Get Outdoors - Emergencies: High Altitude Disorders

Acute mountain sickness can begin as a nuisance, but its presence indicates that the sufferer is on the edge of becoming much more severely ill. The body either needs to adjust or to attain a lower altitude and greater oxygen supply as soon as possible.What is high altitude?

Altitudes of 8,000 to 14,000 feet (2438 to 4267 meters) are attained regularly by skiers, hikers, and climbers in the continental United States. Outside the US, mountain climbers may reach altitudes of up to 29,035 ft (8848 m) (Mount Everest).
Most difficulties at high altitude are a direct result of the lowered concentration of oxygen in the atmosphere. At 18,000 feet (5487 m) there is half the oxygen that is available at sea level. A person transported suddenly to this altitude without time to acclimatize or without the provision of supplemental oxygen would probably lose consciousness.

Signs and symptoms of high altitude illness.

High Altitude Pulmonary Edema (HAPE) - excess fluid in the lungs. Symptoms begin 1 to 3 days after arrival at high altitude.

Symptoms: Shortness of breath, cough, weakness, easy fatigue (especially when walking uphill), and difficulty sleeping.
As greater amounts of fluid accumulate in the lungs, the victim develops drowsiness, severe shortness of breath, and rapid heart rate; the initial dry cough produces white phlegm and then pink froth.
The victim exhibits confusion and bluish discoloration of the skin, particularly noticeable in the nailbeds and lips. Symptoms worsen at night.
Rapidly, the victim becomes extremely agitated, disoriented, sweaty, and in obvious extreme respiratory distress. The victim may show a fever of up to 38.5^o C (101.3^o F).
Confusion, collapse, and coma follow.

Acute Mountain Sickness (AMS) - perhaps indicative of early brain swelling. AMS is the most common altitude-related disorder.

A person who is partially acclimatized may be stricken if he ascends rapidly to a higher altitude, overexerts, or uses sleep medication (which can be a respiratory depressant).
Symptoms (may be quite subtle in the beginning): headache, insomnia, fatigue, loss of appetite, nausea, dizziness, drowsiness, weakness, and apathy. Some persons have described the suffering associated with AMS to be similar to a hangover.
One hallmark of AMS, known as "periodic breathing," is an alteration of the normal sleeping pattern. Sleep is fitful, with periods of wakefulness or disturbing dreams. The pattern of breathing becomes irregular, such that the sleeper has periods of rapid breathing (very deep breaths) alternated with periods of no breathing.
Children are prone to nausea and vomiting as a manifestation of AMS.

High Altitude Cerebral edema (HACE) - indicative of brain swelling.

Symptoms: Difficulty walking (inability to walk a straight line, staggering, or frank inability to walk), headache (often throbbing), confusion, difficulty in speaking, drowsiness, vomiting, and in severe cases, blindness, unconsciousness, paralysis, and/or coma.
Other symptoms may include hallucinations, paralysis of an arm and/or leg, and seizures.
Victims are often gray or pale in appearance.
Imbalance or the inability to walk "heel to toe" in a straight line is a very worrisome sign and should prompt immediate action to treat the victim.

How to treat high altitude disorders.

Pulmonary Edema:

At the earliest sign of pulmonary edema, evacuate (carried if necessary, preferably in the sitting position) to a lower altitude at which there werepreviously no symptoms. Maximal rest is advised.

Keep the victim warm.
In no case should a victim be left to descend by himself. Always have a healthy person accompany the victim.

Administer oxygen, if available, at a flow rate of 5 to 10 liters per minute by face mask. Improvement is rarely noted until oxygen is administered or descent of at least 1,000 to 2,000 feet (304 to 608 m) is accomplished.
The cylinder-shaped Gamow container ('bag') is a small, portable hyperbaric chamber which can be pressurized with a foot pump to 2 pounds per square inch, which simulates a descent of approximately 1600 m (5248 feet); the exact equivalent depends upon the altitude at which the bag is deployed.
Nifedipine is a drug that is being used successfully by physicians to treat HAPE. It lowers obstructive pressure in the pulmonary arterial circulation (that carries de-oxygenated blood from the heart through the lungs).

Acute Mountain Sickness:

Administer rest, adequate fluid intake to avoid dehydration, and mild pain medicine for the headache.
Lead the victim to a lower altitude, preferably at least 1640 feet (500 m) below that where symptoms began.

Many victims of AMS will adjust to the current altitude in 3 to 4 days, and therefore may remain at a stable altitude if symptoms are mild.
In no case should a person attempt to climb to (particularly, to sleep at) a higher altitude until the symptoms of AMS have completely subsided.
With mild AMS, acetazolamide (Diamox) can be administered.

From an oxygen cylinder, low flow (0.5 to 1 liter per minute) oxygen by nasal cannula or face mask is particularly effective if used for sleep. This alone may be adequate treatment to halt the progression of mild AMS and allow a victim to acclimatize without descent to a lower altitude. Do not leave the victim alone until all symptoms of AMS have resolved.

Cerebral Edema:

Descend immediately to an altitude below where there were previously no symptoms.
Administer oxygen at a flow rate of 5 to 10 liters per minute by face mask or nasal cannula.
Administer the steroid drug dexamethasone (Decadron).
A person who suffers from HACE or HAPE may deteriorate rapidly, and most such victims will need to be transported down the mountain.

If the victim becomes severely ill, he should be brought (carried if necessary, preferably in the sitting position) to a lower altitude (below 5,000 feet [1524 m]).

A Gamow bag may be used for treatment.