Am I nuts? Please help me to understand ...

After two wonderful nights sleep, last night was a nightmare. I kept waking up doing the apnea thing - with my machine on, hooked up and no leaks. Twice I had to clear my air way myself (by blowing out hard) the other times, it didn't seem that my air way was closed, I just wasn't breathing. I woke up once with a left leg charlie horse that knocked me for a loop - from the hip down to my toes. . . and of course that wonderful morning headache is back along with the groggy 'hit broadside with a brick' 'it's going to be a sleep walk day'. Who knows how many times I woke up to breath when I wasn't aware of it. I woke up twice out of breath (separate from the above mentioned) - which is weird weird when you have air pumping into you. . . gasping for breath with a cpap mask on is an interesting feat.

So I check my information on my cpap machine: AHI - 7 day average is 1.9 - up from 1.7 from yesterday. The 30 day average is 2.3 - it didn't change. I understand it's an average - but . . .is this right?

I'm going to call the doc today to see if the setting might (probably is, from what I read here - a whole "6") be too low - and get it bumped up.

No, you're not nuts. Because it happens when you sleep, these problems are mysterious. If we were all watched by that nice sleep therapist who originally monitored our polysomnigram, it might be easier to figure out. Often its a variety of problems and we just get to see the aftereffect, like a town hit by a tornado. Some days I wish I had a night vision camera on all night so I could watch my night in fast forward. A common refrain around here is "I fought the mask, and the mask won...". Thats one reason why they suggest a routine, with a stable environment: to make it so you can separate problems and solutions one at a time, since we are left to our own devices. Data capable machines help alot also. Hang in there, keep dinking around with possible solutions, it will work out.

You just maybe had an isolated bad night. Remember- we look at trends, not the data, or how we slept for just one night. There are lots of folks for whom four or six is enough pressure to keep the airway open. The amount of pressure needed has nothing to do with the severity of your sleep apnea. By all means call your Doc if you feel like you should, but I wouldn't put too much stock in one bad night. Good luck and I hope you sleep better tonight.
If this does continue obviously some intervention may be indicated.

Thank you Mary and fasttwingguy.

Heh. . .are all of us newbies so . . . sensitive? **laughing**

Averages are funny things mathematically speaking. The more data you have, the more extreme an outlier data point has to be to affect the average in a meaningful way.

We can work with your specific numbers and simplify things greatly to help you understand this phenomenon. As part of the simplification, however, I have to add a hypothesis: Since you did not indicate how long you typically sleep with the machine every night, I've added the assumption that you sleep 7 hours per night EVERY night with the machine running.

Now let's look at that 7-day average suddenly jumped from 1.7 to 1.9. We'll gloss over the seven individual nights that contributed to the 7-day AHI = 1.7 and make the (highly UNLIKELY) assumption that these seven nights were all more or less the same. So here's how we get the approximate number of TOTAL events for the TOTAL seven day period:

(1.7 events per hour) * (7 hours per night) * (7 nights) = 83.3 events for seven day period

which implies you had about 83 or 84 total events for the seven day period and an average of about 12 events per night on average. Now on the next night (night 8) the data from the first day of the seven day period is dropped and replaced by the data from the last night. Since the 7-day AHI is NOW 1.9, we have:

(1.9 events per hour)*(7 hours per night) * (7 nights) = 93.1 events for the seven day period

Now, the number of events for the first six days of this 7-day period didn't magically increase, so we know that of these 93 events, roughly 6*12=72 events occurred on days 1--6. This is because on days 1--7, we already know that from the previous day's 7-day average, each of these days had about 12 events. NOTE: This is a GROSS simplification and likely introduces some significant round off error into the analysis. More about this later.

So how many events occurred on the night where the 7-day average jumped from 1.7 to 1.9? Well, we'd compute that as follows:

(93 total events) - (72 events for nights 1--6) = 26 events on night 7

And with that gross assumption that you are sleeping about 7 hours per night, that would mean an overnight AHI of 26/7 = 3.7.

Now statistically speaking, there's a heck of a lot WRONG with this analysis, but even a very close more accurate analysis will show that there's been a substantial uptick in terms of number of events on that last day in order to increase the 7-day AHI from 1.7 to 1.9. Some of the finer points I've glossed over that affect the actual numbers include:

• The first 7-day AHI could be as high as 1.74 and still round to 1.7 and the second 7-day AHI could be as low as 1.85 and still round to 1.9. So there's some real room for round off error creeping in EVEN if the seven nights in the first 7-day period are more-or-less identical.
• The seven nights in the FIRST seven day average are most LIKELY NOT identical. And the more variation on their individual overnight AHIs, the LESS LIKELY the estimate that the number of events (72) that occurred during the six days that are common to the two 7-day periods has any basis in reality. And since there's no real way to determine the actual number of events during those 6 days, there is no way to accurately determine just how bad that last night was.
• The assumption that you are sleeping about the same time with the machine every single night is most likely FALSE and with a modest 1/2 variation of sleep time per night will throw off the simplified arithmetic analysis for the last night off quite a bit.

The 30-day average works, the same way, but with more data, it's almost impossible for the 30 day average to change. With your data and my same grossly oversimplified assumptions, the relevant "figures" are:

(2.3 events per hour) * (7 hours per night) * (30 nights) = 483 events for the first thirty day period
and
(2.3 events per hour) * (7 hours per night)*(29 nights) + (events for last night) = 493 events for the second thirty day period

And the AHI for the first thirty days is 483/(7*30) = 2.3.

And the AHI for the second thirty days is 493/(7*30) = 2.347 = 2.3 when rounded to one decimal place.

The only time that 30 day average is likely to change is when the machine is reporting the 30 day AHI = n.d, but when the AHI is carried out to three decimal places, it is very, very close to n.d50. When that happens, a small change in the AHI's second or third decimal place can change the value of the d on the machine's LCD 30-day average.

robysue, the friendly math prof

quietmorning, there's nothing so refreshing and encouraging as a newbie determined to make a success of their therapy. I applaud your concern about changing your pressure. One day you may feel confident enough to do a little tweaking.

Not so much "sensitive" as impatient. (And it ain't just newbies! )

No one likes to feel bad. Everyone wants a perfect night's sleep EVERY night. It's a goal to strive for, but rarely a reality...even for non-CPAPers.

Maybe you should get the software to see what was really happening. Sometimes averages are really deceptive. Only with the software can you really see what happened minute by minute. Most of those events could be happening in side of one hour.

Also now that your body is used to breathing all night, it will react to any apneas with much more stress and wake you up.

We are working on software options. OP has a DME compliance modem right now and unsure if the SD card slot is even available at this point. Once we get things sorted out she will have software and/or Onkor options to see for sure what is going on.

She should have the clinician manual by now and we will start working on what is available or not right now without jeopardizing insurance and DME thing.

Off hand with the reported morning headache I would suspect at the very least some clusters of events even if the overall AHI wasn't remarkable. Just need more data and more time to get things sorted out. Heck, leak may be a factor for all we know.

Were you mouth breathing last night ? Morning headache indicates a lack of therapy.

The jury's still out on whether or not you're nuts, since we don't have enough data...

Speaking of data, grab a bedside pen and paper, and keep track of these aberrations. Your doctor will high-five you when you show him records of odd occurrences instead of just saying "oh, every now and then."

When I'm not of the forum, I'm a nerdy computer guy, and my team gets bug reports when someone even looks at our website the wrong way, and I tell them when they see a new bug report for the first time, they need to keep it in mind and look for more reports. That's what you should do... keep this in mind and see if it happens again. Hopefully it won't... but if it does, knowing the consistency is the first step to knowing the cause, and to troubleshoot the solution.

I'm on my 3rd night too. Awesome isn't it?

Last night when I was settled into bed and falling asleep, the top part of the small tube where the 'exhaust' is (on an opus 360 mask) was whistling some what - I covered the holes to the exhaust to check for leaks, and didn't feel any. This morning when I woke up it was not 'whistling'.

My mouth was closed all night - when it falls open it generally wakes me up pretty quick as I hate sleeping with my mouth open. Each time I woke up last night, it was closed. My sinuses were clear (rare thing) as well.

Hm. . .I like the suggestion of waiting to see if there is a pattern. My follow up appt is the day after tomorrow. . .so we'll see where this all goes. I guess all in all at this point, things are actually going pretty good. (??!!)

Kilgore Trout wrote:The jury's still out on whether or not you're nuts, since we don't have enough data...

Are you kidding? They ran for their lives, and they ain't commin' back!!

Kilgore Trout wrote:Speaking of data, grab a bedside pen and paper, and keep track of these aberrations. Your doctor will high-five you when you show him records of odd occurrences instead of just saying "oh, every now and then."

Will do - thanks!

Kilgore Trout wrote:When I'm not of the forum, I'm a nerdy computer guy, and my team gets bug reports when someone even looks at our website the wrong way, and I tell them when they see a new bug report for the first time, they need to keep it in mind and look for more reports. That's what you should do... keep this in mind and see if it happens again. Hopefully it won't... but if it does, knowing the consistency is the first step to knowing the cause, and to troubleshoot the solution.

My husband is a nerdy computer guy - he said the exact same thing.

Kilgore Trout wrote:I'm on my 3rd night too. Awesome isn't it?

I cannot believe how much better I feel - and this is without all the kinks worked out already!

I have one more "kink" to work out... who starts barking at 4 a.m. to be let outside. *sigh*

Go into the data menu on your machine and check the "AIN (Am I Nuts)" reading and report the number.

Be sure to look at the pressure reading on your machine when you have an incident.

It may help to open your mouth when you have an event and let the air flow through to convince yourself that the machine is blowing properly.