title: Simulated descent v dexamethasone in treatment of acute mountain sickness: a randomised trial.
abstract: OBJECTIVE
  Evaluation and comparison of the therapeutic efficacy of a portable hyperbaric chamber and dexamethasone in the treatment of acute mountain sickness.
  
  
  METHODS
  Randomised trial during the summer mountaineering season.
  
  
  METHODS
  High altitude research laboratory in the Capanna Regina Margherita at 4559m above sea level (Alps Valais).
  
  
  METHODS
  31 climbers with symptoms of acute mountain sickness randomly assigned to different treatments.
  
  
  METHODS
  One hour of treatment in the hyperbaric chamber at a pressure of 193 mbar or oral administration of 8 mg dexamethasone initially, followed by 4 mg after 6 hours.
  
  
  METHODS
  Symptoms of acute mountain sickness (Lake Louise score, clinical score, and AMS-C score) before one and about 11 hours after beginning the different methods of treatment. Permitted intake of mild analgesics before treatment and in the follow up period.
  
  
  RESULTS
  After one hour of treatment compression with 193 mbar caused a significantly greater relief of symptoms of acute mountain sickness than dexamethasone (Lake Louise score: mean (SD) -4.6 (1.9) v -2.5 (1.8); clinical score: -4.0 (1.2) v -1.5 (1.4); AMS-C score: -1.24 (0.51) v -0.54 (0.59)). In contrast after about 11 hours subjects treated with dexamethasone suffered from significantly less severe acute mountain sickness than subjects treated with the hyperbaric chamber (-7.0 (3.6) v -1.6 (3.0); -4.1 (1.9) v -1.0 (1.5); -1.78 (0.73) v -0.75 (0.82) respectively). Intake of analgesics was similar in both groups.
  
  
  CONCLUSIONS
  Both methods were efficient in treatment of acute mountain sickness. One hour of compression with 193 mbar in the hyperbaric chamber, corresponding to a descent of 2250 m, led to short term improvement but had no long term beneficial effect. On the other hand, treatment with dexamethasone in an oral dose of 8 mg initially followed by 4 mg every 6 hours resulted in a longer term clinical improvement. For optimal efficacy the two methods should be combined if descent or evacuation is not possible.
authors.affiliation: University of Zürich, Switzerland.
authors.forename: H R
authors.initials: HR
authors.lastname: Keller
authors.forename: M
authors.initials: M
authors.lastname: Maggiorini
authors.forename: P
authors.initials: P
authors.lastname: Bärtsch
authors.forename: O
authors.initials: O
authors.lastname: Oelz
mesh_terms: D000208:Acute Disease; D000328:Adult; D000532:Altitude Sickness / Q000628:therapy*; D001273:Atmosphere Exposure Chambers; D001274:Atmospheric Pressure; D003907:Dexamethasone / Q000627:therapeutic use*; D004630:Emergencies; D005260:Female; D006801:Humans; D008297:Male; D016896:Treatment Outcome
chemical_list: D003907:Dexamethasone