title: Effects of slow ascent to 4559 M on fluid homeostasis.
abstract: Since acute mountain sickness (AMS) is associated with rapid ascent and with fluid retention, we assessed clinical status and fluid homeostasis in men slowly ascending on foot over 3 d to 4559 m and remaining at this altitude 5 d. We studied 15 male mountaineers, 6 of whom had previously had repeated, severe AMS or high altitude pulmonary edema (HAPE), at 1170 m, 3611 m, and 4559 m. We found that four of the six subjects with previous AMS or HAPE compared with none of nine with no such history, developed these conditions. Those who remained well had a diuresis that could not be overcome by increasing fluid intake and no change in renin activity, plasma aldosterone, or atrial natriuretic peptide (ANP). Those who became ill showed considerable weight gain independent of fluid intake, and a great increase in ANP which correlated with measurements of right atrial cross section. We conclude that mountaineers who have previously experienced repeated AMS or HAPE get fluid retention despite slow ascent and that this is associated with widening of the atrium and an increase in ANP.
authors.affiliation: Department of Medicine and Medizinische Poliklinik, University of Bern, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Bärtsch
authors.forename: N
authors.initials: N
authors.lastname: Pfluger
authors.forename: M
authors.initials: M
authors.lastname: Audétat
authors.forename: S
authors.initials: S
authors.lastname: Shaw
authors.forename: P
authors.initials: P
authors.lastname: Weidmann
authors.forename: P
authors.initials: P
authors.lastname: Vock
authors.forename: W
authors.initials: W
authors.lastname: Vetter
authors.forename: D
authors.initials: D
authors.lastname: Rennie
authors.forename: O
authors.initials: O
authors.lastname: Oelz
mesh_terms: D000328:Adult; D000532:Altitude Sickness / Q000503:physiopathology*; D009320:Atrial Natriuretic Factor / Q000097:blood; D001826:Body Fluids / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D004231:Diuresis / Q000502:physiology*; D004452:Echocardiography; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011654:Pulmonary Edema / Q000000981:diagnostic imaging; D011859:Radiography; D016055:Urinary Retention / Q000503:physiopathology; D014882:Water-Electrolyte Balance / Q000502:physiology
chemical_list: D009320:Atrial Natriuretic Factor