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Gatterer H, Villafuerte FC, Ulrich S, Bhandari SS, Keyes LE, Burtscher M. Altitude illnesses. Nat Rev Dis Primers 2024; 10:43. [PMID: 38902312 DOI: 10.1038/s41572-024-00526-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/02/2024] [Indexed: 06/22/2024]
Abstract
Millions of people visit high-altitude regions annually and more than 80 million live permanently above 2,500 m. Acute high-altitude exposure can trigger high-altitude illnesses (HAIs), including acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE). Chronic mountain sickness (CMS) can affect high-altitude resident populations worldwide. The prevalence of acute HAIs varies according to acclimatization status, rate of ascent and individual susceptibility. AMS, characterized by headache, nausea, dizziness and fatigue, is usually benign and self-limiting, and has been linked to hypoxia-induced cerebral blood volume increases, inflammation and related trigeminovascular system activation. Disruption of the blood-brain barrier leads to HACE, characterized by altered mental status and ataxia, and increased pulmonary capillary pressure, and related stress failure induces HAPE, characterized by dyspnoea, cough and exercise intolerance. Both conditions are progressive and life-threatening, requiring immediate medical intervention. Treatment includes supplemental oxygen and descent with appropriate pharmacological therapy. Preventive measures include slow ascent, pre-acclimatization and, in some instances, medications. CMS is characterized by excessive erythrocytosis and related clinical symptoms. In severe CMS, temporary or permanent relocation to low altitude is recommended. Future research should focus on more objective diagnostic tools to enable prompt treatment, improved identification of individual susceptibilities and effective acclimatization and prevention options.
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Affiliation(s)
- Hannes Gatterer
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy.
- Institute for Sports Medicine, Alpine Medicine and Health Tourism (ISAG), UMIT TIROL-Private University for Health Sciences and Health Technology, Hall in Tirol, Austria.
| | - Francisco C Villafuerte
- Laboratorio de Fisiología del Transporte de Oxígeno y Adaptación a la Altura - LID, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias e Ingeniería, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Sanjeeb S Bhandari
- Mountain Medicine Society of Nepal, Kathmandu, Nepal
- Emergency Department, UPMC Western Maryland Health, Cumberland, MD, USA
| | - Linda E Keyes
- Department of Emergency Medicine, University of Colorado, Aurora, CO, USA
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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2
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Rupp T, Saugy JJ, Bourdillon N, Millet GP. Brain-muscle interplay during endurance self-paced exercise in normobaric and hypobaric hypoxia. Front Physiol 2022; 13:893872. [PMID: 36091393 PMCID: PMC9453479 DOI: 10.3389/fphys.2022.893872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/27/2022] [Indexed: 11/30/2022] Open
Abstract
Purpose: Hypoxia is one major environmental factor, supposed to mediate central motor command as well as afferent feedbacks at rest and during exercise. By using a comparison of normobaric (NH) and hypobaric (HH) hypoxia with the same ambient pressure in oxygen, we examined the potential differences on the cerebrovascular and muscular regulation interplay during a self-paced aerobic exercise. Methods: Sixteen healthy subjects performed three cycling time-trials (250 kJ) in three conditions: HH, NH and normobaric normoxia (NN) after 24 h of exposure. Cerebral and muscular oxygenation were assessed by near-infrared spectroscopy, cerebral blood flow by Doppler ultrasound system. Gas exchanges, peripheral oxygen saturation, power output and associated pacing strategies were also continuously assessed. Results: The cerebral oxygen delivery was lower in hypoxia than in NN but decreased similarly in both hypoxic conditions. Overall performance and pacing were significantly more down-regulated in HH versus NH, in conjunction with more impaired systemic (e.g. saturation and cerebral blood flow) and prefrontal cortex oxygenation during exercise. Conclusions: The difference in pacing was likely the consequence of a complex interplay between systemic alterations and cerebral oxygenation observed in HH compared to NH, aiming to maintain an equivalent cerebral oxygen delivery despite higher adaptive cost (lower absolute power output for the same relative exercise intensity) in HH compared to NH.
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Affiliation(s)
- Thomas Rupp
- LIBM, Inter-university Laboratory of Human Movement Science, University Savoie Mont Blanc, Chambéry, France
| | - Jonas J. Saugy
- ISSUL, Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Bourdillon
- ISSUL, Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Grégoire P. Millet
- ISSUL, Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
- *Correspondence: Grégoire P. Millet,
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Champigneulle B, Doutreleau S, Baillieul S, Brugniaux JV, Robach P, Bouzat P, Verges S. Changes in cardiac function following a speed ascent to the top of Europe at 4808 m. Eur J Appl Physiol 2022; 122:889-902. [PMID: 35103862 DOI: 10.1007/s00421-022-04895-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/18/2022] [Indexed: 01/21/2023]
Abstract
PURPOSE Both prolonged exercise and acute high-altitude exposure are known to induce cardiac changes. We sought to describe the cardiac responses to speed climbing at high-altitude, including left ventricular (LV) performance assessment using the myocardial work index (MWI), a new index derived from 2D speckle tracking echocardiography (STE). METHODS Eleven elite alpinists (9 males, age: 26 ± 4 years) were evaluated before and immediately after a speed ascent of the Mont-Blanc (4808 m) by echocardiography using conventional measurements as well as STE and MWI computation with derivate parameters as global work efficiency (GWE) or global wasted work (GWW). RESULTS Athletes performed a long-duration (8 h 58 min ± 60 min) and intense (78 ± 4% of maximal heart rate) ascent under gradual hypoxic conditions (minimal SpO2 at 4808 m: 71 ± 4%). Hypoxic exercise-induced cardiac fatigue was observed post-ascent with a change in right ventricular (RV) and LV systolic function (RV fractional area change: - 20 ± 23%, p = 0.01; LV global longitudinal strain change: - 8 ± 9%, p = 0.02), as well as LV geometry and RV-LV interaction alterations with emergence of a D-shape septum in 5/11 (46%) participants associated with RV pressure overload (mean pulmonary arterial pressure change: + 55 ± 20%, p < 0.001). Both MWI and GWE were reduced post-ascent (- 21 ± 16%, p = 0.004 and - 4 ± 4%, p = 0.007, respectively). Relative decrease in MWI and GWE were inversely correlated with increase in GWW (r = - 0.86, p = 0.003 and r = -0.97, p < 0.001, respectively). CONCLUSIONS Prolonged high-altitude speed climbing in elite climbers is associated with RV and LV function changes with a major interaction alteration. MWI, assessing the myocardial performance, could be a new tool for evaluating LV exercise-induced cardiac fatigue.
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Affiliation(s)
- Benoit Champigneulle
- HP2 laboratory, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, CS 10217, 38043 Cedex 9, Grenoble, France.
| | - Stéphane Doutreleau
- HP2 laboratory, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, CS 10217, 38043 Cedex 9, Grenoble, France
| | - Sébastien Baillieul
- HP2 laboratory, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, CS 10217, 38043 Cedex 9, Grenoble, France
| | - Julien Vincent Brugniaux
- HP2 laboratory, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, CS 10217, 38043 Cedex 9, Grenoble, France
| | - Paul Robach
- HP2 laboratory, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, CS 10217, 38043 Cedex 9, Grenoble, France
- National School for Mountain Sports, Site of the National School for Skiing and Mountaineering (ENSA), Chamonix, France
| | - Pierre Bouzat
- Univ. Grenoble Alpes, Inserm, U1216, CHU Grenoble Alpes, Grenoble Institut Neurosciences, Grenoble, France
| | - Samuel Verges
- HP2 laboratory, UM Sports Pathologies, Hôpital Sud, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, CS 10217, 38043 Cedex 9, Grenoble, France
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Bärtsch P. The Impact of Nocebo and Placebo Effects on Reported Incidence of Acute Mountain Sickness. High Alt Med Biol 2021; 23:8-17. [PMID: 34964659 DOI: 10.1089/ham.2021.0078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Bärtsch Peter. The impact of nocebo and placebo effects on reported incidence of acute mountain sickness. High Alt Med Biol 00:000-000, 2021. Well comparable studies reporting acute mountain sickness (AMS) in nonacclimatized, acutely exposed individuals performed at 3,450-3,650 m (9 studies) and 4,559-4,675 m (18 studies) at real altitude or in hypobaric or in normobaric hypoxic chambers were analyzed with the hypothesis that the study design impacts occurrence of AMS. Individual symptoms and overall scores of AMS were not different between the three modalities of exposure to a comparable degree of hypoxia, indicating that hypobaria has, if at all, minimal influence on AMS. Studies not focusing versus those focusing on AMS report lower scores and prevalence of AMS at 3,500 m, but not at 4,559 m, while frequent assessment may be associated with more severe AMS. These data suggest that focusing on AMS creates expectations of getting AMS (nocebo effects) and increases its prevalence, while not paying attention reduces negative expectations and thus AMS. On the other hand, interventions promising improvement may cause positive expectations (placebo effect). Information about purpose and dangers of a study, repeated assessments for AMS, previous experiences of AMS, and observation of illness in other study participants are major factors contributing to negative expectations and thus nocebo effects increasing AMS. They should be considered when designing studies and subject information and be reported in detail in publications of studies on AMS.
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Affiliation(s)
- Peter Bärtsch
- Department of Internal Medicine, University Clinic, Heidelberg, Germany
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DiMarco KG, Beasley KM, Shah K, Speros JP, Elliott JE, Laurie SS, Duke JW, Goodman RD, Futral JE, Hawn JA, Roach RC, Lovering AT. No effect of patent foramen ovale on acute mountain sickness and pulmonary pressure in normobaric hypoxia. Exp Physiol 2021; 107:122-132. [PMID: 34907608 DOI: 10.1113/ep089948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/08/2021] [Indexed: 11/08/2022]
Abstract
What is the central question to this study? Is there a relationship between a patent foramen ovale and the development of acute mountain sickness and an exaggerated increase in pulmonary pressure in response to 7-10 hours of normobaric hypoxia? What is the main finding and its importance? Patent foramen ovale presence did not increase susceptibility to acute mountain sickness or result in an exaggerated increase in pulmonary artery systolic pressure with normobaric hypoxia. This data suggest hypobaric hypoxia is integral to the increased susceptibility to acute mountain sickness previously reported in those with patent foramen ovale, and patent foramen ovale presence alone does not contribute to the hypoxic pulmonary pressor response. ABSTRACT: Acute mountain sickness (AMS) develops following rapid ascent to altitude, but its exact causes remain unknown. A patent foramen ovale (PFO) is a right-to-left intracardiac shunt present in ∼30% of the population that has been shown to increase AMS susceptibility with high altitude hypoxia. Additionally, high altitude pulmonary edema (HAPE), is a severe type of altitude illness characterized by an exaggerated pulmonary pressure response, and there is a greater prevalence of PFO in those with a history of HAPE. However, whether hypoxia, per se, is causing the increased incidence of AMS in those with a PFO and whether a PFO is associated with an exaggerated increase in pulmonary pressure in those without a history of HAPE is unknown. Participants (n = 36) matched for biological sex (18 female) and the presence or absence of a PFO (18 PFO+) were exposed to 7-10 hours of normobaric hypoxia equivalent to 4755 m. Presence and severity of AMS was determined using the Lake Louise AMS scoring system. Pulmonary artery systolic pressure, cardiac output, and total pulmonary resistance were measured using ultrasound. We found no significant association of PFO with incidence or severity of AMS and no association of PFO with arterial oxygen saturation. Additionally, there was no effect of a PFO on pulmonary pressure, cardiac output, or total pulmonary resistance. These data suggest that hypobaric hypoxia is necessary for those with a PFO to have increased incidence of AMS and that presence of PFO is not associated with an exaggerated pulmonary pressor response. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Kaitlyn G DiMarco
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
| | - Kara M Beasley
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
| | - Karina Shah
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
| | - Julia P Speros
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
| | - Jonathan E Elliott
- VA Portland Health Care System, Portland, OR, USA.,Oregon Health and Science University, Department of Neurology, Portland, OR, USA
| | - Steven S Laurie
- KBR, Cardiovascular and Vision Laboratory, NASA Johnson Space Center, Houston, TX, USA
| | - Joseph W Duke
- Northern Arizona University, Department of Biological Sciences, Flagstaff, AZ, USA
| | | | | | - Jerold A Hawn
- Oregon Heart and Vascular Institute, Springfield, OR, USA
| | - Robert C Roach
- University of Colorado Anschutz Medical Campus, Altitude Research Center, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Aurora, CO, USA
| | - Andrew T Lovering
- University of Oregon, Department of Human Physiology, Eugene, OR, USA
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Staab JE, Muza SR, Fulco CS, Andrew SP, Beidleman BA. Impact of 2 days of staging at 2500-4300 m on sleep quality and quantity following subsequent exposure to 4300 m. Physiol Rep 2021; 9:e15063. [PMID: 34713967 PMCID: PMC8554773 DOI: 10.14814/phy2.15063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/10/2021] [Accepted: 09/12/2021] [Indexed: 12/21/2022] Open
Abstract
The impact of 2 days of staging at 2500-4300 m on sleep quality and quantity following subsequent exposure to 4300 m was determined. Forty-eight unacclimatized men and women were randomly assigned to stage for 2 days at one of four altitudes (2500, 3000, 3500, or 4300 m) prior to assessment on the summit of Pikes Peak (4300 m) for 2 days. Volunteers slept for one night at sea level (SL), two nights at respective staging altitudes, and two nights at Pikes Peak. Each wore a pulse oximeter to measure sleep arterial oxygen saturation (sSpO2 , %) and number of desaturations (DeSHr, events/hr) and a wrist motion detector to estimate sleep awakenings (Awak, awakes/hr) and sleep efficiency (Eff, %). Acute mountain sickness (AMS) was assessed using the Environmental Symptoms Questionnaire and daytime SpO2 was assessed after AMS measurements. The mean of all variables for both staging days (STG) and Pikes Peak days (PP) was calculated. The sSpO2 and daytime SpO2 decreased (p < 0.05) from SL during STG in all groups in a dose-dependent manner. During STG, DeSHr were higher (p < 0.05), Eff was lower (p < 0.05), and AMS symptoms were higher (p < 0.05) in the 3500 and 4300 m groups compared to the 2500 and 3000 m groups while Awak did not differ (p > 0.05) between groups. At PP, the sSpO2 , DeSHr, Awak, and Eff were similar among all groups but the 2500 m group had greater AMS symptoms (p < 0.05) than the other groups. Two days of staging at 2500-4300 m induced a similar degree of sleep acclimatization during subsequent ascent to 4300 m but the 2500 m group was not protected against AMS at 4300 m.
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Affiliation(s)
- Janet E. Staab
- Military Performance DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Stephen R. Muza
- Strategic Scientific Management OfficeU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Charles S. Fulco
- Thermal and Mountain Medicine DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Sean P. Andrew
- Thermal and Mountain Medicine DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Beth A. Beidleman
- Biophysics and Biomedical Modeling DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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Horiuchi M, Watanabe M, Mitsui S, Uno T. Does change in barometric pressure per given time at high altitude influence symptoms of acute mountain sickness on Mount Fuji? A pilot study. J Physiol Anthropol 2021; 40:6. [PMID: 33962688 PMCID: PMC8105930 DOI: 10.1186/s40101-021-00256-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/07/2021] [Indexed: 11/10/2022] Open
Abstract
Background Acute mountain sickness (AMS) is a common, transient condition characterized primarily by headaches, and it can also be associated with fatigue, dizziness, and nausea with vomiting. The symptoms of AMS are most pronounced after the first night spent at a new altitude. At sea level, changes in barometric pressure per given time have been associated with migraine headaches. We sought to investigate whether changes in barometric pressure, subjective sleep quality index, and other candidates contributed to the risk of developing AMS on Mount Fuji in Japan. Method We surveyed 353 trekkers who stayed overnight at a mountain lodge before summitting Mount Fuji. We collected information regarding sex, age, sleeping altitude at the hut, and perceived sleep quality index including sleep time. AMS was assessed with the Lake Louise Scoring system. Barometric pressure and ambient temperature were collected at the 5th station (2305 m) and at the summit (3776 m). Result The overall prevalence of AMS in our cohort was 41.4% (Lake Louise Score ≥ 3 with headache, n=146). Using logistic regression, three factors were combined to generate a robust model for determining the risk of AMS (with or without AMS). These included (1) Δ barometric pressure during ascent per hour, (2) sleepiness on rising, and (3) sleep refreshment assessed by perceived sleep quality index. Conclusion These results suggest that climbers who stay overnight at the lodge should keep a better physical condition of sleep, and would pay attention to information of barometric pressure condition to decrease their risk of AMS at the summit of Mount Fuji. Our observatory data indicated that an overnight staying in half way up to the summit does not necessarily reduce the AMS risk in both sexes and irrespective of age, at least, until 3776 m elevation. Supplementary Information The online version contains supplementary material available at 10.1186/s40101-021-00256-y.
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Affiliation(s)
- Masahiro Horiuchi
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan.
| | - Misato Watanabe
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan
| | - Satomi Mitsui
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan
| | - Tadashi Uno
- Division of Human Environmental Science, Mount Fuji Research Institute, Kami-yoshida 5597-1, Fujiyoshida, Yamanahsi, 4030005, Japan
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Biollaz J, Buclin T, Hildebrandt W, Décosterd LA, Nussberger J, Swenson ER, Bärtsch P. No renal dysfunction or salt and water retention in acute mountain sickness at 4,559 m among young resting males after passive ascent. J Appl Physiol (1985) 2020; 130:226-236. [PMID: 33180647 DOI: 10.1152/japplphysiol.00382.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examined the role and function of the kidney at high altitude in relation to fluid balance and the development of acute mountain sickness (AMS), avoiding confounders that have contributed to conflicting results in previous studies. We examined 18 healthy male resting volunteers (18-40 yr) not acclimatized to high altitude while on a controlled diet for 24 h at Lausanne (altitude: 560 m) followed by a period of 44 h after reaching the Regina Margherita hut (4,559 m) by helicopter. AMS scores peaked after 20 h at 4,559 m. AMS was defined as functional Lake Louise score ≥ 2. There were no significant differences between 10 subjects with and 8 subjects without AMS for urinary flow, fluid balance, and weight change. Sodium excretion rate was lower in those with AMS after 24 h at altitude. Microalbuminuria increased at altitude but was not different between the groups. Creatinine clearance was not affected by altitude or AMS, whereas clearances of sinistrin and p-aminohippuric acid decreased slightly, somewhat more in those without AMS. Plasma concentrations of epinephrine, norepinephrine, atrial natriuretic factor, and vasopressin increased whereas renin activity, angiotensin, and aldosterone decreased at altitude. Circulating hormone concentrations did not differ between those with and without AMS. Summarizing, in healthy resting young men flown by helicopter to 4,559 m, renal function was not affected by hypoxia except for minor microalbuminuria, high altitude diuresis did not occur, and AMS was not associated with salt and water retention or renal dysfunction.NEW & NOTEWORTHY Kidney function remained essentially unaffected and acute mountain sickness (AMS) was not associated with salt and water retention in healthy young men flown to and resting at the Margherita hut (4,559 m) under strictly controlled conditions maintaining water, salt, and food intake at pre-exposure levels. Thus, renal dysfunction and fluid retention are not essential factors contributing to the pathophysiology of AMS.
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Affiliation(s)
- Jérôme Biollaz
- Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Thierry Buclin
- Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Wulf Hildebrandt
- Institute of Anatomy and Cell Biology, Philipps-University of Marburg, Marburg, Germany.,Department of Internal Medicine, University Clinic, Heidelberg, Germany
| | - Laurent A Décosterd
- Service of Clinical Pharmacology, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Jürg Nussberger
- Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Erik R Swenson
- Department of Internal Medicine, University Clinic, Heidelberg, Germany.,Pulmonary and Critical Care Medicine, Medical Service, Veterans Affairs Puget Sound Health Care System, University of Washington, Seattle, Washington
| | - Peter Bärtsch
- Department of Internal Medicine, University Clinic, Heidelberg, Germany
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Carballo-Fazanes A, Barcala-Furelos R, Eiroa-Bermúdez J, Fernández-Méndez M, Abelairas-Gómez C, Martínez-Isasi S, Murciano M, Fernández-Méndez F, Rodríguez-Núñez A. Physiological demands of quality cardiopulmonary resuscitation performed at simulated 3250 meters high. Am J Emerg Med 2019; 38:2580-2585. [PMID: 31911060 DOI: 10.1016/j.ajem.2019.12.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/19/2019] [Accepted: 12/23/2019] [Indexed: 01/03/2023] Open
Abstract
AIM To analyse the effect of oxygen fraction reduction (O2 14%, equivalent to 3250 m) on Q-CPR and rescuers' physiological demands. METHODOLOGY A quasi-experimental study was carried out in a sample of 9 Q-CPR proficient health care professionals. Participants, in teams of 2 people, performed 10 min CPR on a Laerdal ResusciAnne mannequin (30:2 compression/ventilation ratio and alternating roles between rescuers every 2 min) in two simulated settings: T21-CPR at sea level (FiO2 of 21%) and T14 - CPR at 3250 m altitude (FiO2 of 14%). Effort self-perception was rated from 0 (no effort) to 10 (maximum demand) points. RESULTS Quality of chest compressions was good and similar in both conditions (T21 vs T14). However, the percentage of ventilations with adequate tidal volume was lower in altitude than at sea level conditions (35.9 ± 25.2% vs. 54.7 ± 23.2%, p = 0.035). The subjective perception of effort was significantly higher at simulated altitude (5 ± 2) than at sea level (3 ± 2) (p = 0.038). Maximum heart rate during the tests was similar in both conditions; however, mean oxygen saturation was significantly lower in altitude conditions (90.5 ± 2.5% vs. 99.3 ± 0.5%, p < 0.001). CONCLUSION Although performing CPR under simulated hypoxic altitude conditions significantly increases the physiological demands and subjective feeling of tiredness compared to sea level CPR, trained rescuers are able to deliver good Q-CPR in such conditions, at least in the first 10 min of resuscitation.
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Affiliation(s)
- Aida Carballo-Fazanes
- CLINURSID Research Group, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; Santiago de Compostela's Health Research Institute (IDIS), Santiago de Compostela, Spain
| | - Roberto Barcala-Furelos
- CLINURSID Research Group, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; Santiago de Compostela's Health Research Institute (IDIS), Santiago de Compostela, Spain; Faculty of Education and Sport Sciences, REMOSS Network Research, Universidade de Vigo, Pontevedra, Spain
| | | | - María Fernández-Méndez
- CLINURSID Research Group, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; School of Nursing, REMOSS Network Research, Universidade de Vigo, Pontevedra, Spain
| | - Cristian Abelairas-Gómez
- CLINURSID Research Group, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; Santiago de Compostela's Health Research Institute (IDIS), Santiago de Compostela, Spain; Faculty of Education and Sport Sciences, REMOSS Network Research, Universidade de Vigo, Pontevedra, Spain; Faculty of Education Sciences, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
| | - Santiago Martínez-Isasi
- CLINURSID Research Group, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; Faculty of Nursing, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Manuel Murciano
- Pediatric Department, Hospital Universitario Policlinico Humberto I, Universidad de Roma "Sapienza", Roma, Italy
| | - Felipe Fernández-Méndez
- CLINURSID Research Group, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; School of Nursing, REMOSS Network Research, Universidade de Vigo, Pontevedra, Spain
| | - Antonio Rodríguez-Núñez
- CLINURSID Research Group, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; Santiago de Compostela's Health Research Institute (IDIS), Santiago de Compostela, Spain; Faculty of Nursing, Universidade de Santiago de Compostela, Santiago de Compostela, Spain; Pediatric Intensive Care Unit, University Clinical Hospital of Santiago de Compostela, Santiago de Compostela, Spain
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10
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Bottura RM, Lima GHO, Hipolide DC, Pesquero JB. Association between ACTN3 and acute mountain sickness. Genes Environ 2019; 41:18. [PMID: 31867082 PMCID: PMC6902444 DOI: 10.1186/s41021-019-0133-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/10/2019] [Indexed: 12/17/2022] Open
Abstract
Background During the process of acclimatization, when our organism needs to adjust several metabolic processes in the attempt of establishing a better oxygenation, it is normal that individuals present some symptoms that can lead to the disease of the mountain. However, not everyone presents such symptoms and individuals native of high altitudes regions present genetic differences compared to natives of low altitudes which can generate a better acute adaptation. One of these differences is the higher proportion of type I muscle fibers, which may originate from the R577X polymorphism of the ACTN3 gene. The aim of this study was to compare the response of individuals with different ACTN3 genotypes at simulated 4500 m altitude on the presence of Acute Mountain Sickness (AMS) symptoms. Twenty-three volunteers (RR = 7, RX = 8, XX = 8) spent 4 hours exposed to a simulated altitude of 4500 m inside a normobaric hypoxia chamber. Lactate and glucose concentrations, SpO2, heart rate and the symptoms of AMS were analyzed immediately before entering the chamber and at each hour of exposure. Statistical analysis was performed using IBM SPSS Statistics 21 software. Results Our results point to an association between AMS symptoms and the presence of R allele from R577X polymorphism. Conclusion We conclude that individuals with at least one R allele of the R577X polymorphism seems to be more susceptible to the effects of hypoxia during the acclimatization process and may develop AMS symptoms.
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Affiliation(s)
- Ricardo Muller Bottura
- 1Department of Psychobiology, UNIFESP, Botucatu Street, 862, First Floor, Vila Clementino, SP, ZIP, São Paulo, 04023062 Brazil
| | | | - Debora Cristina Hipolide
- 1Department of Psychobiology, UNIFESP, Botucatu Street, 862, First Floor, Vila Clementino, SP, ZIP, São Paulo, 04023062 Brazil
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11
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Jubeau M, Rupp T, Temesi J, Perrey S, Wuyam B, Millet GY, Verges S. Neuromuscular Fatigue during Prolonged Exercise in Hypoxia. Med Sci Sports Exerc 2017; 49:430-439. [PMID: 27753741 DOI: 10.1249/mss.0000000000001118] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE Prolonged cycling exercise performance in normoxia is limited because of both peripheral and central neuromuscular impairments. It has been reported that cerebral perturbations are greater during short-duration exercise in hypoxia compared with normoxia. The purpose of this study was to test the hypothesis that central deficits are accentuated in hypoxia compared with normoxia during prolonged (three bouts of 80 min separated by 25 min) whole-body exercise at the same relative intensity. METHODS Ten subjects performed two sessions consisting of three 80-min cycling bouts at 45% of their relative maximal aerobic power in normoxia and hypoxia (FiO2 = 0.12). Before exercise and after each bout, maximal voluntary force, voluntary activation assessed with nerve stimulation and transcranial magnetic stimulation, corticospinal excitability (motor evoked potential), intracortical inhibition (cortical silent period), and electrical (M-wave) and contractile (twitch and doublet peak forces) properties of the knee extensors were measured. Prefrontal and motor cortical oxygenation was also recorded during each cycling bout in both conditions. RESULTS A significant but similar force reduction (≈-22%) was observed at the end of exercise in normoxia and hypoxia. The modifications of voluntary activation assessed with transcranial magnetic stimulation and nerve stimulation, motor evoked potential, cortical silent period, and M-wave were also similar in both conditions. However, cerebral oxygenation was reduced in hypoxia compared with normoxia. CONCLUSION These findings show that when performed at the same relative low intensity, prolonged exercise does not induce greater supraspinal fatigue in hypoxia compared with normoxia. Despite lower absolute exercise intensities in hypoxia, reduced brain O2 availability might contribute to similar amounts of central fatigue compared with normoxia.
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Affiliation(s)
- Marc Jubeau
- 1Laboratory HP2, Grenoble Alpes University, Grenoble, FRANCE; 2INSERM U1042, Grenoble, FRANCE; 3Laboratory "Movement, Interactions, Performance" (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, FRANCE; 4Inter-university Laboratory of Human Movement Biology, University Savoie Mont Blanc, Chambéry, FRANCE; 5Inter-university Laboratory of Human Movement Biology, University of Lyon, UJM-Saint-Etienne, Saint-Etienne, FRANCE; 6Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, CANADA; and 7EuroMov, University of Montpellier, FRANCE
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12
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Gonggalanzi, Labasangzhu, Bjertness E, Wu T, Stigum H, Nafstad P. Acute mountain sickness, arterial oxygen saturation and heart rate among Tibetan students who reascend to Lhasa after 7 years at low altitude: a prospective cohort study. BMJ Open 2017; 7:e016460. [PMID: 28698346 PMCID: PMC5726117 DOI: 10.1136/bmjopen-2017-016460] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Objectives The aim of the present study was to estimate the incidence of acute mountain sickness (AMS) and address the changes in arterial oxygen saturation (SaO2) and heart rate (HR) in native Tibetans who reascend to the high-altitude city of Lhasa (3658 m) after a 7-year stay at low altitude. Methods We followed two cohorts of students aged 17–21 years (859 Native Tibetan and 801 Han Chinese), travelling from lowland China until 3 days after their arrival in highland city of Lhasa. Questionnaire information of the symptoms of AMS using the Lake Louise Scoring System, resting SaO2 and HR were assessed both before leaving the lowland and after arriving in Lhasa. Linear regression was performed to compare changes in SaO2 and HR levels from low to high altitude in Tibetan and Han Chinese. Results New cases of AMS occurred in only 1.2% (95% CI 0.4% to 2.0%) of the Tibetan students who came to Lhasa by train compared with 32.7% (95% CI 28.0% to 37.3%) and 42.9% (95% CI 38.0% to 47.7%) of the Han Chinese students who came to Lhasa by train and by air, respectively. Tibetan students had less changes in SaO2 (−2.95 percentage points, 95% CI −3.24% to −2.65%) and HR (10.89 beats per minute (bpm), 95% CI 9.62 to 12.16 bpm) from low to high altitude compared with Han Chinese students, although measurements did not differ between the two groups when measured at low altitude. Conclusions Healthy Tibetans are mostly protected against AMS and primarily maintain their good adaptation to high altitude, even after a long period of stay at low altitude.
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Affiliation(s)
- Gonggalanzi
- Tibet University Medical College, Tibet, China
| | - Labasangzhu
- Tibet University Medical College, Tibet, China
| | - Espen Bjertness
- Tibet University Medical College, Tibet, China.,Faculty of Medicine,University of Oslo, Oslo, Norway
| | - Tianyi Wu
- Tibet University Medical College, Tibet, China.,National Key Laboratory of High-Altitude Medicine, Xining, Qinghai, China
| | - Hein Stigum
- Faculty of Medicine,University of Oslo, Oslo, Norway.,Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
| | - Per Nafstad
- Faculty of Medicine,University of Oslo, Oslo, Norway.,Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
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13
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Luks AM, Swenson ER, Bärtsch P. Acute high-altitude sickness. Eur Respir Rev 2017; 26:26/143/160096. [PMID: 28143879 PMCID: PMC9488514 DOI: 10.1183/16000617.0096-2016] [Citation(s) in RCA: 238] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 10/23/2016] [Indexed: 12/28/2022] Open
Abstract
At any point 1–5 days following ascent to altitudes ≥2500 m, individuals are at risk of developing one of three forms of acute altitude illness: acute mountain sickness, a syndrome of nonspecific symptoms including headache, lassitude, dizziness and nausea; high-altitude cerebral oedema, a potentially fatal illness characterised by ataxia, decreased consciousness and characteristic changes on magnetic resonance imaging; and high-altitude pulmonary oedema, a noncardiogenic form of pulmonary oedema resulting from excessive hypoxic pulmonary vasoconstriction which can be fatal if not recognised and treated promptly. This review provides detailed information about each of these important clinical entities. After reviewing the clinical features, epidemiology and current understanding of the pathophysiology of each disorder, we describe the current pharmacological and nonpharmacological approaches to the prevention and treatment of these diseases. Lack of acclimatisation is the main risk factor for acute altitude illness; descent is the optimal treatmenthttp://ow.ly/45d2305JyZ0
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Affiliation(s)
- Andrew M Luks
- Dept of Medicine, Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, WA, USA
| | - Erik R Swenson
- Dept of Medicine, Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, WA, USA.,Medical Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
| | - Peter Bärtsch
- Dept of Internal Medicine, University Clinic Heidelberg, Heidelberg, Germany
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14
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DiPasquale DM, Muza SR, Gunn AM, Li Z, Zhang Q, Harris NS, Strangman GE. Evidence for cerebral edema, cerebral perfusion, and intracranial pressure elevations in acute mountain sickness. Brain Behav 2016; 6:e00437. [PMID: 27099800 PMCID: PMC4831417 DOI: 10.1002/brb3.437] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION We hypothesized that cerebral alterations in edema, perfusion, and/or intracranial pressure (ICP) are related to the development of acute mountain sickness (AMS). METHODS To vary AMS, we manipulated ambient oxygen, barometric pressure, and exercise duration. Thirty-six subjects were tested before, during and after 8 h exposures in (1) normobaric normoxia (NN; 300 m elevation equivalent); (2) normobaric hypoxia (NH; 4400 m equivalent); and (3) hypobaric hypoxia (HH; 4400 m equivalent). After a passive 15 min ascent, each subject participated in either 10 or 60 min of cycling exercise at 50% of heart rate reserve. We measured tissue absorption and scattering via radio-frequency near-infrared spectroscopy (NIRS), optic nerve sheath diameter (ONSD) via ultrasound, and AMS symptoms before, during, and after environmental exposures. RESULTS We observed significant increases in NIRS tissue scattering of 0.35 ± 0.11 cm(-1) (P = 0.001) in subjects with AMS (i.e., AMS+), consistent with mildly increased cerebral edema. We also noted a small, but significant increase in total hemoglobin concentrations with AMS+, 3.2 ± 0.8 μmolL(-1) (P < 0.0005), consistent with increased cerebral perfusion. No effect of exercise duration was found, nor did we detect differences between NH and HH. ONSD assays documented a small but significant increase in ONSD (0.11 ± 0.02 mm; P < 0.0005) with AMS+, suggesting mildly elevated ICP, as well as further increased ONSD with longer exercise duration (P = 0.005). CONCLUSION In AMS+, we found evidence of cerebral edema, elevated cerebral perfusion, and elevated ICP. The observed changes were small but consistent with the reversible nature of AMS.
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Affiliation(s)
- Dana M DiPasquale
- Psychiatry Department Massachusetts General Hospital Harvard Medical School Charlestown Massachusetts
| | - Stephen R Muza
- Environmental Medicine and Military Performance Division U.S. Army Research Institute of Environmental Medicine Natick Massachusetts
| | - Andrea M Gunn
- Psychiatry Department Massachusetts General Hospital Harvard Medical School Charlestown Massachusetts
| | - Zhi Li
- Psychiatry Department Massachusetts General Hospital Harvard Medical School Charlestown Massachusetts
| | - Quan Zhang
- Psychiatry Department Massachusetts General Hospital Harvard Medical School Charlestown Massachusetts; Center for Space Medicine Baylor College of Medicine Houston Texas
| | - N Stuart Harris
- Department of Emergency Medicine Division of Wilderness Medicine Massachusetts General Hospital Harvard Medical School Boston Massachusetts
| | - Gary E Strangman
- Psychiatry Department Massachusetts General Hospital Harvard Medical School Charlestown Massachusetts; Center for Space Medicine Baylor College of Medicine Houston Texas
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15
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Shah NM, Hussain S, Cooke M, O’Hara JP, Mellor A. Wilderness medicine at high altitude: recent developments in the field. Open Access J Sports Med 2015; 6:319-28. [PMID: 26445563 PMCID: PMC4590685 DOI: 10.2147/oajsm.s89856] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Travel to high altitude is increasingly popular. With this comes an increased incidence of high-altitude illness and therefore an increased need to improve our strategies to prevent and accurately diagnose these. In this review, we provide a summary of recent advances of relevance to practitioners who may be advising travelers to altitude. Although the Lake Louise Score is now widely used as a diagnostic tool for acute mountain sickness (AMS), increasing evidence questions the validity of doing so, and of considering AMS as a single condition. Biomarkers, such as brain natriuretic peptide, are likely correlating with pulmonary artery systolic pressure, thus potential markers of the development of altitude illness. Established drug treatments include acetazolamide, nifedipine, and dexamethasone. Drugs with a potential to reduce the risk of developing AMS include nitrate supplements, propagators of nitric oxide, and supplemental iron. The role of exercise in the development of altitude illness remains hotly debated, and it appears that the intensity of exercise is more important than the exercise itself. Finally, despite copious studies demonstrating the value of preacclimatization in reducing the risk of altitude illness and improving performance, an optimal protocol to preacclimatize an individual remains elusive.
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Affiliation(s)
- Neeraj M Shah
- Division of Asthma, Allergy and Lung Biology, King’s College London, UK
| | - Sidra Hussain
- School of Medicine, University College London, London, UK
| | - Mark Cooke
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - John P O’Hara
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
| | - Adrian Mellor
- Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK
- Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, UK
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16
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Puthon L, Bouzat P, Rupp T, Robach P, Favre-Juvin A, Verges S. Physiological characteristics of elite high-altitude climbers. Scand J Med Sci Sports 2015; 26:1052-9. [DOI: 10.1111/sms.12547] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2015] [Indexed: 11/27/2022]
Affiliation(s)
- L. Puthon
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
- Pôle Anesthésie Réanimation; CHU de Grenoble; Grenoble France
| | - P. Bouzat
- Pôle Anesthésie Réanimation; CHU de Grenoble; Grenoble France
- Grenoble Institute of Neurosciences; INSERM U836; Grenoble France
| | - T. Rupp
- Laboratoire de Physiologie de l'Exercice; Université Savoie Mont Blanc; Chambéry France
| | - P. Robach
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
- Medical Department; Ecole Nationale des Sports de Montagne; site de l'Ecole Nationale de Ski et d'Alpinisme; Chamonix France
| | - A. Favre-Juvin
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
| | - S. Verges
- HP2 Laboratory; Faculté de Médecine; Grenoble Alpes University; Batiment Jean Roget; Grenoble France
- U1042; Faculté de Médecine; INSERM; Batiment Jean Roget; Grenoble France
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17
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Cerebral volumetric changes induced by prolonged hypoxic exposure and whole-body exercise. J Cereb Blood Flow Metab 2014; 34:1802-9. [PMID: 25160673 PMCID: PMC4269757 DOI: 10.1038/jcbfm.2014.148] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/17/2014] [Accepted: 07/28/2014] [Indexed: 11/08/2022]
Abstract
The present study assessed the isolated and synergetic effects of hypoxic exposure and prolonged exercise on cerebral volume and subedema and symptoms of acute mountain sickness (AMS). Twelve healthy males performed three semirandomized blinded 11-hour sessions with (1) an inspiratory oxygen fraction (FiO2) of 12% and 4-hour cycling, (2) FiO2=21% and 4-hour cycling, and (3) FiO2=8.5% to 12% at rest (matching arterial oxygen saturation measured during the first hypoxic session). Volumetric, apparent diffusion coefficient (ADC), and arterial spin labelling 3T magnetic resonance imaging sequences were performed after 30 minutes and 10 hours in each session. Thirty minutes of hypoxia at rest induced a significant increase in white-matter volume (+0.8±1.0% compared with normoxia) that was exacerbated after 10 hours of hypoxia at rest (+1.5±1.1%) or with cycling (+1.6±1.1%). Total brain parenchyma volume increased significantly after 10 hours of hypoxia with cycling only (+1.3±1.1%). Apparent diffusion coefficient was significantly reduced after 10 hours of hypoxia at rest or with cycling. No significant change in cerebral blood flow was observed. These results demonstrate changes in white-matter volume as early as after 30 minutes of hypoxia that worsen after 10 hours, probably due to cytotoxic edema. Exercise accentuates the effect of hypoxia by increasing total brain volume. These changes do not however correlate with AMS symptoms.
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18
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Sightings edited by Erik R. Swenson and Peter Bärtsch. High Alt Med Biol 2014. [DOI: 10.1089/ham.2014.1533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Wang JC, Tsai SH, Chen YL, Hsu CW, Lai KC, Liao WI, Li LY, Kao WF, Fan JS, Chen YH. The physiological effects and quality of chest compressions during CPR at sea level and high altitude. Am J Emerg Med 2014; 32:1183-8. [PMID: 25154345 DOI: 10.1016/j.ajem.2014.07.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/12/2014] [Accepted: 07/04/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Rescuers that undergo acute ascent without acclimatization can experience acute mountain sickness. Although performing cardiopulmonary resuscitation (CPR) for a short period requires intensive effort at sea level, performing CPR at high altitude is even more exhausting and can endanger the rescuer. Therefore, we conducted a pilot study to compare the quality of resuscitation in health professionals at high altitude (3100 m) and that at sea level. METHODS Thirty-eight participants were asked to performed continuous chest compression CPR (CCC-CPR) for 5 minutes at sea level and at high altitude. Cardiopulmonary resuscitation recording technology was used to objectively quantify the quality of the chest compressions (CCs), including the depth and rate thereof. RESULTS At high altitude, rescuers showed a statistically significant decrease in blood oxygen saturation and an increase in systolic blood pressure, diastolic blood pressure, heart rate, and fatigue, as measured with the Borg score, after CCC-CPR compared with resting levels. The analysis of the time-dependent deterioration in the quality of CCC-CPR showed that the depth of CCs declined from the mean depth of the first 30 seconds after CCC-CPR to that at more than 120 seconds after CCC-CPR at both sea level and high altitude. The average number of effective CCs declined after CCC-CPR was performed for 1 minute at sea level and high altitude. CONCLUSIONS The quality of CC rapidly declined at high altitude. At high altitude, the average number of effective CC decreases; and this decrease became significant after continuous CCs had been performed for 1 minute.
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Affiliation(s)
- Jen-Chun Wang
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Hung Tsai
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Long Chen
- Department of Emergency Medicine, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan
| | - Chin-Wang Hsu
- Department of Emergency and Critical Care Medicine, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan
| | - Kuan-Cheng Lai
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Wen-I Liao
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ling-Yuan Li
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Wei-Fong Kao
- Department of Emergency & Critical Care Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Ju-Sing Fan
- Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ying-Hsin Chen
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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Hoshikawa M, Suzuki Y, Oriishi M. Effects of Normobaric Hypoxia Equivalent to 2,000-m Altitude on Sleep and Physiological Conditions of Athletes. J Strength Cond Res 2013; 27:2309-13. [DOI: 10.1519/jsc.0b013e318295d338] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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