The effect of altitude pre-acclimatization on acute mountain sickness during reexposure

T. P. Lyons, S. R. Muza, P. B. Rock, A. Cymerman

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Background: Acclimatization to high altitude appears to prevent acute mountain sickness (AMS), as evidenced by a decline in AMS symptoms as acclimatization progresses. Hypothesis: We hypothesized that partial retention of acclimatization would attenuate the incidence and/or severity of AMS upon reinduction to altitude. Methods: To test this hypothesis 6 male lowlanders returned to sea level after acclimatizing for 16 d at 4300 m (HA). After 8 d at sea level (PA), they were reexposed to 4300 m in a hypobaric chamber for 30 h (RA). AMS symptom severity was determined by the AMS- cerebral (AMS-C) scores calculated from the daily administration of the Environmental Symptoms Questionnaire during HA and RA. Results: The mean AMS- C scores were reduced from 0.6 on HA day 1 (HA1) to 0.1 during RA (p < 0.05). Four subjects were 'sick' (AMS-C > 0.7) during HA1, while only one was 'sick' during RA. The % oxyhemoglobin, hemoglobin concentration and hematocrit were higher during RA compared to HA1. Conclusions: These results suggest that the retention of acclimatization after 8 d at low altitude is sufficient to attenuate AMS upon reinduction to high altitude.

Original languageEnglish
Pages (from-to)957-962
Number of pages6
JournalAviation Space and Environmental Medicine
Volume66
Issue number10
StatePublished - 1 Jan 1995

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Altitude Sickness
Acclimatization
Sea level
Hemoglobin
Oceans and Seas
Oxyhemoglobins
Hematocrit
Hemoglobins
Incidence

Cite this

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abstract = "Background: Acclimatization to high altitude appears to prevent acute mountain sickness (AMS), as evidenced by a decline in AMS symptoms as acclimatization progresses. Hypothesis: We hypothesized that partial retention of acclimatization would attenuate the incidence and/or severity of AMS upon reinduction to altitude. Methods: To test this hypothesis 6 male lowlanders returned to sea level after acclimatizing for 16 d at 4300 m (HA). After 8 d at sea level (PA), they were reexposed to 4300 m in a hypobaric chamber for 30 h (RA). AMS symptom severity was determined by the AMS- cerebral (AMS-C) scores calculated from the daily administration of the Environmental Symptoms Questionnaire during HA and RA. Results: The mean AMS- C scores were reduced from 0.6 on HA day 1 (HA1) to 0.1 during RA (p < 0.05). Four subjects were 'sick' (AMS-C > 0.7) during HA1, while only one was 'sick' during RA. The {\%} oxyhemoglobin, hemoglobin concentration and hematocrit were higher during RA compared to HA1. Conclusions: These results suggest that the retention of acclimatization after 8 d at low altitude is sufficient to attenuate AMS upon reinduction to high altitude.",
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The effect of altitude pre-acclimatization on acute mountain sickness during reexposure. / Lyons, T. P.; Muza, S. R.; Rock, P. B.; Cymerman, A.

In: Aviation Space and Environmental Medicine, Vol. 66, No. 10, 01.01.1995, p. 957-962.

Research output: Contribution to journalArticle

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