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Acute mountain sickness

Anika Frühauf, Martin Burtscher, Elena Pocecco, Martin Faulhaber, Martin Kopp
PURPOSE: There is an ongoing discussion how to assess acute mountain sickness (AMS) in real life conditions. Next to more-item scales with a cut off like the Lake Louise Self-Report (LLS), some authors suggested to use visual analog scales (VAS) to assess AMS. This study tried to contribute to this question using VAS items used for the Subjective Ratings of Drug Effects, including an additional single item for AMS. Furthermore, we investigated if instruments developed to assess psychological well-being might predict AMS assessed via LLS or VAS...
2016: SpringerPlus
Jose V Lafuente, G Bermudez, L Camargo-Arce, S Bulnes
Cerebral syndromes related to high altitude exposure are becoming more frequent as the number of trips to high altitudes has increased in the last decade. The commonest symptom is headache, followed by acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), which can be fatal. The pathophysiology of these syndromes is not fully comprehended. The classical "tight-fit hypothesis" defends the fact that there are some anatomical variations that would obstruct the sinovenous outflow and worsen the vasogenic edema and intracranial hypertension reactive to hypoxia...
September 20, 2016: CNS & Neurological Disorders Drug Targets
Roberta Rosas Petrocinio, Elga Dias Gomes
BACKGROUND: High altitude retinopathy (HAR) includes a number of diseases related to high altitude such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). High altitude retinopathy is mainly characterized by retinal hemorrhages, usually sparing the macular region, a condition specifically known as high altitude retinal hemorrhages (HARH). The pathogenesis of HARH is unclear. Many studies show that lack of oxygen causes an inadequate autoregulation of retinal circulation, causing vascular incompetence...
2016: Aerospace Medicine and Human Performance
Samuel Verges, Thomas Rupp, Marjorie Villien, Laurent Lamalle, Irène Troprés, Camille Poquet, Jan M Warnking, François Estève, Pierre Bouzat, Alexandre Krainik
OBJECTIVE: Hypoxic exposure in healthy subjects can induce acute mountain sickness including headache, lethargy, cerebral dysfunction, and substantial cerebral structural alterations which, in worst case, can lead to potentially fatal high altitude cerebral edema. Within this context, the relationships between high altitude-induced cerebral edema, changes in cerebral perfusion, increased brain parenchyma volume, increased intracranial pressure, and symptoms remain unclear. METHODS: In 11 subjects before and after 6 days at 4350 m, we performed multiparametric magnetic resonance investigations including anatomical, apparent diffusion coefficient and arterial spin labeling sequences...
2016: Frontiers in Physiology
Shi-Zhu Bian, Jun Jin, Jun-Qing Dong, Qian-Ning Li, Jie Yu, Cai-Fa Tang, Shi-Yong Yu, Xiao-Hui Zhao, Jun Qin, Lan Huang
OBJECTIVE: The current study aimed to identify the predictive values of psychological factors that are evaluated by the Symptoms Checklist-90 (SCL-90) for acute mountain sickness (AMS). METHODS: The subjects (n=285, non-acclimatized young Chinese men), who were recruited in July 2013, completed a case report questionnaire. In addition, their vital signs (heart rate [HR], blood pressure and pulse oxygen saturation) were measured, and their psychological factors were examined using the SCL-90 at sea level...
September 14, 2016: Physiology & Behavior
Dangjai Souvannakitti, Paleerath Peerapen, Visith Thongboonkerd
Acute mountain sickness (AMS) can cause capillary hyper-permeability and vasogenic edema. However, its underlying mechanisms remained unclear and there is no previous in vitro study on AMS. We therefore conducted an in vitro study and examined whether continuous hypobaric hypoxia (CHH) could alter expression of junctional protein complex of vascular endothelial cells, causing hyper-permeabilization. EA.hy926 human endothelial cells were exposed to either CHH or normoxia for up to 24 h. Flow cytometry using annexin V/propidium iodide co-staining demonstrated that cell death had no significant difference at 12-h, but was increased by CHH at 24-h...
September 14, 2016: Cell Adhesion & Migration
Soon Bae Kim, Jong Sung Kim, Sang Jun Kim, Su Hee Cho, Dae Chul Suh
Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI...
September 2016: Neurointervention
Philip J Hennis, Kay Mitchell, Edward Gilbert-Kawai, Vassiliki Bountziouka, Angie Wade, Martin Feelisch, Michael P Grocott, Daniel S Martin
: The purpose of this study was to investigate the effects of dietary nitrate supplementation, in the form of beetroot juice, on acute mountain sickness (AMS) symptoms and physiological responses, in a group of young males trekking to Mount Everest Base Camp (EBC). Forty healthy male students (mean age (SD): 16 (1) yrs) trekked to EBC over 11 days. Following an overnight fast, each morning participants completed the Lake Louise AMS questionnaire and underwent a series of physiological tests: resting blood pressure as well as resting and exercising heart rate, respiratory rate, and peripheral oxygen saturation...
September 2, 2016: Nitric Oxide: Biology and Chemistry
Carine Malle, Benoît Ginon, Cyprien Bourrilhon
: Malle, Carine, Benoît Ginon, and Cyprien Bourrilhon. Brief working memory and physiological monitoring during a high-altitude expedition. High Alt Med Biol 00:000-000, 2016. BACKGROUND: Various studies have shown the deleterious effects of high-altitude hypoxia on cognitive functions, including attention and memory. Since optimal cognitive abilities may be crucial for mountain safety, this study was aimed to assess the relevance of a brief working memory test to quickly assess cognition at high altitude...
August 22, 2016: High Altitude Medicine & Biology
Philip E Bickler, John R Feiner, Michael S Lipnick, Paul Batchelder, David B MacLeod, John W Severinghaus
Extended periods of oxygen deprivation can produce acidosis, inflammation, energy failure, cell stress, or cell death. However, brief profound hypoxia (here defined as SaO2 50%-70% for approximately 10 minutes) is not associated with cardiovascular compromise and is tolerated by healthy humans without apparent ill effects. In contrast, chronic hypoxia induces a suite of adaptations and stresses that can result in either increased tolerance of hypoxia or disease, as in adaptation to altitude or in the syndrome of chronic mountain sickness...
August 12, 2016: Anesthesia and Analgesia
Martin J MacInnis, Michael S Koehle
MacInnis, Martin J., and Michael S. Koehle. Evidence for and against genetic predispositions to acute and chronic altitude illnesses. High Alt Med Biol 00:000-000, 2016.-Humans exhibit marked variation in their responses to hypoxia, with susceptibility to acute and chronic altitude illnesses being a prominent and medically important example. Many have hypothesized that genetic differences are the cause of these variable responses to hypoxia; however, until recently, these hypotheses were based primarily on small (and sometimes anecdotal) reports pertaining to apparent differences in altitude illness susceptibility between populations, the notion that a history of altitude illness is indicative of subsequent risk, the heritability of hypoxia-related traits, and candidate gene association studies...
August 8, 2016: High Altitude Medicine & Biology
Gaurav Sikri, Srinivasa Bhattachar
No abstract text is available yet for this article.
September 7, 2016: Neuroreport
Qing Hai Shi, Di Ge, Wei Zhao, Xue Ma, Ke Yan Hu, Yao Lu, Zheng Xiang Liu, Ji Hua Ran, Xiao Ling Li, Yu Zhou, Jian Feng Fu
To evaluate the effect of acute high-altitude exposure on sensory and short-term memory using interactive software, we transported 30 volunteers in a sport utility vehicle to a 4280 m plateau within 3 h. We measured their memory performance on the plain (initial arrival) and 3 h after arrival on the plateau using six measures. Memory performance was significantly poorer on the plateau by four of the six measures. Furthermore, memory performance was significantly poorer in the acute mountain sickness (AMS) group than in the non-AMS group by five of the six measures...
June 2016: Biomedical and Environmental Sciences: BES
Amine N Issa, Nicole M Herman, Robert J Wentz, Bryan J Taylor, Doug C Summerfield, Bruce D Johnson
OBJECTIVE: It is well documented that cognitive performance may be altered with ascent to altitude, but the association of various cognitive performance tests with symptoms of acute mountain sickness (AMS) is not well understood. Our objective was to assess and compare cognitive performance during a high-altitude expedition using several tests and to report the association of each test with AMS, headache, and quality of sleep. METHODS: During an expedition to Mount Everest, 3 cognitive tests (Stroop, Trail Making, and the real-time cognitive assessment tool, an in-house developed motor accuracy test) were used along with a questionnaire to assess health and AMS...
September 2016: Wilderness & Environmental Medicine
Masahiro Horiuchi, Junko Endo, Shohei Dobashi, Masataka Kiuchi, Katsuhiro Koyama, Andrew W Subudhi
What is the central question of this study? Acute hypoxia reduces dynamic cerebral autoregulation (dCA); however, it is unclear what level of hypoxia is necessary to exert this effect. We sought to investigate whether dCA would be reduced during progressive periods of normobaric hypoxia using a duplex Doppler ultrasound technique to evaluate the volumetric blood flow. What is the main finding and its importance? We showed that dCA decreased linearly as inspired O2 decreased from 21 to 12%. Additionally, symptoms of acute mountain sickness were related to changes in dCA...
October 1, 2016: Experimental Physiology
David J Collier, Chris B Wolff, Anne-Marie Hedges, John Nathan, Rod J Flower, James S Milledge, Erik R Swenson
Acetazolamide is the standard carbonic anhydrase (CA) inhibitor used for acute mountain sickness (AMS), however some of its undesirable effects are related to intracellular penetrance into many tissues, including across the blood-brain barrier. Benzolamide is a much more hydrophilic inhibitor, which nonetheless retains a strong renal action to engender a metabolic acidosis and ventilatory stimulus that improves oxygenation at high altitude and reduces AMS. We tested the effectiveness of benzolamide versus placebo in a first field study of the drug as prophylaxis for AMS during an ascent to the Everest Base Camp (5340 m)...
June 2016: Pharmacology Research & Perspectives
Andrew T Lovering, Jonathan E Elliott, James T Davis
The foramen ovale, which is part of the normal fetal cardiopulmonary circulation, fails to close after birth in ∼35% of the population and represents a potential source of right-to-left shunt. Despite the prevalence of patent foramen ovale (PFO) in the general population, cardiopulmonary, exercise, thermoregulatory, and altitude physiologists may have underestimated the potential effect of this shunted blood flow on normal physiological processes in otherwise healthy humans. Because this shunted blood bypasses the respiratory system, it would not participate in either gas exchange or respiratory system cooling and may have impacts on other physiological processes that remain undetermined...
August 1, 2016: Journal of Applied Physiology
Martin Faulhaber, Elena Pocecco, Hannes Gatterer, Martin Niedermeier, Maike Huth, Tobias Dünnwald, Verena Menz, Luciano Bernardi, Martin Burtscher
PURPOSE: The present study evaluated the effects of a pre-acclimatization program comprising 7 passive 1-hour exposures to 4,500 m normobaric hypoxia on the prevalence and severity of acute mountain sickness (AMS) during a subsequent exposure to real high altitude in persons susceptible to AMS. METHODS: The project was designed as a randomized controlled trial including 32 healthy female and male participants with known susceptibility to AMS symptoms. After baseline measurements participants were randomly assigned to the hypoxia or the control group to receive the pre-acclimatization program (7 passive 1-hour exposures within 7 days to normobaric hypoxia or sham hypoxia)...
July 12, 2016: Medicine and Science in Sports and Exercise
Q-N Li, Y Liu, S-F Zhao
Background: To investigate the effect of personality traits on development of acute mountain sickness (AMS). Methods: One hundred and eighty-nine healthy male subjects transported from the plain area (Chengdu, China) to a high altitude area (Tibet, China) were enrolled in this study. Ninety-six subjects experienced AMS within two days after arriving at Tibet plateau (AMS group), while the remaining 93 subjects did not (healthy control without AMS group). The symptoms of AMS, state-trait anxiety and personality traits of the subjects were assessed using self-assessment and AMS questionnaire (Chinese criteria)...
December 10, 2015: West Indian Medical Journal
Adam D Hill
When performing detailed tasks related to climbing or hiking, accurate vision is important for safety. Acetazolamide is a medication commonly used to prevent acute mountain sickness, but it has an uncommon side effect of transient myopia. Reports of this side effect are mainly associated with its use in obstetrics, where it is often prescribed in higher doses than used in acute mountain sickness prophylaxis. We describe the case of a climber taking low-dose acetazolamide who developed transient myopia. We further describe potential mechanisms of this rare side effect as well as a novel approach of field management utilizing possible materials at hand...
September 2016: Wilderness & Environmental Medicine
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