.
I also found that the digit with the highest reading should be used as the most accurate.

Maybe your shoe is too short. Jim

OCD.