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narrowing pressure ranges yields worsening results
#1
over the past 5 months I have been narrowing my pressure ranges in an effort to get better apnea index numbers. the airsense 10 machine pressures include: median, 95%, and maximum of 8.4, 11.1, and 12.4 respectively. So I have been adjusting my pressures to track more closely the machine pressures, one month at a time. 5-20, then 7-14, then 7.6-13.4, then 7.8-13. In doing so, I find that the AHI, AI, and Central numbers are getting worse not better. the best numbers are when the machine is set to 5-20 pressure range. I use nasal pillows and 10 minute ramp time.

does adjusting the pressure ranges really help because so far its not doing much for me. I welcome any opinions or thoughts. I meet with my sleep tech in two weeks and not sure what I should ask.
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#2
Hi chingzzzs,
What is the breakdown of your AHI, OA's, Hypopneas, Centrals, etc?

I don't know what your basing your pressure changes on, but you should be looking at your apnea events in correlation to your pressure on your graphs.

Why not send us a screenshot from sleepyhead of a couple different nights, then someone can take a look.

Include: events graph, pressure graph, FL graph, leak graph, and the detailed info. to the left of the graphs. Don't need calendar, or chart to the very right of graphs.

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#3
Just curious, has your max ever been above 12.4? I ask because initially the machine's max was set to 20, then 14, 13.6, etc, but did your personal max ever hit those high numbers? I wonder if the machine max affects how high it's willing to go for certain situations short of topping out. For example, if the machine's max is set to 14 is there programming that steers the actual max to 95% of that figure, say 13.3, for all except the most dire of circumstances? If that's the case, then anybody who says "I see no need to raise the max since it's never pegged out at 100%" would be mistaken. Hopefully somebody here knows this.
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#4
In general, increasing the minimum pressure of an APAP machine to prevent most obstructive events will reduce AHI; however, this is for someone that is starting out with a wide-open machine. For example when your machine was set to 5-20, and you observed the average pressure was 7.0, it probably helped to raise the pressure to about 7.0. Once you made that change, the average probably increased. I'm not sure how you concluded to set the max pressure to 14 at that point, but if it was the max recorded pressure, that's fine. If you backed it down to the 95% pressure, I would have recommended against that.

There are diminishing returns to increasing pressure to the new average, instead, we are looking for a minimum pressure that eliminates most events, and that is where we leave it. Maximum pressure does not need to be decreased in most cases unless you have numerous unresolved flow limitations or snores that cause the machine to increase pressure automatically far above your therapeutic pressure.

Without knowing what kind of events have increased, it's hard to know how to advise. If the increased events are central, you passed the sweet-spot, and should reduce minimum pressure. If you are having obstructive events, increase the machine max pressure setting.
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#5
(12-03-2015, 09:15 AM)StoopidMonkey81 Wrote: Just curious, has your max ever been above 12.4? I ask because initially the machine's max was set to 20, then 14, 13.6, etc, but did your personal max ever hit those high numbers? I wonder if the machine max affects how high it's willing to go for certain situations short of topping out. For example, if the machine's max is set to 14 is there programming that steers the actual max to 95% of that figure, say 13.3, for all except the most dire of circumstances? If that's the case, then anybody who says "I see no need to raise the max since it's never pegged out at 100%" would be mistaken. Hopefully somebody here knows this.


There is no programming, but the auto machine will raise pressure according to breathing patterns, flow limitation, snores, in anticipation of possible apnea events.
Sometimes there are no events, and some are sensitive to that rise in pressure.

It may be that the minimum pressure needs raised based on events and also
where his 90% numbers are.

I have seen my APAP shoot pressure up to max based on so called snores and flow limitations. That doesn't necessarily mean that that's where my pressure sat all night. If no apnea, then pressure drops back down.

OP claims his Centrals are up, and that is the biggest reason not to raise max pressure. So until he gives us a couple screenshots of his data, it's hard to advise on pressure settings.

My pressure is set to a narrow range because that is what works for me, not necessary someone else. That is why you should study your pressure, event, and leak graphs to judge where your needs are. It takes time to figure all that out.

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#6
(12-03-2015, 09:15 AM)StoopidMonkey81 Wrote: Just curious, has your max ever been above 12.4? I ask because initially the machine's max was set to 20, then 14, 13.6, etc, but did your personal max ever hit those high numbers? I wonder if the machine max affects how high it's willing to go for certain situations short of topping out. For example, if the machine's max is set to 14 is there programming that steers the actual max to 95% of that figure, say 13.3, for all except the most dire of circumstances? If that's the case, then anybody who says "I see no need to raise the max since it's never pegged out at 100%" would be mistaken. Hopefully somebody here knows this.
in the 29 days of study for the month of November, my machine hit a max pressure of 13.3 on 5 nights only. all other nights the max was 11 to 13.1.
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#7
[attachment=1925]
(12-03-2015, 08:51 AM)OpalRose Wrote: Hi chingzzzs,
What is the breakdown of your AHI, OA's, Hypopneas, Centrals, etc?

I don't know what your basing your pressure changes on, but you should be looking at your apnea events in correlation to your pressure on your graphs.

Why not send us a screenshot from sleepyhead of a couple different nights, then someone can take a look.

Include: events graph, pressure graph, FL graph, leak graph, and the detailed info. to the left of the graphs. Don't need calendar, or chart to the very right of graphs.
Quote:

please find THREE different readings for the month of Nov

[attachment=1925]
[attachment=1926]
[attachment=1927]
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#8
I still don't see a reason to raise max pressure.

Your graph on Nov. 24 shows a lower AHI of 6.47, and your medium and 95% pressure seems to hover at close to 10 and 11.

I think this was advised prior, but it looks to me that your starting pressure of 7.6 is too low.
If your medium and 95% pressures are still around 10 and 11, you should start at 9cm. This way the APAP doesn't have that far a reach to take care of apnea events.

I also notice you still have some leak issues, and doesn't look like your sleeping more than a couple hours. Thinking-about

Hopefully, others will look at your data and see something and advise.
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#9
(12-03-2015, 12:57 PM)OpalRose Wrote: I still don't see a reason to raise max pressure.

Your graph on Nov. 24 shows a lower AHI of 6.47, and your medium and 95% pressure seems to hover at close to 10 and 11.

I think this was advised prior, but it looks to me that your starting pressure of 7.6 is too low.
If your medium and 95% pressures are still around 10 and 11, you should start at 9cm. This way the APAP doesn't have that far a reach to take care of apnea events.

I also notice you still have some leak issues, and doesn't look like your sleeping more than a couple hours. Thinking-about

Hopefully, others will look at your data and see something and advise.

thanks Opalrose for the feedback. My rescan software shows a 0 median pressure across the board but the sleepyhead software shows some leakage. I tried a full face mask a few times in Nov and I know I had leakage with that.
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#10
(12-03-2015, 12:57 PM)OpalRose Wrote: I still don't see a reason to raise max pressure.

On the first graph it actually hits the max during a spike at 6:25AM. I take it as long as the max is very brief and doesn't "stay there" and flatline like a maxed out CPU then there's no need to raise the limit?
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