Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 410
Filtrar
1.
Wilderness Environ Med ; 31(2): 157-164, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32205041

RESUMO

INTRODUCTION: A history of preexisting hypertension is common in people participating in mountain activities; however, the relationship between blood pressure (BP), preexisting hypertension, and acute mountain sickness (AMS) is not well studied. We sought to determine these relationships among trekkers in the Everest region of Nepal. METHODS: This was a prospective observational cohort study of a convenience sample of adult, nonpregnant volunteers trekking in the Everest Base Camp region in Nepal. We recorded Lake Louise Scores for AMS and measured BP at 2860 m, 3400 m, and 4300 m. The primary outcome was AMS. RESULTS: A total of 672 trekkers (including 60 with history of preexisting hypertension) were enrolled at 2860 m. We retained 529 at 3400 m and 363 at 4300 m. At 3400 m, 11% of participants had AMS, and 13% had AMS at 4300 m. We found no relationship between AMS and measured BP values (P>0.05), nor was there any relation of BP to AMS severity as measured by higher Lake Louise Scores (P>0.05). Preexisting hypertension (odds ratio [OR] 0.16; 95% CI 0.025-0.57), male sex (OR 0.59; 95% CI 0.37-0.96), and increased SpO2 (OR 0.93; 95% CI 0.87-0.98) were associated with reduced rates of AMS in multivariate analyses adjusting for known risk factors for AMS. CONCLUSIONS: AMS is common in trekkers in Nepal, even at 3400 m. There is no relationship between measured BP and AMS. However, a medical history of hypertension may be associated with a lower risk of AMS. More work is needed to confirm this novel finding.


Assuntos
Doença da Altitude/epidemiologia , Altitude , Hipertensão/complicações , Montanhismo , Doença Aguda/epidemiologia , Adulto , Idoso , Doença da Altitude/etiologia , Doença da Altitude/fisiopatologia , Pressão Sanguínea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nepal/epidemiologia , Prevalência , Estudos Prospectivos , Fatores de Risco
2.
J. health med. sci. (Print) ; 6(1): 9-16, ene.-mar. 2020.
Artigo em Espanhol | LILACS | ID: biblio-1096527

RESUMO

Evidencias en textos históricos Chinos de los años 403 AC y de la Conquista Española en 1590, muestran de las condiciones singulares que afectaban tanto a hombres como a animales al ascender por sectores montañosos por sobre 4000 m., y que ahora reconocemos como mal agudo de montaña. Ya desde el siglo XIX, se ha reconocido que es la falta de oxígeno (hipoxia) el factor determinante de la respuesta aclimatatoria como de la desaclimatización a la hipoxia de altura. El objetivo de la actual revisión fue una puesta al día de definiciones, factores que inciden en una mayor incidencia de mal agudo de montaña, mecanismo fisiológico propuesto, el desarrollo de estrategias farmacológicas para la prevención y/o tratamiento y por último, se ha revisado respecto de las distintas estrategias que se han desarrollado para la evaluación de la susceptibilidad individual, conocido comúnmente como test de hipoxia.


Some Chinese historical text from 403 BC and the Spanish Conquest in 1590 indicates unique conditions that affected both men and animals when climbing mountainous areas over 4000 m. and that is currently known as Acute Mountain Sickness (MAM). Since the XIX century, the lack of oxygen (hypoxia), has been recognized as the main factor of the acclimatization and declimatization to the high altitude hypoxia. The aim of the current revision is an update of definitions, factors that contribute the Acute Mountain Sickness, the proposed physiological mechanism, the development of pharmacological strategies for the prevention and/or treatment, and finally, we reviewed the different strategies developed for the individual susceptibility assessment, generally known as hypoxia test.


Assuntos
Humanos , Doença da Altitude/fisiopatologia , Doença da Altitude/tratamento farmacológico , Doença da Altitude/epidemiologia , Fatores de Risco , Suscetibilidade a Doenças , Doença da Altitude/etiologia
3.
Aerosp Med Hum Perform ; 91(1): 46-50, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31852574

RESUMO

BACKGROUND: Gradual ascent is impractical for personnel deploying to the South Pole due to logistical challenges. Prevention of altitude illness relies on prophylactic medications such as acetazolamide and behavioral modifications including hydration and avoidance of overexertion. We present three recent cases of altitude illness that occurred in previously healthy individuals at the South Pole.CASE REPORTS: 1) A 52-yr-old woman not on prophylactics presented with headache and intractable vomiting 7 h after arriving and hiking around the station. She was treated with acetazolamide, dexamethasone, oxygen, and supportive care. Her symptoms resolved during the evacuation flight. 2) A 23-yr-old man presented with dyspnea at rest 3 d after arriving without prophylactic treatments. He had a Sao2 of 49%, wheezes and crackles on lung exam, and interstitial infiltrates on chest X-ray. His treatment included oxygen, nifedipine, acetazolamide, and dexamethasone. His symptoms resolved during the evacuation flight. 3) A 40-yr-old man presented with dyspnea after a series of strenuous workouts since his arrival 5 d prior. He had a Sao2 of 41%, and his chest X-ray was consistent with high altitude pulmonary edema. He was treated with oxygen, nifedipine, and fluids before descent to sea level, where his symptoms fully resolved 4 d later.DISCUSSION: These patients illustrate that altitude illness may develop despite medical screening, participant education, and availability of prophylactic medications based on published guidelines. These cases could be attributed to noncompliance and misinformation, bringing to light some of the challenges with managing more diverse populations that deploy to remote environments.Rose JS, Law J, Scheuring R, Ramage MH, McKeith JJ. Serious altitude illness at the South Pole. Aerosp Med Hum Perform. 2020; 91(1):46-50.


Assuntos
Doença da Altitude/diagnóstico , Doença da Altitude/prevenção & controle , Adulto , Doença da Altitude/etiologia , Regiões Antárticas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
4.
Curr Neurol Neurosci Rep ; 19(12): 104, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31781974

RESUMO

PURPOSE OF REVIEW: High altitude headache is a common neurological symptom that is associated with ascent to high altitude. It is classified by the International Classification of Headache Disorders, 3rd Edition (ICHD-3) as a disorder of homeostasis. In this article, we review recent clinical and insights into the pathophysiological mechanisms of high altitude and airplane headache. We also report a second case of post-LASIK myopic shift at high altitude exposure secondary hypoxia. Headache attributed to airplane travel is a severe typically unilateral orbital headache that usually improves after landing. This was a relative recent introduction to the ICHD-3 diagnostic criteria. Headache pain with flight travel has long been known and may have been previously considered as a part of barotrauma. Recent studies have helped identify this as a distinct headache disorder. RECENT FINDINGS: Physiologic, hematological, and biochemical biomarkers have been identified in recent high altitude studies. There have been recent advance in identification of molecular mechanisms underlying neurophysiologic changes secondary to hypoxia. Calcitonin gene-related peptide, a potent vasodilator, has been implicated in migraine pathophysiology. Recent epidemiological studies indicate that the prevalence of airplane headache may be more common than we think in the adult as well at the pediatric population. Simulated flight studies have identified potential biomarkers. Although research is limited, there have been advances in both clinical and pathophysiological mechanisms associated with high altitude and airplane headache.


Assuntos
Aeronaves , Doença da Altitude/diagnóstico , Coca , Cefaleia/diagnóstico , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Miopia/diagnóstico , Altitude , Doença da Altitude/etiologia , Doença da Altitude/terapia , Cefaleia/etiologia , Cefaleia/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Miopia/etiologia , Fitoterapia/métodos , Folhas de Planta , Viagem
6.
High Alt Med Biol ; 20(4): 361-374, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31651199

RESUMO

Background: We investigated altitude effects on different cognitive domains among perennial shift-workers at the Atacama Large Millimeter/submillimeter Array Observatory (5050 m), Chile. Materials and Methods: Twenty healthy male workers were recruited and assigned to either a moderate-altitude first (MAF group, Test 1: 2900 m and Test 2: 5050 m) or to a high-altitude first (HAF group, Test 1: 5050 m and Test 2: 2900 m). Test 1 was conducted at the beginning and Test 2 at the end of the shift-work week. Processing speed (RTI, reaction time), attention (AST, attention-switching task, and RVP, rapid visual processing), and executive function (OTS, One Touch Stockings of Cambridge) were assessed. Results: Of the three cognitive domains assessed, only processing speed showed altitude-at-test group interaction (RTI median five choice reaction time: F1, 17 = 6.980, [Formula: see text] = 0.291, p = 0.017). With acclimatization, there was a decrease in AST reaction latency mean (t17 = -2.155, dz = 1.086, p = 0.046), an increase in RVP accuracy (t17 = 2.733, dz = 1.398, p = 0.014), and a decrease in OTS mean latency first choice (t17 = -2.375, dz = 1.211, p = 0.03). Decreased variability in cognitive function was observed in AST reaction latency standard deviation (t17 = -2.524, dz = 1.282, p = 0.022) and in RVP response latency standard deviation (t17 = -2.35, dz = 1.177, p = 0.03) with acclimatization. At 5050 m of elevation, SpO2 was positively correlated with executive function in the MAF group (OTS problems solved on first choice: r(5) = 0.839, p = 0.018) and negatively correlated with executive function latency standard deviations in the HAF group (OTS latency to first choice standard deviation: r(10) = -0.618, p = 0.032). Conclusions: Our findings highlight the importance of acclimatization and improvement of blood oxygen level, even among high altitude-experienced workers, to optimize performance of cognitively demanding work and reduce high altitude-associated health risks.


Assuntos
Doença da Altitude/psicologia , Disfunção Cognitiva/etiologia , Exposição Ambiental/efeitos adversos , Doenças Profissionais/psicologia , Exposição Ocupacional/efeitos adversos , Aclimatação/fisiologia , Adulto , Altitude , Doença da Altitude/etiologia , Chile , Cognição/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doenças Profissionais/etiologia , Tempo de Reação
7.
Trials ; 20(1): 604, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31651350

RESUMO

BACKGROUND: Acute mountain sickness (AMS) is a cluster of symptoms that commonly occur in those ascending to high altitudes. Symptoms can include headaches, nausea, insomnia and fatigue. Exposure to high altitude can also lead to high-altitude cerebral oedema (HACE), which is a potential cause of death whilst mountaineering. Generally, AMS precedes the development of HACE. Historical studies have demonstrated the effectiveness of regular dexamethasone administration in reducing the symptoms of AMS. However, the mechanism by which dexamethasone works to reduce symptoms AMS remains poorly understood. Further studies, simulating altitude using hypoxic tents, have characterised the effect of prolonged exposure to normobaric hypoxia on cerebral oedema and blood flow using MRI. This randomised trial assesses the effect of dexamethasone on hypoxia-induced cerebral oedema in healthy adult volunteers. METHODS/DESIGN: D4H is a double-blind placebo-controlled randomised trial assessing the effect of dexamethasone on hypoxia-induced cerebral oedema. In total, 20 volunteers were randomised in pairs to receive either 8.25 mg dexamethasone or normal saline placebo intravenously after 8 h of hypoxia with an FiO2 of 12%. Serial MRI images of the brain and spinal cord were obtained at hours 0, 7, 11, 22 and 26 of the study along with serum and urinary markers to correlate with the severity of cerebral oedema and the effect of the intervention. DISCUSSION: MRI has been used to identify changes in cerebral vasculature in the development of AMS and HACE. Dexamethasone is effective at reducing the symptoms of AMS; however, the mechanism of this effect is unknown. If this study demonstrates a clear objective benefit of dexamethasone in this setting, future studies may be able to demonstrate that dexamethasone is an effective therapy for oedema associated with brain and spinal cord ischaemia beyond AMS. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03341676 . Registered on 14 November 2017.


Assuntos
Doença da Altitude/tratamento farmacológico , Altitude , Edema Encefálico/tratamento farmacológico , Dexametasona/uso terapêutico , Glucocorticoides/uso terapêutico , Adolescente , Adulto , Doença da Altitude/diagnóstico por imagem , Doença da Altitude/etiologia , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/etiologia , Ensaios Clínicos Fase I como Assunto , Dexametasona/efeitos adversos , Método Duplo-Cego , Inglaterra , Feminino , Glucocorticoides/efeitos adversos , Humanos , Imagem por Ressonância Magnética , Masculino , Projetos Piloto , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
8.
Laeknabladid ; 105(11): 499-507, 2019 Nov.
Artigo em Islandês | MEDLINE | ID: mdl-31663513

RESUMO

Upon reaching a height over 2500 m above seal level symptoms of altitude illness can develop over 1 - 5 days. The risk is mainly -determined by the altitude and rate of ascent and the symptoms vary. Most common are symptoms of acute mountain illness (AMS) but more dangerous high altitude cerebral edema (HACE) and high altitude pulmonary edema (HAPE) can also develop. The causes of AMS, HACE and HAPE are lack of oxygen and insufficient acclimatization, but the presenting form is determined by the responses of the body to the lack of oxygen. The most common symptoms of AMS include headache, fatique and nausea, but insomnia and nausea are also common. The most common symptoms of HAPE are breathlessness and lassitude whereas the cardinal sign of HACE is ataxia, but confusion and loss of consciousness can also develop. In this article all three main forms of altitude illness are reviewed. The emphasis is on preventive measures and treatment but new knowledge on pathogenesis is also addressed.


Assuntos
Doença da Altitude/etiologia , Altitude , Edema Encefálico/etiologia , Edema Pulmonar/etiologia , Doença da Altitude/diagnóstico , Doença da Altitude/fisiopatologia , Doença da Altitude/prevenção & controle , Edema Encefálico/diagnóstico , Edema Encefálico/fisiopatologia , Edema Encefálico/prevenção & controle , Humanos , Prognóstico , Edema Pulmonar/diagnóstico , Edema Pulmonar/fisiopatologia , Edema Pulmonar/prevenção & controle , Medição de Risco , Fatores de Risco
9.
Int J Mol Sci ; 20(17)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443549

RESUMO

Individuals ascending rapidly to altitudes >2500 m may develop symptoms of acute mountain sickness (AMS) within a few hours of arrival and/or high-altitude pulmonary edema (HAPE), which occurs typically during the first three days after reaching altitudes above 3000-3500 m. Both diseases have distinct pathologies, but both present with a pronounced decrease in oxygen saturation of hemoglobin in arterial blood (SO2). This raises the question of mechanisms impairing the diffusion of oxygen (O2) across the alveolar wall and whether the higher degree of hypoxemia is in causal relationship with developing the respective symptoms. In an attempt to answer these questions this article will review factors affecting alveolar gas diffusion, such as alveolar ventilation, the alveolar-to-arterial O2-gradient, and balance between filtration of fluid into the alveolar space and its clearance, and relate them to the respective disease. The resultant analysis reveals that in both AMS and HAPE the main pathophysiologic mechanisms are activated before aggravated decrease in SO2 occurs, indicating that impaired alveolar epithelial function and the resultant diffusion limitation for oxygen may rather be a consequence, not the primary cause, of these altitude-related illnesses.


Assuntos
Doença da Altitude/etiologia , Doença da Altitude/metabolismo , Altitude , Oxigênio/metabolismo , Alvéolos Pulmonares/metabolismo , Doença Aguda , Doença da Altitude/diagnóstico , Doença da Altitude/fisiopatologia , Animais , Difusão , Suscetibilidade a Doenças , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/fisiopatologia , Hipóxia/complicações , Alvéolos Pulmonares/fisiopatologia , Vasoconstrição
10.
Value Health Reg Issues ; 20: 115-121, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31255923

RESUMO

BACKGROUND: Copper mining installations in Chile use a large number of workers who do their jobs at high altitudes, exposing them to the conditions of chronic intermittent hypobaric hypoxia. The Chilean Safety Association implements the surveillance program. OBJECTIVE: This organization, under the sponsorship of the Chilean Superintendency of Social Security, was interested in determining the costs involved in this program to support its decision-making processes and to improve its performance. METHODS: Direct operating costs of the Hypoxia Medical Surveillance Program were determined through on-site surveys applied to the organization's local agencies in charge. The microcosting method was used, quantifying personnel costs, consumables, and equipment and overhead costs. Time-driven activity-based costing was partially adapted for the allocation of personnel and equipment costs. Costs concerning activities, groups of activities and items, and average cost per exposed worker were determined. RESULTS: The annual costs of the program were $127 299.58. The highest costs corresponded to the assessment activities, which were $89 192.13, representing 60.06% of the total. The labor factor costs were $77 568.50, which represents 60.93% of the total. The average cost per worker in the program is $21.17. CONCLUSIONS: The partial adaptation of the time-driven activity-based costing method in combination with the microcosting method provides a suitable solution to determine the total costs of running a healthcare program of this kind. The information generated by this study will aid in the decision-making and management processes of the Hypoxia Medical Surveillance Program.


Assuntos
Doença da Altitude/economia , Cobre , Custos de Cuidados de Saúde/estatística & dados numéricos , Mineração/economia , Doenças Profissionais/economia , Medicina do Trabalho/economia , Doença da Altitude/epidemiologia , Doença da Altitude/etiologia , Doença da Altitude/prevenção & controle , Chile/epidemiologia , Humanos , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Medicina do Trabalho/métodos , Fatores de Tempo
11.
Wilderness Environ Med ; 30(3): 306-309, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301992

RESUMO

High altitude cerebral edema (HACE) is a rare complication of ascent to altitudes of over 2500 m (8200 ft). We are not aware of a previously published case report of HACE in a patient under the age of 18 y. We report on 2 cases of suspected HACE in 2 patients, aged 12 and 16 y, who presented to the Manang Himalayan Rescue Association clinic at 3500 m. The 16-y-old patient presented with severe headache, vomiting, and ataxia after rapid ascent to 3800 m. The 12-y-old patient presented with severe headache, vomiting, visual disturbances, and ataxia at 4500 m, which began to resolve with descent to the clinic at 3500 m. Our cases suggest that HACE can occur in children and adolescents. Because there are no specific guidelines for treatment of acute mountain sickness or HACE in patients under the age of 18 y, we recommend treatment as for adults: oxygen, immediate descent, and dexamethasone. Simulated descent in a portable hyperbaric chamber can be used if oxygen is not available and if actual descent is not possible.


Assuntos
Doença da Altitude/tratamento farmacológico , Edema Encefálico/tratamento farmacológico , Montanhismo , Doença da Altitude/etiologia , Edema Encefálico/etiologia , Criança , Feminino , Humanos , Masculino , Nepal , Resultado do Tratamento
13.
Pract Neurol ; 19(5): 404-411, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31177100

RESUMO

Mountain climbers may develop specific illnesses that largely depend on the altitude reached and the rate of ascent. The popularity of travel to high altitude destinations, extreme tourist activities and mountain climbing means that neurologists in low-altitude countries are increasingly likely to encounter neurological problems and disorders in people exposed to high altitude. Additionally, they may have to advise patients with pre-existing neurological conditions on the risks of ascent to altitude. This article focuses on neurological-related high-altitude illnesses: acute mountain sickness and high-altitude cerebral oedema, as well as high-altitude retinopathy and other neurological disorders. This overview combines current understood pathogenesis with the experience of managing altitude-related illness at the foot of Mount Kilimanjaro in northern Tanzania, the tallest free-standing mountain in the world.


Assuntos
Doença da Altitude , Altitude , Edema Encefálico/etiologia , Neurologia , Doença Aguda , Doença da Altitude/etiologia , Doença da Altitude/prevenção & controle , Animais , Humanos , Tanzânia , Viagem
14.
Wilderness Environ Med ; 30(3): 328-333, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31229369

RESUMO

This wilderness essay about high altitude deterioration will explore the historical mountaineering and medical literature with a limited discussion of physiology. The writings of mountaineers and physician-mountaineers provide an evocative supporting narrative to illustrate one of the problems of living at altitude.


Assuntos
Aclimatação , Doença da Altitude/etiologia , Altitude , Montanhismo/fisiologia , Humanos
15.
Am J Cardiol ; 123(12): 2022-2025, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-30979412

RESUMO

Over 50% of patients who rapidly ascend to extreme altitudes develop various symptoms known as acute mountain sickness (AMS), which rarely can be life threatening. It is unclear why some patients are more susceptible to AMS than others. Our objective was to determine whether patent foramen ovale (PFO) is a risk factor for AMS. Subjects who had hiked to altitudes above 10,000' (∼3,000 meters) on the John Muir Trail in California were recruited. Participants completed a questionnaire and 2-physician adjudication was performed in regard to AMS status. A transcranial Doppler with agitated saline contrast injection was performed to evaluate the presence or absence of PFO. The primary outcome was the development of AMS. From 2016 to 2018, 137 hikers were recruited into the study. There was a higher prevalence of PFO in hikers with AMS 15 of 24 (63%) compared with hikers without AMS 44 of 113 (39%); p = 0.034. In the multivariate model, the presence of a PFO significantly increased the risk for developing AMS: odds ratio 4.15, 95% confidence intervals 1.14 to 15.05; p = 0.030. In conclusion, hikers with a PFO had significantly higher risk of developing AMS relative to hikers without a PFO. Clinicians should consider PFO a risk factor in patients who plan to hike to high altitudes.


Assuntos
Doença da Altitude/etiologia , Forame Oval Patente/diagnóstico , Forame Oval Patente/epidemiologia , Doença Aguda , Adulto , Doença da Altitude/diagnóstico , California , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Fatores de Risco , Ultrassonografia Doppler Transcraniana
16.
Int J Cardiol ; 283: 159-164, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30638985

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) may predispose to symptomatic pulmonary hypertension at high altitude. We investigated hemodynamic changes in lowlanders with COPD ascending rapidly to 3100 m and evaluated whether preventive dexamethasone treatment would mitigate the altitude-induced increase in pulmonary artery pressure. METHODS: In this placebo-controlled, double-blind trial, non-hypercapnic COPD patients living <800 m, were randomized to receive either dexamethasone (8 mg/day) or placebo tablets one day before ascent from 760 m and during a 3-day-stay at 3100 m. Echocardiography was performed at 760 m and after the first night at 3100 m. The trans-tricuspid pressure gradient (RV/RA, main outcome), cardiac output (Q) by velocity-time integral of left ventricular outflow, indices of right and left heart function, blood gases and pulse-oximetry (SpO2) were compared between groups. RESULTS: 95 patients, 79 men, mean ±â€¯SD age 57 ±â€¯8y FEV1 89 ±â€¯21% pred, SpO2 95 ±â€¯2% were included in the analysis. In 52 patients receiving dexamethasone, RV/RA, Q and SpO2 at 760 and 3100 m were 19 ±â€¯5 mm Hg and 26 ±â€¯7 mm Hg, 4.9 ±â€¯0.7 and 5.7 ±â€¯1.1 l/min, SpO2 95 ±â€¯2% and 90 ±â€¯3% (P < 0.05 all changes). In 43 patients receiving placebo the corresponding values were 20 ±â€¯4 mm Hg and 31 ±â€¯9 mm Hg, 4.7 ±â€¯0.9 l/min and 95 ±â€¯3% and 89 ±â€¯3% (P < 0.05 all changes) between group differences of altitude-induced changes were (mean, 95% CI): RV/RA -4.8 (-7.7 to -1.8) mm Hg, Q 0.13 (-0.3 to 0.6) l/min and SpO2 1 (-1 to 2) %. CONCLUSIONS: In lowlanders with COPD travelling to 3100 m preventive dexamethasone treatment mitigates the altitude-induced rise in RV/RA potentially along with a reduced pulmonary vascular resistance and improved oxygenation.


Assuntos
Doença da Altitude/prevenção & controle , Altitude , Dexametasona/administração & dosagem , Ventrículos do Coração/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Pressão Propulsora Pulmonar/efeitos dos fármacos , Administração Oral , Adulto , Idoso , Doença da Altitude/etiologia , Doença da Altitude/fisiopatologia , Gasometria , Relação Dose-Resposta a Droga , Método Duplo-Cego , Ecocardiografia , Feminino , Glucocorticoides/administração & dosagem , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Oximetria , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Pressão Propulsora Pulmonar/fisiologia , Resultado do Tratamento , Adulto Jovem
17.
High Alt Med Biol ; 20(1): 28-34, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30543474

RESUMO

AIMS: Changes in emotions associated with mountain treks have rarely been reported. This study examined emotional state changes in sixth-grade elementary school students before and after a 3-day high-altitude mountain trek from the trailhead (2140 m) to Xue Mountain (3886 m) in Taiwan. METHODS: In June 2011, 201 students participated in the trek. The round-trip distance was 21.8 km. The age, gender, blood group, and family configuration of the participants were documented before the trek. A 36-item short-form survey instrument, including the Mood and Anxiety Symptom Questionnaire and the Positive and Negative Affect Scale for Children, was used to evaluate the participants' emotional states (happiness, anticipation, sadness, and anger). The participants answered the questionnaires 1 month before and 1 week after the trek. A Likert scale was used to evaluate individual items (range 1-4; from strongly disagree to strongly agree). We calculated scores for each index before and after the trek. The incidence and presentation of acute mountain sickness (AMS) among the participants was also studied and published previously. RESULTS: In total, 187 (112 boys and 75 girls) participants (mean age 11.9 ± 0.4 years) completed the trek and the survey. The sadness and anger scores (negative emotions) were significantly lower after than before the trek (39.5 vs. 36.6; p < 0.01). The happiness and anticipation scores (positive emotions) before and after the trek did not differ significantly (49.9 vs. 48.9; p = 0.11). No participant used AMS prophylaxis, while 78 participants met the AMS criteria. Negative emotions decreased more in those with AMS than without AMS (-4.6 vs. -1.8; p = 0.04), and the use of medications or acetazolamide did not alter the emotions. CONCLUSIONS: A 3-day high-altitude mountain trek can reduce children's negative emotions. Negative emotions decreased more in those with AMS, whereas medications or acetazolamide did not alter their emotions.


Assuntos
Doença da Altitude/psicologia , Altitude , Emoções , Montanhismo/psicologia , Negativismo , Doença da Altitude/etiologia , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Taiwan
18.
High Alt Med Biol ; 20(1): 35-44, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30484710

RESUMO

High altitude-induced gastrointestinal (GI) problems are potentially life-threatening. GI tract bleeding and inflammation are the major problems induced by hypobaric hypoxia (HH). In this study, effects of acute exposure to HH up to 14 days at 7620 m on GI immune function have been studied. To fulfill these objectives, Sprague-Dawley (SD) rats were divided into five groups namely Control and HH exposed (1, 3, 7, and 14 days). All groups except control were exposed to 7620 m of HH in an animal decompression chamber for the respective time intervals. Different degrees of intestinal mucosal damage in terms of increased mucosal permeability and disruption of intestinal villi were observed for different time intervals. HH exposure also upregulated secretory immunoglobulin A (sIgA) and proinflammatory cytokines in GI lavage along with proinflammatory markers such as toll-like receptor 4 (TLR4) and inducible nitric oxide synthase (iNOS). HH exposure of rats for 7 days significantly increased interleukin-17 (IL-17) and natural killer (NK) cell and dendritic cell populations compared with unexposed control rats. However, the number of naive T cells was significantly decreased in Peyer's patches. Our results connect HH to GI immune axis and highlight Th17 cells and proinflammatory molecules as potential therapeutic targets to counteract HH-induced GI dysfunction.


Assuntos
Doença da Altitude/imunologia , Altitude , Trato Gastrointestinal/imunologia , Hipóxia/imunologia , Mucosa Intestinal/lesões , Doença Aguda , Doença da Altitude/etiologia , Animais , Citocinas/metabolismo , Células Dendríticas/metabolismo , Hipóxia/etiologia , Interleucina-17/metabolismo , Células Matadoras Naturais/metabolismo , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor 4 Toll-Like/metabolismo , Regulação para Cima/imunologia
19.
High Alt Med Biol ; 19(4): 329-338, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30517038

RESUMO

OBJECTIVE: To determine whether 2 days of staging at 2500-3500 m, combined with either high or low physical activity, reduces acute mountain sickness (AMS) during subsequent ascent to 4300 m. METHODS: Three independent groups of unacclimatized men and women were staged for 2 days at either 2500 m (n = 18), 3000 m (n = 16), or 3500 m (n = 15) before ascending and living for 2 days at 4300 m and compared with a control group that directly ascended to 4300 m (n = 12). All individuals departed to the staging altitudes or 4300 m after spending one night at 2000 m during which they breathed supplemental oxygen to simulate sea level conditions. Half in each group participated in ∼3 hours of daily physical activity while half were sedentary. Women accounted for ∼25% of each group. AMS incidence was assessed using the Environmental Symptoms Questionnaire. AMS was classified as mild (≥0.7 and <1.5), moderate (≥1.5 and <2.6), and severe (≥2.6). RESULTS: While staging, the incidence of AMS was lower (p < 0.001) in the 2500 m (0%), 3000 m (13%), and 3500 m (40%) staged groups than the direct ascent control group (83%). After ascent to 4300 m, the incidence of AMS was lower in the 3000 m (43%) and 3500 m (40%) groups than the 2500 m group (67%) and direct ascent control (83%). Neither activity level nor sex influenced the incidence of AMS during further ascent to 4300 m. CONCLUSIONS: Two days of staging at either 3000 or 3500 m, with or without physical activity, reduced AMS during subsequent ascent to 4300 m but staging at 3000 m may be recommended because of less incidence of AMS.


Assuntos
Aclimatação/fisiologia , Doença da Altitude/prevenção & controle , Altitude , Oxigenoterapia/métodos , Doença Aguda , Doença da Altitude/epidemiologia , Doença da Altitude/etiologia , Exercício Físico/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Incidência , Masculino , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
20.
Respir Med ; 145: 145-152, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30509704

RESUMO

After ascent to high altitude (≥2500 m), the inability of the human body to adapt to the hypobaric and hypoxia environment can induce tissue hypoxia, then a series of high altitude illnesses including acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) would develop. Symptoms of AMS include headache, dizziness, nausea, and vomiting; HAPE is characterized by orthopnea, breathlessness at rest, cough, pink frothy sputum, and results in obvious pulmonary edema that poses significant harm to people; HACE is characterized by ataxia and decreased consciousness, leading to coma and brain herniation which would be fatal if not treated promptly. This review article provides a current understanding of the pathophysiology of these three forms of high altitude illness and elaborates the current prevention and treatment measures of these diseases.


Assuntos
Doença da Altitude/etiologia , Doença da Altitude/prevenção & controle , Acetazolamida/uso terapêutico , Doença Aguda , Doença da Altitude/fisiopatologia , Doença da Altitude/terapia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Inibidores da Anidrase Carbônica/uso terapêutico , Citocinas/metabolismo , Dexametasona/uso terapêutico , Endotelina-1/metabolismo , Hemodinâmica , Humanos , Hipertensão Pulmonar , Mediadores da Inflamação/metabolismo , Nifedipino/uso terapêutico , Óxido Nítrico/metabolismo , Inibidores da Fosfodiesterase 5/uso terapêutico , Alvéolos Pulmonares/metabolismo , Citrato de Sildenafila/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...