title: [Respiratory changes during ascension to 8,000 meters mountain].
abstract: BACKGROUND
  Our goal was to determine whether spirometric alterations occur during expeditions to 8,000-metre peaks, and whether these are modified by acclimatization or are related to acute mountain sickness, to arterial oxygen saturation (SaO2) or to muscular deterioration due to chronic hypoxic exposure.
  
  
  METHODS
  Forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), inspiratory (MIP) and expiratory (MEP) maximal static pressures, grip strength in both hands, and SaO2 at rest and exercise were measured in eight subjects during an expedition to Gasherbrum II (8,035 m).
  
  
  RESULTS
  Upon arrival at the base camp (5,200 m), both FVC and FEV1 decreased, with no changes in the FEV1/FVC ratio. FVC did not improve after a brief pressurisation in a portable hyperbaric chamber. A month later, FVC in the base camp returned to normal values. FVC fall correlated with both the severity of acute mountain sickness and weight loss. Resting SaO2 improved with acclimatisation and correlated with the previous hypoxic ventilatory response, both before and after acclimatisation. Acclimatisation led to a decrease in the exercise-induced SaO2 fall. Stay at a high altitude lowered body weight and grip strength, although MIP and MEP remained unchanged.
  
  
  CONCLUSIONS
  We observed a restrictive alteration was corrected by with acclimatisation. This phenomenon seems to be related to a subclinical high-altitude pulmonary oedema rather than to an increase in the pulmonary vascular volume. Despite the high-altitude muscular deterioration, respiratory muscle weakness was not
authors.affiliation: Servicio de Neumología. Expedición Cinc Segles de la Universitat de València al Gasherbrum II, Spain. compte_lui@gva.es
authors.forename: Luis
authors.initials: L
authors.lastname: Compte Torrero
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Real Soriano
authors.forename: Javier
authors.initials: J
authors.lastname: Botella De Maglia
authors.forename: Alfredo
authors.initials: A
authors.lastname: de Diego Damiá
authors.forename: Vicente
authors.initials: V
authors.lastname: Macián Gisbert
authors.forename: Miguel
authors.initials: M
authors.lastname: Perpiñá Tordera
mesh_terms: D000328:Adult; D000531:Altitude; D005260:Female; D006801:Humans; D008297:Male; D012119:Respiration