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Another camping off the grid thread - Breathetonight - 01-09-2015

As a recent member of the CPAP club, I realize I have a lot to learn. What better place for a nubie to learn than from those here with direct experience. I'm on a Resmed airsence 10 at a 7cw setting. I have no issues with things at present; but looking ahead I know I need a lot of advice from the experienced folk here.

We travel some in the summer with our 13 ft Scamp trailer. We are often on shore power but do boondock in the mountains of Montana for several weeks at a time. Up till now our trailer battery powers a couple 12v lights and an occasional furnace fan run for weeks at a time just fine; but, I know from my readings that will not be the case with my CPAP.

I am thinking in terms of running the CPAP off my 12V trailer battery using a solar charger to recharge the battery. ( High mountains = intense sun) I will need a 12Vto 24V converter to use my present machine and perhaps a separate deep cycle battery for this setup.

However,I don't really want to take the new machine out in the boonies. I've been thinking about trying to get a smaller older 12V machine that might have a lower amp draw that I could use on these outings avoiding the power loss in the converter. I understand that I'd still need a voltage regulator or filter thingy to insure clean power. Unfortunately, I have no idea which models of the older machines would most suitable for my needs.

A small generator is a possibility; we'd just rather not lug one just yet.

Also, Resmed 10 is rated up to 8500ft ........of course our preferred campground is at 8800ft - 8900ft. What problems have you folks encountered with altitude wrt the operation of your machines?

I know there are tons of posts on this subject here but I'm not sure how to find the ones most valuable to my needs. I'd appreciate any advice any of you can offer on equipment and setups that you use or direction to the threads that best discuss this.

Dave



RE: Another camping off the grid thread - PaytonA - 01-09-2015

I have not thought this through very thoroughly but I think you might be all right with no changes above 8500 ft elevation. Especially since 8900 ft is not that much higher. The deal, as I see it, is that the pressure measurement that the machine does is to measure the amount of pressure above atmospheric pressure. At higher elevations, the atmospheric pressure is lower and in order to maintain the same absolute pressure, one would have to increase the machine pressure a little.

I remember seeing something from Resmed that I can not find right now and if I remember correctly they said to add .1 or .2cm/H2O of pressure for each 1000 ft. above 8500. Hopefully someone will come along and give us the definitive info.

Best Regards,

PaytonA


RE: Another camping off the grid thread - trish6hundred - 01-09-2015

Hi Breathetonight,
WELCOME! to the forum.!
Hang in there for more suggestions and much success to you with your CPAP therapy.


RE: Another camping off the grid thread - Evpraxia - 01-10-2015

Good question about altitude! The clinician's manual for the ResMed S9 AutoSet does not say anything about adjusting if it is being used above 8,500 feet altitude. I may face the same issue when we start traveling in a motorhome.


RE: Another camping off the grid thread - vsheline - 01-10-2015

(01-09-2015, 05:14 PM)PaytonA Wrote: I remember seeing something from Resmed that I can not find right now and if I remember correctly they said to add .1 or .2cm/H2O of pressure for each 1000 ft. above 8500. Hopefully someone will come along and give us the definitive info.

Hi Breathetonight,

Yes, I think the automatic correction for elevation is fairly small and is somewhere in the range PayonA mentioned.

I think it is the change in the density of the air which requires the slight adjustment in the CPAP Pressure Setting, to maintain the same relative pressure as when operating at a lower elevation.

I think the ideal change in the CPAP Pressure setting needed for 8500 ft elevation versus 8900 ft elevation would be fairly small, so I think the automatic adjustment your machine makes for changes in elevation up to 8500 ft would still be adequate at 8900 ft, and I would leave the settings alone when changing elevations.

HOWEVER: Central Apnea is usually made far worse at higher elevations, so I suggest keeping an eye on your Central Apnea Index (CAI, the average number of central apneas per hour of therapy) and also the percentage of the night spent in Periodic Breathing, which I think is an early symptom of our central nervous system not regulating our CO2 levels optimally.

Someone with virtually no central apneas at sea level may have many central apneas per hour at a higher elevation. (I suppose this may have contributed to the deaths of many who have attempted to climb Mount Everest, elevation 29,029 ft, but who "got sick" and died at extremely high altitude, despite having brought supplemental O2 to breathe.)

You would not be able to do that (keep an eye on your CAI) unless you use a fairly new machine (like your present machine), which is fully data-capable and distinguishes central apnea versus obstructive apnea, both in its reporting and in its treatment algorithms.

A basic "travel" CPAP machine may not be adequate.

Take care,
--- Vaughn

By the way, The "absolute" atmospheric pressure difference between sea level and 8500 ft elevation is very huge, compared to the very slight CPAP pressure adjustment needed to maintain the same treatment effectiveness as a lower elevation would need.

The absolute atmospheric pressure at sea level is around 14.7 pounds per square inch (equivalent to 1034 cmH2O), versus around 10.5 psi (equivalent to 738 cmH2O) at 9,000 ft elevation, so in absolute terms the absolute atmospheric pressure difference between sea level and 9,000 ft elevation would be around 296 cmH2O.

Absolute atmospheric pressure data:
http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html

Pressure Conversion calculator:
http://www-users.med.cornell.edu/~spon/picu/calc/pressure.htm




RE: Another camping off the grid thread - Breathetonight - 01-10-2015

Thanks for the info and advice. I don't know much about my CAI; but, now I know to ask. My sleep study was 29, low by the standards I've seen reported here but I did drop to 78 on the oxygen sat. once during my test. We have been camping in that Campground over 20 years It will be interesting to see if I can sleep alot better on the machine at altitude. I already know I do at low elevation here in the flat lands and I've been on it less than a month.


RE: Another camping off the grid thread - vsheline - 01-10-2015

(01-10-2015, 05:11 PM)Breathetonight Wrote: I don't know much about my CAI; but, now I know to ask. My sleep study was 29, low by the standards I've seen reported here but I did drop to 78 on the oxygen sat. once during my test. We have been camping in that Campground over 20 years It will be interesting to see if I can sleep alot better on the machine at altitude. I already know I do at low elevation here in the flat lands and I've been on it less than a month.

Hi Breathetonight,

I suggest using the free SleepyHead data display software to look over your sleep data as recorded in your machine's SD card.

SH will show the CAI and percentage of Periodic Breathing, and lots more, such as when during the night are the events happening, which would give us clues on how the machine's settings may be optimized to improve therapy effectiveness. (Events may be spread out in time or clustered together, mostly when pressure is low, or mostly when pressure is high, or mostly during periods of high Leak, etc.)

Link to SH discussion thread:
http://www.apneaboard.com/forums/Thread-SleepyHead-Software-Beginner-s-Guide-Questions-Answers-Discussion?pid=72963#pid72963




RE: Another camping off the grid thread - Breathetonight - 01-12-2015


Hi Breathetonight,

I suggest using the free SleepyHead data display software to look over your sleep data as recorded in your machine's SD card.




I checked on the sleepyhead soft ware you menrtioned and it appears that for the Resmed 10 it is still in the development / beta stage. is anyone using it yet. art there any bugs?


RE: Another camping off the grid thread - PaytonA - 01-12-2015

In actual fact, it is my understanding that is completely in the beta phase and that is why the version number (or release number) is what it is. It is still a very useful piece of software.


RE: Another camping off the grid thread - vsheline - 01-12-2015

(01-12-2015, 06:40 PM)Breathetonight Wrote: I checked on the sleepyhead soft ware you menrtioned and it appears that for the Resmed 10 it is still in the development / beta stage. is anyone using it yet. art there any bugs?

Hi Breathetonight,

With AirSense 10 and AirCurve 10 devices, I am not sure what bugs may be in SH version v0.9.8-1-testing (2014-10-03, 27Mb).

Because you have a ResMed machine, your other choice is ResScan 5.1 or 5.2, which is somewhat less user friendly, but I think works great

Take care,
--- Vaughn