Automatic Altitude Adjustment

[forumadmin]

Automatic altitude adjustment allows the patient to travel to different altitudes without having the pressure setting adjusted. Because atmospheric pressure changes with altitude, most machines need adjustment in order to provide the correct pressure at a different altitude.

[Sleeprider]

High altitude can present many problems for certain people that a CPAP machine cannot compensate for. If you experience headaches, sleeplessness, confusion, dizzyness, breathlessness and similar symptoms at altitudes above 7000 feed, you may be suffering from Acute Mountain Sickness. Be aware that sedatives and sleep medications can make this problem worse, especially for people that suffer from sleep apnea, because those drugs cause Cheyne-Stokes respiration at high altitude. The most recognized treatment for high altitude is Diamox (acetazolamide), which can be taken at the direction of your doctor before you arrive at high altitude. Please read this article for more information http://www.epicski.com/wiki/altitude-ad ... n-sickness.

Acute mountain sickness is a constellation of disorders caused by acute exposure to low pressure and low oxygen levels. It appears to be caused by swelling of the brain- a mild form of HACE (see below). Diagnosis (by the Lake Louise Criteria, which were formulated at the Hypoxia Symposium there a number of years ago) requires the presence of headache and one or more of the following:

* GI symptoms (nausea, loss of appetite)
* Fatigue or weakness
* dizziness or lightheadedness
* difficulty sleeping

A large study in Colorado found that 25% of people from low altitude ascending rapidly and sleeping at 8200ft (2500m) will develop AMS. These people may feel lousy for short while, but most of them will get better in a few days and not get sicker. About 1%, however, will develop more severe illness- high altitude cerebral edema (HACE, or brain swelling) or high altitude pulmonary edema (HAPE, or high blood pressure and fluid in the lungs). Both of these are life-threatening emergencies, and require immediate medical attention and descent if at all possible. For most people who suffer AMS (but not HACE), significant relief from symptoms is possible with treatment using Diamox and ensuring good hydration, limiting exertion and avoiding alcohol.

[billbolton]

most machines need adjustment in order to provide the correct pressure at a different altitude.

The range of altitude adjustment, whether manual or automatic, on most machines is limited to a maximum of about 2400 metres, which is the "cabin pressure" equivalent for most commercial aircraft.

Cheers,

Bill

[timbalionguy]

The adjustment range varies with the machine. Specs for this should be in the manual, or can be found in places like https://www.cpap.com. The newer the machine, generally the bigger the altitude range it will adapt to. The more complex the machine, generally the less it will automatically adapt.

I am occasionally above 8,000 feet in the course of my job, and sometimes for fun. I haven't experienced any significant symptoms until I am above about 10,000 feet.

[sierragail]

I've been at 8000 ft for about 4 years. My hematocrit and hemoglobin counts adjusted, but it didn't matter much bc my lungs and heart could not adjust. I had the persistent headache and all the other symptoms that Sleeprider listed in his post. Lack of O2 has been slowly killing me. When you put sleep apnea on top of that, plus high blood presssure, tachycardia, diabetes, and Sjogren's Syndrome, I felt like I had one foot in the grave all the time and I had no idea why. Honestly, no one was able to tell me why I felt like the walking dead. I had to hold onto the walls of buildings in town so I wouldn't fall down. I walked like a drunkard and my memory was shot.

It got to where I dreaded going to sleep because I knew I would wake up feeling more tired than when I went to bed. I also would put off bedtime in hopes of wearing myself out more, thinking it would help me sleep more soundly. Or I'd exhaust myself with physical labor. But nothing worked and I just felt worse and worse. Everything I read online said that altitude sickness does not occur at 8000 ft, and so I ruled it out. I was reading the wrong websites obviously. And the point to remember is that we are not all alike and our bodies do not react in the same way. The way we adjust (or not adjust) to altitude is hard-wired into our DNA.

Looking back in time, like we all probably have since being diagnosed, I realize I've had sleep apnea for at least 15 years, most of those years being at sea level.

With Diamox (treatment for acute mountain sickness) I've been able to throw out my tachycardia meds~~not one episode of rapid heart beats since I started taking Diamox, not one. The weird thing is that the tachy started years ago when I was living at only 3500 ft in NC.

My AHIs are now between 3 and 0.7, and no more periodic breathing either. My machine adjusts for this altitude, but my body doesn't.

I feel like I've returned to the land of the living.