Mountain Living

PREVENTION
2-127. HAPE is prevented by good nutrition, hydration, and gradual ascent to altitude (no more than
1,000 to 2,000 feet per day to an area of sleep). A rest day, with no gain in altitude or heavy physical
exertion, is planned for every 3,000 feet of altitude gained. If a Soldier develops symptoms despite
precautions, immediate descent is mandatory where he receives prompt treatment, rest, warmth, and
oxygen. He is quickly evacuated to lower altitudes as a litter patient. A descent of 300 meters may help;
manual descent is not delayed to await air evacuation. If untreated, HAPE may become irreversible and
cause death. Cases that are recognized early and treated promptly may expect to recover with no
aftereffects. Soldiers who have had previous attacks of HAPE are prone to second attacks.

TREATMENT









Immediate descent (2,000 to 3,000 feet minimum) if possible; if not, then treatment in a
monoplace hyperbaric chamber.
Rest (litter evacuation).
Supplemental oxygen if available.
Morphine for the systemic vasodilatation and reduction of preload. This should be carefully
considered due to the respiratory depressive properties of the drug.
Furosemide (Lasix), which is a diuretic, given orally can also be effective.
DO NOT use mannitol. It crystalizes at low temperatures and, since almost all high-altitude
environments are cold, mannitol could be fatal.
Nifidipine (Procardia), which inhibits calcium ion flux across cardiac and smooth muscle cells,
decreasing contractility and oxygen demand. It may also dilate coronary arteries and arterioles.
Diphenhydramine (Benadryl) can help alleviate the histamine response that increases mucosal
secretions. It also causes drowsiness.

HIGH-ALTITUDE CEREBRAL EDEMA
2-128. HACE is the accumulation of fluid in the brain, which results in swelling and a depression of brain
function that may result in death. It is caused by a rapid ascent to altitude without progressive
acclimatization. Prevention of HACE is the same as for HAPE. HAPE and HACE may occur in
experienced, well-acclimated mountaineers without warning or obvious predisposing conditions. Both
types of edema can be fatal. When the first symptoms occur, immediate descent is mandatory.

CONTRIBUTING FACTORS



Rapid ascent to heights over 8,000 feet.
Aggravation by overexertion.

SYMPTOMS
2-129. Symptoms include mild personality changes, paralysis, stupor, convulsions, coma, inability to
concentrate, headaches, vomiting, decrease in urination, and lack of coordination. The main symptom of
HACE is a severe headache. A headache combined with any other physical or psychological disturbances
should be assumed to be manifestations of HACE. Headaches may be accompanied by a loss of
coordination, confusion, hallucinations, and unconsciousness. These may be combined with symptoms of
HAPE. The victim is often mistakenly left alone since others may think he is only irritable or
temperamental; no one should ever be ignored. The symptoms may rapidly progress to death. Prompt
descent to a lower altitude is vital.
2-130. Preventive measures include good eating habits, maintaining hydration, and using a gradual ascent
to altitude. Rest, warmth, and oxygen at lower elevations enhance recovery. Left untreated, HACE can
cause death.

26 July 2012

TC 3-97.61

2-25