title: Acetazolamide in the treatment of acute mountain sickness: clinical efficacy and effect on gas exchange.
abstract: OBJECTIVE
  To determine the efficacy of acetazolamide in the treatment of patients with acute mountain sickness and the effect of the drug on pulmonary gas exchange in acute mountain sickness.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled trial.
  
  
  METHODS
  The Denali Medical Research Project high-altitude research station (4200 m) on Mt. McKinley, Alaska.
  
  
  METHODS
  Twelve climbers attempting an ascent of Mt. McKinley (summit, 6150 m) who presented to the medical research station with acute mountain sickness.
  
  
  METHODS
  Climbers were randomly assigned to receive acetazolamide, 250 mg orally, or placebo at 0 (baseline) and 8 hours after inclusion in the study.
  
  
  METHODS
  An assessment of acute mountain sickness using a symptom score and pulmonary gas exchange measurements was done at baseline and at 24 hours.
  
  
  RESULTS
  After 24 hours, five of six climbers treated with acetazolamide were healthy, whereas all climbers who received placebo still had acute mountain sickness (P = 0.015). Arterial blood gas specimens were obtained from three of the six acetazolamide recipients and all of the placebo recipients. The alveolar to arterial oxygen pressure difference (PAO2-PaO2 difference) decreased slightly over 24 hours in the acetazolamide group (-0.8 +/- 1.2 mm Hg) but increased in the placebo group (+3.3 +/- 2.3 mm Hg) (P = 0.024). Acetazolamide improved PaO2 over 24 hours (+2.9 +/- 0.8 mm Hg) when compared with placebo (-1.3 +/- 2.8 mm Hg) (P = 0.045).
  
  
  CONCLUSIONS
  In established cases of acute mountain sickness, treatment with acetazolamide relieves symptoms, improves arterial oxygenation, and prevents further impairment of pulmonary gas exchange.
authors.affiliation: Denali Medical Research Project, School of Health Professions, University of Alaska-Anchorage.
authors.forename: C K
authors.initials: CK
authors.lastname: Grissom
authors.forename: R C
authors.initials: RC
authors.lastname: Roach
authors.forename: F H
authors.initials: FH
authors.lastname: Sarnquist
authors.forename: P H
authors.initials: PH
authors.lastname: Hackett
mesh_terms: D000086:Acetazolamide / Q000627:therapeutic use*; D000208:Acute Disease; D000328:Adult; D000532:Altitude Sickness / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis / Q000097:blood; D011650:Pulmonary Alveoli / Q000737:chemistry; D011659:Pulmonary Gas Exchange / Q000187:drug effects*
chemical_list: D000086:Acetazolamide; D010100:Oxygen