{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T20:28:06Z","timestamp":1792787286784,"version":"4.5.0"},"reference-count":45,"publisher":"BMJ","issue":"1","license":[{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"content-version":"unspecified","delay-in-days":20,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Swiss national Science Foundation","award":["32003B_219199 \/ 1"],"award-info":[{"award-number":["32003B_219199 \/ 1"]}],"id":[{"id":"https:\/\/ror.org\/00yjd3n13","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open Resp Res"],"accepted":{"date-parts":[[2026,9,4]]},"published-print":{"date-parts":[[2026,9]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Exercise-induced desaturation is a common symptom in chronic lung disease (CLD) and is associated with functional limitation and increased mortality. Although portable low-flow supplemental oxygen therapy (SOT) is commonly prescribed for exercise-induced hypoxaemia, evidence for SOT to improve performance is inconsistent.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Method<\/jats:title>\n                    <jats:p>This pragmatic, randomised, controlled, non-inferiority crossover trial enrolled patients with chronic obstructive pulmonary and interstitial lung disease who exhibited exercise-induced oxygen desaturation of &gt;3%. Each patient performed two 6-minute walk distance (6MWD) tests in randomised order: one breathing ambient air and one using low-flow SOT delivered by a portable backpack concentrator (1\u20132\u2009L\/min). The primary outcome was 6MWD, secondary outcomes included perceived exertion and preference of the interventions. A predefined non-inferiority margin of 35 m was used.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Forty patients were enrolled (mean age 66\u00b113 years; 14 women; 20 with chronic obstructive pulmonary disease (COPD), 20 with interstitial lung disease (ILD)). The mean difference in 6MWD between ambient air and SOT was 0 m (95% CI \u221214 to 13 m; p&lt;0.001 for non-inferiority). Secondary outcomes demonstrated significantly lower dyspnoea scores with SOT both overall and within COPD\/ILD subgroups. Patient preferences were split, with 49% favouring ambient air and 51% preferring SOT. A clinically meaningful improvement in 6MWD of &gt;35\u2009m was found in five patients.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>In patients with CLD and exercise-induced desaturation, ambient air was non-inferior to pulsed low-dose SOT by portable concentrator in 6MWD, but SOT improved dyspnoea. These findings highlight the need for more effective, patient-acceptable oxygen delivery systems and further research to identify responders to SOT.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT06385301\">NCT06385301<\/jats:ext-link>\n                      .\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjresp-2025-004048","type":"journal-article","created":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T15:29:12Z","timestamp":1790522952000},"page":"e004048","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Portable low-flow nasal oxygen versus ambient air in patients with chronic lung disease and exercise-induced hypoxaemia: a randomised controlled crossover non-inferiority trial"],"prefix":"10.1136","volume":"13","clinical-trial-number":[{"clinical-trial-number":"nct06385301","registry":"10.18810\/clinical-trials-gov"},{"clinical-trial-number":"nct06385301","registry":"10.18810\/clinical-trials-gov"}],"author":[{"given":"Mona","family":"Lichtblau","sequence":"first","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, Z\u00fcrich, Switzerland"},{"name":"Faculty of Medicine, University of Zurich, Z\u00fcrich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-9895-2476","authenticated-orcid":false,"given":"Carmen","family":"Wick","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, Z\u00fcrich, Switzerland"},{"name":"Faculty of Medicine, University of Zurich, Z\u00fcrich, 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