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Sevik A, Gaisl T, Forrer A, Graf L, Ulrich S, Bloch KE, Lichtblau M, Furian M. High altitudes and partial pressure of arterial oxygen in patients with chronic obstructive pulmonary disease - A systematic review and meta-analysis. Pulmonology 2024:S2531-0437(24)00095-3. [PMID: 39030093 DOI: 10.1016/j.pulmoe.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 05/13/2024] [Accepted: 06/04/2024] [Indexed: 07/21/2024] Open
Abstract
IMPORTANCE Prior study in healthy subjects has shown a reduction of partial pressure of arterial oxygen (PaO2) by -1.60 kPa/kilometre of altitude gain. However, the association of altitude-related change in PaO2 and altitude-related adverse health effects (ARAHE) in patients with chronic obstructive pulmonary disease (COPD) remain unknown. OBJECTIVE To provide an effect size estimate for the decline in PaO2 with each kilometre of altitude gain and to identify ARAHE in relation to altitude in patients with COPD. www.crd.york.ac.uk/prospero: CRD42020217938. DATA SOURCES A systematic search of PubMed and Embase was performed from inception to May 30, 2023. STUDY SELECTION Peer-reviewed and prospective studies in patients with COPD staying at altitudes >1500 m providing arterial blood gases within the first 3 days at the target altitude. DATA EXTRACTION AND SYNTHESIS Aggregate data (AD) on study characteristics were extracted, and individual patient data (IPD) were requested. Estimates were pooled using random-effects meta-analysis. MAIN OUTCOME AND MEASURES Relative risk estimates and 95 % confidence intervals for the association between PaO2 and altitude in patients with COPD. RESULTS Thirteen studies were included in the AD analysis, of which 6 studies (222 patients, 45.2 % female) provided IPD, thus were included in the quantitative analysis. The estimated effect size of PaO2 was -0.84 kPa [95 %CI, -0.92 to -0.76] per 1000 m of altitude gain (I2=65.0 %, P < 0.001). In multivariable regression analysis, COPD severity, baseline PaO2, age and time spent at altitude were predictors for PaO2 at altitude. Overall, 37.8 % of COPD patients experienced an ARAHE, whereas older age, female sex, COPD severity, baseline PaO2, and target altitude were predictors for the occurrence of ARAHE (area under ROC curve: 0.9275, P < 0.001). CONCLUSIONS AND RELEVANCE This meta-analysis, providing altitude-related decrease in PaO2 and risk of ARAHE in patients with COPD ascending to altitudes >1500 m, revealed a lower altitude-related decrease in PaO2 in COPD patients compared with healthy. However, these findings might improve patient care and facilitate decisions about initiating preventive measures against hypoxaemia and ARAHE in patients with COPD planning an altitude sojourn or intercontinental flight, i.e. supplemental oxygen or acetazolamide.
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Affiliation(s)
- A Sevik
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - T Gaisl
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - A Forrer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - L Graf
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - S Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic
| | - K E Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic
| | - M Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic
| | - M Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland; Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Bishkek, Switzerland, Kyrgyz Republic; Research Department, Swiss University for Traditional Chinese Medicine, Bad Zurzach, Switzerland.
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Liu B, Yuan M, Yang M, Zhu H, Zhang W. The Effect of High-Altitude Hypoxia on Neuropsychiatric Functions. High Alt Med Biol 2024; 25:26-41. [PMID: 37815821 DOI: 10.1089/ham.2022.0136] [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: 10/11/2023] Open
Abstract
Liu, Bo, Minlan Yuan, Mei Yang, Hongru Zhu, and Wei Zhang. The effect of high-altitude hypoxia on neuropsychiatric functions. High Alt Med Biol. 25:26-41, 2024. Background: In recent years, there has been a growing popularity in engaging in activities at high altitudes, such as hiking and work. However, these high-altitude environments pose risks of hypoxia, which can lead to various acute or chronic cerebral diseases. These conditions include common neurological diseases such as acute mountain sickness (AMS), high-altitude cerebral edema, and altitude-related cerebrovascular diseases, as well as psychiatric disorders such as anxiety, depression, and psychosis. However, reviews of altitude-related neuropsychiatric conditions and their potential mechanisms are rare. Methods: We conducted searches on PubMed and Google Scholar, exploring existing literature encompassing preclinical and clinical studies. Our aim was to summarize the prevalent neuropsychiatric diseases induced by altitude hypoxia, the potential pathophysiological mechanisms, as well as the available pharmacological and nonpharmacological strategies for prevention and intervention. Results: The development of altitude-related cerebral diseases may arise from various pathogenic processes, including neurovascular alterations associated with hypoxia, cytotoxic responses, activation of reactive oxygen species, and dysregulation of the expression of hypoxia inducible factor-1 and nuclear factor erythroid 2-related factor 2. Furthermore, the interplay between hypoxia-induced neurological and psychiatric changes is believed to play a role in the progression of brain damage. Conclusions: While there is some evidence pointing to pathophysiological changes in hypoxia-induced brain damage, the precise mechanisms responsible for neuropsychiatric alterations remain elusive. Currently, the range of prevention and intervention strategies available is primarily focused on addressing AMS, with a preference for prevention rather than treatment.
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Affiliation(s)
- Bo Liu
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
- Zigong Mental Health Center, Zigong, China
| | - Minlan Yuan
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
| | - Mei Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China School of Basic Medical Sciences and Forensic Medicine, Chengdu, Sichuan
| | - Hongru Zhu
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
| | - Wei Zhang
- Mental Health Center and Psychiatric Laboratory, West China Hospital of Sichuan University, Chengdu, China
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
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Bloch KE, Sooronbaev TM, Ulrich S, Lichtblau M, Furian M. Counseling Patients with Chronic Obstructive Pulmonary Disease Traveling to High Altitude. High Alt Med Biol 2023; 24:158-166. [PMID: 37646641 PMCID: PMC10516222 DOI: 10.1089/ham.2023.0053] [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] [Received: 04/15/2023] [Accepted: 07/13/2023] [Indexed: 09/01/2023] Open
Abstract
Bloch, Konrad E., Talant M. Sooronbaev, Silvia Ulrich, Mona Lichtblau, and Michael Furian. Clinician's corner: counseling patients with chronic obstructive pulmonary disease traveling to high altitude. High Alt Med Biol. 24:158-166, 2023.-Mountain travel is increasingly popular also among patients with chronic obstructive pulmonary disease (COPD), a highly prevalent condition often associated with cardiovascular and systemic manifestations. Recent studies have shown that nonhypercapnic and only mildly hypoxemic lowlanders with moderate to severe airflow obstruction owing to COPD experience dyspnea, exercise limitation, and sleep disturbances when traveling up to 3,100 m. Altitude-related adverse health effects (ARAHE) in patients with COPD include severe hypoxemia, which may be asymptomatic but expose patients to the risk of excessive systemic and pulmonary hypertension, cardiac arrhythmia, and even myocardial or cerebral ischemia. In addition, hypobaric hypoxia may impair postural control, psycho-motor, and cognitive performance in patients with COPD during altitude sojourns. Randomized, placebo-controlled trials have shown that preventive treatment with oxygen at night or with acetazolamide reduces the risk of ARAHE in patients with COPD while preventive dexamethasone treatment improves oxygenation and altitude-induced excessive sleep apnea, and lowers systemic and pulmonary artery pressure. This clinical review provides suggestions for pretravel assessment and preparations and measures during travel that may reduce the risk of ARAHE and contribute to pleasant mountain journeys of patients with COPD.
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Affiliation(s)
- Konrad E. Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - Talant M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Bishkek, Kyrgyz Republic
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Bauer M, Müller J, Schneider SR, Buenzli S, Furian M, Ulrich T, Carta AF, Bader PR, Lichtblau M, Taalaibekova A, Raimberdiev M, Champigneulle B, Sooronbaev T, Bloch KE, Ulrich S. Hypoxia-altitude simulation test to predict altitude-related adverse health effects in COPD patients. ERJ Open Res 2023; 9:00488-2022. [PMID: 36923563 PMCID: PMC10009702 DOI: 10.1183/23120541.00488-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/09/2022] [Indexed: 12/24/2022] Open
Abstract
Background/aims Amongst numerous travellers to high altitude (HA) are many with the highly prevalent COPD, who are at particular risk for altitude-related adverse health effects (ARAHE). We then investigated the hypoxia-altitude simulation test (HAST) to predict ARAHE in COPD patients travelling to altitude. Methods This prospective diagnostic accuracy study included 75 COPD patients: 40 women, age 58±9 years, forced expiratory volume in 1 s (FEV1) 40-80% pred, oxygen saturation measured by pulse oximetry (S pO2 ) ≥92% and arterial carbon dioxide tension (P aCO2 ) <6 kPa. Patients underwent baseline evaluation and HAST, breathing normobaric hypoxic air (inspiratory oxygen fraction (F IO2 ) of 15%) for 15 min, at low altitude (760 m). Cut-off values for a positive HAST were set according to British Thoracic Society (BTS) guidelines (arterial oxygen tension (P aO2 ) <6.6 kPa and/or S pO2 <85%). The following day, patients travelled to HA (3100 m) for two overnight stays where ARAHE development including acute mountain sickness (AMS), Lake Louise Score ≥4 and/or AMS score ≥0.7, severe hypoxaemia (S pO2 <80% for >30 min or 75% for >15 min) or intercurrent illness was observed. Results ARAHE occurred in 50 (66%) patients and 23 out of 75 (31%) were positive on HAST according to S pO2 , and 11 out of 64 (17%) according to P aO2 . For S pO2 /P aO2 we report a sensitivity of 46/25%, specificity of 84/95%, positive predictive value of 85/92% and negative predictive value of 44/37%. Conclusion In COPD patients ascending to HA, ARAHE are common. Despite an acceptable positive predictive value of the HAST to predict ARAHE, its clinical use is limited by its insufficient sensitivity and overall accuracy. Counselling COPD patients before altitude travel remains challenging and best focuses on early recognition and treatment of ARAHE with oxygen and descent.
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Affiliation(s)
- Meret Bauer
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Julian Müller
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Simon R. Schneider
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Simone Buenzli
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Michael Furian
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Tanja Ulrich
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Arcangelo F. Carta
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Patrick R. Bader
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Mona Lichtblau
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Ajian Taalaibekova
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Madiiar Raimberdiev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Benoit Champigneulle
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- HP2 Laboratory, Inserm U1300, Grenoble Alpes University, CHU Grenoble Alpes, Grenoble, France
| | - Talant Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Konrad E. Bloch
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Silvia Ulrich
- University of Zurich and University Hospital of Zurich, Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
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Schneider SR, Lichtblau M, Furian M, Mayer LC, Berlier C, Müller J, Saxer S, Schwarz EI, Bloch KE, Ulrich S. Cardiorespiratory Adaptation to Short-Term Exposure to Altitude vs. Normobaric Hypoxia in Patients with Pulmonary Hypertension. J Clin Med 2022; 11:jcm11102769. [PMID: 35628896 PMCID: PMC9147287 DOI: 10.3390/jcm11102769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/05/2022] [Accepted: 05/12/2022] [Indexed: 02/01/2023] Open
Abstract
Prediction of adverse health effects at altitude or during air travel is relevant, particularly in pre-existing cardiopulmonary disease such as pulmonary arterial or chronic thromboembolic pulmonary hypertension (PAH/CTEPH, PH). A total of 21 stable PH-patients (64 ± 15 y, 10 female, 12/9 PAH/CTEPH) were examined by pulse oximetry, arterial blood gas analysis and echocardiography during exposure to normobaric hypoxia (NH) (FiO2 15% ≈ 2500 m simulated altitude, data partly published) at low altitude and, on a separate day, at hypobaric hypoxia (HH, 2500 m) within 20−30 min after arrival. We compared changes in blood oxygenation and estimated pulmonary artery pressure in lowlanders with PH during high altitude simulation testing (HAST, NH) with changes in response to HH. During NH, 4/21 desaturated to SpO2 < 85% corresponding to a positive HAST according to BTS-recommendations and 12 qualified for oxygen at altitude according to low SpO2 < 92% at baseline. At HH, 3/21 received oxygen due to safety criteria (SpO2 < 80% for >30 min), of which two were HAST-negative. During HH vs. NH, patients had a (mean ± SE) significantly lower PaCO2 4.4 ± 0.1 vs. 4.9 ± 0.1 kPa, mean difference (95% CI) −0.5 kPa (−0.7 to −0.3), PaO2 6.7 ± 0.2 vs. 8.1 ± 0.2 kPa, −1.3 kPa (−1.9 to −0.8) and higher tricuspid regurgitation pressure gradient 55 ± 4 vs. 45 ± 4 mmHg, 10 mmHg (3 to 17), all p < 0.05. No serious adverse events occurred. In patients with PH, short-term exposure to altitude of 2500 m induced more pronounced hypoxemia, hypocapnia and pulmonary hemodynamic changes compared to NH during HAST despite similar exposure times and PiO2. Therefore, the use of HAST to predict physiological changes at altitude remains questionable. (ClinicalTrials.gov: NCT03592927 and NCT03637153).
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Affiliation(s)
- Simon R. Schneider
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
- Department of Health Sciences and Medicine, University of Lucerne, Frohburgstrasse 3, 6005 Lucerne, Switzerland
| | - Mona Lichtblau
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Michael Furian
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Laura C. Mayer
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Charlotte Berlier
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Julian Müller
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Stéphanie Saxer
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Esther I. Schwarz
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Konrad E. Bloch
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
| | - Silvia Ulrich
- Department of Pulmonology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland; (S.R.S.); (M.L.); (M.F.); (L.C.M.); (C.B.); (J.M.); (S.S.); (E.I.S.); (K.E.B.)
- Correspondence:
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Furian M, Mademilov M, Buergin A, Scheiwiller PM, Mayer L, Schneider S, Emilov B, Lichtblau M, Bitos K, Muralt L, Groth A, Reiser AE, Sevik A, Sheraliev U, Marazhapov NH, Aydaralieva S, Muratbekova A, Tabyshova A, Abdraeva A, Buenzli S, Sooronbaev TM, Ulrich S, Bloch KE. Acetazolamide to Prevent Adverse Altitude Effects in COPD and Healthy Adults. NEJM EVIDENCE 2022; 1:EVIDoa2100006. [PMID: 38296630 DOI: 10.1056/evidoa2100006] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
BACKGROUND: We evaluated the efficacy of acetazolamide in preventing adverse altitude effects in patients with moderate to severe chronic obstructive pulmonary disease (COPD) and in healthy lowlanders 40 years of age or older. METHODS: Trial 1 was a randomized, double-blind, parallel-design trial in which 176 patients with COPD were treated with acetazolamide capsules (375 mg/day) or placebo, starting 24 hours before staying for 2 days at 3100 m. The mean (±SD) age of participants was 57±9 years, and 34% were women. At 760 m, COPD patients had oxygen saturation measured by pulse oximetry of 92% or greater, arterial partial pressure of carbon dioxide less than 45 mm Hg, and mean forced expiratory volume in 1 second of 63±11% of predicted. The primary outcome in trial 1 was the incidence of the composite end point of altitude-related adverse health effects (ARAHE) at 3100 m. Criteria for ARAHE included acute mountain sickness (AMS) and symptoms or findings relevant to well-being and safety, such as severe hypoxemia, requiring intervention. Trial 2 comprised 345 healthy lowlanders. Their mean age was 53±7 years, and 69% were women. The participants in trial 2 underwent the same protocol as did the patients with COPD in trial 1. The primary outcome in trial 2 was the incidence of AMS assessed at 3100 m by the Lake Louise questionnaire score (the scale of self-assessed symptoms ranges from 0 to 15 points, indicating absent to severe, with 3 or more points including headache, indicating AMS). RESULTS: In trial 1 of patients with COPD, 68 of 90 (76%) receiving placebo and 42 of 86 (49%) receiving acetazolamide experienced ARAHE (hazard ratio, 0.54; 95% confidence interval [CI], 0.37 to 0.79; P<0.001). The number needed to treat (NNT) to prevent one case of ARAHE was 4 (95% CI, 3 to 8). In trial 2 of healthy individuals, 54 of 170 (32%) receiving placebo and 38 of 175 (22%) receiving acetazolamide experienced AMS (hazard ratio, 0.48; 95% CI, 0.29 to 0.80; chi-square statistic P=0.035). The NNT to prevent one case of AMS was 10 (95% CI, 5 to 141). No serious adverse events occurred in these trials. CONCLUSIONS: Preventive treatment with acetazolamide reduced the incidence of adverse altitude effects requiring an intervention in patients with COPD and the incidence of AMS in healthy lowlanders 40 years of age or older during a high-altitude sojourn. (Funded by the Swiss National Science Foundation [Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung], Lunge Zürich, and the Swiss Lung Foundation; ClinicalTrials.gov numbers, NCT03156231 and NCT03561675.)
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Affiliation(s)
- Michael Furian
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Maamed Mademilov
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Aline Buergin
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Philipp M Scheiwiller
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Laura Mayer
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Simon Schneider
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Berik Emilov
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Konstantinos Bitos
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Lara Muralt
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Alexandra Groth
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Aurelia E Reiser
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Ahmet Sevik
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Ulan Sheraliev
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Nuriddin H Marazhapov
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Shoira Aydaralieva
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Aybermet Muratbekova
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Aizhamal Tabyshova
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ainura Abdraeva
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Simone Buenzli
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Talant M Sooronbaev
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Konrad E Bloch
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High-Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
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7
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Schneider SR, Mayer LC, Lichtblau M, Berlier C, Schwarz EI, Saxer S, Tan L, Furian M, Bloch KE, Ulrich S. Effect of a day-trip to altitude (2500 m) on exercise performance in pulmonary hypertension: randomised crossover trial. ERJ Open Res 2021; 7:00314-2021. [PMID: 34651040 PMCID: PMC8502941 DOI: 10.1183/23120541.00314-2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/21/2021] [Indexed: 11/20/2022] Open
Abstract
Question addressed by the study To investigate exercise performance and hypoxia-related health effects in patients with pulmonary hypertension (PH) during a high-altitude sojourn. Patients and methods In a randomised crossover trial in stable (same therapy for >4 weeks) patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) with resting arterial oxygen tension (PaO2) ≥7.3 kPa, we compared symptom-limited constant work-rate exercise test (CWRET) cycling time during a day-trip to 2500 m versus 470 m. Further outcomes were symptoms, oxygenation and echocardiography. For safety, patients with sustained hypoxaemia at altitude (peripheral oxygen saturation <80% for >30 min or <75% for >15 min) received oxygen therapy. Results 28 PAH/CTEPH patients (n=15/n=13); 13 females; mean±sd age 63±15 years were included. After >3 h at 2500 m versus 470 m, CWRET-time was reduced to 17±11 versus 24±9 min (mean difference −6, 95% CI −10 to −3), corresponding to −27.6% (−41.1 to −14.1; p<0.001), but similar Borg dyspnoea scale. At altitude, PaO2 was significantly lower (7.3±0.8 versus 10.4±1.5 kPa; mean difference −3.2 kPa, 95% CI −3.6 to −2.8 kPa), whereas heart rate and tricuspid regurgitation pressure gradient (TRPG) were higher (86±18 versus 71±16 beats·min−1, mean difference 15 beats·min−1, 95% CI 7 to 23 beats·min−1) and 56±25 versus 40±15 mmHg (mean difference 17 mmHg, 95% CI 9 to 24 mmHg), respectively, and remained so until end-exercise (all p<0.001). The TRPG/cardiac output slope during exercise was similar at both altitudes. Overall, three (11%) out of 28 patients received oxygen at 2500 m due to hypoxaemia. Conclusion This randomised crossover study showed that the majority of PH patients tolerate a day-trip to 2500 m well. At high versus low altitude, the mean exercise time was reduced, albeit with a high interindividual variability, and pulmonary artery pressure at rest and during exercise increased, but pressure–flow slope and dyspnoea were unchanged. Short-time exposure to high altitude in pulmonary hypertension induces hypoxaemia, reduces constant work-rate cycle time compared to ambient air and is well tolerated overallhttps://bit.ly/3xUAFMs
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Affiliation(s)
- Simon R Schneider
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland.,Dept of Health Sciences and Medicine, University of Lucerne, Lucerne, Switzerland
| | - Laura C Mayer
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Charlotte Berlier
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Esther I Schwarz
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Stéphanie Saxer
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Lu Tan
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Michael Furian
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
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Lichtblau M, Latshang TD, Aeschbacher SS, Huber F, Scheiwiller PM, Ulrich S, Schneider SR, Hasler ED, Furian M, Bloch KE, Saxer S, Ulrich S. Effect of Nocturnal Oxygen Therapy on Daytime Pulmonary Hemodynamics in Patients With Chronic Obstructive Pulmonary Disease Traveling to Altitude: A Randomized Controlled Trial. Front Physiol 2021; 12:689863. [PMID: 34305642 PMCID: PMC8294087 DOI: 10.3389/fphys.2021.689863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/31/2021] [Indexed: 11/30/2022] Open
Abstract
Introduction We investigated whether nocturnal oxygen therapy (NOT) mitigates the increase of pulmonary artery pressure in patients during daytime with chronic obstructive pulmonary disease (COPD) traveling to altitude. Methods Patients with COPD living below 800 m underwent examinations at 490 m and during two sojourns at 2,048 m (with a washout period of 2 weeks < 800 m between altitude sojourns). During nights at altitude, patients received either NOT (3 L/min) or placebo (ambient air 3 L/min) via nasal cannula according to a randomized crossover design. The main outcomes were the tricuspid regurgitation pressure gradient (TRPG) measured by echocardiography on the second day at altitude (under ambient air) and various other echocardiographic measures of the right and left heart function. Patients fulfilling predefined safety criteria were withdrawn from the study. Results Twenty-three COPD patients [70% Global Initiative for Chronic Obstructive Lung Disease (GOLD) II/30% GOLD III, mean ± SD age 66 ± 5 years, FEV1 54% ± 13% predicted] were included in the per-protocol analysis. TRPG significantly increased when patients traveled to altitude (from low altitude 21.7 ± 5.2 mmHg to 2,048 m placebo 27.4 ± 7.3 mmHg and 2,048 m NOT 27.8 ± 8.3 mmHg) difference between interventions (mean difference 0.4 mmHg, 95% CI −2.1 to 3.0, p = 0.736). The tricuspid annular plane systolic excursion was significantly higher after NOT vs. placebo [2.6 ± 0.6 vs. 2.3 ± 0.4 cm, mean difference (95% confidence interval) 0.3 (0.1 − 0.5) cm, p = 0.005]. During visits to 2,048 m until 24 h after descent, eight patients (26%) using placebo and one (4%) using NOT had to be withdrawn because of altitude-related adverse health effects (p < 0.001). Conclusion In lowlanders with COPD remaining free of clinically relevant altitude-related adverse health effects, changes in daytime pulmonary hemodynamics during a stay at high altitude were trivial and not modified by NOT. Clinical Trial Registration www.ClinicalTrials.gov, identifier NCT02150590.
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Affiliation(s)
- Mona Lichtblau
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Tsogyal D Latshang
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | | | - Fabienne Huber
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | | | - Stefanie Ulrich
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Simon R Schneider
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Elisabeth D Hasler
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Michael Furian
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Stéphanie Saxer
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland
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Why Hydrocephalus Patients Suffer When the Weather Changes: A New Hypothesis. ACTA NEUROCHIRURGICA. SUPPLEMENT 2021. [PMID: 33839865 DOI: 10.1007/978-3-030-59436-7_59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Hydrocephalus patients complain about symptoms related to weather changes, especially changes in atmospheric pressure (pat). We aimed to determine which physical, physiological, and pathophysiological effects can explain this phenomenon. We hypothesized that intracranial pressure (ICP) is influenced by changes of intracranial blood volume caused by autoregulatory changes in arterial diameter as a reaction to changing levels of arterial CO2 partial pressure (paCO2) caused by changes in atmospheric pressure (pat). To test this hypothesis, we investigated the influence of pat on paCO2, and then assessed the influence of paCO2 on ICP by extrapolating data found in the literature. Using conservative assumptions, we found that a change of pat of about 50 hPa will result in a change in ICP of above 1.65 mmHg, which could explain the symptoms patients reported.
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Luks AM, Grissom CK. Return to High Altitude After Recovery from Coronavirus Disease 2019. High Alt Med Biol 2021; 22:119-127. [PMID: 33978479 DOI: 10.1089/ham.2021.0049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Luks, Andrew M. and Colin K. Grissom. Return to high altitude after recovery from coronavirus disease 2019. High Alt Med Biol. 22: 119-127, 2021.-With the increasing availability of coronavirus disease 2019 (COVID-19) vaccines and the eventual decline in the burden of the disease, it is anticipated that all forms of tourism, including travel to high altitude, will rebound in the near future. Given the physiologic challenges posed by hypobaric hypoxia at high altitude, it is useful to consider whether high-altitude travel will pose risks to those previously infected with severe acute respiratory syndrome coronavirus 2, particularly those with persistent symptoms after resolution of their infection. Although no studies have specifically examined this question as of yet, available data on the cardiopulmonary sequelae of COVID-19 provide some sense of the problems people may face at high altitude and who warrants evaluation before such endeavors. On average, most individuals who have recovered from COVID-19 have normal or near normal gas exchange, pulmonary function testing, cardiovascular function, and exercise capacity, although a subset of individuals have persistent functional deficits in some or all of these domains when examined up to 5 months after infection. Evaluation is warranted before planned high-altitude travel in individuals with persistent symptoms at least 2 weeks after a positive test or hospital discharge as well as in those who required care in an intensive care unit or suffered from myocarditis or arterial or venous thromboembolism. Depending on the results of this testing, planned high-altitude travel may need to be modified or even deferred pending resolution of the identified abnormalities. As more people travel to high altitude after the pandemic and further studies are conducted, additional data should become available to provide further guidance on these issues.
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Affiliation(s)
- Andrew M Luks
- Division of Pulmonary, Critical Care and Sleep Medicine, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | - Colin K Grissom
- Division of Pulmonary and Critical Care Medicine, Intermountain Medical Center and the University of Utah, Salt Lake City, Utah, USA
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11
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Furian M, Flueck D, Scheiwiller PM, Mueller-Mottet S, Urner LM, Latshang TD, Ulrich S, Bloch KE. Nocturnal cerebral tissue oxygenation in lowlanders with chronic obstructive pulmonary disease travelling to an altitude of 2,590 m: Data from a randomised trial. J Sleep Res 2021; 30:e13365. [PMID: 33902162 DOI: 10.1111/jsr.13365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 11/29/2022]
Abstract
Altitude exposure induces hypoxaemia in patients with chronic obstructive pulmonary disease (COPD), particularly during sleep. The present study tested the hypothesis in patients with COPD staying overnight at high altitude that nocturnal arterial hypoxaemia is associated with impaired cerebral tissue oxygenation (CTO). A total of 35 patients with moderate-to-severe COPD, living at <800 m (mean [SD] age 62.4 [12.3] years, forced expiratory volume in 1 s [FEV1 ] 61 [16]% predicted, awake pulse oximetry ≥92%) underwent continuous overnight monitoring of pulse oximetry (oxygen saturation [SpO2 ]) and near-infrared spectroscopy of prefrontal CTO, respectively, at 490 m and 2,590 m. Regression analysis was used to evaluate whether nocturnal arterial desaturation (COPDDesat , SpO2 <90% for >30% of night-time) at 490 m predicted CTO at 2,590 m when controlling for baseline variables. At 2,590 m, mean nocturnal SpO2 and CTO were decreased versus 490 m, mean change -8.8% (95% confidence interval [CI] -10.0 to -7.6) and -3.6% (95% CI -5.7 to -1.6), difference in change ΔCTO-ΔSpO2 5.2% (95% CI 3.0 to 7.3; p < .001). Moreover, frequent cyclic desaturations (≥4% dips/hr) occurred in SpO2 and CTO, mean change from 490 m 35.3/hr (95% CI 24.9 to 45.7) and 3.4/hr (95% CI 1.4 to 5.3), difference in change ΔCTO-ΔSpO2 -32.8/hr (95% CI -43.8 to -21.8; p < .001). Regression analysis confirmed an association of COPDDesat with lower CTO at 2,590 m (coefficient -7.6%, 95% CI -13.2 to -2.0; p = .007) when controlling for several confounders. We conclude that lowlanders with COPD staying overnight at 2,590 m experience altitude-induced hypoxaemia and periodic breathing in association with sustained and intermittent cerebral deoxygenation. Although less pronounced than the arterial deoxygenation, the altitude-induced cerebral tissue deoxygenation may represent a risk of brain dysfunction, especially in patients with COPD with nocturnal hypoxaemia at low altitude.
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Affiliation(s)
- Michael Furian
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Deborah Flueck
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Philipp M Scheiwiller
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Séverine Mueller-Mottet
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Lorenz M Urner
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Tsogyal D Latshang
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
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12
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Schneider SR, Mayer LC, Lichtblau M, Berlier C, Schwarz EI, Saxer S, Furian M, Bloch KE, Ulrich S. Effect of Normobaric Hypoxia on Exercise Performance in Pulmonary Hypertension: Randomized Trial. Chest 2020; 159:757-771. [PMID: 32918899 DOI: 10.1016/j.chest.2020.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/24/2020] [Accepted: 09/04/2020] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Many patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension (PH) wish to travel to altitude or by airplane, but their risk of hypoxia-related adverse health effects is insufficiently explored. RESEARCH QUESTION How does hypoxia, compared with normoxia, affect constant work-rate exercise test (CWRET) time in patients with PH, and which physiologic mechanisms are involved? STUDY DESIGN AND METHODS Stable patients with PH with resting Pao2 ≥ 7.3 kPa underwent symptom-limited cycling CWRET (60% of maximal workload) while breathing normobaric hypoxic air (hypoxia; Fio2, 15%) and ambient air (normoxia; Fio2, 21%) in a randomized cross-over design. Borg dyspnea score, arterial blood gases, tricuspid regurgitation pressure gradient, and mean pulmonary artery pressure/cardiac output ratio (mean PAP/CO) by echocardiography were assessed before and during end-CWRET. RESULTS Twenty-eight patients (13 women) were included: median (quartiles) age, 66 (54; 74) years; mean pulmonary artery pressure, 41 (29; 49) mm Hg; and pulmonary vascular resistance, 5.4 (4; 8) Wood units. Under normoxia and hypoxia, CWRET times were 16.9 (8.0; 30.0) and 6.7 (5.5; 27.3) min, respectively, with a median difference (95% CI) of -0.7 (-3.1 to 0.0) min corresponding to -7 (-32 to 0.0)% (P = .006). At end-exercise in normoxia and hypoxia, respectively, median values and differences in corresponding variables were as follows: Pao2: 8.0 vs 6.4, -1.7 (-2.7 to -1.1) kPa; arterial oxygen content: 19.2 vs 17.2, -1.7 (-3 to -0.1) mL/dL; Paco2: 4.7 vs 4.3, -0.3 (-0.5 to -0.1) kPa; lactate: 3.7 vs 3.7, 0.9 (0.1 to 1.6) mM (P < .05 all differences). Values for Borg scale score: 7 vs 6, 0.5 (0 to 1); tricuspid pressure gradient: 89 vs 77, -3 (-9 to 16) mm Hg; and mean PAP/CO: 4.5 vs 3.3, 0.3 (-0.8 to 1.4) Wood units remained unchanged. In multivariable regression, baseline pulmonary vascular resistance was the sole predictor of hypoxia-induced change in CWRET time. INTERPRETATION In patients with PH, short-time exposure to hypoxia was well tolerated but reduced CWRET time compared with normoxia in association with hypoxemia, lactacidemia, and hypocapnia. Because pulmonary hemodynamics and dyspnea at end-exercise remained unaltered, the hypoxia-induced exercise limitation may be due to a reduced oxygen delivery causing peripheral tissue hypoxia, augmented lactic acid loading and hyperventilation. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT03592927; URL: www.clinicaltrials.gov.
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Affiliation(s)
- Simon R Schneider
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland; Department of Health Sciences and Medicine, University of Lucerne, Lucerne, Switzerland
| | - Laura C Mayer
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Charlotte Berlier
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Esther I Schwarz
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Stéphanie Saxer
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Michael Furian
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Konrad E Bloch
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Clinic of Pulmonology, University Hospital of Zurich, Zurich, Switzerland.
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Zabor EC, Kaizer AM, Hobbs BP. Randomized Controlled Trials. Chest 2020; 158:S79-S87. [PMID: 32658656 PMCID: PMC8176647 DOI: 10.1016/j.chest.2020.03.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/19/2019] [Accepted: 03/09/2020] [Indexed: 12/18/2022] Open
Abstract
Randomized controlled trials (RCTs) are considered the highest level of evidence to establish causal associations in clinical research. There are many RCT designs and features that can be selected to address a research hypothesis. Designs of RCTs have become increasingly diverse as new methods have been proposed to evaluate increasingly complex scientific hypotheses. This article reviews the principles and general concepts behind many common RCT designs and introduces newer designs that have been proposed, such as adaptive and cluster randomized trials. A focus on the many choices for randomization within an RCT is described, along with their potential tradeoffs. To illustrate their diversity, examples of RCTs from the literature are provided. Statistical considerations, such as power and type I error rates, are discussed with the intention of providing practical guidance about how to specify study hypotheses that address the scientific question while being statistically appropriate. Finally, the freely available Consolidated Standards of Reporting Trials guidelines and US Food and Drug Administration guidance documents are introduced, along with a set of guidelines one should consider when planning an RCT or reviewing RCTs submitted for publication in peer-reviewed academic journals.
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Affiliation(s)
- Emily C Zabor
- Department of Quantitative Health Sciences & Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH.
| | - Alexander M Kaizer
- Department of Quantitative Health Sciences & Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH
| | - Brian P Hobbs
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado-Anschutz Medical Campus, Aurora, CO
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Lichtblau M, Furian M, Aeschbacher SS, Bisang M, Sheraliev U, Mademilov M, Marazhapov NH, Ulrich S, Sooronbaev T, Bloch KE, Ulrich S. Right-to-left shunts in lowlanders with COPD traveling to altitude: a randomized controlled trial with dexamethasone. J Appl Physiol (1985) 2019; 128:117-126. [PMID: 31751183 DOI: 10.1152/japplphysiol.00548.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Right-to-left shunts (RLS) are prevalent in patients with chronic obstructive pulmonary disease (COPD) and might exaggerate oxygen desaturation, especially at altitude. The aim of this study was to describe the prevalence of RLS in patients with COPD traveling to altitude and the effect of preventive dexamethasone. Lowlanders with COPD [Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1-2, oxygen saturation assessed by pulse oximetry (SpO2) >92%] were randomized to dexamethasone (4 mg bid) or placebo starting 24 h before ascent from 760 m and while staying at 3,100 m for 48 h. Saline-contrast echocardiography was performed at 760 m and after the first night at altitude. Of 87 patients (81 men, 6 women; mean ± SD age 57 ± 9 yr, forced expiratory volume in 1 s 89 ± 22% pred, SpO2 95 ± 2%), 39 were assigned to placebo and 48 to dexamethasone. In the placebo group, 19 patients (49%) had RLS, of which 13 were intracardiac. In the dexamethasone group 23 patients (48%) had RLS, of which 11 were intracardiac (P = 1.0 vs. dexamethasone). Eleven patients receiving placebo and 13 receiving dexamethasone developed new RLS at altitude (P = 0.011 for both changes, P = 0.411 between groups). RLS prevalence at 3,100 m was 30 (77%) in the placebo and 36 (75%) in the dexamethasone group (P = not significant). Development of RLS at altitude could be predicted at lowland by a higher resting pulmonary artery pressure, a lower arterial partial pressure of oxygen, and a greater oxygen desaturation during exercise but not by treatment allocation. Almost half of lowlanders with COPD revealed RLS near sea level, and this proportion significantly increased to about three-fourths when traveling to 3,100 m irrespective of dexamethasone prophylaxis.NEW & NOTEWORTHY The prevalence of intracardiac and intrapulmonary right-to-left shunts (RLS) at altitude in patients with chronic obstructive pulmonary disease (COPD) has not been studied so far. In a large cohort of patients with moderate COPD, our randomized trial showed that the prevalence of RLS increased from 48% at 760 m to 75% at 3,100 m in patients taking placebo. Preventive treatment with dexamethasone did not significantly reduce the altitude-induced recruitment of RLS. Development of RLS at 3,100 m could be predicted at 760 m by a higher resting pulmonary artery pressure and arterial partial pressure of oxygen and a more pronounced oxygen desaturation during exercise. Dexamethasone did not modify the RLS prevalence at 3,100 m.
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Affiliation(s)
- Mona Lichtblau
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Michael Furian
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Sayaka S Aeschbacher
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Maya Bisang
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Ulan Sheraliev
- National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Maamed Mademilov
- National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | | | - Stefanie Ulrich
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Talant Sooronbaev
- National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Konrad E Bloch
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Pulmonary Division and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
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Lichtblau M, Furian M, Aeschbacher SS, Bisang M, Ulrich S, Saxer S, Sheraliev U, Marazhapov NH, Osmonov B, Estebesova B, Sooronbaev T, Bloch KE, Ulrich S. Dexamethasone improves pulmonary hemodynamics in COPD-patients going to altitude: A randomized trial. Int J Cardiol 2019; 283:159-164. [DOI: 10.1016/j.ijcard.2018.12.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/25/2018] [Accepted: 12/18/2018] [Indexed: 11/27/2022]
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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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17
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Furian M, Lichtblau M, Aeschbacher SS, Estebesova B, Emilov B, Sheraliev U, Marazhapov NH, Mademilov M, Osmonov B, Bisang M, Ulrich S, Latshang TD, Ulrich S, Sooronbaev TM, Bloch KE. Effect of Dexamethasone on Nocturnal Oxygenation in Lowlanders With Chronic Obstructive Pulmonary Disease Traveling to 3100 Meters: A Randomized Clinical Trial. JAMA Netw Open 2019; 2:e190067. [PMID: 30794302 PMCID: PMC6484579 DOI: 10.1001/jamanetworkopen.2019.0067] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
IMPORTANCE During mountain travel, patients with chronic obstructive pulmonary disease (COPD) are at risk of experiencing severe hypoxemia, in particular, during sleep. OBJECTIVE To evaluate whether preventive dexamethasone treatment improves nocturnal oxygenation in lowlanders with COPD at 3100 m. DESIGN, SETTING, AND PARTICIPANTS A randomized, placebo-controlled, double-blind, parallel trial was performed from May 1 to August 31, 2015, in 118 patients with COPD (forced expiratory volume in the first second of expiration [FEV1] >50% predicted, pulse oximetry at 760 m ≥92%) who were living at altitudes below 800 m. The study was conducted at a university hospital (760 m) and high-altitude clinic (3100 m) in Tuja-Ashu, Kyrgyz Republic. Patients underwent baseline evaluation at 760 m, were taken by bus to the clinic at 3100 m, and remained at the clinic for 2 days and nights. Participants were randomized 1:1 to receive either dexamethasone, 4 mg, orally twice daily or placebo starting 24 hours before ascent and while staying at 3100 m. Data analysis was performed from September 1, 2015, to December 31, 2016. INTERVENTIONS Dexamethasone, 4 mg, orally twice daily (dexamethasone total daily dose, 8 mg) or placebo starting 24 hours before ascent and while staying at 3100 m. MAIN OUTCOMES AND MEASURES Difference in altitude-induced change in nocturnal mean oxygen saturation measured by pulse oximetry (Spo2) during night 1 at 3100 m between patients receiving dexamethasone and those receiving placebo was the primary outcome and was analyzed according to the intention-to-treat principle. Other outcomes were apnea/hypopnea index (AHI) (mean number of apneas/hypopneas per hour of time in bed), subjective sleep quality measured by a visual analog scale (range, 0 [extremely bad] to 100 [excellent]), and clinical evaluations. RESULTS Among the 118 patients included, 18 (15.3%) were women; the median (interquartile range [IQR]) age was 58 (52-63) years; and FEV1 was 91% predicted (IQR, 73%-103%). In 58 patients receiving placebo, median nocturnal Spo2 at 760 m was 92% (IQR, 91%-93%) and AHI was 20.5 events/h (IQR, 12.3-48.1); during night 1 at 3100 m, Spo2 was 84% (IQR, 83%-85%) and AHI was 39.4 events/h (IQR, 19.3-66.2) (P < .001 both comparisons vs 760 m). In 60 patients receiving dexamethasone, Spo2 at 760 m was 92% (IQR, 91%-93%) and AHI was 25.9 events/h (IQR, 16.3-37.1); during night 1 at 3100 m, Spo2 was 86% (IQR, 84%-88%) (P < .001 vs 760 m) and AHI was 24.7 events/h (IQR, 13.2-33.7) (P = .99 vs 760 m). Altitude-induced decreases in Spo2 during night 1 were mitigated by dexamethasone vs placebo by a mean of 3% (95% CI, 2%-3%), and increases in AHI were reduced by 18.7 events/h (95% CI, 12.0-25.3). Similar effects were observed during night 2. Subjective sleep quality was improved with dexamethasone during night 2 by 12% (95% CI, 0%-23%). Sixteen (27.6%) patients using dexamethasone had asymptomatic hyperglycemia. CONCLUSIONS AND RELEVANCE In lowlanders in Central Asia with COPD traveling to a high altitude, preventive dexamethasone treatment improved nocturnal oxygen saturation, sleep apnea, and subjective sleep quality. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02450994.
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Affiliation(s)
- Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | | | - Bermet Estebesova
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Berik Emilov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ulan Sheraliev
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Nuriddin H. Marazhapov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Maamed Mademilov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Batyr Osmonov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Maya Bisang
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Stefanie Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Tsogyal D. Latshang
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Talant M. Sooronbaev
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Konrad E. Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
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18
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Muralt L, Furian M, Lichtblau M, Aeschbacher SS, Clark RA, Estebesova B, Sheraliev U, Marazhapov N, Osmonov B, Bisang M, Ulrich S, Latshang TD, Ulrich S, Sooronbaev TM, Bloch KE. Postural Control in Lowlanders With COPD Traveling to 3100 m: Data From a Randomized Trial Evaluating the Effect of Preventive Dexamethasone Treatment. Front Physiol 2018; 9:752. [PMID: 29988503 PMCID: PMC6024910 DOI: 10.3389/fphys.2018.00752] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/29/2018] [Indexed: 11/28/2022] Open
Abstract
Objective: To evaluate the effects of acute exposure to high altitude and preventive dexamethasone treatment on postural control in patients with chronic obstructive pulmonary disease (COPD). Methods: In this randomized, double-blind parallel-group trial, 104 lowlanders with COPD GOLD 1-2 age 20–75 years, living near Bishkek (760 m), were randomized to receive either dexamethasone (2 × 4 mg/day p.o.) or placebo on the day before ascent and during a 2-day sojourn at Tuja-Ashu high altitude clinic (3100 m), Kyrgyzstan. Postural control was assessed with a Wii Balance BoardTM at 760 m and 1 day after arrival at 3100 m. Patients were instructed to stand immobile on both legs with eyes open during five tests of 30 s each, while the center of pressure path length (PL) was measured. Results: With ascent from 760 to 3100 m the PL increased in the placebo group from median (quartiles) 29.2 (25.8; 38.2) to 31.5 (27.3; 39.3) cm (P < 0.05); in the dexamethasone group the corresponding increase from 28.8 (22.8; 34.5) to 29.9 (25.2; 37.0) cm was not significant (P = 0.10). The mean difference (95% CI) between dexamethasone and placebo groups in altitude-induced changes (treatment effect) was -0.3 (-3.2 to 2.5) cm, (P = 0.41). Multivariable regression analysis confirmed a significant increase in PL with higher altitude (coefficient 1.6, 95% CI 0.2 to 3.1, P = 0.031) but no effect of dexamethasone was shown (coefficient -0.2, 95% CI -0.4 to 3.6, P = 0.925), even when controlled for several potential confounders. PL changes were related more to antero-posterior than lateral sway. Twenty-two of 104 patients had an altitude-related increase in the antero-posterior sway velocity of >25%, what has been associated with an increased risk of falls in previous studies. Conclusion: Lowlanders with COPD travelling from 760 to 3100 m revealed postural instability 24 h after arriving at high altitude, and this was not prevented by dexamethasone. Trial Registration:clinicaltrials.gov Identifier: NCT02450968.
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Affiliation(s)
- Lara Muralt
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Sayaka S Aeschbacher
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Ross A Clark
- School of Health and Sports Science, University of the Sunshine Coast, Sunshine Coast, QLD, Australia
| | - Bermet Estebesova
- Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Ulan Sheraliev
- Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Nuriddin Marazhapov
- Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Batyr Osmonov
- Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Maya Bisang
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Stefanie Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Tsogyal D Latshang
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan
| | - Talant M Sooronbaev
- Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Konrad E Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Kyrgyz-Swiss High Altitude Clinic and Medical Research Center, Tuja-Ashu, Kyrgyzstan.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
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