Pediatric emergency medicine trisk 1958 1958
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considered if there is any indication of infection.
HIGH-ALTITUDE ILLNESS
Goals of Treatment
Early recognition and treatment can lead to complete recovery. Severe illness
needs to be treated with cardiopulmonary resuscitation and descent to prevent
pulmonary edema and cerebral edema.
CLINICAL PEARLS AND PITFALLS
The four major illnesses seen with altitude include high-altitude
headache (HAH), acute mountain sickness (AMS), high-altitude
cerebral edema (HACE), and high-altitude pulmonary edema (HAPE).
Treatment for HAH or mild AMS includes acetazolamide, analgesics,
hydration, and antiemetics.
For more severe AMS or HACE, oxygen, hyperbaric therapy, and
dexamethasone are indicated, along with immediate descent if feasible.
Current Evidence
Physiologic changes accompanying altitude may be attributed to hypobaric
hypoxia. As altitude increases, barometric pressure decreases, resulting in a
reduction in the partial pressure of oxygen. Temperature also decreases with
altitude, so hypothermia can compound these hypoxic effects. The individual’s
response to hypoxia is to increase ventilation, which raises alveolar oxygen while
reducing alveolar carbon dioxide simultaneously. Hypocapnia produces an
alkalosis that, in turn, will serve as a “check and balance” for the body by limiting
further increases in the respiratory rate. With time the pH returns to neutral as the
kidneys excrete bicarbonate in response to this alkalosis. Acetazolamide
(Diamox) is used to inhibit carbonic anhydrase-dependent bicarbonate resorption
in the tubules to facilitate bicarbonate excretion, inducing a metabolic acidosis
that allows the ventilatory rate to remain high and to maintain better oxygenation.
Clinical Recognition
The four major illnesses seen with altitude include high-altitude headache (HAH),
acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and highaltitude pulmonary edema (HAPE). Headache is typically the initial symptom
upon climbing to higher altitudes; it may occur alone as in HAH or progress to
