{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,4,24]],"date-time":"2025-04-24T04:57:42Z","timestamp":1745470662900,"version":"3.40.4"},"reference-count":4,"publisher":"S. Karger AG","issue":"5","license":[{"start":{"date-parts":[[2007,1,1]],"date-time":"2007-01-01T00:00:00Z","timestamp":1167609600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2007,1,1]],"date-time":"2007-01-01T00:00:00Z","timestamp":1167609600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Respiration"],"published-print":{"date-parts":[[2007]]},"abstract":"<jats:p>&lt;i&gt;Background:&lt;\/i&gt; Obstructive sleep apnoea is caused by collapse of the upper airway. The presence of CO&lt;sub&gt;2&lt;\/sub&gt; in the upper airway lumen evokes a number of reflexes which favour upper airway re-opening, and we have proposed previously that CO&lt;sub&gt;2&lt;\/sub&gt; would build up in the upper airway following airway collapse and that this would contribute to reflex airway re-opening. However, it is not known if CO&lt;sub&gt;2&lt;\/sub&gt; can transfer from the alveoli to the anatomical dead space of the upper airway during apnoea. &lt;i&gt;Objectives:&lt;\/i&gt; To determine if alveolar CO&lt;sub&gt;2&lt;\/sub&gt; can enter the upper airway during breath-holds and Muller manoeuvres. &lt;i&gt;Material and Methods:&lt;\/i&gt; With local ethics committee approval, 6 male volunteers (aged 22\u201348 years), following a quiet inspiration, carried out breath-holds and Muller manoeuvres until breaking point. CO&lt;sub&gt;2&lt;\/sub&gt; was measured continuously in samples obtained from the hypopharynx using an infrared analyser with a sample rate of 50 ml\/min. Muller manoeuvres (forced inspirations against a closed upper airway) mimic the respiratory efforts which occur during obstructive apnoeas. &lt;i&gt;Results:&lt;\/i&gt; In all cases, CO&lt;sub&gt;2&lt;\/sub&gt; increased progressively during apnoeas. There was a much larger increase in Muller manoeuvres (3.78 \u00b1 0.51%, mean \u00b1 SEM at breaking point) compared to breath-holds. &lt;i&gt;Discussion:&lt;\/i&gt; These results show that upper airway CO&lt;sub&gt;2&lt;\/sub&gt; concentration rises substantially during apnoeas and suggest that transfer of CO&lt;sub&gt;2&lt;\/sub&gt; from the lungs to the upper airway may evoke a number of reflex effects which could affect breathing and upper airway re-opening during obstructive apnoeas.<\/jats:p>","DOI":"10.1159\/000098884","type":"journal-article","created":{"date-parts":[[2007,1,24]],"date-time":"2007-01-24T13:35:29Z","timestamp":1169645729000},"page":"533-536","source":"Crossref","is-referenced-by-count":1,"title":["The Effects of Breath-Holds and Muller Manoeuvres on Upper Airway Carbon Dioxide Concentration in Humans"],"prefix":"10.1159","volume":"74","author":[{"given":"A.","family":"Raza","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"T.","family":"Farrell","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K.D.","family":"O\u2019Halloran","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A.","family":"Bradford","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2007,1,24]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1183%2F09031936.96.09040773"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1159%2F000089814"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1007%2FBF00374321"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1183%2F09031936.97.10112566"}],"container-title":["Respiration"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/98884","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/98884","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,24]],"date-time":"2025-04-24T02:35:27Z","timestamp":1745462127000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000098884"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007]]},"references-count":4,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2007,8,1]]}},"URL":"https:\/\/doi.org\/10.1159\/000098884","archive":["Portico"],"relation":{},"ISSN":["0025-7931","1423-0356"],"issn-type":[{"type":"print","value":"0025-7931"},{"type":"electronic","value":"1423-0356"}],"subject":[],"published":{"date-parts":[[2007]]}}}