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ResMed S9 & 14000 ft. altitude
#1
Question 
ResMed S9 & 14000 ft. altitude
I have had my machine for 9 months and working great. We are getting ready to go on vacation for three weeks in China, 4 days I will be using the CPAP at 14,000ft. altitude (Tibet). I cannot get any input on what I should adjust the machine to. ResMed tech support only says machine has only been tested to 8500 ft. Doctor's staff says continue to use machine (duh?). I read online that increases the pressure range will solve the problem, but I don't know how much to adjust. Any help will be appreciated. Also, I will be taking Diamox to prevent altitude sickness--, but dosage changes depending on who you talk to. No one I have talked with has experience with this altitude and CPAP machine.

I have the information on how to change pressures, but have never messed with the set up of the machine.
acc
#2
RE: ResMed S9 & 14000 ft. altitude
(03-26-2012, 08:13 PM)acc Wrote: I have had my machine for 9 months and working great. We are getting ready to go on vacation for three weeks in China, 4 days I will be using the CPAP at 14,000ft. altitude (Tibet). I cannot get any input on what I should adjust the machine to. ResMed tech support only says machine has only been tested to 8500 ft. Doctor's staff says continue to use machine (duh?). I read online that increases the pressure range will solve the problem, but I don't know how much to adjust. Any help will be appreciated. Also, I will be taking Diamox to prevent altitude sickness--, but dosage changes depending on who you talk to. No one I have talked with has experience with this altitude and CPAP machine.

I have the information on how to change pressures, but have never messed with the set up of the machine.
acc

hello, braver than me..... welcome to the forum. i have no clue other than i have enough trouble at sea level and would never try something like that. good luck to you.
First Diagnosed July 1990

MSgt (E-7) USAF (Medic)
Retired 1968-1990
#3
RE: ResMed S9 & 14000 ft. altitude
Which S9 do you have? If you have an autoset, easiest solution would be to increase the upper number 2-3 points. Then, if possible, read your data every other day or so to see what ranges you actually used.

One place I just read information for said he called National Jewish Hospital Lung Line for information. After doing some math and research for his pressure of 6, he was told that at 13,000ft (Peru) to raise it to 7.5.

So it doesn't sound like that big of an increase is needed.
#4
RE: ResMed S9 & 14000 ft. altitude
acc must have the S9 AutoSet as in profile CPAP Pressure: 12-16
As Paula said check your data on the LCD screen and if the 95% percentile pressure shows at the maximum set pressure than you know the S9 want to go higher. Download ResScan software so you see more details
http://www.apneaboard.com/forums/Thread-...rsion-3-16
#5
RE: ResMed S9 & 14000 ft. altitude
Yes, it is the AutoSet
#6
RE: ResMed S9 & 14000 ft. altitude
Hi acc,

The S9 series boasts of an "Automatic altitude adjustment"

Is that what ResMed tech support is referring to when they say "the machine has only been tested to 8500 ft"?
"Goodnight Chesty wherever you are!"
#7
RE: ResMed S9 & 14000 ft. altitude
Quote:Is that what ResMed tech support is referring to when they say "the machine has only been tested to 8500 ft"?

I would assume so.

Quote:Yes, it is the AutoSet

Way cool. Then just bump the upper pressure 3 points or so and that's that. Still, take a look at your data (you can read some of it on the screen, right?) each morning before noon. But then, there's the time difference thing....
#8
RE: ResMed S9 & 14000 ft. altitude
(03-26-2012, 08:13 PM)acc Wrote: I have had my machine for 9 months and working great. We are getting ready to go on vacation for three weeks in China, 4 days I will be using the CPAP at 14,000ft. altitude (Tibet). I cannot get any input on what I should adjust the machine to. ResMed tech support only says machine has only been tested to 8500 ft. Doctor's staff says continue to use machine (duh?). I read online that increases the pressure range will solve the problem, but I don't know how much to adjust. Any help will be appreciated. Also, I will be taking Diamox to prevent altitude sickness--, but dosage changes depending on who you talk to. No one I have talked with has experience with this altitude and CPAP machine.

I have the information on how to change pressures, but have never messed with the set up of the machine.
acc

I recommend that you take personal responsibility for your own health, and not depend too heavily on secondhand opinions.

Your Autoset might autoadjust just fine at 14K feet. You wrote that it had simply not been tested, and that it worked fine from zero to 8.5K feet. Why would it break down, necessarily from 8.5K to 14K?

I am skeptical that the max presssure needs to be increased. I don't see the reason, and no one here has provided a rationale for why the pressure should be increased. Just some place said so, without explaining why.

Contrary to this opinion of some hospital, I can imagine why high altitude might reduce obstructive apnea, and thus one could reduce their max pressure. At sea level, atmospheric pressure presses all over our body, including our neck. Without a PAP device, the pressure is also applied to the inside of our airway, hence no difference inside or out. Put on a PAP however, and the external pressure presses in, and the internal pressure presses out, and the internal pressure is the sum of atmospheric pressure plus your PAP pressure; thus your PAP inflates your airway due to this differential pressure from your PAP machine.

Increasing the altitude will not affect the differential pressure, but it will reduce the absolute pressure on the outside of your neck, so it is going to expand more. Exactly as a weather ballon expands as it ascends because it is moving into a lower pressure zone. So the need for PAP might decrease as altitude increases.

Another thing to consider is leakage. Increasing pressure at sea level causes mask leakage to increase, and this is under the fairly high atmospheric pressure at sea level that presses on the outside seal of our masks, thereby helping the seal contain the internal pressure from the PAP. Removing this helpful external pressure from most of the atmosphere by going to high altitude is surely going to increase leakage, because now the mask seal has to do all of the work because the atmosphere is not helping so much pressing on the seal from the outside.

So I think your mask is going to leak like a sieve if you leave the pressures unchanged and go to 14K. And if you increase your max pressure, then I think it will almost blow the mask off of your face. I exaggerate, of course, to make the point, but I do strongly predict your mask will leak like crazy if you both increase the internal pressure and decrease the external pressure by going to high altitude. I think this is just common sense.

I strongly suggests that you experiment extensively while fully awake during the day time with your equipment, starting with your Mask Fit test, which you access by holding down the SET button for a few seconds. This simple test will tell you immediately if your mask leaks more because you have gone to high altitude.

Also, ask some pilots about pressure changes, and how altitude will affect things such as mask leakages. Pilots have very direct common sense explanations of these things.

I strongly recommend that you get the Sleepyhead software from the forum archive here, and install it asap to learn how to read the pressures, leakages, and the various components of AHI particularly the Obstructive apnea and hypopneas. This software will give you the data it takes to see what is happening with changes in atmospheric pressure.

Let me know if this helps.


My age is none of my mind's business. --- Netskier
#9
RE: ResMed S9 & 14000 ft. altitude
I didn't provide a link because I wasn't sure if the site was commercial or not. I looked at the site better today and it is the forum from the American Sleep Apnea Association. A simple Google search on "CPAP at high altitude" gave me the link. I don't post information that is incorrect or if I am uncomfortable with their statements.

(I had the link to the thread here but this forum software changed it to be ***. Do a Google search and it should be fairly high up the result list)
Quote:I posted a question several months ago about using a CPAP at high altitudes, and I finally have some information to share. A little background: I use a CPAP and live in Denver, CO (the mile high city) and the manual for my CPAP says that on the highest altitude setting the machine is good for 7500 feet. I'm traveling to Peru and Bolivia in April and will be at altitudes ranging from 8500 feet to 13000 feet.

I called the Lung Line at National Jewish Hospital (http://www.nationaljewish.org). National Jewish is the #1 respiratory hospital in the US, and I'm fortunate that it's located here in Denver. Lung Line is at 800-222-LUNG, a free service where registered nurses can answer questions about respiratory issues from 8 am to 4:30 pm Mountain Time (2 hours earlier than Eastern time). I was referred to another number and after a couple of weeks, someone returned my call.

An adjustment in pressure is called for when using a CPAP high altitudes, and I'll be going in to see someone to learn about how to make those adjustments in the near future. Specifically, an increase in pressure is required. The woman I spoke with was able to calculate what my pressure would need to be at three specific altitudes where I'll be spending nights. The adjustments needed aren't huge. My normal pressure is 6 (cm h2o), and the highest the pressure will need to be - for 13,000 feet - is 7.5.

I hope this information is helpful...

Further down the posts are some links that should be valid enough.

http://chestjournal.chestpubs.org/conten...7.abstract - the short version
http://chestjournal.chestpubs.org/conten...7.full.pdf - the full version

Of particular interest to those of us who do not understand journal articles is page 5 with the Discussion and Conclusion.
#10
RE: ResMed S9 & 14000 ft. altitude
In my opinion, I wouldn't change anything. The machines are self altitude adjusting. Even though it has only been factory tested up to 8500ft, we don;t know high much higher it would self adjust. Even if it stopped adjusting automaticly at 8500, the difference of 5500 more feet, I doubt would be noticible to you.
I agree with a lot of what NETSKIER posted. Makes good common sense to me.
Yesterday is history; Tomorrow is a mystery; Today is a gift; Thats why its called "The Present".  


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