Acute mountain sickness, characterized by headache, anorexia, insomnia and malaise, is usually self-limited but may progress to life-threatening high-altitude pulmonary or cerebral edema. Grissom and associates conducted a study to evaluate the effectiveness of acetazolamide in the treatment of acute mountain sickness and its effect on pulmonary gas exchange.
The study included 12 climbers attempting an ascent of Mt. McKinley (summit: 6,150 m [20,230 ft]) who presented to the medical research station (4,200 m [13,780 ft]) with acute mountain sickness. Subjects were randomly assigned to receive 250 mg orally of acetazolamide or placebo at baseline and again eight hours later. Illness severity was assessed using a symptom score and pulmonary gas exchange measurement at baseline and after 24 hours of treatment.
After 24 hours, five of the six patients treated with acetazolamide were healthy, whereas all of the patients who received placebo were still sick. Arterial blood gas specimens were obtained in three of the six patients who received acetazolamide and in all of the patients who received placebo. The alveolar-arterial oxygen pressure difference ([PAO.sub.2]-[PaO.sub.2]) decreased by 0.8 mm Hg over 24 hours in the treated group but increased by 3.3 mm Hg in the placebo group. Acetazolamide improved [PaO.sub.2] over 24 hours (an increase of 2.9 mm Hg), compared with placebo (a decrease of 1.3 mm Hg).
The authors conclude that acetazolamide relieves symptoms of acute mountain sickness, improves arterial oxygenation and prevents further impairment of pulmonary gas exchange. (Annals of Internal Medicine, March 15, 1992, vol. 116, p. 461).
COPYRIGHT 1992 American Academy of Family Physicians
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