Higher pressure setting for higher altitude?

Hi,

I've been on CPAP for a year and half at pressure setting 12. It's been very successful, with AHI below 2. I recently went to a town that is 2,500 feet higher in elevation, and got 2 lousy night's sleep. I checked the info on the card (with Sleepyhead software) and it showed a startling 25 AHI. There was no excessive leakage. Should I set the pressure higher than 12 when I go to this town?

DanH wrote:Hi,

I've been on CPAP for a year and half at pressure setting 12. It's been very successful, with AHI below 2. I recently went to a town that is 2,500 feet higher in elevation, and got 2 lousy night's sleep. I checked the info on the card (with Sleepyhead software) and it showed a startling 25 AHI. There was no excessive leakage. Should I set the pressure higher than 12 when I go to this town?

Higher than what?
The machine you show in your profile has automatic altitude adjustment.
All data-capable machines have automatic altitude adjustment.
Check you manuals and it will tell you what altitudes it will adapt to. Usually it's up to about 8000'.


Den

.

There is more to sleep then cpap.
Did you have any alcohol?
Are you more allergic in this place?
Did they have bed bugs or dust mites?
Did you eat strange foods?
Did you share your bed with strange people?
Was the mattress much harder or softer?

Hi,

I checked the owners manual and it says that it will adjust to an altitude of 7,500 feet. Well I was at 7,000 feet, and I have a hunch that the pressure was just not reaching up to 12 cm H2O at that altitude. The back of my throat was sore, from snoring I believe, the soreness went away later in the day. I never have that soreness here at home, at 4,500 feet elevation.

Is there any harm in raising the pressure to say 14 or 15 the next time that I go to this town?

I'd try it at 13-14, but have you considered that you might need to bump up your humidity - as in e.g. Colorado is quite dry because of the distance from ambient ground water/sea level?

DanH wrote:Hi,

I checked the owners manual and it says that it will adjust to an altitude of 7,500 feet. Well I was at 7,000 feet, and I have a hunch that the pressure was just not reaching up to 12 cm H2O at that altitude. The back of my throat was sore, from snoring I believe, the soreness went away later in the day. I never have that soreness here at home, at 4,500 feet elevation.

Is there any harm in raising the pressure to say 14 or 15 the next time that I go to this town?

I'm with Julie on this. Sounds like you were mouth-breathing and your humidity needed a little adjustment. With the low relative humidity, your nasal passages can dry out. Also, going up to that altitude from where you normally live can make you sleep like a rock in the less-oxygenated air (and result in more events). If you were to move to a higher altitude like that, it would probably take you about a month or more to get acclimated to the "thinner" air.
I think you'd be fine bumping up your pressure a couple of centimeters.


Den

.

If you don't have a problem with auto changes in pressure, you can increase your range and let it take care of you. I live in Seattle, barely above sea level. I have traveled to Colorado a few times. I haven't had to change anything, and my sleep stays good. The pressure does go a little higher longer than normal, but I didn't have any problems with it.

I'd stay out of that town. Jim

Cross it off my bucket list!

At higher altitudes everyone becomes more sensitive to central apneas. Although the altitude was not that high, this could be the cause of your rise in AHI if you are susceptible. It probably has nothing to do with your machine pressure which should compensate. The reasoning behind it is the small reduction O2 levels causes mild hyperventilation pushing CO2 levels down close to the apnea threshold causing central events. I do not know if this is the case with you here but it is certainly a possibility. Do you have a machine capable of distinguishing central or clear airway events?

Further to previous post. Just read more carefully and see you were at 7000ft. This is certainly high enough to give excess central events in a good proportion of people.
Ian

Sorry me again. Just Googled article from Colarado school of Medicine in Journal of Clinical Sleep Medicine. Apparently at that altitude the average AHI on successful treatment is over 19! Reference if interested J Clin Sleep Med 2011;7(6):610-615 or just Google Altitude+ Central+ Apnea. Thanks.

Why do you think you should raise the pressure? Maybe it needs to be lowered. I started cpap with a pressure of 8 and was getting ahi of a little less than 5. They lowered it to 6 and now I seldom have a reading above 1. But as others have said. There may be factors other ahan altitude involved.

igdoc wrote:Just Googled article from Colarado school of Medicine in Journal of Clinical Sleep Medicine. Apparently at that altitude the average AHI on successful treatment is over 19! Reference if interested J Clin Sleep Med 2011;7(6):610-615 or just Google Altitude+ Central+ Apnea. Thanks.

I did the seach and found this article.
"The Effects of Altitude Associated Central Apnea on the Diagnosis and Treatment of Obstructive Sleep Apnea"

http://www.ncbi.nlm.nih.gov/pmc/article ... .6.610.pdf

Hi,

Thank you for all of the responses. I needed to update my equipment list, as I now use a passover humidifier and as a result I never have dried out sinuses.

My CPAP machine lists:

Clear airway apnea
Obstructive apnea
periodic breathing
pressure pulse
respiratory effect related arousal
vibratory snore

I don't know if these will indicate central apnea events.

I read the file:

http://www.ncbi.nlm.nih.gov/pmc/article ... .6.610.pdf

and it indicates that supplemental oxygen is effective in reducing the AHI at high altitude.

So I have some suggestions to try.

Thank you all again.

Most central events should be classified on your machine as clear airway events or periodic breathing. Supplemental oxygen is certainly the cure for altitude (low oxygen) induced hyperventilation central apneas.

In theory reducing the exhalation relief (EPR/CFLEX) on your CPAP might work but you may well find that this makes you too breathless for comfort at this altitude. We have evidence this works for some people with high centrals near sea level but have no information about this at altitude. You might be the first guinea pig! Anyway good luck.