Typical AHI variability

I am a recent xpap user and started in early November 2009. See below for my machine and mask type. I have been using autopap and my overall results are very good. My average AHI for the past 2 months is 3.5. I am rarely sleepy, I do not wake up gasping for air, and I no longer wake up with a headache. My average pressure is just about 7 and it ranges from around 5 to 9 on most nights.

However, I have noticed that there is a fair amount of variability in my daily AHI. For example, this week one night a had an AHI of 1.7 and the following night I had an AHI of 5.5. This is a fairly large variation for me as I usually range from 2.5 to 4.5.

For me I am definately sensitive to positional sleep apnea and my AHI rises significantly if I sleep on my back, while it is lower when I sleep on my side. My question is this: what is a fairly typical range of AHI variability for other xpap users? What are your experiences?

I will mention what I would do with a situation like yours. I would up the min pressure to 7 and train myself to sleep on sides and tummy (Falcon position) always avoiding the back. Actually, that is what I have already done.

I always try to sleep on my side but occassionally I wake up to find I am sleeping on my back. My respiratory therapist told me to sleep however I felt comfortable and let the autopap take it from there. I do find if I sleep on my back that my AHI tends to be closer to 5 and if I sleep on my side it is closer to 3. So, even though my RT told me to sleep in the position I find most comfortable (which is on my back), I still try to sleep on my side to avoid the higher AHI.

Snorkler wrote:I always try to sleep on my side but occassionally I wake up to find I am sleeping on my back. My respiratory therapist told me to sleep however I felt comfortable and let the autopap take it from there. I do find if I sleep on my back that my AHI tends to be closer to 5 and if I sleep on my side it is closer to 3. So, even though my RT told me to sleep in the position I find most comfortable (which is on my back), I still try to sleep on my side to avoid the higher AHI.

If you have the software look at the Daily Details report. You are likely to find clusters of apneas during the times you roll onto your back. This could explain the major portion of variability in your AHI. The nights you entirely avoid supine position your AHI is very low and on nights when you do some backsleeping your AHI goes up. Speculation of course, but your data may confirm it.

Snorkler wrote:I am a recent xpap user and started in early November 2009. See below for my machine and mask type. I have been using autopap and my overall results are very good. My average AHI for the past 2 months is 3.5. I am rarely sleepy, I do not wake up gasping for air, and I no longer wake up with a headache. My average pressure is just about 7 and it ranges from around 5 to 9 on most nights.

However, I have noticed that there is a fair amount of variability in my daily AHI. For example, this week one night a had an AHI of 1.7 and the following night I had an AHI of 5.5. This is a fairly large variation for me as I usually range from 2.5 to 4.5.

For me I am definately sensitive to positional sleep apnea and my AHI rises significantly if I sleep on my back, while it is lower when I sleep on my side. My question is this: what is a fairly typical range of AHI variability for other xpap users? What are your experiences?

The AHI variations you mentioned you've had seem like normal variations to me, especially since you said you usually get a higher AHI when sleeping on your back.

What range is your autopap set for? From what you said here, it sounds like the minimum pressure is set for 5 cm H2O, right?

Snorkler wrote:My average pressure is just about 7 and it ranges from around 5 to 9 on most nights.

If it were me, and I wanted to continue to be able to sleep on my back as well as on my side, I'd raise the minimum pressure to 7, as rooster suggested.

Snorkler wrote:I am a recent xpap user and started in early November 2009
[snip]
This is a fairly large variation for me as I usually range from 2.5 to 4.5?

Do you feel better or worse rested between the a night at 2.5 and a night at 4.5?

If the answer is basically no, and you feel you are generally sleeping OK, don't worry about it at this stage of your xPAP journey.

It takes a while for everything to settle down

Cheers,

Bill

rested gal wrote:The AHI variations you mentioned you've had seem like normal variations to me, especially since you said you usually get a higher AHI when sleeping on your back.

What range is your autopap set for? From what you said here, it sounds like the minimum pressure is set for 5 cm H2O, right?

Belive it or not, the range is set wide open, 4-20, which seems crazy at first blush. But, I titrated at 5 so I think that is why the RX was 4-20. In other words, the machine starts at 4 and basically trends up to 7, and sometimes higher give or take. The pressure has never gone past 12 and rarely gets to 9. I am not bothered by the pressure changes.

rested gal wrote: If it were me, and I wanted to continue to be able to sleep on my back as well as on my side, I'd raise the minimum pressure to 7, as rooster suggested.

Yes, I have given this some serious consideration and will probably do just that.

billbolton wrote:

Snorkler wrote:I am a recent xpap user and started in early November 2009
[snip]
This is a fairly large variation for me as I usually range from 2.5 to 4.5?

Do you feel better or worse rested between the a night at 2.5 and a night at 4.5?

If the answer is basically no, and you feel you are generally sleeping OK, don't worry about it at this stage of your xPAP journey.

It takes a while for everything to settle down

Cheers,

Bill

I seem to feel a little better when my AHI is closer to say 2, than 5. But the difference is not too great. I was just trying to learn what the typical AHI range is for others.