Getting High, Safely
People who travel to higher altitudes will have special health concerns associated with their trip – not as much oxygen as at sea level. This is due to barometric pressure. Most people consider high altitude to be 8,000 feet above sea level. Moderate altitude is found between 8,000 and 12,000 feet above sea level. Extreme high altitude is anything greater than 19,000 feet.
This decrease in oxygen causes unique problems in your body. First, you are used to breathing and saturating (filling) your blood full of oxygen. At higher altitudes, this is not possible because of lower pressure. Instead of having an oxygen saturation (measure of how much oxygen is in your blood) of 100%, you could be as low as 90%, or even lower – a great difference for your body.
AMS is Acute Mountain Sickness; a condition brought on by the lower amounts of oxygen found at higher altitude. Headache, tiredness, dizziness, nausea and insomnia are common symptoms. AMS can begin as quickly as one to ten hours after arrival in the area of high altitude. That means you could get off your airplane and begin to start feeling badly before you even reach your accommodation!
Most symptoms appear six to fifteen hours after arrival. They usually disappear after two to three days. Signs leave because your body adjusts to the altitude (acclimatizes). It can take a few days to weeks, though.
HACE stands for High Altitude Cerebral Edema; a much more severe form of AMS, and usually seen in high-altitude mountain climbers. It's a swelling of the brain, due to the lower oxygen available at high altitude. The symptoms of this dreaded illness include all those associated with AMS, plus confusion and difficulty walking. If left untreated, coma and death will result, considered a medical emergency, requiring immediate treatment. Administration of dexamethasone 4mg Po every eight hours should be considered.
HAPE is High Altitude Pulmonary Edema; another more severe version of AMS, but it involves the lungs. The lungs literally fill with fluid, making breathing difficult or impossible. It is recognized by shortness of breath while resting, a new cough and bluish lips and fingers. It is also a medical emergency. Nifedipine has been shown to decrease symptoms, as well as sildenafil, (Viagra).
There are a few ways to prevent the problems of higher altitude. Be in your best physical shape, well before the trip. This can make it easier for your body to acclimatize to the altitude. A slow ascent up the mountain also gives your body time to adjust. A slow ascent is considered rising no more than 1,800 feet per day, when traveling above 8,000 feet. Staying at a certain level for an extra day works well too. For each 3,500 feet gained above 8,000 feet, make sure to stay put for an extra day.
Researchers advise participating in mild exercise on the day of arrival to higher altitude. For example, if your plane lands in Peru on your way to see ruins, do some walking around that evening. Basic, easy exercises help your body adjust quicker to the altitude. Adequate hydration has also been shown to improve acclimatization. Lastly, more important than physical condition, is rate of ascent. People who get into trouble are those who ascend too fast. Super-fit hikers and climbers have this problem because they are in good shape, enough to climb rapidly. People who “car tour” experience difficulty too because they climb quickly in a bus or car, reaching high altitudes in a matter of hours.
A few medicines can treat symptoms of altitude sickness. Acetazolomide is one that is used by some mountain climbers to combat AMS, HACE and HAPE. Now, for the real question. Should a tourist traveling to a mountain town, between 8,000 and 12,000 feet above sea level, take acetazolomide? There are arguments for and against. Some believe the side effects are less with the 125mg dose taken twice per day versus the 250 mg daily dose. Diamox (acetazolamide) is a diuretic. Make sure you drink enough fluids since Daimox can cause low blood pressure.
Acetazolomide is most effective against preventing AMS. AMS affects 25% of tourists who visit mountain towns above 8,000 feet. If you look at an average vacation length of one week, spending two to three days sick is not a good option. The medicine is inexpensive and effective. Seventy five percent of tourists climb above 8,000 feet, and do not have problems with AMS. Acetazolamide is a sulfa-based drug; sulfa allergies are common. The medicine has a metallic taste. Exercise on the first day of arrival has generally been shown to decrease incidents of AMS. For the more serious climbers, there is a lot of argument and speculation. The literature is trying to catch up to the high altitude mountaineers, but it comes slowly.
Much discussion is going on about the use of various doses of acetazolamide. Nifedipine is a medication that is giving some promising data towards treating HAPE. Sildenafil (Viagra) is another medication of the vaso-dilator variety that is being looked at for HAPE, even HACE now. Lastly, there is the GAMOW bag. This is a mini-hyperbaric chamber that is portable. The idea is that if someone suffers from AMS, HACE, HAPE, etc. and a Gamow bag is available, the person can be placed inside and stabilized. The bag allows a climber to be in an environment of lower altitude, helps adjustment – a last resort treatment and used to prepare for an evacuation to a lower camp.
Read more about health and adventure at Adventure Doc.