Adventure Doc Altitude

People who travel to higher altitude will have special health concerns associated with their trip. At higher altitudes, there is 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 above sea level.

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 altitude, this is not possible due to the 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! This is a great difference to your body.

AMS is Acute Mountain Sickness. This is a condition that is 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 1-10 hours after arrival to the area of high altitude. So, that means that you could get off your airplane and begin to start feeling bad before you even get to your hotel! Most symptoms begin to appear 6-15 hours after arrival and usually disappear after 2-3 days. The symptoms disappear because your body adjusts to the altitude (acclimatizes). But, this can take a few days to weeks.

HACE stands for High Altitude Cerebral Edema. This is a much more severe form of AMS and is usually seen in high-altitude mountain climbers. This is a swelling of the brain, due to the lower oxygen available at high altitude. The symptoms of this dreaded illness include all the symptoms of AMS plus confusion and difficulty walking. If left untreated, coma and death will result. This is a medical emergency and needs treatment. Descent is the best treatment. Dexamethasone 4mg Po every 8 hours should be considered.

HAPE stands for High Altitude Pulmonary Edema. This is another more severe version of AMS, but it involves the lungs. Your lungs literally fill with fluid, making breathing difficult or impossible. This can be recognized by shortness of breath while resting, a new cough and bluish lips and fingers. This is a medical emergency and needs treatment. Nifedipine has been shown to decrease symptoms, as well as sildenafil (Viagra). Descent is still the best treatment.

There are a few ways to prevent the problems of higher altitude. First, being in your best physical shape, well before the trip, can make it easier for your body to acclimatize (adjust) 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 also works well. For each 3,500 feet gained, above 8,000 feet, make sure to stay put for an extra day. This gives your body time to acclimatize. Researchers also advise to participate in a bit of mild exercise on the day of arrival to higher altitude. For example, if your plane lands in Peru on your way to see ruins, that evening do some walking around. Some basic, easy exercise helps 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. The people who get into trouble are those who ascend very quickly. Super-fit hikers and climbers have this problem because they are fit enough to climb rapidly. People who are “car touring” have this problem because they are climbing quickly in a bus or car and can reach high altitudes in a matter of hours.

There are a few medicines that are used to treat symptoms of altitude sickness. Acetazolomide is a medicine 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 8000 and 12,000 feet above sea level, take acetazolomide? There is an argument for this and against it, here they are. 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, so make sure you are drinking enough fluids, and can cause low blood pressure.

75% of tourists to altitudes above 8,000 feet do not have problems with AMS. Acetazolamide is a sulfa-based drug and sulfa allergies are common. The medicine causes a metallic taste when eating or drinking. Exercise on the first day of arrival has generally been shown to decrease incidents of AMS.

Acetazolomide is very effective against preventing AMS. AMS effects 25% of tourists that visit mountain towns above 8,000 feet. If you look at an average vacation length of one week, spending 2-3 days sick is not a good option. The medicine is inexpensive and effective.

For the more serious climbers out there, there is a lot of argument and speculation. The literature is trying to catch up to the high altitude mountaineers, but coming up slow. There is a lot of argument about the use of various doses of acetazolamide and their efficacy.

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 and 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 there is a Gamow bag present, they can be placed inside and stabilized. The bag allows a climber to be placed in an environment of lower altitude and helps them better adjust. This is a last resort treatment and should be used while preparing for an evacuation to a lower camp.