{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T07:59:38Z","timestamp":1784793578410,"version":"3.55.0"},"reference-count":40,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2022,5,14]],"date-time":"2022-05-14T00:00:00Z","timestamp":1652486400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100005646","name":"Janssen-Cilag AG, Switzerland","doi-asserted-by":"publisher","award":["unrestricted"],"award-info":[{"award-number":["unrestricted"]}],"id":[{"id":"10.13039\/100005646","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>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 \u00b1 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% \u2248 2500 m simulated altitude, data partly published) at low altitude and, on a separate day, at hypobaric hypoxia (HH, 2500 m) within 20\u201330 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 &lt; 85% corresponding to a positive HAST according to BTS-recommendations and 12 qualified for oxygen at altitude according to low SpO2 &lt; 92% at baseline. At HH, 3\/21 received oxygen due to safety criteria (SpO2 &lt; 80% for &gt;30 min), of which two were HAST-negative. During HH vs. NH, patients had a (mean \u00b1 SE) significantly lower PaCO2 4.4 \u00b1 0.1 vs. 4.9 \u00b1 0.1 kPa, mean difference (95% CI) \u22120.5 kPa (\u22120.7 to \u22120.3), PaO2 6.7 \u00b1 0.2 vs. 8.1 \u00b1 0.2 kPa, \u22121.3 kPa (\u22121.9 to \u22120.8) and higher tricuspid regurgitation pressure gradient 55 \u00b1 4 vs. 45 \u00b1 4 mmHg, 10 mmHg (3 to 17), all p &lt; 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).<\/jats:p>","DOI":"10.3390\/jcm11102769","type":"journal-article","created":{"date-parts":[[2022,5,14]],"date-time":"2022-05-14T09:27:56Z","timestamp":1652520476000},"page":"2769","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Cardiorespiratory Adaptation to Short-Term Exposure to Altitude vs. Normobaric Hypoxia in Patients with Pulmonary Hypertension"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3635-0515","authenticated-orcid":false,"given":"Simon","family":"Schneider","sequence":"first","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"},{"name":"Department of Health Sciences and Medicine, University of Lucerne, Frohburgstrasse 3, 6005 Lucerne, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mona","family":"Lichtblau","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Furian","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Mayer","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Charlotte","family":"Berlier","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julian","family":"M\u00fcller","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"St\u00e9phanie","family":"Saxer","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8840-981X","authenticated-orcid":false,"given":"Esther","family":"Schwarz","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Konrad","family":"Bloch","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Silvia","family":"Ulrich","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, R\u00e4mistrasse 100, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e2102463118","DOI":"10.1073\/pnas.2102463118","article-title":"Global and country-level estimates of human population at high altitude","volume":"118","author":"Tremblay","year":"2021","journal-title":"Proc. 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