Flat-lining

[Tigers Fan]

For those who own and/or know anything about using a pulse oximeter ......

Based on my SpO2 chart and the number of events it indicates, I've been doing a little tweaking of my CPAP (the NHS one that records only hours used!) and I've come up with a new hobby! SpO2 flat-lining.

Now, purely a guess, when I'm in REM sleep - but maybe not - my SpO2 and pulse settle down. The record so far is a constant 96% saturation for fifty minutes, pulse constant within a few decimal points.

My guess is - this is a question really - that the closer I get the CPAP settings to 'perfect' for that night, the longer and more frequent will be the periods of flat-lining. Anyone know if that is true or just my fantasy?

What I do know is that the mornings I wake all bright eyed and bushy tailed - the past several - are the mornings I find I've been flat-lining a lot during the night.

This is based on very flimsy evidence - seven nights worth of data from my new toy - but a trend seems to be apparent.

TF

[symmit]

I'm neither or doctor nor a sleep-tech - but I feel like I'm getting to understand my own sleep and how it makes me feel the next day.

As you'll see from a (low detail) extract of one of my "good" examples - this is what I expect to see from mine.

from 0100 to 0130 is me relaxing and falling asleep - the jumps in SpO2 and pulse are mostly fidgeting...

from 0130 to 0230 SpO2 is stable and pulse dropping, which I believe is the first stages of sleep, body relaxing, breathing deeper, pulse strong and slow.

0245 is a big SpO2 blip, and pulse goes up. This also coincides with a reduction in system flow on my Auto-CPAP graph - so I'm breathing at a lower volume. I'm guessing this is a transition to another sleep phase - one of the REM sleep phases, as it lasts about 30 mins and is acompanied by lots of pulse and saturation fluctuations.

About 0340 is a big dropout in the SpO2 reading - this will be movement or other misreading. Or maybe I died.

0400 looks like another REM cycle starting

0445 to 0515 is very chilled and relaxed and still

0530 is alarm clocks beginning to go off in the house and awakening beginnning.

Interstingly, this is with my apap set for Min 8 Max 20, and that night it only rose to 10.5 during the night. What I'm finding is that my machine has never gone above 13 in normal use, and that if it's set at 8 or 9 minimum the increase of about 4 notches never wakes me. If it's set wide open (4-20) then the sudden rises to stop the apnoea events awaken me (not fully) enough to feel not right the next day. If it's set higher (11 or more) then I sleep well but have a headache in the morning, though turning on flex mode helps alleviate that.

I'm 100% convinced that my current setting of auto, 8-20, for me, with the sleepweaver, is as good as it gets!

spo2 sample.JPG
sample apap.JPG

[Berneta]

I Love Charts and Fantasies

Hi Guys--I love what you are doing. Research on Sleep Apnea. I wish clinics would do this kind of research--we would know a lot more about what is going on. Too bad they don't do it, I suspect that you are learning something about what goes on with all of us while sleeping---and not just about yourselves. Happy you have been feeling better in the mornings--and hope it continues. I admit I am not into understanding the charts and numbers--so I am very happy someone is, and can explain it in a way that the average person can understand. If Clinics and Hospitals would do the work you are doing--then maybe Drs would know more about Sleep Apnea and how it should be treated. Right now--I think there is a lot of guess work going on with Medical Staff, Good Going! x Berneta

[Tigers Fan]

Trust me, Berneta, it would not be a difficult task to find people who knows more about this than do I.

That said, I had an early night last noght after a very late one - and in the nine hours I had two events -not an AHI of 2 but two events or AHI 0.2 - and yards of flat-lining.

I know for a fact that this is going to cost me a new mask - unless Carol comes good at the General - the new Quattro FX ff has taken my fancy as a way of improving my stats. I'm quickly coming to the conclusion that pulsr oximeters should be built into PAP machines.

Tigers are still in it but we have an away match in the quarter finals, which is not a good way of getting to the semis!

TF

[Tigers Fan]

Hi symmit

You say of a massive dip in O2 saturation, "About 0340 is a big dropout in the SpO2 reading - this will be movement or other misreading. Or maybe I died." I have totally discounted such massive dips as well - my explanation is the sensor jolting off the finger nail.

BUT ......

What if something is actually happening? Can we really desaturate and then saturate again, both almost instantaneously? I think not, especially if the pulse rate remains 'constant'. But .....

TF

[Sparticus]

Sleep Stages

Hope this may help

How low can sleep apnea oxygen level get before it is a concern? What is the sleep apnea effect on blood oxygen level? How can you monitor your oxygen saturation levels?
Oxygen levels are so important in maintaining a healthy system. In a recent study from Sydney University's Woolcock Institute used magnetic resonance spectroscopy to study the brain of thirteen men with severe, untreated obstructive sleep apnea.
In this study, the researchers found that even a moderate degree of oxygen desaturation during the patient's sleep had significant effects on the brain's bioenergetic status.
The lack of oxygen in the brain during even a small time increments of obstructive sleep apnea caused the levels of adenosine triphosphates to fall and the levels of inorganic phosphate to rise, without the usual changes in phosphocreatine (brain PH) - the mechanisms that normally would protect the brain against oxygen depletion.
This biochemical mechanism is similar to what is seen in somebody who has had a very severe stroke or is dying.
The researchers suggest that the brain could be basically resetting its bioenergetics to make itself more resistant to lack of oxygen and it may be a compensatory mechanism to keep you alive, but even if this is so, it's not likely to be doing you much good.
The study about sleep apnea oxygen levels is published in the May edition of Journal of Cerebral Blood Flow and Metabolism.

A normal blood oxygen level should be 94% to 98%. However, as a result of not breathing for 30 seconds or more during sleep, your oxygen levels would drop to 80 or less.
Keep in mind that anything below 90% oxygen level is dangerous to your body and require intervention. Another thing to consider is the brain can only survive four minutes once oxygen is completely cut off.
So, if you have a low blood oxygen level, follow up with the sleep study as soon as possible. Continued drops in O2 levels will cause damage to cognitive function, short term memory, stroke and heart attack in your sleep, and a host of other problems.

If your doctor prescribed CPAP therapy, you should NEVER go a night EVER without a CPAP on or even take a nap without one.

You can have a low blood oxygen level even if you have CPAP treatment, which means that your CPAP doesn't have the desired effect. That's why is important to monitor your oxygen and pulse rate.
You can use a portable oxygen saturation monitor or oximeter, a cool little device that can record your sleep apnea oxygen level and pulse rate during sleep. A medical approved oximeter is truly a great tool to see how well CPAP is working for you.
A tip before buying an oximeter: you would do well to invest in a recording oximeter with software. You can upload your data in a computer, and you can go to your sleep specialist with the results.
To keep a better eye on your sleep apnea oxygen level you might consider purchasing a finger pulse oximeter.
Don't use inferior equipment to measure your well-being and don't change anything without checking that information with a second opinion or proper equipment.

[symmit]

What if something is actually happening? Can we really desaturate and then saturate again, both almost instantaneously? I think not, especially if the pulse rate remains 'constant'. But .....

TF

I don't think so! Your body uses oxygen to convert sugars and fats to energy, so it consumes it at a steady rate, faster in times of stress and concentration. So you need less of it at night, and more when active, but a big jump is pretty much not possible.

[James @ Intus]

"Artifact" is often seen, perhaps even more so in the cheaper models from far-away countries. Low perfusion, the sensor coming off etc. there can be many reasons why you get funny looking graphs.

That's why the auto-scoring isn't used in sleep studies. A sleep tech would go over every event and score them manually, removing artifact, discounting events that were identified by the algorithms that in fact aren't, and adding events where the software missed one. It makes the resulting AHI/ODI etc. more accurate.

As far as flat-lining goes, as long as it's not at 0% then it's probably a good thing. But dreams will often cause some movement in HR and SpO2 so you'd have to meditate in your sleep for it to be flat for 7 hours.

I doubt "healthy" people get a horizontal line at 99% so don't keep your hopes up of setting a record. But no doubt, a steady line seems like it will least disrupt your sleep.

[tallishbloke]

Dear all

I'm loving all this fixation on oxygen saturations and oximetry and so on. It would be wise to remember that it is fairly normal for anybody's oxygen saturations to drop while they are sleeping (with or without sleep apnoea). This is why many clinics use limited variable polysomnography as a way of accurately determining severity of sleep apnoea. SImple oximetry is generally more useful when the idividual is likely to have "barndoor" case of OSA or OHVS (obesity hypoventilation syndrome) and the oximetry is used to confirm the suspicion that the clinic has.

Have fun with your flatlining!

TB