Apnea Board Forum - CPAP | Sleep Apnea
Pressure at altitude vs. pressure at lower elevations? - 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: Pressure at altitude vs. pressure at lower elevations? (/Thread-Pressure-at-altitude-vs-pressure-at-lower-elevations)

Pages: 1 2


Pressure at altitude vs. pressure at lower elevations? - S.L. Ping Beauty - 10-17-2017

I live at and am used to my CPAP at altitude (about 9,800 feet.)  I will be traveling soon to the mid-west to an altitude of about 700 feet.

Do I need to adjust my pressure for any compensation of the altitude difference?  I kinda' recall that when I used the CPAP there last visit that the pressure effect or sensation seemed to be diminished.  I will only be at that lower location for 3 days/ 2 nights.

Comments, opinions...?


RE: Pressure at altitude vs. pressure at lower elevations...? - PaulaO2 - 10-17-2017

It will adjust itself.


RE: Pressure at altitude vs. pressure at lower elevations...? - S.L. Ping Beauty - 10-17-2017

I am not sure what you mean.

My doctor prescribed pressure is 7 with 45 minute ramp time to get up to that pressure. I can manually adjust the pressure in the "clinical" settings, but need to know if it should be increased to compensate for altitude.


RE: Pressure at altitude vs. pressure at lower elevations...? - Walla Walla - 10-17-2017

The machine auto adjusts for altitude.


RE: Pressure at altitude vs. pressure at lower elevations...? - KSMatthew - 10-17-2017

(10-17-2017, 12:20 PM)S.L. Ping Beauty Wrote: I am not sure what you mean.  

My doctor prescribed pressure is 7 with 45 minute ramp time to get up to that pressure.  I can manually adjust the pressure in the "clinical" settings, but need to know if it should be increased to compensate for altitude.

There is probably an automatic elevation setting.  I'm trying to find a manual for that machine, but it should tell you in there.  Some of the older CPAPs had a Low-Med-High setting for elevation from sea level up to about 10k', but I am pretty sure the newer ones all adjust themselves.

You won't have to make any pressure settings - leave it at 7, the CPAP will automatically recalibrate itself.

edit:

Interestingly enough, I did not find anything in the manual about altitude compensation. I'm sure it's automatic.

I did see this in the specs:

>>>
Operating altitude: Sea level to 8,500' (2,591 m); air pressure range 1013 hPa to 738 hPa.
<<<

You're actually outside the operating range of your CPAP. You might feel a little difference at lower elevations.


RE: Pressure at altitude vs. pressure at lower elevations...? - Sleeprider - 10-17-2017

(10-17-2017, 11:43 AM)S.L. Ping Beauty Wrote: I live at and am used to my CPAP at altitude (about 9,800 feet.)  I will be traveling soon to the mid-west to an altitude of about 700 feet.

Do I need to adjust my pressure for any compensation of the altitude difference?  I kinda' recall that when I used the CPAP there last visit that the pressure effect or sensation seemed to be diminished.  I will only be at that lower location for 3 days/ 2 nights.

Comments, opinions...?

Seriously? 45 minutes of ramp?  How is that working out for you?  That is a very long ramp period and most people do best at Off Auto or a shorter period. What are your pressure settings that you need such a long period of ramp? What is the ramp starting pressure?


RE: Pressure at altitude vs. pressure at lower elevations...? - S.L. Ping Beauty - 10-17-2017

45 ramp time was set up by my machine provider. It starts out at 4 sand goes to 7.


RE: Pressure at altitude vs. pressure at lower elevations...? - KSMatthew - 10-17-2017

7 is actually pretty low as a treatment pressure. You might think about turning the ramp off and see how it works for you. No point in 45 minutes of less than optimal if going straight to 7 doesn't bother you.

I think the ramp on/off setting can be done without going into the clinician's setup. It's more of a comfort thing than anything else.

When I go from 1000' elevation from where I live to 8500' when I visit family, I can't tell a difference in the machine pressure. As mentioned before, at 9800' you are actually above the limit of where your CPAP was designed to operate. That doesn't mean it isn't working, but it is outside the specs. Can you get your CPAP tested at that altitude? (Is your DME local?) They will plug it into a mechanism that will display the output air pressure and compare it to your 7 cm setting to verify. It's possible you are getting something other than 7 at 9800' and that might be why it feels different when you go to a lower elevation.


RE: Pressure at altitude vs. pressure at lower elevations...? - S.L. Ping Beauty - 10-17-2017

I forget what DME stands for but I know it is my device provider and they are local and are aware of the limits in my area and account for it as there are several patients to whom they serve.

The 7 and 45 were what the doctor prescribed although I have learned how to set and adjust on my own- I manually turned off the "EXP" (<--- I am doing this from memory... I think it is called exp???)

My apnea occurrences per hour are quite low. Perhaps that is why I am only at 7?? The DME mentioned that the ramp of 45 is for comfort level of getting used to the increasing pressure that would come on low and increase as I fall asleep.

All this feedback has me curious because I am more exhausted than ever since starting CPAP about a year ago. I literally wake up tired- I will usually sit on the side of the bed when I rise and will yawn several time while I sit and try to become aware of who and where I am at. I have put on about 20 pounds since about a year ago too. And I seem to be more forgetful than ever before. Oh, and one other thing...


RE: Pressure at altitude vs. pressure at lower elevations...? - Sleeprider - 10-17-2017

A 45 minute ramp is the default on all machines I'm aware of. No science is involved. Ramp is a comfort feature that new users may need to transition to therapeutic pressure, however your pressure is very low. As long as you tolerate the pressure ramp is unnecessary. For your machine, the Resmed Airsense 10 Autoset, if you need ramp, you should use auto mode, at the highest beginning pressure you find comfortable. A 4 cm starting ramp is almost stressful for many of us. You look at the Flow Rate chart on your Sleepyhead data, you may notice the respiration rate/flow is much higher when you start...oops, you're not using data. My mistake.

I think you would find turning off ramp is better.