6-38
Plan:
Treatment
Primary: Stop ascent! Descend to lower altitude until symptoms resolve. Once symptoms resolve,
continue ascent slowly (See Preventive below). Treat with acetazolamide 125-150 mg po tid/qid. Aspirin,
acetaminophen, ibuprofen, indomethacin, or naproxen in usual doses can be used to treat headache pain.
Nausea and vomiting can be treated with prochlorperazine 10 mg po every six hours or 25 mg by rectal
suppository every 12 hours.
Alternative: Stay at higher altitude during day, but sleep at lower altitude (See Preventive below). Dexa-
methasone 4 mg po 4 qid (Save for people allergic to acetazolamide or other sulfa drugs).
Primitive: Descent is the best treatment for all altitude illnesses (e.g., AMS, HACE, HAPE). Native people of
the Andes Mountains in South America chew coca leaves or drink coca tea to prevent and treat AMS.
- These medications can be stopped 1-2 days after symptoms resolve. AMS symptoms may recur after
stopping dexamethasone, but do not recur after stopping acetazolamide.
Patient Education
General: AMS is caused by ascending too rapidly, before body has chance to adjust to altitude. Symptoms
will improve over several days as body adjusts to altitude.
Activity: Avoid strenuous activity until acclimatized to altitude.
Diet: Stay hydrated. High carbohydrate (starches and sugars) diet to decreas symptoms.
Medications: Acetazolamide causes tingling sensations in lips, nose and fingertips and makes carbonated
beverages to taste funny. Do not stop taking acetazolamide because of these side effects.
Prevention and Hygiene: Ascend slowly (1000 - 2000 feet/day above 8000 ft) with a rest day (no ascent)
every 3-4 days. Sleep at least 1000-2000 ft lower than working altitude. Acetazolamide 125-250 mg
po tid/qid beginning 12-24 hours before starting ascent and continuing for 48 hours after reach destination
altitude.
No Improvement/Deterioration: Seek medical aid if headache worsens, develop difficulty with walking,
coordination, cough, cough up frothy, pink or bloody sputum, ‘gurgling’ sounds in chest when breathing.
Follow-up Action
Reevaluation: No follow up is necessary unless symptoms return.
Evacuation/Consultation Criteria: Evacuate to lower altitude as discussed above.
There is no way to predict which person is more susceptible to AMS. Consider medical profile limiting
deployment to altitude for those with recurrent or prolonged AMS.
High Altitude Illnesses: High Altitude Cerebral Edema
COL Paul Rock, MC, USA & LTC Brian Campbell, MC, USAIntroduction: High altitude cerebral edema (HACE) is a potentially fatal accumulation of fluid (edema) in brain
tissue which sometimes occurs in people from low altitude (less than 5000 feet) who ascend rapidly to high
altitude (greater than 8,000 feet; but rare below 11,500 feet) and remain there for several days. It is caused
by the decreased amount of oxygen available to the body in the low pressure atmosphere at high altitude
(see Aerospace Medicine: Hypoxia). HACE is a severe form of acute mountain sickness (AMS) (see Acute
Mountain Sickness section) and most often occurs in people who have AMS symptoms and continue to
ascend. Although rare (usually less than 1-2% of persons going to high altitude), if left untreated, HACE can
progress to coma and death in 12 hours or less. High altitude pulmonary edema (HAPE), which can also be
rapidly fatal, often occurs with HACE. (see High Altitude Pulmonary Edema in following section.)
Subjective: Symptoms
Early: Symptoms of AMS (severe headache, nausea with vomiting, decreased appetite and fatigue); later:
progressive weakness, fatigue and clumsiness; confusion and disorientation; vivid hallucinations (visual and/or
auditory).