AHI varies a lot from day to day--do others have this?

[newguy]

My AHI averages about 6 over a period of a month or so, but varies a lot from day to day. Over the last week, it was 3, 12, 5, 19, 14, 4, 2. I can sure tell the difference between a 2 or 3 and a 12 or 14. It's a long ways to a sleep doctor from here, so before I go, I'm just wondering whether this is unusual or just the way life is with OSA...

[Wulfman]

Do you have one of the Encore programs (Pro or Viewer) to see your detailed data? (or are you getting the info from the LCD?)
What are your pressure settings?
What is your mask leak rate? Is is "normal"? (There should have been a graph in the mask user manual.)

Den

[newguy]

Yes, the data are from the Encore Viewer. Pressure is only 5 cm and straight CPAP. Been on that for 1+ year. Only had the viewer for a month, so did not know that the AHI was varying so much. The leak rate is nearly always < 30 and below the rated leak rate.

[Wulfman]

Yes, the data are from the Encore Viewer. Pressure is only 5 cm and straight CPAP. Been on that for 1+ year. Only had the viewer for a month, so did not know that the AHI was varying so much. The leak rate is nearly always < 30 and below the rated leak rate.

Yikes! That's like almost NO pressure. If you have an Auto (as showing in your profile) why don't you set it to APAP mode with maybe 10 as your maximum pressure? Did you have any Central Apneas in your sleep study? If so, 10 would be a good place to stop.....until you see some newer data.

Den

[newguy]

Yeh I know it's not much pressure. My situation may be a little odd. Yes, the sleep study showed there are centrals, about half the total apneas. The sleep study showed increased apneas as pressure was raised, and that's what happens at home if I raise the pressure either in fixed increments (e.g., to 6 or 7) or by putting it on auto. On auto, the pressure just goes up and stays at whatever the maximum setting was, and I can't sleep at all...

[Wulfman]

Yeh I know it's not much pressure. My situation may be a little odd. Yes, the sleep study showed there are centrals, about half the total apneas. The sleep study showed increased apneas as pressure was raised, and that's what happens at home if I raise the pressure either in fixed increments (e.g., to 6 or 7) or by putting it on auto. On auto, the pressure just goes up and stays at whatever the maximum setting was, and I can't sleep at all...

RATS!!!

Den

[newguy]

Yep, it sucks--I think something is kind of wrong with my particular story. But, maybe I should be happy with an average AHI of 6. I was diagnosed at 35, so something is working. ..just not very well every day...

[ozij]

Rats it right, but you're not stuck with that yet.

People whose obstructive sleep apnea can't be handled by regular cpap because then they get centrals have a condition called complex sleep apnea (Compsa), aka complex SDB. The condition was identified about 2 year ago, and is treated with a different kind of machine. Respironics and Resmed both make that type.

http://www.resmed.com/en-au/assets/docu ... 0933r1.pdf

Does the severity of OSA predispose the patient to a higher risk of developing CSA and CompSA?
Actually, it’s probably the opposite. The more severe a patient’s OSA, the more likely they’ll respond to CPAP treatment. CompSA is unique in that it is, by definition, only diagnosed as a result of what happens during CPAP treatment.

Your average AHI, it too high, as are the highs you get to.
If it were me, I'd look for a second opinion by a certified sleep doctor - and if possible, one affiliated with an academic hospital - they tend to be more on top of things than others.

O.

[Guest]

Ozij...thanks for the link. This is helpful. The possibility of complex sleep apnea has been mentioned to me before. I am now pursuing an appointment with a sleep doctor at National Jewish Hospital in Denver, which I hear is one of the best sleep disease places in this area.

[BadBreath]

Your centrals are not necessarily caused by CSA but can be CPAP induced centrals where the exhale pressure is too much for you to breath against. The presence of unresponsive centrals should have immediately moved the study to BiPap, where the exhale pressure can remain low enough to prevent centrals while the inhale pressure can be high enough to prevent collapse. Unfortunately, undue influence from insurance companies cause the study centers to avoid BiPap until CPAP has been entirely disqualified, but there is often not enough time during the study (especially a spit-night study) to reach that point.

A new study is in order with instructions from the sleep doc to the techs to move to BiPap as soon as there is any indication it may be required.

[Guest]

Badbreath--thanks for another explanation, that I will certainly mention to the sleep doctor if it does not come up. The link to the CSA bulletin mentioned another factor, which is high elevation--I'm at 7200' and apparently that can add to or perhaps explain some centrals.

[feeling_better]

Yeh I know it's not much pressure. My situation may be a little odd. Yes, the sleep study showed there are centrals, about half the total apneas. The sleep study showed increased apneas as pressure was raised, and that's what happens at home if I raise the pressure either in fixed increments (e.g., to 6 or 7) or by putting it on auto. On auto, the pressure just goes up and stays at whatever the maximum setting was, and I can't sleep at all...

I have almost exactly the same situation. Fortunately for me, I have managed to get reasonable AHI numbers (<5) most days; but for this I had to reduce my pressure to 5.5! BTW, most of the AHI is from Hs, my As is very very low (but my untreated AHI was ~30). Yes, most people on this forum would laugh at that low pressure I use. At the beginning, when I started with APAP, it kept going to the maximum, whatever the maximum was and I could not sleep at all. I am using CPAP now, and arrived at this lower AHI by trying different pressures every 5 days or so.

I am finding that I can reduce the Hs somewhat by decreasing the CO2 washout, still early in my experimental stage to draw any conclusion. In order to continue this line of experiment, I may have to also monitor my Oxygen desat; I do not have a meter for that yet. I do not know if the insurance will allow rental of an O2 meter, or I have to buy one. I have not discussed this with my doc yet ...

[mymontreal]

Very interesting article - thanks for posting the newsletter!

Mike

[Snoredog]

a lot of things can influence AHI, positional sleeping, having a glass of wine with dinner, allergies etc.

But if you take those AHI numbers and average them out over say 7 days or a month and it is consistently higher than 5 it may mean you need to increase the Minimum pressure and note the change.

[Guest]

I am finding that I can reduce the Hs somewhat by decreasing the CO2 washout, still early in my experimental stage to draw any conclusion. In order to continue this line of experiment, I may have to also monitor my Oxygen desat; I do not have a meter for that yet. I do not know if the insurance will allow rental of an O2 meter, or I have to buy one. I have not discussed this with my doc yet ...

Feeling better--glad to hear your story, which is indeed similar to mine. How do you decrease the CO2 washout and how would the O2 meter fit in? I think there has been discussion of these things, so maybe I can find this from a search...