Which variables raise/lower the AHI ?

[Physician]

Within the 0-5 normal range, what makes for the difference from night to night ? Diet ? Stress ? Alcohol ? Sleeping meds ? Eating later at night ? Dreaming ? Ambient temperature ?

[chunkyfrog]

mask fit;
also, start of bedtime.
If I stay up too late--higher AHI.

[Muse-Inc]

Primarily, mask fit (leak) & sleep position. Secondarily, high stress & being too tired.

EDIT: Too, number of wakeups. A night with a lot of wakeups will usually have higher hypops, tho not necessarily at the same time...at least not during the nights I logged wakeup times.

[Breathe Jimbo]

Aggressiveness of hunting dog in seeking snug valley between CPAP user and wife.

[Big Daddy RRT,RPSGT]

Alcohol use, some medications, sleep position, mask leaks, mouth breathing, nasal congestion and others.

[Wulfman]

Within the 0-5 normal range, what makes for the difference from night to night ? Diet ? Stress ? Alcohol ? Sleeping meds ? Eating later at night ? Dreaming ? Ambient temperature ?

What pressure settings are we talking about.......and is it fixed or a range?
I suppose it might be worthwhile to ask what humidifier setting is being used, too.


Den

[Zeke351]

For me it is definitely if I am over-tired. If I fall into bed already exhausted (last week after a 90 hour work week!!!) and immediately into a deep sleep my hypopneas go way up. Last week I had one night that had 32 hyopneas over an 8 hour period with 20 of those in the first hour.

Zeke351

[Physician]

Within the 0-5 normal range, what makes for the difference from night to night ? Diet ? Stress ? Alcohol ? Sleeping meds ? Eating later at night ? Dreaming ? Ambient temperature ?

What pressure settings are we talking about.......and is it fixed or a range?
I suppose it might be worthwhile to ask what humidifier setting is being used, too.

• Autoset range 8-16, pressure titrates at 12-13 consistently.

• No humidifier

[torontoCPAPguy]

mask fit;
also, start of bedtime.
If I stay up too late--higher AHI.

Now THAT is interesting. More tired... deeper sleep.... more hypopnea/lower SpO2..... more apnea events? This confounded thing we have has nothing to do with science and ticks me off. I cannot with any certainty say that 1 + 1 = 2 every time. I find out stuff more by 'patterns' of cause and result than anything else.

I can tell you this for sure and that is that AHI is not the number I am watching closely - rather it is instantaneous SpO2 as I think it is far more critical to observe. I believe higher AHI causes desaturations, of course. But at what point does one say OK, my AHI is okay, my apnea events are under control as is my hypopnea.... what the heck is going on with my desaturations? They're all over the place unless I push X amount of O2 into the CPAP line and even then it's not scientific but rather is more like observing the grass grow... one has to watch a pattern develop and cannot take one night's results as indicative of the efficacy of treatment. Drives me nuts.

I am trying to figure out why such minor changes in oxygen content of the air being pushed into my nose can make such huge differences from night to night in AHI/apnea/hypopnea/SpO2/etc.

I am just itching to put together a feedback loop O2 infuser like gvz did but waiting to pay off the credit cards this month and maybe next (big bills coming in) before I shell out $1200 for an addressable oxygen valve, essentially the last piece I require for a basic system.

Next, a used EEG machine!!!

Doktor. Vere are dese vires to go?


Oh, when I say instantaneous SpO2 I am suggesting that one should be using a fairly reliable oximeter and recording all night while asleep so that instantaneous values can be observed... anything under 90% and I want answers. First night with 4L/M of O2 I ran 97% SpO2 all night with zero desats. Anything lower produced desats during the night, likely in synch with REM sleep... made perfect sense except that when I hit 2L/M I went back to 97% stright line all night. Nuts.

[Wulfman]

Within the 0-5 normal range, what makes for the difference from night to night ? Diet ? Stress ? Alcohol ? Sleeping meds ? Eating later at night ? Dreaming ? Ambient temperature ?

What pressure settings are we talking about.......and is it fixed or a range?
I suppose it might be worthwhile to ask what humidifier setting is being used, too.

• Autoset range 8-16, pressure titrates at 12-13 consistently.

• No humidifier

That right there explains to me why you have such a variance in your AHI.


Den

[mckooi]

mind stages.
tiredness.
eat too late.
no exercise.
drinking.
humidity.
sleep position.
temperature of the room.
position of your mask.

[BlackSpinner]

Life.

[DoriC]

Within the 0-5 normal range, what makes for the difference from night to night ? Diet ? Stress ? Alcohol ? Sleeping meds ? Eating later at night ? Dreaming ? Ambient temperature ?

What pressure settings are we talking about.......and is it fixed or a range?
I suppose it might be worthwhile to ask what humidifier setting is being used, too.

• Autoset range 8-16, pressure titrates at 12-13 consistently.

• No humidifier

That right there explains to me why you have such a variance in your AHI.


Den

I'm not a physician but I wonder why you've got your minimum set so low when your avg pressure is 12-13? Your machine sure has a long way to go to prevent or eliminate your apneas. Have you tried raising your minimum? JMHO.

[Geminidream]

Life.

LOL...I think you are on to something, BlackSpinner!

[Physician]

• Autoset range 8-16, pressure titrates at 12-13 consistently.

• No humidifier


That right there explains to me why you have such a variance in your AHI.

Huh ? Why would the humidifier play a role here ?

And as for the range, it's the same range which gave me zero leak and zero AHI with the Activa, and the same settings since 7/1/2010. The Autoset gets to the titrated pressure within 30 minutes so it's similar to RAMPing.

Last night I changed from the very comfortable Comfort Classic back my usual Activa, and AHI was 0.1, again keeping the Auto set range 8-16, and as always, no humidifier.