To test whether the 6-minute walk test (6MWT), including postexercise vital sign measurements and distance walked, predicts summit success on Denali, AK.
This was a prospective observational study of healthy volunteers between the ages of 18 and 65 years who had been at 4267 m for less than 24 hours on Denali. Physiologic measurements were made after the 6MWT. Subjects then attempted to summit at their own pace and, at the time of descent, completed a Lake Louise Acute Mountain Sickness Questionnaire and reported maximum elevation reached.
One hundred twenty-one participants enrolled in the study. Data were collected on 111 subjects (92% response rate), of whom 60% summited. On univariate analysis, there was no association between any postexercise vital sign and summit success. Specifically, there was no significant difference in the mean postexercise peripheral oxygen saturation (Spo2) between summiters (75%) and nonsummiters (74%; 95% CI, -3 to 1; P = .37). The distance a subject walked in 6 minutes (6MWTD) was longer in summiters (617 m) compared with nonsummiters (560 m; 95% CI, 7.6 to 106; P = .02). However, this significance was not maintained on a multivariate analysis performed to control for age, sex, and guide status (P = .08), leading to the conclusion that 6MWTD was not a robust predictor of summit success.
This study did not show a correlation between postexercise oxygen saturation or 6MWTD and summit success on Denali.
The examinations were carried out during the 27th Soviet Antarctic expedition. Baseline data were collected before the departure of the test subjects to the Antarctic Region. Prior to their ascent to the high mountain area they were divided into two groups with a high and a low level of hypoxic tolerance in terms of the work capacity index calculated on the basis of standard bicycle ergometry tests. Heart rate, body temperature and salivary content of sodium and potassium were measured 6 times a day at 4-hour intervals. The results obtained were treated by nonparametric tests. It was found that on adaptation day 30 the subjects with low hypoxic tolerance and nonspecific resistance developed changes in biorhythm amplitudes and phases and showed ultradian components with a 12-hour period. By contrast, the subjects with high hypoxic tolerance retained the ability to maintain circadian patterns. By the middle of the wintering time the circadian rhythms shifted towards ultradian components regardless of individual hypoxic tolerance.
Though skiing, except for low altitude, is characteristically a mountain actvitiy, altitude is rarely a problem. The physiological principles involved are simple, though a detailed explanation may seem somewhat complex.
Available upon request at the Alaska Medical Library, located in UAA/APU Consortium Library. Ask for accession no. 312324.
To evaluate an ambulatory physiological monitoring system during a mountaineering expedition. We hypothesized that the Environmental Symptoms Questionnaire, combined with frequent measurement of oxygen saturation and core temperature, would accurately identify cases of environmental illness.
Twelve military mountaineers took a daily Environmental Symptoms Questionnaire, monitored fingertip oxygen saturations, and recorded core temperatures while climbing a 4,949-m peak. Illnesses identified by the system were compared with those identified by spontaneous reports.
The system correctly identified one case of high-altitude pulmonary edema and two illnesses that were not reported to the physician (one case of acute mountain sickness and one of self-limited symptomatic desaturation). However, it did not identify two illnesses that were severe enough to preclude further climbing (one case of sinus headache and one of generalized fatigue).
Our monitoring system may complement, but cannot replace, on-site medical personnel during mountaineering expeditions.
Lethal cases in mountain tourism and sports in the Republic of Kabardino-Balkaria were studied for 1978-1995. A total of 152 accidental deaths were analysed. Most of the victims were males under 30 years of age. The greatest number of the accidents took place on Monday, in July and August. Many amateur visitors from abroad were among the victims. The main cause of death in the mountains of Kabardino-Balkaria for the 18 years studied was multitrauma of the body (69.7%). Hypothermia and obturation asphyxia with snow and compression asphyxia due to snowbreak account for 11.8 and 13.2% deaths, respectively; lightning killed 4%. Combination of high mountain hypoxia with exacerbated chronic somatic disease or hypothermia caused death in 1% victims. The authors propose how to improve forensic-medical expert examination of accidental death and safety in the mountains.
Based on papers from a workshop held in Kongsvold, Norway, Aug. 17-20, 1993.
Contents: Patterns and causes of arctic plant community diversity / M.D. Walker -- Causes of arctic plant diversity : origin and evolution / D.F. Murray -- Patterns and causes of genetic diversity in arctic plants / J.B. McGraw -- Alpine plant diversity : a global survey and functional interpretations / Ch. Ko¨rner -- Origin and evolution of the mountain flora in Middle Asia and neighbouring mountain regions / O. Agakhanjanz and S.-W. Breckle -- Diversity of the Arctic terrestrial fauna / Yu. I. Chernov -- Animal diversity at high altitudes in the Austrian central Alps / E. Meyer and K. Thaler -- Arctic tundra biodiversity : a temporal perspective from late Quaternary pollen records / L.B. Brubaker, P.M. Anderson, and F.S. Hu -- Effects of mammals on ecosystem change at the Pleistocene-Holocene boundary / S.A. Zimov [and others] -- Palaeorecords of plant biodiversity in the Alps / B. Ammann -- Implications for changes in arctic plant biodiversity from environmental manipulation experiments / T.V. Callaghan and S. Jonasson -- Patterns and current changes in alpine plant diversity / G. Grabherr [and others] -- Anthropogenic impacts on biodiversity in the Arctic / O.R. Young and F.S. Chapin III -- Plant functional diversity and resource control of primary production in Alaskan Arctic tundras / G.R. Shaver -- Direct and indirect effects of plant species on biogeochemical processes in arctic ecosystems / S.E. Hobbie -- Causes and consequences of plant functional diversity in arctic ecosystems / F.S. Chapin III [and others] -- Ecosystem consequences of microbial diversity and community structure / J. Schimel -- Diversity of biomass and nitrogen distribution among plant species in arctic and alpine tundra ecosystems / J. Pastor -- The plant-vertebrate herbivore interface in arctic ecosystems / R.L. Jefferies and J.P. Bryant -- Insect diversity, life history, and trophic dynamics in arctic streams, with particular emphasis on black flies (Diptera: Simuliidae) / A.E. Hershey, R.W. Merritt, and M.C. Miller -- Land-water interactions : the influence of terrestrial diversity on aquatic ecosystems / G.W. Kling -- Patterns, causes, changes, and consequences of biodiversity in arctic and alpine ecosystems / F.S. Chapin III and Ch. Ko¨rner.