Want better AHI? Never wake up!!!!

This morning, when I woke up at 7:15 AM, my AHI was 2.2, AI O.O and HI 2.2 -- 0.0 leaks
I stayed in the bed, mask on, not sleeping. At 8: 17 my AHI was 6.7, AI 1,7 and HI 5.0 -- 0.0 leaks

How can this be explained!!!!

I believe it has been said that data collected while you are awake is irrelevant.

LoQ wrote:I believe it has been said that data collected while you are awake is irrelevant.

Can someone cant tell me why it would be irrelevant? The machine doesn't know that you are awake!

apnez wrote:The machine doesn't know that you are awake!

Precisely!

apnez wrote:

LoQ wrote:I believe it has been said that data collected while you are awake is irrelevant.

Can someone cant tell me why it would be irrelevant? The machine doesn't know that you are awake!

One reason it can be irrelevant when collected when I am awake is that I have a pretty consistent record of AHIs around 20 when I am sleeping (which apparently includes me tossing and turning in and out of sleep even if I am not aware of it). Now if I spend a few hours on the machine while I am awake, during those few hours, I hopefully would have no apneas or hypopneas, which if combined with my sleeping data, would make my data look much much better.

Now in YOUR case, where you had a very very nice AHI while you slept, I have no idea what it means when you add your awake time to the data and it ends up being not nearly as good.

Do you know FOR SURE that you were awake during that time? I've noticed that during the time when I am kind of going in and out of sleep, I can have high As and Hs (but we should set that aside because we really don't know what is going on with me so I'm not sure how relevant my data is to this discussion). Anyway, is there a possibility that you were on your back (a position that is more likely to cause As and Hs) and is there a possibility that rather than being awake the entire time, you were actually dozing off here and there?

Otherwise I don't know

BTW, I think you need to put some lanolin on your nose...it seems to be getting a little pink)
mar

robertmarilyn wrote: Do you know FOR SURE that you were awake during that time? I've noticed that during the time when I am kind of going in and out of sleep, I can have high As and Hs (but we should set that aside because we really don't know what is going on with me so I'm not sure how relevant my data is to this discussion). Anyway, is there a possibility that you were on your back (a position that is more likely to cause As and Hs) and is there a possibility that rather than being awake the entire time, you were actually dozing off here and there?

Thanks Robert. You have very good points but none applies to me. As a matter of fact, it did happened twice before. One time I decided to go for a nap in the afternoon... without success and terrible figures. It also happened another morning about 2 weeks ago in the same circumstances.

Believe it or not, this morning, while still in the bed, I was expecting those results and even thinking about all or nearly all the above points!

Since you undoubtedly took these readings from the machine's display (while you were in bed) and not from your software, it's quite possible that you are mixing up your weekly/monthly averages (from inadvertantly double-tapping the enter button) with your most recent daily stats. That would explain the sudden dramatic shift in your recorded sleep performance.

apnez wrote:This morning, when I woke up at 7:15 AM, my AHI was 2.2, AI O.O and HI 2.2 -- 0.0 leaks
I stayed in the bed, mask on, not sleeping. At 8: 17 my AHI was 6.7, AI 1,7 and HI 5.0 -- 0.0 leaks

How can this be explained!!!!

I have noticed this too. I have also noticed if im tired in the afternoon and decide to take a short hour or so nap all hosed up on cpap. my numbers from the nap are very high. I guess i can attribute this to the nap not being fully asleep like when i sleep at nite.

I do now take cpap mask off as soon as i wake to avoid skewed numbers . I think the cpap works better when you are fully asleep and relaxed.

I, too, have noticed this and confirmed it repeatedly. My guess -- and I'm hoping someone with actual knowledge will chime in here -- is that xpap machines, particularly when exhalation relief is applied, have some difficulty distinguishing inhalations from exhalations when breathing becomes a bit shallow and even a tiny bit uneven. When awake, our nervous systems function quite differently; most people tend to breathe both more shallowly than when deeply asleep and far more unevenly as our bodies respond to various stimuli including our waking thoughts. If breathing timing alters, it seems logical for the machines to lose the precision of their tracking and record irregular breathing events that are sampling artifacts rather than actual apneas or hypopneas.

Especially during the early morning hours, you are very likely to be somewhat restless, during which time you may hold your breathe for brief periods while shifting, or even just thinking about something. If you have the software, so that you can see when and how breathing events occur, this is very easy to identify.

That is why the Resmed Autoset has a period called settling, when it does not adjust your pressure. It gives you time to settle into sleep without reacting to the sighs, breath holds, and adjustments that happen as you drift off to sleep. The same things are happening when you are drowsing but basically awake in the morning.

Even though you get good data off the LCD, the details on the software can help you understand better how the machine responds to your breathing and sleep patterns.

apnez wrote:This morning, when I woke up at 7:15 AM, my AHI was 2.2, AI O.O and HI 2.2 -- 0.0 leaks
I stayed in the bed, mask on, not sleeping. At 8: 17 my AHI was 6.7, AI 1,7 and HI 5.0 -- 0.0 leaks

How can this be explained!!!!

I can confirm similar experience here; I see this consistently. A year ago when I started I had asked about this in the forum. I sometimes stay in bed for 30 minutes or so after I wake up, and I can clearly see this in my daily detailed graphs. I see during the awake period the frequency of Hs (Hs for that period divided by the period) is much much higher than while sleeping 3 to 5 times higher! The As seems not to be affected like this.

The explanation I have come to think is true is that while awake we do hold our breaths while we are thinking of various things or trying to move around. And since the machine does not know you are awake, they get counted. It probably never goes to a full obstruction type long enough, hence the A event is not registered by the machine.

So what I generally do when looking at my data is this: Often discount (ignore) the Hs in the first 10 minutes, and the last 15-30 minutes. If my HI is higher than normal, then I try to see if I remember being awake for any extended periods (say more than 10 minutes so) during the night and see if there is particularly large cluster of Hs during that time, if so I discount them.

BTW, this may be quite different for different type of people. Some of may be more prone to irregular and shallow breathing while we are very relaxed and awake.

I think the people who do not not believe these Hs during awake period, can test it themselves by putting the cpap on during the daytime, and looking at their data for that period.

A related curiosirty of mine is: If my above reasoning is true, what is the chance that such shallow and irregular breathing to occur while we are asleep too? That may not be all that abnormal or a disease; which will inflate our normal sleep HI we measure with our cpap. The only way to test if this is causing a problem, IMO, is to have an oxygen monitor at the same time --- during sleep and awake --- and see if the oxygen level goes too low during the shallow breathing. I have tried some experiments, but I have not been able to correlate the data well enough because at least my oxygen monitor looses contact momentarily for similar periods. It is even possible these shallow breathers have a problem during their wakeful time too!!

I just woke up from an 1hr nap checked my numbers had an ahi of 20.9 normaly my ahi is around 6.0

apnez wrote:This morning, when I woke up at 7:15 AM, my AHI was 2.2, AI O.O and HI 2.2 -- 0.0 leaks
I stayed in the bed, mask on, not sleeping. At 8: 17 my AHI was 6.7, AI 1,7 and HI 5.0 -- 0.0 leaks

How can this be explained!!!!

Perhaps I completely misunderstand the way my Resmed equipment reported data on its LCD screen. Presuming that you slept for six hours (from 1:15am to 7:15am), your initial report of an AHI: 2.2 / AI: 0 / HI: 2.2 was the average over the past six hours of sleep. Your next reading (if indeed it continued to be the daily reading and not the weekly or monthly one) you advise was AHI: 6.7 / AI: 1.7 / HI: 5.0 now over the seven hours of sleep (from 1:15am to 8:15am).

I'm not very good at math, but I believe that the only way you could have increased your AHI rate from 2.2/6 hours to 6.7/7 hours would have been to experience an AHI rate of 33.7 events during the period between 6:15 and 7:15. At a minimum of 10 seconds apiece, you would have been limited to a whopping four minutes of rest without an event between 6:15 and 7:15 if every one of those events only lasted ten seconds. It also means that you completely stopped breathing twelve times (or about once every five minutes) for a period of at least ten seconds.

Could your awakened breathing be that poor even while receiving xpap therapy? Based upon your noctural readings it seems improbable.

Just to humour me, what does your LCD report as your weekly and monthly AHI/AI/HI averages? What does your software report as the experience for the night/morning in question?

For the record, (and to my shame) I continue to nap every day for about two hours usually between 5:00 and 7:00 PM. Without exception, these continue to be my best numbers as I usually awake before a REM cycle which is when my numbers generally start to deteriorate. I guess that this only goes to show that our personal experiences with this condition may vary greatly.

All of you made very good comments on this and I am happy... to a certain extent... to see that I am not alone on my island!

These are especially interesting according to my experience :

xpap machines, particularly when exhalation relief is applied, have some difficulty distinguishing inhalations from exhalations when breathing becomes a bit shallow and even a tiny bit uneven. When awake, our nervous systems function quite differently; most people tend to breathe both more shallowly than when deeply asleep and far more unevenly as our bodies respond to various stimuli including our waking thoughts. If breathing timing alters, it seems logical for the machines to lose the precision of their tracking and record irregular breathing events that are sampling artifacts rather than actual apneas or hypopneas.

The explanation I have come to think is true is that while awake we do hold our breaths while we are thinking of various things or trying to move around. And since the machine does not know you are awake, they get counted. It probably never goes to a full obstruction type long enough, hence the A event is not registered by the machine.

This is also surely true :

BTW, this may be quite different for different type of people.

And this is a very interesting and address a fundamental question :

...what is the chance that such shallow and irregular breathing to occur while we are asleep too? That may not be all that abnormal or a disease; which will inflate our normal sleep HI we measure with our cpap. The only way to test if this is causing a problem, IMO, is to have an oxygen monitor at the same time --- during sleep and awake --- and see if the oxygen level goes too low during the shallow breathing.

As a matter of fact I crosschecked many times my data with my oxymetry report and there is no doubt that many H and even A are NOT correlated with SPO2 spikes and/or higher pulse rate.

By the way I also noticed that I frequently had apneas registered within minutes after returning to bed from the bathroom in the middle of the night. Those are also probably not true apneas.

Algorithms are quite good but our machines are not yet sharp or intelligent enough to distinguish between those true and false events. As a matter of fact they are relatively dumb.

Globally speaking I think we have to be careful with too strict or difficult to reach AHI objectives. If we could remove all the false A and H out of our daily results, many of us would have a much better average on the bat! Observance is more important than anything else as we can not rely on really foolproof results.

Thanks to :

hummer3d

I just woke up from an 1hr nap checked my numbers had an ahi of 20.9 normaly my ahi is around 6.0

and spitintheocean :

I believe that the only way you could have increased your AHI rate from 2.2/6 hours to 6.7/7 hours would have been to experience an AHI rate of 33.7 events during the period between 6:15 and 7:15.
....
Could your awakened breathing be that poor even while receiving xpap therapy?

You won't believe me but my USB link with my machine stopped working this Saturday morning and I am expecting a reaction from CPAP.com for an exchange as I bought it about 1.5 month ago. I can't give you my monthly figures but they are not as good as the previous 6 hours. But you just pinpoint something globally true. I thought about it before but didn't made the calculations. As a matter of fact, intuitively, I was aware that figures could be very high. hummer3d figures are also very high. No doubt that "something" makes this possible. This "something" is probably multifactorial. This is the exact purpose of my question. I think some of you brought very good points yet.