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Lagman-Bartolome AM, Im J, Gladstone J. Headaches Attributed to Disorders of Homeostasis. Neurol Clin 2024; 42:521-542. [PMID: 38575264 DOI: 10.1016/j.ncl.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Headaches attributed to disorders of homeostasis include those different headache types associated with metabolic and systemic diseases. These are headache disorders occurring in temporal relation to a disorder of homeostasis including hypoxia, high altitude, airplane travel, diving, sleep apnea, dialysis, autonomic dysreflexia, hypothyroidism, fasting, cardiac cephalalgia, hypertension and other hypertensive disorders like pheochromocytoma, hypertensive crisis, and encephalopathy, as well as preeclampsia or eclampsia. The proposed mechanism behind the causation of these headache subtypes including diagnostic criteria, evaluation, treatment, and overall management will be discussed.
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Affiliation(s)
- Ana Marissa Lagman-Bartolome
- Department of Pediatrics, Division of Neurology, The Hospital for Sick Children, University of Toronto; Department of Pediatrics, Division of Neurology, Children's Hospital, London Health Sciences Center, Schulich School of Medicine & Dentistry, University of Western Ontario, 800 Commissioner's Road East, London, Ontario N6A5W9, Canada.
| | - James Im
- Department of Medicine, Division of Adult Neurology, St. Michael's Hospital, University of Toronto, 30 Bond Street, Toronto, Ontario M5B1W8, Canada
| | - Jonathan Gladstone
- Department of Pediatrics, Division of Neurology, The Hospital for Sick Children, University of Toronto; Gladstone Headache Clinic, 1333 Sheppard Avenue E, Suite 122, North York, Ontario M2J1V1, Canada
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2
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Ma J, Ma Y, Yi J, Lei P, Fang Y, Wang L, Liu F, Luo L, Zhang K, Jin L, Yang Q, Sun D, Zhang C, Wu D. Rapid altitude displacement induce zebrafish appearing acute high altitude illness symptoms. Heliyon 2024; 10:e28429. [PMID: 38590888 PMCID: PMC10999933 DOI: 10.1016/j.heliyon.2024.e28429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 03/17/2024] [Accepted: 03/19/2024] [Indexed: 04/10/2024] Open
Abstract
Rapid ascent to high-altitude areas above 2500 m often leads to acute high altitude illness (AHAI), posing significant health risks. Current models for AHAI research are limited in their ability to accurately simulate the high-altitude environment for drug screening. Addressing this gap, a novel static self-assembled water vacuum transparent chamber was developed to induce AHAI in zebrafish. This study identified 6000 m for 2 h as the optimal condition for AHAI induction in zebrafish. Under these conditions, notable behavioral changes including slow movement, abnormal exploration behavior and static behavior in the Novel tank test. Furthermore, this model demonstrated changes in oxidative stress-related markers included increased levels of malondialdehyde, decreased levels of glutathione, decreased activities of superoxide dismutase and catalase, and increased levels of inflammatory markers IL-6, IL-1β and TNF-α, and inflammatory cell infiltration and mild edema in the gill tissue, mirroring the clinical pathophysiology observed in AHAI patients. This innovative zebrafish model not only offers a more accurate representation of the high-altitude environment but also provides a high-throughput platform for AHAI drug discovery and pathogenesis research.
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Affiliation(s)
- Jiahui Ma
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
- National and Local Joint Engineering Research Center of Ecological Treatment Technology of Urban Water Pollution, College of Life and Environmental Science, Wenzhou University, Wenzhou, 325035, China
| | - Yilei Ma
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
| | - Jia Yi
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
| | - Pengyu Lei
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
| | - Yimeng Fang
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
| | - Lei Wang
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, 325000, China
| | - Fan Liu
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
| | - Li Luo
- Affiliated Dongguang Hospital, Southern Medical University, Dongguang, 523059, China
| | - Kun Zhang
- Bioengineering College of Chongqing University, Chongqing, 400044, China
| | - Libo Jin
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
| | - Qinsi Yang
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, 325000, China
| | - Da Sun
- Institute of Life Sciences & Biomedical Collaborative Innovation Center of Zhejiang Province, Wenzhou University, Wenzhou, 325000, China
- Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou, 325000, China
| | - Chi Zhang
- Department of Clinical Translational Research, The Third Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325200, China
| | - Dejun Wu
- Emergency Department, Quzhou People's Hospital, Quzhou, 324000, China
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Cates VC, Bruce CD, Marullo AL, Isakovich R, Saran G, Leacy JK, O′Halloran KD, Brutsaert TD, Sherpa MT, Day TA. Steady-state chemoreflex drive captures ventilatory acclimatization during incremental ascent to high altitude: Effect of acetazolamide. Physiol Rep 2022; 10:e15521. [PMID: 36461658 PMCID: PMC9718940 DOI: 10.14814/phy2.15521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023] Open
Abstract
Ventilatory acclimatization (VA) is important to maintain adequate oxygenation with ascent to high altitude (HA). Transient hypoxic ventilatory response tests lack feasibility and fail to capture the integrated steady-state responses to chronic hypoxic exposure in HA fieldwork. We recently characterized a novel index of steady-state respiratory chemoreflex drive (SSCD), accounting for integrated contributions from central and peripheral respiratory chemoreceptors during steady-state breathing at prevailing chemostimuli. Acetazolamide is often utilized during ascent for prevention or treatment of altitude-related illnesses, eliciting metabolic acidosis and stimulating respiratory chemoreceptors. To determine if SSCD reflects VA during ascent to HA, we characterized SSCD in 25 lowlanders during incremental ascent to 4240 m over 7 days. We subsequently compared two separate subgroups: no acetazolamide (NAz; n = 14) and those taking an oral prophylactic dose of acetazolamide (Az; 125 mg BID; n = 11). At 1130/1400 m (day zero) and 4240 m (day seven), steady-state measurements of resting ventilation (V̇I ; L/min), pressure of end-tidal (PET )CO2 (Torr), and peripheral oxygen saturation (SpO2 ; %) were measured. A stimulus index (SI; PET CO2 /SpO2 ) was calculated, and SSCD was calculated by indexing V̇I against SI. We found that (a) both V̇I and SSCD increased with ascent to 4240 m (day seven; V̇I : +39%, p < 0.0001, Hedges' g = 1.52; SSCD: +56.%, p < 0.0001, Hedges' g = 1.65), (b) and these responses were larger in the Az versus NAz subgroup (V̇I : p = 0.02, Hedges' g = 1.04; SSCD: p = 0.02, Hedges' g = 1.05). The SSCD metric may have utility in assessing VA during prolonged stays at altitude, providing a feasible alternative to transient chemoreflex tests.
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Affiliation(s)
- Valerie C. Cates
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Christina D. Bruce
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Anthony L. Marullo
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
- Department of Physiology. School of MedicineUniversity Cork CollegeCorkIreland
| | - Rodion Isakovich
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Gurkarn Saran
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
| | - Jack K. Leacy
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
- Department of Physiology. School of MedicineUniversity Cork CollegeCorkIreland
| | - Ken D. O′Halloran
- Department of Physiology. School of MedicineUniversity Cork CollegeCorkIreland
| | | | | | - Trevor A. Day
- Department of Biology, Faculty of Science and TechnologyMount Royal UniversityCalgaryAlbertaCanada
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Pham K, Frost S, Parikh K, Puvvula N, Oeung B, Heinrich EC. Inflammatory gene expression during acute high‐altitude exposure. J Physiol 2022; 600:4169-4186. [PMID: 35875936 PMCID: PMC9481729 DOI: 10.1113/jp282772] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 06/22/2022] [Indexed: 11/08/2022] Open
Abstract
Abstract The molecular signalling pathways that regulate inflammation and the response to hypoxia share significant crosstalk and appear to play major roles in high‐altitude acclimatization and adaptation. Several studies demonstrate increases in circulating candidate inflammatory markers during acute high‐altitude exposure, but significant gaps remain in our understanding of how inflammation and immune function change at high altitude and whether these responses contribute to high‐altitude pathologies, such as acute mountain sickness. To address this, we took an unbiased transcriptomic approach, including RNA sequencing and direct digital mRNA detection with NanoString, to identify changes in the inflammatory profile of peripheral blood throughout 3 days of high‐altitude acclimatization in healthy sea‐level residents (n = 15; five women). Several inflammation‐related genes were upregulated on the first day of high‐altitude exposure, including a large increase in HMGB1 (high mobility group box 1), a damage‐associated molecular pattern (DAMP) molecule that amplifies immune responses during tissue injury. Differentially expressed genes on the first and third days of acclimatization were enriched for several inflammatory pathways, including nuclear factor‐κB and Toll‐like receptor (TLR) signalling. Indeed, both TLR4 and LY96, which encodes the lipopolysaccharide binding protein (MD‐2), were upregulated at high altitude. Finally, FASLG and SMAD7 were associated with acute mountain sickness scores and peripheral oxygen saturation levels on the first day at high altitude, suggesting a potential role of immune regulation in response to high‐altitude hypoxia. These results indicate that acute high‐altitude exposure upregulates inflammatory signalling pathways and might sensitize the TLR4 signalling pathway to subsequent inflammatory stimuli.
![]() Key points Inflammation plays a crucial role in the physiological response to hypoxia. High‐altitude hypoxia exposure causes alterations in the inflammatory profile that might play an adaptive or maladaptive role in acclimatization. In this study, we characterized changes in the inflammatory profile following acute high‐altitude exposure. We report upregulation of novel inflammation‐related genes in the first 3 days of high‐altitude exposure, which might play a role in immune system sensitization. These results provide insight into how hypoxia‐induced inflammation might contribute to high‐altitude pathologies and exacerbate inflammatory responses in critical illnesses associated with hypoxaemia.
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Affiliation(s)
- Kathy Pham
- Division of Biomedical Sciences School of Medicine University of California Riverside Riverside CA USA
| | - Shyleen Frost
- Division of Biomedical Sciences School of Medicine University of California Riverside Riverside CA USA
| | - Keval Parikh
- Division of Biomedical Sciences School of Medicine University of California Riverside Riverside CA USA
| | - Nikhil Puvvula
- Division of Biomedical Sciences School of Medicine University of California Riverside Riverside CA USA
| | - Britney Oeung
- Division of Biomedical Sciences School of Medicine University of California Riverside Riverside CA USA
| | - Erica C. Heinrich
- Division of Biomedical Sciences School of Medicine University of California Riverside Riverside CA USA
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5
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Gao D, Wang Y, Zhang R, Zhang Y. Efficacy of acetazolamide for the prophylaxis of acute mountain sickness: A systematic review, meta-analysis, and trial sequential analysis of randomized clinical trials. Ann Thorac Med 2021; 16:337-346. [PMID: 34820021 PMCID: PMC8588948 DOI: 10.4103/atm.atm_651_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 04/08/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Acute mountain sickness (AMS) is a benign and self-limiting syndrome, but can progress to life-threatening conditions if leave untreated. This study aimed to assess the efficacy of acetazolamide for the prophylaxis of AMS, and disclose factors that affect the treatment effect of acetazolamide. METHODS Randomized controlled trials comparing the use of acetazolamide versus placebo for the prevention of AMS were included. The incidence of AMS was our primary endpoint. Meta-regression analysis was conducted to explore factors that associated with acetazolamide efficacy. Trial sequential analyses were conducted to estimate the statistical power of the available data. RESULTS A total of 22 trials were included. Acetazolamide at 125, 250, and 375 mg/bid significantly reduced incidence of AMS compared to placebo. TAS indicated that the current evidence was adequate confirming the efficacy of acetazolamide at 125, 250, and 375 mg/bid in lowering incidence of AMS. There was no evidence of an association between efficacy and dose of acetazolamide, timing at start of acetazolamide treatment, mode of ascent, AMS assessment score, timing of AMS assessment, baseline altitude, and endpoint altitude. CONCLUSION Acetazolamide is effective prophylaxis for the prevention of AMS at 125, 250, and 375 mg/bid. Future investigation should focus on personal characteristics, disclosing the correlation between acetazolamide efficacy and body mass, height, degree of prior acclimatization, individual inborn susceptibility, and history of AMS.
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Affiliation(s)
- Daiquan Gao
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yuan Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Rujiang Zhang
- Department of Neurology, The People's Hospital of RuiLi, Yunnan, China
| | - Yunzhou Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
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Lipman GS, Moritz Berger M. Re: "Altitude, Acute Mountain Sickness, and Acetazolamide: Recommendations for Rapid Ascent" by Toussaint et al. High Alt Med Biol 2021; 22:429-430. [PMID: 34551273 DOI: 10.1089/ham.2021.0074] [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
Affiliation(s)
- Grant S Lipman
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, California, USA
| | - Marc Moritz Berger
- Department of Anesthesiology, Perioperative and General Critical Care Medicine, Salzburg General Hospital, Paracelsus Medical University, Salzburg, Austria
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Sibomana I, Foose DP, Raymer ML, Reo NV, Karl JP, Berryman CE, Young AJ, Pasiakos SM, Mauzy CA. Urinary Metabolites as Predictors of Acute Mountain Sickness Severity. Front Physiol 2021; 12:709804. [PMID: 34588992 PMCID: PMC8475947 DOI: 10.3389/fphys.2021.709804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/19/2021] [Indexed: 11/15/2022] Open
Abstract
Individuals sojourning at high altitude (≥2,500m) often develop acute mountain sickness (AMS). However, substantial unexplained inter-individual variability in AMS severity exists. Untargeted metabolomics assays are increasingly used to identify novel biomarkers of susceptibility to illness, and to elucidate biological pathways linking environmental exposures to health outcomes. This study used untargeted nuclear magnetic resonance (NMR)-based metabolomics to identify urine metabolites associated with AMS severity during high altitude sojourn. Following a 21-day stay at sea level (SL; 55m), 17 healthy males were transported to high altitude (HA; 4,300m) for a 22-day sojourn. AMS symptoms measured twice daily during the first 5days at HA were used to dichotomize participants according to AMS severity: moderate/severe AMS (AMS; n=11) or no/mild AMS (NoAMS; n=6). Urine samples collected on SL day 12 and HA days 1 and 18 were analyzed using proton NMR tools and the data were subjected to multivariate analyses. The SL urinary metabolite profiles were significantly different (p≤0.05) between AMS vs. NoAMS individuals prior to high altitude exposure. Differentially expressed metabolites included elevated levels of creatine and acetylcarnitine, and decreased levels of hypoxanthine and taurine in the AMS vs. NoAMS group. In addition, the levels of two amino acid derivatives (4-hydroxyphenylpyruvate and N-methylhistidine) and two unidentified metabolites (doublet peaks at 3.33ppm and a singlet at 8.20ppm) were significantly different between groups at SL. By HA day 18, the differences in urinary metabolites between AMS and NoAMS participants had largely resolved. Pathway analysis of these differentially expressed metabolites indicated that they directly or indirectly play a role in energy metabolism. These observations suggest that alterations in energy metabolism before high altitude exposure may contribute to AMS susceptibility at altitude. If validated in larger cohorts, these markers could inform development of a non-invasive assay to screen individuals for AMS susceptibility prior to high altitude sojourn.
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Affiliation(s)
- Isaie Sibomana
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson AFB, Dayton, OH, United States
| | - Daniel P. Foose
- Department of Computer Science and Engineering, Wright State University, Dayton, OH, United States
| | - Michael L. Raymer
- Department of Computer Science and Engineering, Wright State University, Dayton, OH, United States
| | - Nicholas V. Reo
- Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - J. Philip Karl
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Claire E. Berryman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
- Department of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, FL, United States
- Oak Ridge Institute of Science and Education, Belcamp, MD, United States
| | - Andrew J. Young
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
- Oak Ridge Institute of Science and Education, Belcamp, MD, United States
| | - Stefan M. Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Camilla A. Mauzy
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson AFB, Dayton, OH, United States
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Pham K, Parikh K, Heinrich EC. Hypoxia and Inflammation: Insights From High-Altitude Physiology. Front Physiol 2021; 12:676782. [PMID: 34122145 PMCID: PMC8188852 DOI: 10.3389/fphys.2021.676782] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 04/26/2021] [Indexed: 12/19/2022] Open
Abstract
The key regulators of the transcriptional response to hypoxia and inflammation (hypoxia inducible factor, HIF, and nuclear factor-kappa B, NF-κB, respectively) are evolutionarily conserved and share significant crosstalk. Tissues often experience hypoxia and inflammation concurrently at the site of infection or injury due to fluid retention and immune cell recruitment that ultimately reduces the rate of oxygen delivery to tissues. Inflammation can induce activity of HIF-pathway genes, and hypoxia may modulate inflammatory signaling. While it is clear that these molecular pathways function in concert, the physiological consequences of hypoxia-induced inflammation and how hypoxia modulates inflammatory signaling and immune function are not well established. In this review, we summarize known mechanisms of HIF and NF-κB crosstalk and highlight the physiological consequences that can arise from maladaptive hypoxia-induced inflammation. Finally, we discuss what can be learned about adaptive regulation of inflammation under chronic hypoxia by examining adaptive and maladaptive inflammatory phenotypes observed in human populations at high altitude. We aim to provide insight into the time domains of hypoxia-induced inflammation and highlight the importance of hypoxia-induced inflammatory sensitization in immune function, pathologies, and environmental adaptation.
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Affiliation(s)
| | | | - Erica C. Heinrich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
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Urdampilleta A, León-Guereño P, Calleja-González J, Roche E, Mielgo-Ayuso J. Inclusion of resistance routines in a hypoxia training program does not interfere with prevention of acute mountain sickness. PHYSICIAN SPORTSMED 2021; 49:151-157. [PMID: 32578478 DOI: 10.1080/00913847.2020.1786344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Acclimatization strategies have been shown to be the best solutions to avoid acute mountain sickness. In this context, we have designed a protocol performed in hypoxia that includes resistance routines in combination with classical endurance training exercises with mountain trekking at mid altitude. METHODS Thirty-two volunteers preparing different mountain expeditions participated in the study distributed into two groups. One group trained at 2000 m, while another group trained at 4500-5800 m of simulated altitude in a hypoxic chamber. Acute mountain sickness was monitored by answering the Lake Louise Scale questionnaire during 2 sleeping sessions at 4800 m of simulated altitude at the beginning and at the end of the study. At the same time, oxygen saturation was determined in both groups to monitor physiologic adaptation. Data were also collected from the base camps in each expedition before ascension. RESULTS Acute mountain sickness incidence in the hypoxic group decreased from 100% at the beginning to 12% of individuals at the end of the training period, and it was 25% at the base camps of expeditions. On the other hand, the control group passed from 100% to 88% of individuals at the end of the intervention and 70% at the base camps. At the same time, acute mountain sickness severity was mild in the experimental group compared to moderate-severe in the control group. These data were supported by the oxygen saturation values, indicating adequate adaptation changes for altitude in the hypoxic group. CONCLUSION The inclusion of resistance workouts in combination with endurance exercises, all performed in hypoxic conditions, does not interfere with an optimal adaptation to altitude and to prevent acute mountain sickness.
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Affiliation(s)
| | | | - Julio Calleja-González
- Department of Physical Education and Sports, University of Basque Country (UPV-EHU), Vitoria, Spain
| | - Enrique Roche
- Department of Applied Biology-Nutrition, Institute of Bioengineering, University Miguel Hernandez (Elche). Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain.,CIBERobn (Fisiopatología De La Obesidad Y La Nutrición CB12/03/30038) Instituto De Salud Carlos III, Spain
| | - Juan Mielgo-Ayuso
- Department of Biochemistry, Molecular Biology and Physiology, Faculty of Physical Therapy, University of Valladolid, Soria, Spain
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High-altitude illnesses: Old stories and new insights into the pathophysiology, treatment and prevention. SPORTS MEDICINE AND HEALTH SCIENCE 2021; 3:59-69. [PMID: 35782163 PMCID: PMC9219347 DOI: 10.1016/j.smhs.2021.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/11/2021] [Accepted: 04/11/2021] [Indexed: 01/19/2023] Open
Abstract
Areas at high-altitude, annually attract millions of tourists, skiers, trekkers, and climbers. If not adequately prepared and not considering certain ascent rules, a considerable proportion of those people will suffer from acute mountain sickness (AMS) or even from life-threatening high-altitude cerebral (HACE) or/and pulmonary edema (HAPE). Reduced inspired oxygen partial pressure with gain in altitude and consequently reduced oxygen availability is primarily responsible for getting sick in this setting. Appropriate acclimatization by slowly raising the hypoxic stimulus (e.g., slow ascent to high altitude) and/or repeated exposures to altitude or artificial, normobaric hypoxia will largely prevent those illnesses. Understanding physiological mechanisms of acclimatization and pathophysiological mechanisms of high-altitude diseases, knowledge of symptoms and signs, treatment and prevention strategies will largely contribute to the risk reduction and increased safety, success and enjoyment at high altitude. Thus, this review is intended to provide a sound basis for both physicians counseling high-altitude visitors and high-altitude visitors themselves.
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11
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Gao D, Wang Y, Zhang R, Zhang Y. Efficacy of Acetazolamide for the Prophylaxis of Acute Mountain Sickness: A Systematic Review, Meta-Analysis and Trial Sequential Analysis of Randomized Clinical Trials. Am J Med Sci 2021; 361:635-645. [PMID: 33587912 DOI: 10.1016/j.amjms.2020.12.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/24/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
BACKGROUND Acute mountain sickness (AMS) is a benign and self-limiting syndrome but can progress to life-threatening conditions if leave untreated. This study aimed to assess the efficacy of acetazolamide for the prophylaxis of AMS and disclose potential factors that affect the treatment effect of acetazolamide. MATERIALS AND METHODS Randomized controlled trials comparing the use of acetazolamide versus placebo for the prevention of AMS were included. The incidence of AMS was the primary endpoint. Meta-regression analysis was conducted to explore potential factors associated with acetazolamide efficacy. Trial sequential analysis (TSA) was conducted to estimate the statistical power of the available data. RESULTS A total of 22 trials were included. Acetazolamide at 125, 250, and 375 mg/ twice daily (bid) significantly reduced incidence of AMS compared to placebo. TAS indicated that the current evidence was adequate confirming the efficacy of acetazolamide at 125, 250, and 375 mg/bid in lowering incidence of AMS. There was no evidence of an association between efficacy and dose of acetazolamide, timing at start of acetazolamide treatment, mode of ascent, AMS assessment score, timing of AMS assessment, baseline altitude, and endpoint altitude. CONCLUSION Acetazolamide is effective prophylaxis for the prevention of AMS in doses of 125, 250, and 375 mg/bid. Future investigations should focus on personal characteristics, disclosing the correlation between acetazolamide efficacy and body mass, height, degree of prior acclimatization, individual inborn susceptibility, and history of AMS.
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Affiliation(s)
- Daiquan Gao
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Xicheng District, Beijing, China
| | - Yuan Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Xicheng District, Beijing, China
| | - Rujiang Zhang
- Department of Neurology, The People's Hospital of RuiLi, Yunnan, China
| | - Yunzhou Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Xicheng District, Beijing, China.
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12
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A Randomized Controlled Trial of the Lowest Effective Dose of Acetazolamide for Acute Mountain Sickness Prevention. Am J Med 2020; 133:e706-e715. [PMID: 32479750 DOI: 10.1016/j.amjmed.2020.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/06/2020] [Accepted: 05/06/2020] [Indexed: 01/19/2023]
Abstract
BACKGROUND Acetazolamide is the most common medication used for acute mountain sickness prevention, with speculation that a reduced dose may be as efficacious as standard dosing with fewer side effects. METHODS This double-blind, randomized, controlled noninferiority trial compared acetazolamide 62.5 mg twice daily to the standard dose acetazolamide 125 mg twice daily starting the evening prior to ascent from 1240 m (4100 ft) to 3810 m (12,570 ft) over 4 hours. The primary outcome was acute mountain sickness incidence (ie, headache, Lake Louise Questionnaire ≥3, and another symptom). RESULTS A total of 106 participants were analyzed, with 51 (48%) randomized to 125 mg and 55 (52%) to 62.5 mg, with a combined acute mountain sickness incidence of 53 (50%) and mean severity of 3 (± 2.1). The 62.5-mg group failed to fall within the prespecified 26% noninferiority margin for acute mountain sickness incidence (62.5 mg = 30 [55%] vs 125 mg = 23 [45%], 95% confidence interval [CI] -11% to 30%). Participants in the 62.5-mg group had a higher risk of acute mountain sickness (odds ratio = 1.5, 95% CI 0.7-3.2) and moderate acute mountain sickness (odds ratio = 1.8, 95% CI 0.6-5.9), with a number needed to harm (NNH) of 9, with a number needed to treat (NNT) in the 125-mg group of 4.8. Increased acute mountain sickness incidence and symptom severity corresponded to lower weight-based and body mass index dosing, with similar side effects between groups. CONCLUSION Acetazolamide 62.5 mg twice daily failed to demonstrate equal effectiveness to 125 mg twice daily for prevention of acute mountain sickness. With increased risk and no demonstrable symptomatic or physiologic benefits, acetazolamide 62.5 mg twice daily should not be recommended for acute mountain sickness prevention.
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Toussaint CM, Kenefick RW, Petrassi FA, Muza SR, Charkoudian N. Altitude, Acute Mountain Sickness, and Acetazolamide: Recommendations for Rapid Ascent. High Alt Med Biol 2020; 22:5-13. [PMID: 32975448 DOI: 10.1089/ham.2019.0123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Toussaint, Claudia M., Robert W. Kenefick, Frank A. Petrassi, Stephen R. Muza, and Nisha Charkoudian. Altitude, acute mountain sickness, and acetazolamide: recommendations for rapid ascent. High Alt Med Biol. 22:5-13, 2021. Background: Sea level natives ascending rapidly to altitudes above 1,500 m often develop acute mountain sickness (AMS), including nausea, headaches, fatigue, and lightheadedness. Acetazolamide (AZ), a carbonic anhydrase inhibitor, is a commonly used medication for the prevention and treatment of AMS. However, there is continued debate about appropriate dosing, particularly when considering rapid and physically demanding ascents to elevations above 3,500 m by emergency medical and military personnel. Aims: Our goal in the present analysis was to evaluate and synthesize the current literature regarding the use of AZ to determine the most effective dosing for prophylaxis and treatment of AMS for rapid ascents to elevations >3,500 m. These circumstances are specifically relevant to military and emergency medical personnel who often need to ascend rapidly and perform physically demanding tasks upon arrival at altitude. Methods: We conducted a literature search from April 2018 to February 2020 using PubMed, Google Scholar, and Web of Science to identify randomized controlled trials that compared AZ with placebo or other treatment with the primary endpoint of AMS incidence and severity. We included only research articles/studies that focused on evaluation of AZ use during rapid ascent. Results: Four doses of AZ (125, 250, 500, and 750 mg daily) were identified as efficacious in decreasing the incidence and/or severity of AMS during rapid ascents, with evidence of enhanced effectiveness with higher doses. Conclusions: For military, emergency medical, or other activities involving rapid ascent to altitudes >3,500 m, doses 500-750 mg/day within 24 hours of altitude exposure appear to be the most effective for minimizing symptoms of AMS.
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Affiliation(s)
- Claudia M Toussaint
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA.,Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Robert W Kenefick
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Frank A Petrassi
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Stephen R Muza
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Nisha Charkoudian
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
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Molano Franco D, Nieto Estrada VH, Gonzalez Garay AG, Martí‐Carvajal AJ, Arevalo‐Rodriguez I. Interventions for preventing high altitude illness: Part 3. Miscellaneous and non-pharmacological interventions. Cochrane Database Syst Rev 2019; 4:CD013315. [PMID: 31012483 PMCID: PMC6477878 DOI: 10.1002/14651858.cd013315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND High altitude illness (HAI) is a term used to describe a group of mainly cerebral and pulmonary syndromes that can occur during travel to elevations above 2500 metres (˜ 8200 feet). Acute mountain sickness (AMS), high altitude cerebral oedema (HACE), and high altitude pulmonary oedema (HAPE) are reported as potential medical problems associated with high altitude ascent. In this, the third of a series of three reviews about preventive strategies for HAI, we assessed the effectiveness of miscellaneous and non-pharmacological interventions. OBJECTIVES To assess the clinical effectiveness and adverse events of miscellaneous and non-pharmacological interventions for preventing acute HAI in people who are at risk of developing high altitude illness in any setting. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) in January 2019. We adapted the MEDLINE strategy for searching the other databases. We used a combination of thesaurus-based and free-text search terms. We scanned the reference lists and citations of included trials and any relevant systematic reviews that we identified for further references to additional trials. SELECTION CRITERIA We included randomized controlled trials conducted in any setting where non-pharmacological and miscellaneous interventions were employed to prevent acute HAI, including preacclimatization measures and the administration of non-pharmacological supplements. We included trials involving participants who are at risk of developing high altitude illness (AMS or HACE, or HAPE, or both). We included participants with, and without, a history of high altitude illness. We applied no age or gender restrictions. We included trials where the relevant intervention was administered before the beginning of ascent. DATA COLLECTION AND ANALYSIS We used the standard methodological procedures employed by Cochrane. MAIN RESULTS We included 20 studies (1406 participants, 21 references) in this review. Thirty studies (14 ongoing, and 16 pending classification (awaiting)) will be considered in future versions of this suite of three reviews as appropriate. We report the results for the primary outcome of this review (risk of AMS) by each group of assessed interventions.Group 1. Preacclimatization and other measures based on pressureUse of simulated altitude or remote ischaemic preconditioning (RIPC) might not improve the risk of AMS on subsequent exposure to altitude, but this effect is uncertain (simulated altitude: risk ratio (RR) 1.18, 95% confidence interval (CI) 0.82 to 1.71; I² = 0%; 3 trials, 140 participants; low-quality evidence. RIPC: RR 3.0, 95% CI 0.69 to 13.12; 1 trial, 40 participants; low-quality evidence). We found evidence of improvement of this risk using positive end-expiratory pressure (PEEP), but this information was derived from a cross-over trial with a limited number of participants (OR 3.67, 95% CI 1.38 to 9.76; 1 trial, 8 participants; low-quality evidence). We found scarcity of evidence about the risk of adverse events for these interventions.Group 2. Supplements and vitaminsSupplementation of antioxidants, medroxyprogesterone, iron or Rhodiola crenulata might not improve the risk of AMS on exposure to high altitude, but this effect is uncertain (antioxidants: RR 0.58, 95% CI 0.32 to 1.03; 1 trial, 18 participants; low-quality evidence. Medroxyprogesterone: RR 0.71, 95% CI 0.48 to 1.05; I² = 0%; 2 trials, 32 participants; low-quality evidence. Iron: RR 0.65, 95% CI 0.38 to 1.11; I² = 0%; 2 trials, 65 participants; low-quality evidence. R crenulata: RR 1.00, 95% CI 0.78 to 1.29; 1 trial, 125 participants; low-quality evidence). We found evidence of improvement of this risk with the administration of erythropoietin, but this information was extracted from a trial with issues related to risk of bias and imprecision (RR 0.41, 95% CI 0.20 to 0.84; 1 trial, 39 participants; very low-quality evidence). Regarding administration of ginkgo biloba, we did not perform a pooled estimation of RR for AMS due to considerable heterogeneity between the included studies (I² = 65%). RR estimates from the individual studies were conflicting (from 0.05 to 1.03; low-quality evidence). We found scarcity of evidence about the risk of adverse events for these interventions.Group 3. Other comparisonsWe found heterogeneous evidence regarding the risk of AMS when ginkgo biloba was compared with acetazolamide (I² = 63%). RR estimates from the individual studies were conflicting (estimations from 0.11 (95% CI 0.01 to 1.86) to 2.97 (95% CI 1.70 to 5.21); low-quality evidence). We found evidence of improvement when ginkgo biloba was administered along with acetazolamide, but this information was derived from a single trial with issues associated to risk of bias (compared to ginkgo biloba alone: RR 0.43, 95% CI 0.26 to 0.71; 1 trial, 311 participants; low-quality evidence). Administration of medroxyprogesterone plus acetazolamide did not improve the risk of AMS when compared to administration of medroxyprogesterone or acetazolamide alone (RR 1.33, 95% CI 0.50 to 3.55; 1 trial, 12 participants; low-quality evidence). We found scarcity of evidence about the risk of adverse events for these interventions. AUTHORS' CONCLUSIONS This Cochrane Review is the final in a series of three providing relevant information to clinicians, and other interested parties, on how to prevent high altitude illness. The assessment of non-pharmacological and miscellaneous interventions suggests that there is heterogeneous and even contradictory evidence related to the effectiveness of these prophylactic strategies. Safety of these interventions remains as an unclear issue due to lack of assessment. Overall, the evidence is limited due to its quality (low to very low), the relative paucity of that evidence and the number of studies pending classification for the three reviews belonging to this series (30 studies either awaiting classification or ongoing). Additional studies, especially those comparing with pharmacological alternatives (such as acetazolamide) are required, in order to establish or refute the strategies evaluated in this review.
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Affiliation(s)
- Daniel Molano Franco
- Fundacion Universitaria de Ciencias de la Salud, Hospital de San JoséDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Víctor H Nieto Estrada
- Los Cobos Medical Centre. Grupo Investigacion GRIBOSDepartment of Critical CareBogotaBogotaColombia
| | | | | | - Ingrid Arevalo‐Rodriguez
- Hospital Universitario Ramón y Cajal (IRYCIS), CIBER Epidemiology and Public Health (CIBERESP)Clinical Biostatistics UnitCtra. Colmenar Km. 9,100MadridSpain28034
- Cochrane Associate Centre of MadridMadridSpain
- Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio Espejo, Universidad Tecnológica EquinoccialCochrane EcuadorQuitoEcuador
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McIntosh SE, Hemphill M, McDevitt MC, Gurung TY, Ghale M, Knott JR, Thapa GB, Basnyat B, Dow J, Weber DC, K. Grissom C. Reduced Acetazolamide Dosing in Countering Altitude Illness: A Comparison of 62.5 vs 125 mg (the RADICAL Trial). Wilderness Environ Med 2019; 30:12-21. [DOI: 10.1016/j.wem.2018.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/06/2018] [Accepted: 09/11/2018] [Indexed: 11/30/2022]
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Burns P, Lipman GS, Warner K, Jurkiewicz C, Phillips C, Sanders L, Soto M, Hackett P. Altitude Sickness Prevention with Ibuprofen Relative to Acetazolamide. Am J Med 2019; 132:247-251. [PMID: 30419226 DOI: 10.1016/j.amjmed.2018.10.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 10/31/2018] [Accepted: 10/31/2018] [Indexed: 12/01/2022]
Abstract
BACKGROUND Acute mountain sickness is a common occurrence for travel to high altitudes. Although previous studies of ibuprofen have shown efficacy for the prevention of acute mountain sickness, recommendations have been limited, as ibuprofen has not been compared directly with acetazolamide until this study. METHODS Before their ascent to 3810 m on White Mountain in California, adult volunteers were randomized to ibuprofen (600 mg, 3 times daily, started 4 hours before the ascent), or to acetazolamide (125 mg, twice daily, started the night before the ascent). The main outcome measure was acute mountain sickness incidence, using the Lake Louise Questionnaire (LLQ), with a score of >3 with headache. Sleep quality and headache severity were measured with the Groningen Sleep Quality Survey (GSQS). This trial was registered at ClinicalTrials.gov: NCT03154645 RESULTS: Ninety-two participants completed the study: 45 (49%) on ibuprofen and 47 (51%) on acetazolamide. The total incidence of acute mountain sickness was 56.5%, with the incidence for the ibuprofen group being 11% greater than that for acetazolamide, surpassing the predetermined 26% noninferiority margin (62.2% vs 51.1%; 95% confidence interval [CI], -11.1 to 33.5). No difference was found in the total LLQ scores or subgroup symptoms between drugs (P = .8). The GSQS correlated with LLQ sleep (r = 0.77; 95% CI, 0.67-0.84)=%. The acetazolamide group had higher peripheral capillary oxygen saturation than the ibuprofen group (88.5% vs 85.6%; P = .001). CONCLUSION Ibuprofen was slightly inferior to acetazolamide for acute mountain sickness prevention and should not be recommended over acetazolamide for rapid ascent. Average symptoms and severity were similar between drugs, suggesting prevention of disease.
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Affiliation(s)
- Patrick Burns
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, Calif.
| | - Grant S Lipman
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, Calif
| | - Keiran Warner
- Stanford/Kaiser Emergency Medicine Residency, Stanford University School of Medicine, Stanford, Calif
| | - Carrie Jurkiewicz
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, Calif
| | - Caleb Phillips
- Department of Computer Science, University of Colorado, Boulder
| | - Linda Sanders
- Department of Emergency Medicine, Swedish Edmonds Hospital, Edmonds, Wash
| | - Mario Soto
- Department of Emergency Medicine, Madigan Army Medical Center, Tacoma, Wash
| | - Peter Hackett
- Altitude Research Center, Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora
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Li Y, Zhang Y, Zhang Y. Research advances in pathogenesis and prophylactic measures of acute high altitude illness. Respir Med 2018; 145:145-152. [DOI: 10.1016/j.rmed.2018.11.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 09/14/2018] [Accepted: 11/06/2018] [Indexed: 12/30/2022]
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Tsai TY, Wang SH, Lee YK, Su YC. Ginkgo biloba extract for prevention of acute mountain sickness: a systematic review and meta-analysis of randomised controlled trials. BMJ Open 2018; 8:e022005. [PMID: 30121603 PMCID: PMC6104799 DOI: 10.1136/bmjopen-2018-022005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE Trials of ginkgo biloba extract (GBE) for the prevention of acute mountain sickness (AMS) have been published since 1996. Because of their conflicting results, the efficacy of GBE remains unclear. We performed a systematic review and meta-analysis to assess whether GBE prevents AMS. METHODS The Cochrane Library, EMBASE, Google Scholar and PubMed databases were searched for articles published up to 20 May 2017. Only randomised controlled trials were included. AMS was defined as an Environmental Symptom Questionnaire Acute Mountain Sickness-Cerebral score ≥0.7 or Lake Louise Score ≥3 with headache. The main outcome measure was the relative risk (RR) of AMS in participants receiving GBE for prophylaxis. Meta-analyses were conducted using random-effects models. Sensitivity analyses, subgroup analyses and tests for publication bias were conducted. RESULTS Seven study groups in six published articles met all eligibility criteria, including the article published by Leadbetter et al, where two randomised controlled trials were conducted. Overall, 451 participants were enrolled. In the primary meta-analysis of all seven study groups, GBE showed trend of AMS prophylaxis, but it is not statistically significant (RR=0.68; 95% CI 0.45 to 1.04; p=0.08). The I2 statistic was 58.7% (p=0.02), indicating substantial heterogeneity. The pooled risk difference (RD) revealed a significant risk reduction in participants who use GBE (RD=-25%; 95% CI, from a reduction of 45% to 6%; p=0.011) The results of subgroup analyses of studies with low risk of bias, low starting altitude (<2500 m), number of treatment days before ascending and dosage of GBE are not statistically significant. CONCLUSION The currently available data suggest that although GBE may tend towards AMS prophylaxis, there are not enough data to show the statistically significant effect of GBE on preventing AMS. Further large randomised controlled studies are warranted.
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Affiliation(s)
- Tou-Yuan Tsai
- School of Medicine, Tzu Chi University, Hualien, Taiwan
- Emergency Department, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
| | - Shih-Hao Wang
- Emergency Department, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Chiayi, Chiayi, Taiwan
- Department of Recreation and Leisure Industry Management, College of Management, National Taiwan Sport University, Taoyuan, Taiwan
| | - Yi-Kung Lee
- School of Medicine, Tzu Chi University, Hualien, Taiwan
- Emergency Department, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
| | - Yung-Cheng Su
- School of Medicine, Tzu Chi University, Hualien, Taiwan
- Emergency Department, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
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Lundeberg J, Feiner JR, Schober A, Sall JW, Eilers H, Bickler PE. Increased Cytokines at High Altitude: Lack of Effect of Ibuprofen on Acute Mountain Sickness, Physiological Variables, or Cytokine Levels. High Alt Med Biol 2018; 19:249-258. [PMID: 29924642 DOI: 10.1089/ham.2017.0144] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Lundeberg, Jenny, John R. Feiner, Andrew Schober, Jeffrey W. Sall, Helge Eilers, and Philip E. Bickler. Increased cytokines at high altitude: lack of effect of ibuprofen on acute mountain sickness, physiological variables or cytokine levels. High Alt Med Biol. 19:249-258, 2018. INTRODUCTION There is no consensus on the role of inflammation in high-altitude acclimatization. AIMS To determine the effects of a nonsteroidal anti-inflammatory drug (ibuprofen 400 mg every 8 hours) on blood cytokines, acclimatization, acute mountain sickness (AMS, Lake Louise Score), and noninvasive oxygenation in brain and muscle in healthy volunteers. MATERIALS AND METHODS In this double-blind study, 20 volunteers were randomized to receive ibuprofen or placebo at sea level and for 48 hours at 3800 m altitude. Arterial, brain, and leg muscle saturation with near infrared spectroscopy, pulse oximetry, and heart rate were measured. Blood samples were collected for cytokine levels and cytokine gene expression. RESULTS All of the placebo subjects and 8 of 11 ibuprofen subjects developed AMS at altitude (p = 0.22, comparing placebo and ibuprofen). On arrival at altitude, the oxygen saturation as measured by pulse oximetry (SpO2) was 84.5% ± 5.4% (mean ± standard deviation). Increase in blood interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), and granulocyte-macrophage colony-stimulating factor (GM-CSF) levels occurred comparably in the placebo and ibuprofen groups (all not significant, univariate test by Wilcoxon rank sum). Increased IL-6 was associated with higher AMS scores (p = 0.002 by Spearman rank correlation). However, we found no difference or association in AMS score and blood or tissue oxygenation between the ibuprofen and placebo groups. CONCLUSIONS We found that ibuprofen, at the package-recommended adult dose, did not have a significant effect on altitude-related increases in cytokines, AMS scores, blood, or tissue oxygenation in a population of healthy subjects with a high incidence of AMS.
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Affiliation(s)
- Jenny Lundeberg
- 1 Department of Anesthesia and Intensive Care, Institution for Clinical Science, Karolinska Institutet, Danderyds University Hospital , Stockholm, Sweden
| | - John R Feiner
- 2 Department of Anesthesia and Perioperative Care, University of California San Francisco , San Francisco, California
| | - Andrew Schober
- 2 Department of Anesthesia and Perioperative Care, University of California San Francisco , San Francisco, California
| | - Jeffrey W Sall
- 2 Department of Anesthesia and Perioperative Care, University of California San Francisco , San Francisco, California
| | - Helge Eilers
- 2 Department of Anesthesia and Perioperative Care, University of California San Francisco , San Francisco, California
| | - Philip E Bickler
- 2 Department of Anesthesia and Perioperative Care, University of California San Francisco , San Francisco, California
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Paul S, Gangwar A, Bhargava K, Khurana P, Ahmad Y. Diagnosis and prophylaxis for high-altitude acclimatization: Adherence to molecular rationale to evade high-altitude illnesses. Life Sci 2018; 203:171-176. [PMID: 29698652 DOI: 10.1016/j.lfs.2018.04.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/13/2018] [Accepted: 04/21/2018] [Indexed: 11/25/2022]
Abstract
Lack of zero side-effect, prescription-less prophylactics and diagnostic markers of acclimatization status lead to many suffering from high altitude illnesses. Although not fully translated to the clinical setting, many strategies and interventions are being developed that are aimed at providing an objective and tangible answer regarding the acclimatization status of an individual as well as zero side-effect prophylaxis that is cost-effective and does not require medical supervision. This short review brings together the twin problems associated with high-altitude acclimatization, i.e. acclimatization status and zero side-effect, easy-to-use prophylaxis, for the reader to comprehend as cogs of the same phenomenon. We describe current research aimed at preventing all the high-altitude illnesses by considering them an assault on redox and energy homeostasis at the molecular level. This review also entails some proteins capable of diagnosing either acclimatization or high-altitude illnesses. The future strategies based on bioinformatics and systems biology is also discussed.
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Affiliation(s)
- Subhojit Paul
- Peptide & Proteomics Division, Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi 110054, India
| | - Anamika Gangwar
- Peptide & Proteomics Division, Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi 110054, India
| | - Kalpana Bhargava
- Peptide & Proteomics Division, Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi 110054, India
| | - Pankaj Khurana
- Peptide & Proteomics Division, Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi 110054, India
| | - Yasmin Ahmad
- Peptide & Proteomics Division, Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi 110054, India.
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Gonzalez Garay AG, Molano Franco D, Nieto Estrada VH, Martí‐Carvajal AJ, Arevalo‐Rodriguez I. Interventions for preventing high altitude illness: Part 2. Less commonly-used drugs. Cochrane Database Syst Rev 2018; 2018:CD012983. [PMID: 29529715 PMCID: PMC6494375 DOI: 10.1002/14651858.cd012983] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND High altitude illness (HAI) is a term used to describe a group of mainly cerebral and pulmonary syndromes that can occur during travel to elevations above 2500 metres (˜ 8200 feet). Acute mountain sickness (AMS), high altitude cerebral oedema (HACE) and high altitude pulmonary oedema (HAPE) are reported as potential medical problems associated with high altitude ascent. In this second review, in a series of three about preventive strategies for HAI, we assessed the effectiveness of five of the less commonly used classes of pharmacological interventions. OBJECTIVES To assess the clinical effectiveness and adverse events of five of the less commonly used pharmacological interventions for preventing acute HAI in participants who are at risk of developing high altitude illness in any setting. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) in May 2017. We adapted the MEDLINE strategy for searching the other databases. We used a combination of thesaurus-based and free-text search terms. We scanned the reference lists and citations of included trials and any relevant systematic reviews that we identified for further references to additional trials. SELECTION CRITERIA We included randomized controlled trials conducted in any setting where one of five classes of drugs was employed to prevent acute HAI: selective 5-hydroxytryptamine(1) receptor agonists; N-methyl-D-aspartate (NMDA) antagonist; endothelin-1 antagonist; anticonvulsant drugs; and spironolactone. We included trials involving participants who are at risk of developing high altitude illness (AMS or HACE, or HAPE, or both). We included participants with and without a history of high altitude illness. We applied no age or gender restrictions. We included trials where the relevant medication was administered before the beginning of ascent. We excluded trials using these drugs during ascent or after ascent. DATA COLLECTION AND ANALYSIS We used the standard methodological procedures employed by Cochrane. MAIN RESULTS We included eight studies (334 participants, 9 references) in this review. Twelve studies are ongoing and will be considered in future versions of this review as appropriate. We have been unable to obtain full-text versions of a further 12 studies and have designated them as 'awaiting classification'. Four studies were at a low risk of bias for randomization; two at a low risk of bias for allocation concealment. Four studies were at a low risk of bias for blinding of participants and personnel. We considered three studies at a low risk of bias for blinding of outcome assessors. We considered most studies at a high risk of selective reporting bias.We report results for the following four main comparisons.Sumatriptan versus placebo (1 parallel study; 102 participants)Data on sumatriptan showed a reduction of the risk of AMS when compared with a placebo (risk ratio (RR) = 0.43, CI 95% 0.21 to 0.84; 1 study, 102 participants; low quality of evidence). The one included study did not report events of HAPE, HACE or adverse events related to administrations of sumatriptan.Magnesium citrate versus placebo (1 parallel study; 70 participants)The estimated RR for AMS, comparing magnesium citrate tablets versus placebo, was 1.09 (95% CI 0.55 to 2.13; 1 study; 70 participants; low quality of evidence). In addition, the estimated RR for loose stools was 3.25 (95% CI 1.17 to 8.99; 1 study; 70 participants; low quality of evidence). The one included study did not report events of HAPE or HACE.Spironolactone versus placebo (2 parallel studies; 205 participants)Pooled estimation of RR for AMS was not performed due to considerable heterogeneity between the included studies (I² = 72%). RR from individual studies was 0.40 (95% CI 0.12 to 1.31) and 1.44 (95% CI 0.79 to 2.01; very low quality of evidence). No events of HAPE or HACE were reported. Adverse events were not evaluated.Acetazolamide versus spironolactone (1 parallel study; 232 participants)Data on acetazolamide compared with spironolactone showed a reduction of the risk of AMS with the administration of acetazolamide (RR = 0.36, 95% CI 0.18 to 0.70; 232 participants; low quality of evidence). No events of HAPE or HACE were reported. Adverse events were not evaluated. AUTHORS' CONCLUSIONS This Cochrane Review is the second in a series of three providing relevant information to clinicians and other interested parties on how to prevent high altitude illness. The assessment of five of the less commonly used classes of drugs suggests that there is a scarcity of evidence related to these interventions. Clinical benefits and harms related to potential interventions such as sumatriptan are still unclear. Overall, the evidence is limited due to the low number of studies identified (for most of the comparison only one study was identified); limitations in the quality of the evidence (moderate to low); and the number of studies pending classification (24 studies awaiting classification or ongoing). We lack the large and methodologically sound studies required to establish or refute the efficacy and safety of most of the pharmacological agents evaluated in this review.
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Affiliation(s)
- Alejandro G Gonzalez Garay
- National Institute of PediatricsMethodology Research UnitInsurgentes Sur 3700 ‐ CCol. Insurgentes Cuicuilco, CoyoacanMexico CityDistrito FederalMexico04530
| | - Daniel Molano Franco
- Fundacion Universitaria de Ciencias de la Salud, Hospital de San JoséDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Víctor H Nieto Estrada
- Fundacion Universitaria Sanitas, Colombia ClinicDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | | | - Ingrid Arevalo‐Rodriguez
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoAv. Mariscal Sucre s/n y Av. Mariana de JesúsQuitoEcuador
- Hospital Universitario Ramon y Cajal (IRYCIS)Clinical Biostatistics UnitMadridSpain
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Haslam NR, Garth R, Kelly N. Inappropriate Dexamethasone Use by a Trekker in Nepal: A Case Report. Wilderness Environ Med 2017; 28:318-321. [DOI: 10.1016/j.wem.2017.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 06/21/2017] [Accepted: 06/23/2017] [Indexed: 10/18/2022]
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Nieto Estrada VH, Molano Franco D, Medina RD, Gonzalez Garay AG, Martí‐Carvajal AJ, Arevalo‐Rodriguez I. Interventions for preventing high altitude illness: Part 1. Commonly-used classes of drugs. Cochrane Database Syst Rev 2017; 6:CD009761. [PMID: 28653390 PMCID: PMC6481751 DOI: 10.1002/14651858.cd009761.pub2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND High altitude illness (HAI) is a term used to describe a group of cerebral and pulmonary syndromes that can occur during travel to elevations above 2500 metres (8202 feet). Acute hypoxia, acute mountain sickness (AMS), high altitude cerebral oedema (HACE) and high altitude pulmonary oedema (HAPE) are reported as potential medical problems associated with high altitude. In this review, the first in a series of three about preventive strategies for HAI, we assess the effectiveness of six of the most recommended classes of pharmacological interventions. OBJECTIVES To assess the clinical effectiveness and adverse events of commonly-used pharmacological interventions for preventing acute HAI. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OVID), Embase (OVID), LILACS and trial registries in January 2017. We adapted the MEDLINE strategy for searching the other databases. We used a combination of thesaurus-based and free-text terms to search. SELECTION CRITERIA We included randomized-controlled and cross-over trials conducted in any setting where commonly-used classes of drugs were used to prevent acute HAI. DATA COLLECTION AND ANALYSIS We used standard methodological procedures as expected by Cochrane. MAIN RESULTS We included 64 studies (78 references) and 4547 participants in this review, and classified 12 additional studies as ongoing. A further 12 studies await classification, as we were unable to obtain the full texts. Most of the studies were conducted in high altitude mountain areas, while the rest used low pressure (hypobaric) chambers to simulate altitude exposure. Twenty-four trials provided the intervention between three and five days prior to the ascent, and 23 trials, between one and two days beforehand. Most of the included studies reached a final altitude of between 4001 and 5000 metres above sea level. Risks of bias were unclear for several domains, and a considerable number of studies did not report adverse events of the evaluated interventions. We found 26 comparisons, 15 of them comparing commonly-used drugs versus placebo. We report results for the three most important comparisons: Acetazolamide versus placebo (28 parallel studies; 2345 participants)The risk of AMS was reduced with acetazolamide (risk ratio (RR) 0.47, 95% confidence interval (CI) 0.39 to 0.56; I2 = 0%; 16 studies; 2301 participants; moderate quality of evidence). No events of HAPE were reported and only one event of HACE (RR 0.32, 95% CI 0.01 to 7.48; 6 parallel studies; 1126 participants; moderate quality of evidence). Few studies reported side effects for this comparison, and they showed an increase in the risk of paraesthesia with the intake of acetazolamide (RR 5.53, 95% CI 2.81 to 10.88, I2 = 60%; 5 studies, 789 participants; low quality of evidence). Budenoside versus placebo (2 parallel studies; 132 participants)Data on budenoside showed a reduction in the incidence of AMS compared with placebo (RR 0.37, 95% CI 0.23 to 0.61; I2 = 0%; 2 studies, 132 participants; low quality of evidence). Studies included did not report events of HAPE or HACE, and they did not find side effects (low quality of evidence). Dexamethasone versus placebo (7 parallel studies; 205 participants)For dexamethasone, the data did not show benefits at any dosage (RR 0.60, 95% CI 0.36 to 1.00; I2 = 39%; 4 trials, 176 participants; low quality of evidence). Included studies did not report events of HAPE or HACE, and we rated the evidence about adverse events as of very low quality. AUTHORS' CONCLUSIONS Our assessment of the most commonly-used pharmacological interventions suggests that acetazolamide is an effective pharmacological agent to prevent acute HAI in dosages of 250 to 750 mg/day. This information is based on evidence of moderate quality. Acetazolamide is associated with an increased risk of paraesthesia, although there are few reports about other adverse events from the available evidence. The clinical benefits and harms of other pharmacological interventions such as ibuprofen, budenoside and dexamethasone are unclear. Large multicentre studies are needed for most of the pharmacological agents evaluated in this review, to evaluate their effectiveness and safety.
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Affiliation(s)
- Víctor H Nieto Estrada
- Fundacion Universitaria Sanitas, Colombia ClinicDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Daniel Molano Franco
- Fundacion Universitaria de Ciencias de la Salud, Hospital de San JoséDepartment of Critical CareCarrera 19 # 8‐32BogotaBogotaColombia11001
| | - Roger David Medina
- Fundación Universitaria de Ciencias de la SaludDivision of ResearchCarrera 19 # 8‐32Bogotá D.C.Colombia
| | - Alejandro G Gonzalez Garay
- National Institute of PediatricsMethodology Research UnitInsurgentes Sur 3700 ‐ CCol. Insurgentes Cuicuilco, CoyoacanMexico CityDistrito FederalMexico04530
| | | | - Ingrid Arevalo‐Rodriguez
- Universidad Tecnológica EquinoccialCochrane Ecuador. Centro de Investigación en Salud Pública y Epidemiología Clínica (CISPEC). Facultad de Ciencias de la Salud Eugenio EspejoAv. Mariscal Sucre s/n y Av. Mariana de JesúsQuitoEcuador
- Hospital Universitario Ramon y Cajal (IRYCIS)Clinical Biostatistics UnitMadridSpain
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Xiong J, Lu H, Wang R, Jia Z. Efficacy of ibuprofen on prevention of high altitude headache: A systematic review and meta-analysis. PLoS One 2017. [PMID: 28632763 PMCID: PMC5478153 DOI: 10.1371/journal.pone.0179788] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Objective Ibuprofen is used to prevent high altitude headache (HAH) but its efficacy remains controversial. We conducted a systematic review and meta-analysis of randomized, placebo-controlled trials (RCTs) of ibuprofen for the prevention of HAH. Methods Studies reporting efficacy of ibuprofen for prevention of HAH were identified by searching electronic databases (until December 2016). The primary outcome was the difference in incidence of HAH between ibuprofen and placebo groups. Risk ratios (RR) were aggregated using a Mantel-Haenszel random effect model. Heterogeneity of included trials was assessed using the I2 statistics. Results In three randomized-controlled clinical trials involving 407 subjects, HAH occurred in 101 of 239 subjects (42%) who received ibuprofen and 96 of 168 (57%) who received placebo (RR = 0.79, 95% CI 0.66 to 0.96, Z = 2.43, P = 0.02, I2 = 0%). The absolute risk reduction (ARR) was 15%. Number needed to treat (NNT) to prevent HAH was 7. Similarly, The incidence of severe HAH was significant in the two groups (RR = 0.40, 95% CI 0.17 to 0.93, Z = 2.14, P = 0.03, I2 = 0%). Severe HAH occurred in 3% treated with ibuprofen and 10% with placebo. The ARR was 8%. NNT to prevent severe HAH was 13. Headache severity using a visual analogue scale was not different between ibuprofen and placebo. Similarly, the difference between the two groups in the change in SpO2 from baseline to altitude was not different. One included RCT reported one participant with black stools and three participants with stomach pain in the ibuprofen group, while seven participants reported stomach pain in the placebo group. Conclusions Based on a limited number of studies ibuprofen seems efficacious for the prevention of HAH and may therefore represent an alternative for preventing HAH with acetazolamide or dexamethasone.
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Affiliation(s)
- Juan Xiong
- Key Laboratory of the plateau of the environmental damage control, Lanzhou General Hospital of Lanzhou Military Command, Lanzhou, China
| | - Hui Lu
- Key Laboratory of the plateau of the environmental damage control, Lanzhou General Hospital of Lanzhou Military Command, Lanzhou, China
- * E-mail: (HL); (ZPJ)
| | - Rong Wang
- Key Laboratory of the plateau of the environmental damage control, Lanzhou General Hospital of Lanzhou Military Command, Lanzhou, China
| | - Zhengping Jia
- Key Laboratory of the plateau of the environmental damage control, Lanzhou General Hospital of Lanzhou Military Command, Lanzhou, China
- * E-mail: (HL); (ZPJ)
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Liu B, Huang H, Wu G, Xu G, Sun BD, Zhang EL, Chen J, Gao YQ. A Signature of Circulating microRNAs Predicts the Susceptibility of Acute Mountain Sickness. Front Physiol 2017; 8:55. [PMID: 28228730 PMCID: PMC5296306 DOI: 10.3389/fphys.2017.00055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/23/2017] [Indexed: 12/21/2022] Open
Abstract
Background: Acute mountain sickness (AMS) is a common disabling condition in individuals experiencing high altitudes, which may progress to life-threatening high altitude cerebral edema. Today, no established biomarkers are available for prediction the susceptibility of AMS. MicroRNAs emerge as promising sensitive and specific biomarkers for a variety of diseases. Thus, we sought to identify circulating microRNAs suitable for prediction the susceptible of AMS before exposure to high altitude. Methods: We enrolled 109 healthy man adults and collected blood samples before their exposure to high altitude. Then we took them to an elevation of 3648 m for 5 days. Circulating microRNAs expression was measured by microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). AMS was defined as Lake Louise score ≥3 and headache using Lake Louise Acute Mountain Sickness Scoring System. Results: A total of 31 microRNAs were differentially expressed between AMS and Non-AMS groups, 15 up-regulated and 16 down-regulated. Up-regulation of miR-369-3p, miR-449b-3p, miR-136-3p, and miR-4791 in patients with AMS compared with Non-AMS individuals were quantitatively confirmed using qRT-PCR (all, P < 0.001). With multiple logistic regression analysis, a unique signature encompassing miR-369-3p, miR-449b-3p, and miR-136-3p discriminate AMS from Non-AMS (area under the curve 0.986, 95%CI 0.970–1.000, P < 0.001, LR+: 14.21, LR–: 0.08). This signature yielded a 92.68% sensitivity and a 93.48% specificity for AMS vs. Non-AMS. Conclusion: The study here, for the first time, describes a signature of three circulating microRNAs as a robust biomarker to predict the susceptibility of AMS before exposure to high altitude.
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Affiliation(s)
- Bao Liu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - He Huang
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Gang Wu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Gang Xu
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Bing-Da Sun
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Er-Long Zhang
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Jian Chen
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
| | - Yu-Qi Gao
- Institute of Medicine and Hygienic Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China; Key Laboratory of High Altitude Environmental Medicine, Third Military Medical University, Ministry of EducationChongqing, China; Key Laboratory of High Altitude Medicine, PLAChongqing, China
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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: 224] [Impact Index Per Article: 32.0] [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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Abstract
High-altitude illness (HAI) encompasses an array of conditions that may occur in individuals who travel to high elevations, including acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema. Individuals with a history of HAI are predisposed to developing HAI; however, other risk factors are not well defined. The primary method of preventing HAI is acclimatization through gradual ascent to high altitude. In addition, many studies have assessed the use of pharmacologic prophylaxis. The most studied and widely recommended prophylactic agent is acetazolamide; additional agents that have been considered include dexamethasone, Gingko biloba, antioxidant vitamins, nifedipine, aspirin, and salmeterol. The treatment of choice for all forms of HAI is descent to lower altitude. The use of additional treatments, including supplemental oxygen, varies depending on the severity of the clinical presentation. Acetazolamide and dexamethasone have been studied as adjunctive treatments for acute mountain sickness, while nitric oxide and nifedipine have been evaluated for the treatment of high-altitude pulmonary edema. Data with analgesics and phosphodiesterase-5 inhibitors, while limited, are promising. This review will present the evidence supporting the use of pharmacotherapy for prevention and treatment of HAI.
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Affiliation(s)
- Linda M. Spooner
- Massachusetts College of Pharmacy and Health Sciences, School of Pharmacy-Worcester/Manchester, Worcester, Massachusetts
| | - Jacqueline L. Olin
- Ernest Mario School of Pharmacy at Rutgers University, Piscataway, New Jersey
| | - Ronald J. Debellis
- Massachusetts College of Pharmacy and Health Sciences, School of Pharmacy-Worcester/Manchester, Worcester, Massachusetts
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Donegani E, Paal P, Küpper T, Hefti U, Basnyat B, Carceller A, Bouzat P, van der Spek R, Hillebrandt D. Drug Use and Misuse in the Mountains: A UIAA MedCom Consensus Guide for Medical Professionals. High Alt Med Biol 2016; 17:157-184. [PMID: 27583821 DOI: 10.1089/ham.2016.0080] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Donegani, Enrico, Peter Paal, Thomas Küpper, Urs Hefti, Buddha Basnyat, Anna Carceller, Pierre Bouzat, Rianne van der Spek, and David Hillebrandt. Drug use and misuse in the mountains: a UIAA MedCom consensus guide for medical professionals. High Alt Med Biol. 17:157-184, 2016.-Aims: The aim of this review is to inform mountaineers about drugs commonly used in mountains. For many years, drugs have been used to enhance performance in mountaineering. It is the UIAA (International Climbing and Mountaineering Federation-Union International des Associations d'Alpinisme) Medcom's duty to protect mountaineers from possible harm caused by uninformed drug use. The UIAA Medcom assessed relevant articles in scientific literature and peer-reviewed studies, trials, observational studies, and case series to provide information for physicians on drugs commonly used in the mountain environment. Recommendations were graded according to criteria set by the American College of Chest Physicians. RESULTS Prophylactic, therapeutic, and recreational uses of drugs relevant to mountaineering are presented with an assessment of their risks and benefits. CONCLUSIONS If using drugs not regulated by the World Anti-Doping Agency (WADA), individuals have to determine their own personal standards for enjoyment, challenge, acceptable risk, and ethics. No system of drug testing could ever, or should ever, be policed for recreational climbers. Sponsored climbers or those who climb for status need to carefully consider both the medical and ethical implications if using drugs to aid performance. In some countries (e.g., Switzerland and Germany), administrative systems for mountaineering or medication control dictate a specific stance, but for most recreational mountaineers, any rules would be unenforceable and have to be a personal decision, but should take into account the current best evidence for risk, benefit, and sporting ethics.
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Affiliation(s)
- Enrico Donegani
- 1 Department of Cardiovascular Surgery, Sabah Al-Ahmed Cardiac Center , Al-Amiri Hospital, Kuwait, State of Kuwait
| | - Peter Paal
- 2 Department of Anaesthesiology and Critical Care Medicine, Innsbruck University Hospital , Innsbruck, Austria .,3 Department of Perioperative Medicine, Barts Heart Centre, St. Bartholomew's Hospital, Barts Health NHS Trust, Queen Mary University of London, London, United Kingdom .,4 Perioperative Medicine, St. Bartholomew's Hospital , London, United Kingdom
| | - Thomas Küpper
- 5 Institute of Occupational and Social Medicine, RWTH Aachen University , Aachen, Germany
| | - Urs Hefti
- 6 Department of Orthopedic and Trauma Surgery, Swiss Sportclinic , Bern, Switzerland
| | - Buddha Basnyat
- 7 Oxford University Clinical Research Unit-Nepal , Nepal International Clinic, and Himalayan Rescue, Kathmandu, Nepal
| | - Anna Carceller
- 8 Sports Medicine School, Instituto de Medicina de Montaña y del Deporte (IMMED), Federació d'Entitats Excursionistes (FEEC), University of Barcelona , Barcelona, Spain
| | - Pierre Bouzat
- 9 Department of Anesthesiology and Critical Care, University Hospital, INSERM U1236, Neuroscience Institute, Alps University, Grenoble, France
| | - Rianne van der Spek
- 10 Department of Endocrinology and Metabolism, Academic Medical Center Amsterdam, University of Amsterdam , Amsterdam, The Netherlands
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Abstract
RATIONALE Accurate assessment of medication adherence is critical for determination of medication efficacy in clinical trials, but most current methods have significant limitations. This study tests a subtherapeutic (microdose) of acetazolamide as a medication ingestion marker because acetazolamide is rapidly absorbed and excreted without metabolism in urine and can be noninvasively sampled. METHODS In a double-blind, placebo-controlled, residential study, 10 volunteers received 15 mg oral acetazolamide for 4 consecutive days. Acetazolamide pharmacokinetics were assessed on day 3, and its pharmacokinetic and pharmacodynamic interactions with a model medication (30 mg oxycodone) were examined on day 4. The rate of acetazolamide elimination into urine was followed for several days after dosing cessation. RESULTS Erythrocyte sequestration (half-life = 50.2 ± 18.5 h, mean ± SD, n = 6), resulted in the acetazolamide microdose exhibiting a substantially longer plasma half-life (24.5 ± 5.6 hours, n = 10) than previously reported for therapeutic doses (3-6 hours). After cessation of dosing, the rate of urinary elimination decreased significantly (F3,23 = 247: P < 0.05, n = 6) in a predictable manner with low intersubject variability and a half-life of 16.1 ± 3.8 h (n = 10). For each of 4 consecutive mornings after dosing cessation, the rates of urinary acetazolamide elimination remained quantifiable.There was no overall effect of acetazolamide on the pharmacodynamics, Cmax, Tmax, or elimination half-life of the model medication tested. Acetazolamide may have modestly increased overall oxycodone exposure (20%, P < 0.05) compared with one of the 2 days when oxycodone was given alone, but there were no observed effects of acetazolamide on oxycodone pharmacodynamic responses. CONCLUSIONS Coformulation of a once-daily trial medication with an acetazolamide microdose may allow estimation of the last time of medication consumption for up to 96 hours postdose. Inclusion of acetazolamide may therefore provide an inexpensive new method to improve estimates of medication adherence in clinical trials.
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Abstract
Altitude-related illness is a frequent cause of morbidity and occasional mortality among recreational sports travelers in the United States and throughout the world. High-altitude illness describes the cerebral and pulmonary syndromes (acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema) that can occur in unacclimatized persons ascending too rapidly to high altitude. The pathogenesis of these syndromes is primarily hypobaric hypoxia that causes compensatory changes in the brain and lungs, resulting in hyperperfusion of microvascular beds, increased capillary pressure, and a microvascular leak with resulting edema and a characteristic constellation of symptoms. Prevention and treatment involve education about rate of ascent; diet; alcohol intake; physical activity; oxygen; hyperbaric chambers; and pharmacotherapy, including acetazolamide, dexamethasone, nifedipine, and salmeterol in selected circumstances.
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Affiliation(s)
- Allan Ellsworth
- Department of Family Medicine, University of Washington, Box 354775, 4245 Roosevelt Way NE, Seattle, WA 98105,
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Abstract
Headache is the most prevalent symptom of acute mountain sickness. We conducted a pilot clinical trial at an altitude of 3500 m to evaluate the efficacy of gabapentin in treatment of high-altitude headache (HAH). Twenty-four adult HAH patients (10 female, 14 male; age 18–50 years) were randomly assigned to receive either 300 mg of gabapentin capsule or identical placebo. After 1 h the presence of HAH and need to receive supplementary analgesic were assessed. The duration of the HAH-free phase after taking additional analgesic was also registered. Four patients in the gabapentin group asked for additional analgesics, whereas nine placebo recipients did not find primary medication satisfactory after the first hour of treatment ( P = 0.04). The mean HAH-free period was 17.10 h in the gabapentin group, which was significantly higher than in the placebo group with a mean of 10.08 h ( P = 0.02). This preliminary observation indicates that gabapentin is effective in treatment and alleviation of HAH.
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Affiliation(s)
- S Jafarian
- Department of Neurology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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Impact of Study Design on Reported Incidences of Acute Mountain Sickness: A Systematic Review. High Alt Med Biol 2015; 16:204-15. [DOI: 10.1089/ham.2015.0022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Carod-Artal F. Cefalea de elevada altitud y mal de altura. Neurologia 2014; 29:533-40. [DOI: 10.1016/j.nrl.2012.04.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 04/21/2012] [Indexed: 11/29/2022] Open
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Pandit A, Karmacharya P, Pathak R, Giri S, Aryal MR. Efficacy of NSAIDs for the prevention of acute mountain sickness: a systematic review and meta-analysis. J Community Hosp Intern Med Perspect 2014; 4:24927. [PMID: 25317267 PMCID: PMC4185145 DOI: 10.3402/jchimp.v4.24927] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/18/2014] [Accepted: 08/01/2014] [Indexed: 01/10/2023] Open
Abstract
Background Acute mountain sickness (AMS) can occur in anyone going to a high altitude. Non-steroidal anti-inflammatory drugs (NSAIDs) have been studied for the prevention of AMS with mixed results. In this systematic review, we analyze all existing data on the use of NSAIDs to prevent AMS using the Lake Louise Scoring System (LLSS) in different randomized clinical trials (RCTs). Methods Electronic literature searches for relevant studies were identified through MEDLINE, EMBASE, SCOPUS, and Cochrane library up to June 2013. RCTs involving NSAIDs compared to placebo in patients undergoing ascent to a height of at least 3,800 m were included. Odds ratios (OR) were calculated and combined using fixed-effect model meta-analysis if I2=0%. Differences between groups were calculated using the inverse variance of the standard mean differences. Between-study heterogeneity was assessed using the I2 statistics. Results In three clinical trials involving 349 patients, AMS using LLSS occurred in 26.92% of patients on NSAIDs and 43.71% on placebo (OR 0.43; CI [confidence interval] 0.27–0.69, I2=0%, p=0.0005), NNT=6. Minor outcome of end point Spo2 was not significant in the two groups (IV=0.74; 95% CI −0.20–1.69, I2=81%, p=0.12). Similarly, a change in Spo2 from baseline was also not significant in the two groups (IV=0.05; 95% CI −0.28–0.37, I2=44%, p=0.78). Conclusion NSAIDs might be a safe and effective alternative for the prevention of AMS. However, further larger population studies and studies comparing NSAIDs to acetazolamide and dexamethasone in the future may provide further data to its relative efficacy.
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Affiliation(s)
- Anil Pandit
- Division of Cardiovascular Diseases, Mayo Clinic, Scottsdale, AZ, USA
| | - Paras Karmacharya
- Department of Internal Medicine, Reading Health System, West Reading, PA, USA
| | - Ranjan Pathak
- Department of Internal Medicine, Reading Health System, West Reading, PA, USA
| | - Smith Giri
- Mountain Medicine Society, Kathmandu, Nepal
| | - Madan R Aryal
- Department of Internal Medicine, Reading Health System, West Reading, PA, USA
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Dehnert C, Böhm A, Grigoriev I, Menold E, Bärtsch P. Sleeping in moderate hypoxia at home for prevention of acute mountain sickness (AMS): a placebo-controlled, randomized double-blind study. Wilderness Environ Med 2014; 25:263-71. [PMID: 24931591 DOI: 10.1016/j.wem.2014.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 04/03/2014] [Accepted: 04/04/2014] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Acclimatization at natural altitude effectively prevents acute mountain sickness (AMS). It is, however, unknown whether prevention of AMS is also possible by only sleeping in normobaric hypoxia. METHODS In a placebo-controlled, double-blind study 76 healthy unacclimatized male subjects, aged 18 to 50 years, slept for 14 consecutive nights at either a fractional inspired oxygen (Fio2) of 0.14 to 0.15 (average target altitude 3043 m; treatment group) or 0.209 (control group). Four days later, AMS scores and incidence of AMS were assessed during a 20-hour exposure in normobaric hypoxia at Fio2 = 0.12 (equivalent to 4500 m). RESULTS Because of technical problems with the nitrogen generators, target altitude was not achieved in the tents and only 21 of 37 subjects slept at an average altitude considered sufficient for acclimatization (>2200 m; average, 2600 m). Therefore, in a subgroup analysis these subjects were compared with the 21 subjects of the control group with the lowest sleeping altitude. This analysis showed a significantly lower AMS-C score (0.38; 95% CI, 0.21 to 0.54) vs 1.10; 95% CI, 0.57 to 1.62; P = .04) and lower Lake Louise Score (3.1; 95% CI, 2.2 to 4.1 vs 5.1; 95% CI, 3.6 to 6.6; P = .07) for the treatment subgroup. The incidence of AMS defined as an AMS-C score greater than 0.70 was also significantly lower (14% vs 52%; P < .01). CONCLUSIONS Sleeping 14 consecutive nights in normobaric hypoxia (equivalent to 2600 m) reduced symptoms and incidence of AMS 4 days later on exposure to 4500 m.
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Affiliation(s)
- Christoph Dehnert
- University Hospital, Medical Clinic, Internal Medicine VII, Sports Medicine, Heidelberg, Germany.
| | - Astrid Böhm
- University Hospital, Medical Clinic, Internal Medicine VII, Sports Medicine, Heidelberg, Germany
| | - Igor Grigoriev
- University Hospital, Medical Clinic, Internal Medicine VII, Sports Medicine, Heidelberg, Germany
| | - Elmar Menold
- University Hospital, Medical Clinic, Internal Medicine VII, Sports Medicine, Heidelberg, Germany
| | - Peter Bärtsch
- University Hospital, Medical Clinic, Internal Medicine VII, Sports Medicine, Heidelberg, Germany
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McDevitt M, McIntosh SE, Rodway G, Peelay J, Adams DL, Kayser B. Risk Determinants of Acute Mountain Sickness in Trekkers in the Nepali Himalaya: a 24-Year Follow-Up. Wilderness Environ Med 2014; 25:152-9. [DOI: 10.1016/j.wem.2013.12.027] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 11/29/2022]
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Zafren K. Prevention of high altitude illness. Travel Med Infect Dis 2014; 12:29-39. [DOI: 10.1016/j.tmaid.2013.12.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/05/2013] [Accepted: 12/10/2013] [Indexed: 11/28/2022]
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Chiu TF, Chen LLC, Su DH, Lo HY, Chen CH, Wang SH, Chen WL. Rhodiola crenulata extract for prevention of acute mountain sickness: a randomized, double-blind, placebo-controlled, crossover trial. Altern Ther Health Med 2013; 13:298. [PMID: 24176010 PMCID: PMC4228457 DOI: 10.1186/1472-6882-13-298] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 10/28/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND Rhodiola crenulata (R. crenulata) is widely used to prevent acute mountain sickness in the Himalayan areas and in Tibet, but no scientific studies have previously examined its effectiveness. We conducted a randomized, double-blind, placebo-controlled crossover study to investigate its efficacy in acute mountain sickness prevention. METHODS Healthy adult volunteers were randomized to 2 treatment sequences, receiving either 800 mg R. crenulata extract or placebo daily for 7 days before ascent and 2 days during mountaineering, before crossing over to the alternate treatment after a 3-month wash-out period. Participants ascended rapidly from 250 m to 3421 m on two separate occasions: December 2010 and April 2011. The primary outcome measure was the incidence of acute mountain sickness, as defined by a Lake Louise score ≥ 3, with headache and at least one of the symptoms of nausea or vomiting, fatigue, dizziness, or difficulty sleeping. RESULTS One hundred and two participants completed the trial. There were no demographic differences between individuals taking Rhodiola-placebo and those taking placebo-Rhodiola. No significant differences in the incidence of acute mountain sickness were found between R. crenulata extract and placebo groups (all 60.8%; adjusted odds ratio (AOR) = 1.02, 95% confidence interval (CI) = 0.69-1.52). The incidence of severe acute mountain sickness in Rhodiola extract vs. placebo groups was 35.3% vs. 29.4% (AOR = 1.42, 95% CI = 0.90-2.25). CONCLUSIONS R. crenulata extract was not effective in reducing the incidence or severity of acute mountain sickness as compared to placebo. TRIAL REGISTRATION ClinicalTrials.gov NCT01536288.
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Abedi F, Wickremasinghe S, Richardson AJ, Makalic E, Schmidt DF, Sandhu SS, Baird PN, Guymer RH. Variants in the VEGFA gene and treatment outcome after anti-VEGF treatment for neovascular age-related macular degeneration. Ophthalmology 2012; 120:115-21. [PMID: 23149126 DOI: 10.1016/j.ophtha.2012.10.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Revised: 10/02/2012] [Accepted: 10/02/2012] [Indexed: 01/21/2023] Open
Abstract
PURPOSE To determine the association of genetic variants of the VEGFA gene with outcome of anti-vascular endothelial growth factor (VEGF) treatment in neovascular age-related macular degeneration (AMD). DESIGN A prospective cohort study. PARTICIPANTS We included 201 consecutive patients receiving anti-VEGF injections for neovascular AMD. METHODS Patients were followed over 12 months. They were treated with 3 initial monthly ranibizumab or bevacizumab injections. Thereafter, the decision to retreat was made by clinicians at each follow-up visit on the basis of retreatment criteria. Seven tagged single nucleotide polymorphisms (tSNPs) in the VEGFA gene were selected and examined. Multivariate data analysis was used to determine the role of each tSNP in treatment outcome. MAIN OUTCOME MEASURES The influence of selected VEGFA tSNPs on visual acuity (VA) outcome at 6 months. RESULTS Mean baseline VA was 51±17 Early Treatment Diabetic Retinopathy Study (ETDRS) letter scores. Overall, the mean change in VA from baseline was +6.5±12, +4.4±13.4, and +2.3±14.6 letters at 3, 6, and 12 months, respectively. The tSNP rs3025000 was the only SNP significantly associated (P<1 × 10(-4)) with visual outcome at 6 months with multiple correction. The presence of the T allele (TC or TT genotypes) at this tSNP predicted a better outcome of +7 letters at 6 months compared with the CC genotype. In a subgroup analysis, presence of the T allele predicted a significantly higher chance of the patients belonging to the responder group (gain of ≥5 letters from baseline) after 3, 6, and 12 months treatment (odds ratio, 2.7, 3.5, and 2.4; 95% confidence interval, 1.46-5.07, 1.82-6.71, and 1.27-4.57, respectively) than any other outcome group. CONCLUSIONS Pharmacogenetic association with anti-VEGF treatments may influence the visual outcomes in neovascular AMD. In patients with the T allele in tSNP rs3025000, there was a significantly better visual outcome at 6 months and a greater chance of the patients belonging to the responder group with anti-VEGF treatment at 3, 6, and 12 months. The VA outcomes of patients harboring the T allele at SNP rs3025000 were comparable with those of the pivotal clinical trials but with fewer injections, making the treatment perhaps more cost effective in certain subgroups of patients. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.
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Affiliation(s)
- Farshad Abedi
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Victoria, Australia.
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Seupaul RA, Welch JL, Malka ST, Emmett TW. In reply. Ann Emerg Med 2012. [DOI: 10.1016/j.annemergmed.2012.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Zafren K. Prophylaxis for Acute Mountain Sickness. Ann Emerg Med 2012; 60:671; author reply 672. [DOI: 10.1016/j.annemergmed.2012.05.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 04/28/2012] [Accepted: 05/01/2012] [Indexed: 11/16/2022]
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Altitude Sickness in Climbers and Efficacy of NSAIDs Trial (ASCENT): randomized, controlled trial of ibuprofen versus placebo for prevention of altitude illness. Wilderness Environ Med 2012; 23:307-15. [PMID: 23098412 DOI: 10.1016/j.wem.2012.08.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 07/22/2012] [Accepted: 08/06/2012] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To study the effectiveness of ibuprofen versus placebo in preventing acute mountain sickness (AMS) and high altitude headache (HAH). METHODS Double-blind, randomized, placebo-controlled trial. RESULTS Two hundred ninety-four healthy Western trekkers were recruited on the Everest approach at 4280 m or 4358 m and randomly assigned to receive either 600 mg of ibuprofen or placebo 3 times daily before and during ascent to 4928 m. One hundred eighty-three of 294 participants completed the trial. Of the participants who did not complete the trial, 62 were lost to follow-up and another 49 broke trial protocol. In an intent-to-treat analysis (232 participants), ibuprofen was found to be more effective than placebo in reducing the incidence of AMS (24.4% vs 40.4%; P = .01) and the incidence of HAH (42.3% vs 60.5%; P < .01). Ibuprofen was also superior to placebo in reducing the severity of HAH (4.9% vs 14.7%; P = .01). The end point of oxygen saturation was also higher in the ibuprofen group (80.8 % vs 82.4%; P = .035). For the 183 participants who completed the trial and conformed to the protocol, the incidence of AMS between placebo and treatment groups was not significant (32.9% vs 22.7%; P = .129 for AMS incidence, 9.6% vs 8.2%; P = .74 for AMS severity, 54.8% vs 42.7%; P = .11 for HAH incidence, and 8.2% vs 3.6%; P = .18 for HAH severity). CONCLUSIONS Ibuprofen was found to be effective in preventing AMS in the intent-to-treat analysis group but not in those who completed the trial. This loss of significance in the subjects who completed the trial may be explained by persons in the placebo group having a higher burden of illness and associated decreased compliance with the protocol. An important limitation of this study may be the possibility that ibuprofen can mask headache, which is a compulsory criterion for the diagnosis of AMS.
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Low EV, Avery AJ, Gupta V, Schedlbauer A, Grocott MPW. Identifying the lowest effective dose of acetazolamide for the prophylaxis of acute mountain sickness: systematic review and meta-analysis. BMJ 2012; 345:e6779. [PMID: 23081689 PMCID: PMC3475644 DOI: 10.1136/bmj.e6779] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVES To assess the efficacy of three different daily doses of acetazolamide in the prevention of acute mountain sickness and to determine the lowest effective dose. DESIGN Systematic review and meta-analysis. DATA SOURCES Medline and Embase along with a hand search of selected bibliographies. No language restrictions were applied. STUDY SELECTION Randomised controlled trials assessing the use of acetazolamide at 250 mg, 500 mg, or 750 mg daily versus placebo in adults as a drug intervention for the prophylaxis of acute mountain sickness. Included studies were required to state the administered dose of acetazolamide and to randomise participants before ascent to either acetazolamide or placebo. Two reviewers independently carried out the selection process. DATA EXTRACTION Two reviewers extracted data concerning study methods, pharmacological intervention with acetazolamide, method of assessment of acute mountain sickness, and event rates in both control and intervention groups, which were verified and analysed by the review team collaboratively. DATA SYNTHESIS 11 studies (with 12 interventions arms) were included in the review. Acetazolamide at doses of 250 mg, 500 mg, and 750 mg were all effective in preventing acute mountain sickness above 3000 m, with a combined odds ratio of 0.36 (95% confidence interval 0.28 to 0.46). At a dose of 250 mg daily the number needed to treat for acetazolamide to prevent acute mountain sickness was 6 (95% confidence interval 5 to 11). Heterogeneity ranged from I(2)=0% (500 mg subgroup) to I(2)=44% (750 mg subgroup). CONCLUSIONS Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness. Acetazolamide 250 mg daily is the lowest effective dose to prevent acute mountain sickness for which evidence is available.
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Affiliation(s)
- Emma V Low
- School of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
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Dumont L, Lysakowski C, Tramèr MR, Kayser B. Controversies in altitude medicine. Travel Med Infect Dis 2012; 3:183-8. [PMID: 17292037 DOI: 10.1016/j.tmaid.2004.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Accepted: 12/02/2004] [Indexed: 11/19/2022]
Abstract
Two areas of controversy in altitude medicine are briefly reviewed. The first area concerns the prevention of acute mountain sickness (AMS) with acetazolamide. It is argued that for full prevention of AMS symptoms 500-750mg a day is necessary, but that symptom attenuation may be possible with lower doses. The second concerns the study of the relationship between cerebral blood flow and acute mountain sickness. Multiple methodological problems can be identified; some are related to the experimental settings and some to limitations of the technical tools that are used to estimate cerebral blood flow. For the moment it remains unknown whether or not a change in cerebral blood flow is an etiological factor for the development of acute mountain sickness.
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Affiliation(s)
- Lionel Dumont
- Division of Anesthesiology, Geneva University Hospitals, Rue Micheli-du-Crest 24, CH-1211 Geneva 14, Switzerland
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Nussbaumer-Ochsner Y, Schuepfer N, Ursprung J, Siebenmann C, Maggiorini M, Bloch KE. Sleep and breathing in high altitude pulmonary edema susceptible subjects at 4,559 meters. Sleep 2012; 35:1413-21. [PMID: 23024440 PMCID: PMC3443768 DOI: 10.5665/sleep.2126] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Susceptible subjects ascending rapidly to high altitude develop pulmonary edema (HAPE). We evaluated whether HAPE leads to sleep and breathing disturbances that are alleviated by dexamethasone. DESIGN Double-blind, randomized, placebo-controlled trial with open-label extension. SETTING One night in sleep laboratory at 490 m, 2 nights in mountain hut at 4,559 m. PARTICIPANTS 21 HAPE susceptibles. INTERVENTION Dexamethasone 2 × 8 mg/d, either 24 h prior to ascent and at 4,559 m (dex-early), or started on day 2 at 4,559 m only (dex-late). MEASUREMENTS Polysomnography, questionnaires on sleep and acute mountain sickness. RESULTS Polysomnographies at 490 m were normal. In dex-late (n = 12) at 4,559 m, night 1 and 3, median oxygen saturation was 71% and 80%, apnea/hypopnea index 91.3/h and 9.6/h. In dex-early (n = 9), corresponding values were 78% and 79%, and 85.3/h and 52.3/h (P < 0.05 vs. 490 m, all instances). In dex-late, ascending from 490 m to 4,559 m (night 1), sleep efficiency decreased from 91% to 65%, slow wave sleep from 20% to 8% (P < 0.05, both instances). In dex-early, corresponding sleep efficiencies were 96% and 95%, slow wave sleep 18% and 9% (P < 0.05). From night 1 to 3, sleep efficiency remained unchanged in both groups while slow wave sleep increased to 20% in dex-late (P < 0.01). Compared to dex-early, initial AMS scores in dex-late were higher but improved during stay at altitude. CONCLUSIONS HAPE susceptibles ascending rapidly to high altitude experience pronounced nocturnal hypoxemia, and reduced sleep efficiency and deep sleep. Dexamethasone taken before ascent prevents severe hypoxemia and sleep disturbances, while dexamethasone taken 24 h after arrival at 4,559 m increases oxygenation and deep sleep.
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Affiliation(s)
- Yvonne Nussbaumer-Ochsner
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Nicole Schuepfer
- Institute of Human Movement Sciences and Sports, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Justyna Ursprung
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Christoph Siebenmann
- Institute of Human Movement Sciences and Sports, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Marco Maggiorini
- Medical Intensive Care Unit, University Hospital of Zurich, and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Konrad E. Bloch
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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Ritchie ND, Baggott AV, Andrew Todd WT. Acetazolamide for the prevention of acute mountain sickness--a systematic review and meta-analysis. J Travel Med 2012; 19:298-307. [PMID: 22943270 DOI: 10.1111/j.1708-8305.2012.00629.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 03/22/2012] [Accepted: 03/26/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND Acetazolamide has been reported to be effective in the prevention of acute mountain sickness (AMS). Our aim was to conduct a systematic review of randomized, placebo-controlled trials of acetazolamide in the prevention of AMS. METHODS Studies were identified by searching the MEDLINE, Embase, Cochrane Clinical Trials Register, and ClinicalTrials.gov databases. Primary end point was difference in incidence of AMS between acetazolamide and placebo groups. RESULTS Acetazolamide prophylaxis was associated with a 48% relative-risk reduction compared to placebo. There was no evidence of an association between efficacy and dose of acetazolamide. Adverse effects were often not systematically reported but appeared to be common but generally mild. One study found that adverse effects of acetazolamide were dose related. CONCLUSIONS Acetazolamide is effective prophylaxis for the prevention of symptoms of AMS in those going to high altitude. A dose of 250 mg/day has similar efficacy to higher doses and may have a favorable side-effect profile.
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Affiliation(s)
- Neil D Ritchie
- Institute of Infection, Immunity and Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK.
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Kayser B, Dumont L, Lysakowski C, Combescure C, Haller G, Tramèr MR. Reappraisal of Acetazolamide for the Prevention of Acute Mountain Sickness: A Systematic Review and Meta-Analysis. High Alt Med Biol 2012; 13:82-92. [DOI: 10.1089/ham.2011.1084] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Bengt Kayser
- Institute of Movement Sciences and Sports Medicine, Medical Faculty, University of Geneva, Geneva, Switzerland
| | - Lionel Dumont
- Division of Anesthesiology, Geneva University Hospitals, Geneva, Switzerland
| | | | | | - Guy Haller
- Division of Anesthesiology, Geneva University Hospitals, Geneva, Switzerland
- Clinical Trial Unit, Geneva University Hospitals, Geneva, Switzerland
| | - Martin R. Tramèr
- Division of Anesthesiology, Geneva University Hospitals, Geneva, Switzerland
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Pharmacologic Prophylaxis for Acute Mountain Sickness: A Systematic Shortcut Review. Ann Emerg Med 2012; 59:307-317.e1. [DOI: 10.1016/j.annemergmed.2011.10.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 10/11/2011] [Accepted: 10/12/2011] [Indexed: 11/24/2022]
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