{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T09:58:35Z","timestamp":1791453515275,"version":"4.3.3"},"reference-count":11,"publisher":"Springer Science and Business Media LLC","issue":"5","license":[{"start":{"date-parts":[[2022,5,16]],"date-time":"2022-05-16T00:00:00Z","timestamp":1652659200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2022,5,16]],"date-time":"2022-05-16T00:00:00Z","timestamp":1652659200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Universit\u00e4tsklinikum Hamburg-Eppendorf (UKE)"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Infection"],"published-print":{"date-parts":[[2022,10]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Purpose<\/jats:title>\n                <jats:p>Symptoms often persistent for more than 4 weeks after COVID-19\u2014now commonly referred to as \u2018Long COVID\u2019. Independent of initial disease severity or pathological pulmonary functions tests, fatigue, exertional intolerance and dyspnea are among the most common COVID-19 sequelae. We hypothesized that respiratory muscle dysfunction might be prevalent in persistently symptomatic patients after COVID-19 with self-reported exercise intolerance.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Methods<\/jats:title>\n                <jats:p>In a small cross-sectional pilot study (<jats:italic>n<\/jats:italic>\u2009=\u200967) of mild-to-moderate (nonhospitalized) and moderate-to-critical convalescent (formerly hospitalized) patients presenting to our outpatient clinic approx. 5\u00a0months after acute infection, we measured neuroventilatory activity <jats:italic>P<\/jats:italic><jats:sub>0.1<\/jats:sub>, inspiratory muscle strength (<jats:italic>P<\/jats:italic>I<jats:sub>max<\/jats:sub>) and total respiratory muscle strain (<jats:italic>P<\/jats:italic><jats:sub>0.1<\/jats:sub>\/<jats:italic>P<\/jats:italic>I<jats:sub>max<\/jats:sub>) in addition to standard pulmonary functions tests, capillary blood gas analysis, 6\u00a0min walking tests and functional questionnaires.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>Pathological <jats:italic>P<\/jats:italic><jats:sub>0.1<\/jats:sub>\/<jats:italic>P<\/jats:italic>I<jats:sub>max<\/jats:sub> was found in 88% of symptomatic patients. Mean <jats:italic>P<\/jats:italic>I<jats:sub>max<\/jats:sub> was reduced in hospitalized patients, but reduced <jats:italic>P<\/jats:italic>I<jats:sub>max<\/jats:sub> was also found in 65% of nonhospitalized patients. Mean <jats:italic>P<\/jats:italic><jats:sub>0.1<\/jats:sub> was pathologically increased in both groups. Increased <jats:italic>P<\/jats:italic><jats:sub>0.1<\/jats:sub> was associated with exercise-induced deoxygenation, impaired exercise tolerance, decreased activity and productivity and worse Post-COVID-19 functional status scale. Pathological changes in <jats:italic>P<\/jats:italic><jats:sub>0.1<\/jats:sub>, <jats:italic>P<\/jats:italic>I<jats:sub>max<\/jats:sub> or <jats:italic>P<\/jats:italic><jats:sub>0.1<\/jats:sub>\/<jats:italic>P<\/jats:italic>I<jats:sub>max<\/jats:sub> were not associated with pre-existing conditions.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>Our findings point towards respiratory muscle dysfunction as a novel aspect of COVID-19 sequelae. Thus, we strongly advocate for systematic respiratory muscle testing during the diagnostic workup of persistently symptomatic, convalescent COVID-19 patients.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1007\/s15010-022-01840-9","type":"journal-article","created":{"date-parts":[[2022,5,16]],"date-time":"2022-05-16T03:24:11Z","timestamp":1652671451000},"page":"1391-1397","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":54,"title":["Respiratory muscle dysfunction in long-COVID patients"],"prefix":"10.1007","volume":"50","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7784-8267","authenticated-orcid":false,"given":"Jan K.","family":"Hennigs","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marie","family":"Huwe","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annette","family":"Hennigs","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tim","family":"Oqueka","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcel","family":"Simon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lars","family":"Harbaum","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jakob","family":"K\u00f6rbelin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefan","family":"Schmiedel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julian","family":"Schulze zur Wiesch","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marylyn M.","family":"Addo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefan","family":"Kluge","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hans","family":"Klose","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2022,5,16]]},"reference":[{"key":"1840_CR1","doi-asserted-by":"publisher","first-page":"268","DOI":"10.7326\/M20-2003","volume":"173","author":"D Wichmann","year":"2020","unstructured":"Wichmann D, Sperhake JP, Lutgehetmann M, Steurer S, Edler C, Heinemann A, Heinrich F, Mushumba H, Kniep I, Schroder AS, et al. 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