Apnea while awake?

[Benny]

After reading posts about differences in identifying and recording apneas I decided to use my new gear (Resmed auto w/aflex) while I was awake and wathching TV in a sitting up position. I assumed the pressure would stay constant (set at 9 with no ramp) and no events would be recorded. I did this for about 1/2 hour, then prepared and went to sleep as normal. After downloading the data today I had recorded a couple of AI and HI events during that first 1/2 hour even though I simply wathced TV and breathed normally.

Is the machine to sensitive ? Does it record too many "false positives"? Did I have unknown apneas while just sitting there?

I repeated the test a few days later and again found it recorded an apnea event AND the pressure changed during the period.

Anyone else experience this? Any ideas?

[Wulfman]

It's been asked many, many times before. The answer is that the data from the machines is only "valid" if you're asleep. Otherwise, they'll score whatever they THINK is an "event" as defined in their algorithms.

Den

[khvn]

But why?

Why is the data only valid if the patient asleep?

Or should I chalk this one up as yet another one of those unexplained CPAP mysteries?

[feeling_better]

khvn,

I am with you on that question. At this point it appears to be one of those 'faith based' items. Perhaps it is scientifically explained in some research; more likely: when somebody like you pointed out this inaccuracy of their software at the manufacturer the marketing guy came with 'we know what we are doing' type of cover up -- it is only true for when are your asleep -- because we have got that even in our printed brochure, now how are you going to show they might be false when you are asleep Just my opinion

See a related recent post of mine:
viewtopic.php?t=32409&highlight=

[Wulfman]

But why?

Why is the data only valid if the patient asleep?

Or should I chalk this one up as yet another one of those unexplained CPAP mysteries?

This therapy is for "SLEEP APNEA" which is a BREATHING DISORDER WHILE YOU SLEEP and the software/machine algorithms that are used to monitor it give us a better picture of what's happening WHILE WE'RE SLEEPING.

You breathe differently when you're awake. These machines aren't designed to monitor AWAKE APNEA......because it basically doesn't exist. You may stop breathing while you're awake if you're intent on watching something on TV (like was mentioned in the original post).....but it's not from an OBSTRUCTION.......like OSA. (Obstructive Sleep Apnea)


Den

[DreamDiver]

When I was at the sleep lab, they asked me how long I thought it took me to go to sleep. I said 'half an hour.' They told me it took 8 minutes. I cannot dispute it because they were measuring my brain waves too. Everything on their dials pointed to me as being asleep. I wonder if you weren't asleep far before you thought you were.

As to why the data is only valid when you're asleep - you have complete control over what your lungs do when you're awake. It's thought that the part of the brain that controls breathing when you're asleep is not the same part that controls breathing when you're awake. You can breathe, hold your breath, exhale, hold it out, breathe deeply, sing, prolong your exhale or stop mid-inhale when you're awake. You have complete control of your breath. However, your autonomic nervous system takes over when you're asleep. Measuring breath when you're awake is therefore considered useless. You're really supposed to be measuring autonomic control.

It's thought that only during REM sleep (when you dream) that we have the ability to wake up while asleep and once again take control of the breath consciously. While it is the norm to dream unconsciously, I remember that my sleep doctor told me that one of the worst times for apneas is REM sleep. It makes me wonder if this is because the body tenuously allows the conscious mind to have control of breathing during this time if you happen to wake in your dreams. The threshold between autonomic and conscious control of breath during this time may be a very thin line indeed.

Yoga Nidra is a good example of experimenting with consciousness vs. wakefulness. It's a great method to learn conscious dreaming or 'wakeful sleep,' and useful for pain management when pain killers don't work for you. With enough skill and practice in Yoga Nidra, you can skip the unconscious steps from alpha through to theta/delta and go into REM directly. During the time that you are conscious but your body is sleeping, you cannot move any part of your body except for your breath. Have you ever found yourself immobilized late at night but awake? That's because you woke up in REM sleep. Your body is 'unhooked' from its motor functions so you don't perform an action you'll regret in the real world because of what you are dreaming. It's a protective response. (Ambien accidents are a great example of a drug overriding that protective response.)

I often dream right up to the time I get out of the bed. I have images in my mind of people, places, things, as if I was right there in the moment. Then - boom - I wake up. Yet, when this happened at the sleep center, they told me I was not dreaming. I wasn't in REM sleep, according to their devices. Go figure. But when you see startlingly clear droplets of water dripping down remarkably colorful blossoms in a jungle or hear non-existent gunfire three feet away, seconds before waking, what else can it be?

There seem to be at least two axes to consider: Wakefulness vs. Sleep and Consciousness vs. Unconsciousness. And maybe a third: somatic vs. autonomic nervous response. While the axes often emulate each other in most of us, most of the time, I can tell you from experience - they are not identical all of the time.

The understanding of these states is still somewhat nebulous, regardless of what the experts tell you. You say you fell asleep after half an hour. Who knows where the real threshold lies?

Machines can only give you so many answers. Regardless of the data your machine gives you, it was only designed to assess autonomous breathing during the unconscious part of your sleep when your autonomous nervous system is fulfilling its task. Until someone does the study and makes the machine that can interpret the data correctly, data during consciousness on your machine is likely useless.

[Needsdecaf]

As to why the data is only valid when you're asleep - you have complete control over what your lungs do when you're awake. It's thought that the part of the brain that controls breathing when you're asleep is not the same part that controls breathing when you're awake. You can breathe, hold your breath, exhale, hold it out, breathe deeply, sing, prolong your exhale or stop mid-inhale when you're awake. You have complete control of your breath. However, your autonomic nervous system takes over when you're asleep. Measuring breath when you're awake is therefore considered useless. You're really supposed to be measuring autonomic control.

This is not quite true.

Your body controls your breathing with the same part of the brain during conscious periods as unconscious periods. This is why you don't need to walk around saying "in - out - in - out".

However during conscious periods you can override this portion of your brain with the conscious portion of your brain. Up unitl you pass out, which is when this override ceases.

[Benny]

Thanks for the thoughtful answers - especially Dreamdiver. It makes sense to me. Just to be clear, I realize I fall asleep within a few minutes of putting my head on the pillow - sometimes within seconds. That was not the case here. I was fully awake the whole time, sitting up, watching the entire news weather and sports - precisely to try and get used to it before I even got into bed or tried to sleep.

[DreamDiver]

Your body controls your breathing with the same part of the brain during conscious periods as unconscious periods. This is why you don't need to walk around saying "in - out - in - out".

OMG - 40 plus years of needless chanting to myself - "in - out - in - out" !

Thanks for clarifying, Needsdecaf.