Apnea Board Forum - CPAP | Sleep Apnea
Adjust Min or Max Pressure for High OA - Printable Version

+- Apnea Board Forum - CPAP | Sleep Apnea (https://www.apneaboard.com/forums)
+-- Forum: Public Area (https://www.apneaboard.com/forums/Forum-Public-Area)
+--- Forum: Main Apnea Board Forum (https://www.apneaboard.com/forums/Forum-Main-Apnea-Board-Forum)
+--- Thread: Adjust Min or Max Pressure for High OA (/Thread-Adjust-Min-or-Max-Pressure-for-High-OA)



Adjust Min or Max Pressure for High OA - TheLionSleeps - 07-26-2016

I have been concentrating on finding my maximum pressure to allow CPAP to treat my range of Hypopneas and OA, without getting more and more leaks which becomes a cycle of getting nowhere.
However, from the Forums online, it has been brought to my attention that often the minimum pressure is the culprit, especially when you have an auto machine like my dreamstation which retreats slowly to the minimum after an event and then takes awhile to respond from that minimum for the next event, often arriving too late to shut it down.
My pressure right now is 7-10.5 and after last nights poor showing of 14 OA 's and 19 Hypopneas with AHI of 4.5 - and 7 hours sleep, 98% mask fit, I am looking to make an adjustment, probably just one at a time, and hope that the nights return to better as in my first 3 weeks of treatment. I have yet to input my data into sleepyhead to see the graphs and when the OA's are occurring as that should help with the decision.
Any input would be appreciated as I am trying to get a good night's sleep after 2 years and therapy of 5 weeks.
Thanks. In the Jungle, the Lion Sleeps tonight.


RE: Adjust Min or Max Pressure for High OA - 0rangebear - 07-26-2016

(07-26-2016, 04:38 PM)TheLionSleeps Wrote: I have been concentrating on finding my maximum pressure to allow CPAP to treat my range of Hypopneas and OA, to shut it down.
My pressure right now is 7-10.5 and after last nights poor showing of 14 OA 's and 19 Hypopneas with AHI of 4.5 - 7 hours sleep, sleep after 2 years and therapy of 5 weeks.
Thanks. In the Jungle, the Lion Sleeps tonight.

I would up both of them upward in small increments once a week. A seven day sample should allow you to do some data analysis in sleepyhead.

When I was looking for my sweet spot I adjusted min in .2 increments. 7.2 -10.7 would be a good staring point. As you move the settings upward the HY and OA should go down.

Watch for:
1) The appearance of CA's
2) The number of awakenings.
3) The length of your sleep cycle
4) The average pressure and the 95 Percentile

Your range looks good as many find bracketing around the 95% @ +/- 2 CMH20 to be good settings.





RE: Adjust Min or Max Pressure for High OA - Sn00zeAlarm - 07-27-2016

My APAP is set to a narrow range of 5-7 and from SH my 90% pressure is the maximum, 7cm. That suggests to me that the machine thinks it should go higher. There is a low background of "flow restriction" events - maybe that is what is keeping the pressure up.

But my AHI is in a nice range, generally under 2.0 and sometimes under 0.6. mostly Hypopneas and a few CA. Attached is a typical chart.


RE: Adjust Min or Max Pressure for High OA - Crimson Nape - 07-27-2016

Sn00zeAlarm,
It would be more beneficial to see the Pressure graph instead of the Mask Pressure one. The Pressure graph will show your pressure range and if it's plateauing. I haven't found any use for Mask Pressure to date.



RE: Adjust Min or Max Pressure for High OA - PoolQ - 07-27-2016

When you look at you plotted data you need to find out if the apneas are happening right as you are going to sleep or when you are waking up, this is called sleep/wake junk and does not really count in the total.

If they are not happening as above, then with an auto machine, you may be able to increase the lower pressure to keep them from happening. What the machine is doing is looking for anything (like flow limitations and hypopneas) that typically lead to apneas and increasing the pressure to prevent a full blown apnea from happening. It is possible to increase the lower pressure setting to just keep these events from happening, so the machine no longer has to respond to them- they are just not happening to begin with.

The upper limit should be set higher than the 90% level, typically by 1 or 2 CM, if the machine wants to go higher, there is a reason for that and typically if the machine want to go higher, you should let it.

Now that being said if you AHI is in a reasonable range and raising the top pressure higher makes it so you cannot tolerate using CPAP, creates leaks that you just can't get under control, or you start trading OA's for new CA's then you may want to reconsider increasing the high end pressure.

Look at the graphs, think (and ask) about what might be going on, make small changes (if called for), and watch the plots to see how you are reacting.


RE: Adjust Min or Max Pressure for High OA - PaulaO2 - 07-27-2016

Yes, the key is to make a change and then wait and watch. Watch for ten to 14 days minimum between each change. We look for trends. Data for a single night isn't worth much except to add to the rest.
Consider starting a sleep diary, noting down what kind of day you had, if you did anything different, if you had drinks with friends, lots of activity, etc. Then in the morning, note how you feel, how you slept, if you dreamt, etc.