Is ASV useful for AHI around 6, of which 4 are Centrals?

[yarrow]

I seem to do OK when my AHI is under 3, not as well from 3 to 5, and quite poorly when it's over 5. These days it's mostly 5-6, and most of those are centrals. I'm wondering if an ASV machine would be something to try. Has anybody gone to ASV from CPAP with a relatively low AHI like mine? If so, how did it work for you? (My sleep doc is wondering about narcolepsy, given that my sleepiness is pretty bad at an AHI of 6ish -- but I'd rather not add on another drug-to-take-for-life if there is an alternative.)

Here's a fairly typical night (though the apneas are usually spread slightly more evenly):

[JohnBFisher]

Most of the centrals seem to cluster .. Thus, I suspect you were awakening and/or falling back asleep. Those centrals would be eliminated on a sleep study (since they occur during the sleep state transition). I would be surprised if either an insurance company agreed to or a sleep doctor prescribed ASV under those circumstances.

As to whether it would help or not ... ASV is not a "cure all". It might help. But the changing pressure can disturb sleep quite as much as the apneas.

[yarrow]

Most of the centrals seem to cluster

Thanks for the reply. That night they did indeed cluster. Here's another night, with less clustering:



I agree that getting insurance to pay would be borderline at best. Even if a respiratory tech read the night above exactly as the machine did (and assuming I'm reading my insurance documents correctly), the night above would just barely qualify, since centrals are over half the apneas and centrals plus hypopneas are over 5 (5.03!). But last night my total AHI was 4.14, which would not qualify.

As to whether it would help or not ... ASV is not a "cure all". It might help. But the changing pressure can disturb sleep quite as much as the apneas.

I'm grasping at straws here -- I seem to have really bad sleepiness at AHI levels that are not objectively all that bad. My sleep doc wants to check for narcolepsy, but I'm sceptical -- I don't have cataplexy or sleep paralysis. My guess is that I'm borderline there too, and (again if I'm reading my insurance documents right), they pay for a year of drugs and then test you again. I'd be afraid of getting dependent on the drugs and then having them taken away the next year. (I'm not thrilled about getting dependent on the drugs, period, for that matter.)

[Pugsy]

Meds?

Do you have a lot of fragmented sleep? Wake up often? Tossing and turning?

[yarrow]

Meds?

Do you have a lot of fragmented sleep? Wake up often? Tossing and turning?

Current meds for high blood pressure & cholesterol, and a nasal spray for allergies (antihistimine plus steriod). Maybe once a week I wake up in the middle of the night and have a 50/50 chance of getting back to sleep; otherwise don't wake much (that I remember).

[Pugsy]

Is your main symptom during the day just excessive sleepiness? Extreme need to nap? Nod off easily?
Or are there other symptoms during the day ...fatigue?

Have you researched your meds in great deal as to all possible side effects to see if they might be a contributing factor?

[yarrow]

Is your main symptom during the day just excessive sleepiness? Extreme need to nap? Nod off easily?
Or are there other symptoms during the day ...fatigue?

I'm never sure of the difference between sleepiness and fatigue. I work from 9:30am to 6pm, and somewhere between 2pm and 4pm it starts to be hard to think. Generally I don't in fact sleep -- sometimes the drowsiness lifts in the evening, and since my rule is "no sleep without the mask", drifting off isn't something I let myself do.

Have you researched your meds in great deal as to all possible side effects to see if they might be a contributing factor?

Last year, about this time, before CPAP, I wondered if the simvastatin might be the problem -- stopped using it, but no apparent improvement. CPAP did help (after a moderately rough into period), but things have been getting gradually worse since the Fall.

Fatigue is also listed as an occasional side effect of valsartin, my blood pressure med.

I just got an oximeter, which usually reads 93-94 during the day and averages a bit under 93 at night. Those numbers don't seem great, but not awful either.

[Pugsy]

Okay... here's a thought...going way out on the limb here so bear with me.

Like John I suspect your centrals are most likely sleep transition or sleep onset centrals. They just don't fit the pattern of "real" cpap induced centrals that we usually see with complex sleep apnea...not enough of them and not in the pattern we would expect.

So let's assume sleep stage transition or sleep onset centrals. I am just speculating here... if they are sleep onset or turn over in bed...maybe there is an arousal there that you aren't aware of. So maybe sleep quality isn't optimal.
Now we don't know why but you say you feel better with a lower AHI...maybe with a lower AHI your sleep quality is improved with less arousals and thus less chance for those maybe sleep onset centrals (assuming that is what they are for now).

Don't know why the arousals (if they are occurring) but maybe variations in pressure in APAP mode is maybe a contributing factor.

Have you ever tried cpap mode? Your flow limitation graph looks pretty ugly. Maybe those flow limitations are a factor in arousals?????
Have you tried reducing or turning off EPR? Do you like EPR? Do you need the ramp?
I might be tempted to try cpap mode at 11 with EPR of 2 and see what happens to that Flow limitation graph and how you feel during the day? Just a thought.

[yarrow]

Have you ever tried cpap mode? Your flow limitation graph looks pretty ugly. Maybe those flow limitations are a factor in arousals?????

Ah -- I've never known what the flow limitation meant, so mostly ignored it.

Have you tried reducing or turning off EPR? Do you like EPR? Do you need the ramp?
I might be tempted to try cpap mode at 11 with EPR of 2 and see what happens to that Flow limitation graph and how you feel during the day? Just a thought.

The current setting of 6-12cm, EPR 2 is from the sleep doc. (New sleep doc -- the old one's phone got disconnected. Has a new phone number now, but somehow I don't want to go back. ) I'd tried EPR for a few days some time ago, but it seemed to increase my AHI, so I stopped.

Before that, I was using 11cm, no EPR, with a average AHI of 5.69, on the advice of the same sleep doc, pre sleep-study. Before that, I'd been doing 8-12cm, no EPR, with an average AHI of 5.62.

Because Old Sleep Doc didn't get my medical records to New Sleep Doc, I had to do a split-night study, during which I had only hypopneas for the first part, and one central during the second part, at a pressure of 6cm. So I went home and set the machine to 6cm for two nights -- AHI of 10.18, split about equally between obstructives, centrals, and hypopneas. Tried 7, 8, and 9 -- also bad, though 9 was 7.4 AHI. Did two nights at 10cm, which averaged 3.64 AHI. But promised the doc I wouldn't mess with the 6-12 settings until I saw him again.

Thanks for your patience with this mess!

[Pugsy]

Your report at the top is showing EPR at 2...
It reflects in EPAP and IPAP numbers...see the 2 cm difference.
It hasn't been turned off on the 14th report unless you turned off after that date.
For flow limitations usually a little more pressure...if you turn off EPR then that increases the overall pressure average so that pressure isn't dropping on exhale. In theory the elimination of EPR is a way to offer a little more pressure without changing the overall settings. Using EPR at 2...half the night (during exhale) the pressure is reduced by 2 cm...sometimes that little reduction allows the airway tissues to collapse a little.

Flow limitations are reductions in air flow that don't meet the criteria for hyponea or apnea. Flow limitations are part of the apap algorithm trigger factors for increasing pressure.

Compare yours to mine. Mine is pretty near textbook perfect. Your is maybe pushing coyote ugly as Mollete would say.
http://s1081.photobucket.com/user/Onesh ... ort=3&o=37

Flow limitations can cause arousals...that's where a lot of the UARS thinking comes from UARS Upper Airway Resistance Syndrome. You might google it and do a bit of reading and see if you see yourself in those side effects which are a lot like OSA side effects.

[yarrow]

Your report at the top is showing EPR at 2...
It reflects in EPAP and IPAP numbers...see the 2 cm difference.

Yes, the doc apparently is fond of EPR.

It hasn't been turned off on the 14th report unless you turned off after that date.
For flow limitations usually a little more pressure...if you turn off EPR then that increases the overall pressure average so that pressure isn't dropping on exhale. In theory the elimination of EPR is a way to offer a little more pressure without changing the overall settings. Using EPR at 2...half the night (during exhale) the pressure is reduced by 2 cm...sometimes that little reduction allows the airway tissues to collapse a little.

Flow limitations are reductions in air flow that don't meet the criteria for hyponea or apnea. Flow limitations are part of the apap algorithm trigger factors for increasing pressure.

Compare yours to mine. Mine is pretty near textbook perfect. Your is maybe pushing coyote ugly as Mollete would say.
http://s1081.photobucket.com/user/Onesh ... ort=3&o=37

Flow limitations can cause arousals...that's where a lot of the UARS thinking comes from UARS Upper Airway Resistance Syndrome. You might google it and do a bit of reading and see if you see yourself in those side effects which are a lot like OSA side effects.

Interesting! My immediate impulse would be to try increasing the pressure until the flow limitation goes away (while watching for increased centrals), and see if that helps the sleepiness.

Is there a rule of thumb like "flow limitation mostly under 0.2 is OK", or under 0.1, or ... ?

[Pugsy]

Is there a rule of thumb like "flow limitation mostly under 0.2 is OK", or under 0.1, or ... ?

Don't know....Mollete got into it a bit with some good explanations in Amy's thread ...I look but couldn't find it ....let me go look again. Your FL may not be quite as ugly as hers but it's close...For hers I was being a bit nice and say "yes those are a bit ugly and Mollete came along and said "A it ugly" How about coyote ugly Any I can find that thread and what he said about ResMed way of using this graph .

Let me go see if I can find it.

BRB.

[yarrow]

Let me go see if I can find it.

Searching for "coyote ugly" found it. (Graphs are gone, though): viewtopic.php?f=1&t=88265&st=0&sk=t&sd= ... y&start=15

Off to bed. Need to get up way too early tomorrow!

[Pugsy]

Searching for "coyote ugly" found it. (Graphs are gone, though):

Yeah, I discovered the graphs were gone also. I remember them though...Your FL graphs would be right up there with the coyote ugly ones.

[sleepstar]

what was your AHI originally?