Why higher AHI during naps?

pjwalman · Post by **pjwalman** » Thu Apr 17, 2008 5:44 pm

I've only got two weeks of CPAP use and reports, but I've noticed the same thing in both weeks and wondered, from you experts, why the AHI on a mid-morning nap would be so much higher than a full night of sleep.

I work at home and have a screwy schedule, so I get up at 5:30, work from 6-8 a.m., and then I usually go back to bed for a nap before I start my next job. Both weeks, during morning naps, I had much higher AHIs than during my nights where I slept much longer. The first week, in a nap of 75 minutes, I had an AHI of 13. 1, and this week, during a nap of two hours, I had an AHI of 14.7, a 30-minute nap an AHI of 15.8, a two and a half hour nap 12.2. This is compared to nights that range from 3.1 to 6.4 AHI.

Now, why would the naps be so much worse than the nights? I usually have a cocktail in the early evening, and I'm taking Benadryl before bed. Is this the difference? I know these things are touted as being things that could prevent me from waking up with an apnea, but with the machine I *don't* wake up and am not supposed to. Right? It's supposed to sense things *for* me? I don't get it. I know I'm stupid about this, and I would love to be educated. It just seems weird.

Thanks for another lesson in my Apnea 101!

Peggy

Guest · Post by **Guest** » Thu Apr 17, 2008 7:37 pm

Well, I don't think what's being recorded is really meaningful during your naps as the machine is programmed to recognize only 'naps' of 4 hours or more (but not less) as being valid sleep times. Maybe your naps are producing 'artefact', but not proper data that you should go by. But I'm way far from being an expert on this, so maybe someone else will jump in.

Moby · Post by **Moby** » Thu Apr 17, 2008 7:42 pm

I'm not an expert, so I may be corrected in this.

From my software I've noticed I have more events when I am falling asleep.
eg last night my stats were AI 0.2 and Hi 2.1. But in the first two hours I had two apnoeas and 6 hypops.

i have also noticed that if I wake up naturally I have lots of hypops as I wake up/lie half awake.

During a long nights sleep these falling asleep/waking up events are diluted. But during a nap they would be concentrated into a shorter time span.

Di

WNJ · Post by **WNJ** » Thu Apr 17, 2008 7:58 pm

Anonymous wrote:Well, I don't think what's being recorded is really meaningful during your naps as the machine is programmed to recognize only 'naps' of 4 hours or more (but not less) as being valid sleep times. . . .

I must take issue with this. There is a (somewhat artificial) yardstick of 4 hours in each 24 hour period as a measure of "compliance." Insurance companies seem to want patients to use the machine at least 4 hours per day on at least 70 percent of the days. This is their definition of "compliant."

If the M Series and Encore Viewer act like my tank and Encore Pro, it will record valid data on pressures, apneas, hypopneas, snores, leaks, etc., beginning about 15 or 20 minutes after the machine is turned on. It will accurately compute AHI for each "session." If you have a break of more than one hour in the use of the machine, it will treat it as a new session in Encore Pro.

Peggy -- Not sure why your AHI should be higher during brief daytime naps. Mine is usually lower. Not sure why that is, either. Are you sleeping in a different position? Wearing restrictive clothing? Is there something different about the conditions under which you are taking a nap that would make your airway more likely to collapse?

I think you should try to figure out what conditions are different during your naps. This may help you figure out the reason for the difference in your AHI.

Wayne

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GumbyCT · Post by **GumbyCT** » Thu Apr 17, 2008 8:03 pm

I think its the way the math is done - you prob need to bump up your lower pressure. But need more info 1st.
1. Post what your settings are -
2. the time (in hours) you normally sleep,
3. & how long (in Hours) your naps usu. are.

Guest · Post by **Guest** » Thu Apr 17, 2008 8:31 pm

In response to Wayne, I'm ashamed to admit I'm still in my jammies for my naps since I climb out of bed, go to work in my office, and then climb back into bed for my nap, so no restrictive clothes. I don't sleep in any different position. I'm pretty much a side sleeper with very rare exceptions. I do take a Requip in the morning along with a Prilosec OTC, but I take an even stronger dosage of Requip at night plus an Atenolol. So really the only thing that seems to be different is that I've had a drink in early evening and then my Benadryl right before bed.

In response to GumbyCT, my ramp started at 5 from the DME, lasting 30 minutes. I bumped it up to 6 a few days later and then up to 6.5 after my one-week visit with the DME where my AHI average for the first week was 10. This morning I bumped it up to 7, still a ramp of 30 minutes. My overall pressure is 11.

I'm open to suggestions, other than I'm not brave enough to go to APAP without permission since I have yet to discuss the large number of centrals in the sleep study (more than half) with the doctor and I'm too chicken to mess with much until I know more about whether those are hooey or something to be concerned about. It kind of ticks me off that I have to wait until the 28th to talk with him, but I assume they know what they're doing when they schedule the follow-ups that far out. I was thinking maybe I'd get a call from the office about adjusting my pressure with an average AHI of 10 for the first week but nothing. This week my average is at nine point something or other for the two weeks, seven something or other for the six days I printed out today.

Thanks again for helping me figure this out. I just thought it was interesting that there would be such a difference. I'd be tempted to knock back a cocktail or pop a Benadryl in the morning before my nap, but I don't think that would bode well for the rest of my workday.

Peggy

Snoredog · Post by **Snoredog** » Thu Apr 17, 2008 8:50 pm

Anonymous wrote:Well, I don't think what's being recorded is really meaningful during your naps as the machine is programmed to recognize only 'naps' of 4 hours or more (but not less) as being valid sleep times. Maybe your naps are producing 'artefact', but not proper data that you should go by. But I'm way far from being an expert on this, so maybe someone else will jump in.

sorry, but your understanding of how the machine functions is incorrect,

it reports the number of 4 hour sessions ONLY for compliance needs to satisfy insurance requirements, it has nothing at all to do with the function of the machine and or how it records events.

it will record events from the time you turn it on if capable of doing so.

Guest · Post by **Guest** » Fri Apr 18, 2008 4:52 am

Thank you for straightening that out - I wasn't sure about it, but now I am.

alnhwrd · Post by **alnhwrd** » Fri Apr 18, 2008 5:21 am

OT, but how was your weekend, PJ?

I have no input on the toic you presented, sorry

Alan

pjwalman · Post by **pjwalman** » Fri Apr 18, 2008 6:51 am

Alan, the beach was absolutely beautiful on Saturday! Thank you for asking!! In ideal circumstances, I would have grabbed a book and a blanket and just vegged out on the beach the whole day. However...the couple through whom we were able to get the duplex for free brought their 3-year-old and 6-year-old whiny, bratty grandkids , and there ended up being not one darned relaxing aspect to the weekend. Should have stayed home, masked up, and slept the whole weekend instead.

Peggy

pjwalman · Post by **pjwalman** » Fri Apr 18, 2008 8:15 pm

Found this in another thread. There is no explanation for the statement, but I'd be interesting in hearing it if anybody knows. I should have made note of the author. It was Ozjmi or something similar, I think.

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"You should definitely use the machine and mask for naps - but don't make and decisions based on nap data. Napping is not normal sleep, and can't tell you much about night needs."

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I guess I understand the argument that you shouldn't let the higher AHI skew your results from naps, but bottom line is, regardless of the numbers being skewed, it's still apneas and hypopneas that are making you feel crappy. Right? I am two weeks in and can't figure out why I feel *worse* now than before I started. I'm getting up less times to pee, I'm getting all this lovely forced oxygen and am having WAY less events, so why do I feel like I've been drug backwards through a knothole today? (Can't blame all that on horrific gas and looking through puffy, dark-circled eyes now, can I?)

Just having a bad day and need to whine a little. Thanks for putting up with me!

Peggy

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