{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T00:12:34Z","timestamp":1792800754352,"version":"4.5.0"},"reference-count":20,"publisher":"SAGE Publications","issue":"3","license":[{"start":{"date-parts":[[2025,11,17]],"date-time":"2025-11-17T00:00:00Z","timestamp":1763337600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Respiratory Care"],"published-print":{"date-parts":[[2026,3]]},"abstract":"\n Background:<\/jats:title>\n \n High-flow nasal cannula (HFNC) therapy was originally considered only for its targeted O\n 2<\/jats:sub>\n delivery but has been shown to also assist in the removal of end-expiratory CO\n 2<\/jats:sub>\n . Variables that influence the capability of this modality to reduce end-expiratory CO\n 2<\/jats:sub>\n are being proposed and investigated. Two types of HFNC therapy were precisely modeled at numerous mouth openings to investigate the effect that mouth open percent (MOP) had on airway CO\n 2<\/jats:sub>\n reduction (flush) and upper airway pressure generation for each therapy.\n <\/jats:p>\n <\/jats:sec>\n \n Methods:<\/jats:title>\n \n Computational fluid dynamics models were run at MOPs of 0%, 2%, 5%, 10%, 20%, 30%, 40%, and 100%, and each was administered therapy via a large-bore cannula, small-bore cannula, or no therapy. All models were initially run with less accurate, but cheaper, modeling parameters to establish the range of MOPs to be tested with higher-accuracy modeling parameters. Higher-accuracy models were run for MOPs of 5%, 10%, 20%, 30%, and 100%. CO\n 2<\/jats:sub>\n and pressure in the upper airway were analyzed to provide information on the effect of MOP, therapy type, and therapy flow.\n <\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n \n The distinction between cannulas peaked at an MOP of 20%, with large-bore having \u223c3.5\u2009mg more CO\n 2<\/jats:sub>\n entrained at end-exhale than small-bore. Increasing MOP and increasing therapy flow each decreased CO\n 2<\/jats:sub>\n retention in the airway. Therapy with a large-bore cannula resulted in less CO\n 2<\/jats:sub>\n flush than with a small-bore cannula, if all other factors were identical. Decreasing MOP and increasing therapy flow each increased distending pressure generation, while small-bore generated higher pressures than large-bore when all other factors were the same.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions:<\/jats:title>\n \n The results collected using the lower-cost models highlighted the necessity of high-accuracy modeling methodology. The CO\n 2<\/jats:sub>\n and pressure results from the higher-accuracy models can inform clinicians as to the benefits of certain HFNC modalities at intermediate mouth openings (pursed-lip breathing).\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1177\/19433654251384230","type":"journal-article","created":{"date-parts":[[2025,11,8]],"date-time":"2025-11-08T01:19:06Z","timestamp":1762564746000},"page":"289-298","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["The Effect of Simulated Mouth Opening on CO\n 2<\/sub>\n Removal During High Flow Nasal Cannula Therapy"],"prefix":"10.1177","volume":"71","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5608-4993","authenticated-orcid":false,"given":"Robert P.","family":"Kacinski","sequence":"first","affiliation":[{"name":"Mr. Kacinski and Dr. Strasser are affiliated with Department of Mechanical Engineering, Liberty University, Lynchburg, Virginia, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wayne S.","family":"Strasser","sequence":"additional","affiliation":[{"name":"Mr. Kacinski and Dr. Strasser are affiliated with Department of Mechanical Engineering, Liberty University, Lynchburg, Virginia, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jonathan B.","family":"Waugh","sequence":"additional","affiliation":[{"name":"Dr. Waugh is affiliated with Respiratory Therapy Program, Department of Allied Health, School of Health Professions, Liberty University, Lynchburg, Virginia, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2025,11,17]]},"reference":[{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.4081\/mrm.2020.693"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1111\/eci.13435"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajem.2019.03.004"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1177\/1024907919886245"},{"issue":"2","key":"e_1_3_4_6_2","first-page":"1239","article-title":"High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy in intensive care unit patients after extubation","volume":"15","author":"Chen X","year":"2023","unstructured":"Chen X, , Tan C, , Jiang H. High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy in intensive care unit patients after extubation. Am J Transl Res, 2023; 15(2):1239\u20131246.","journal-title":"Am J Transl Res"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jcrc.2022.154023"},{"key":"e_1_3_4_8_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00134-019-05590-5"},{"key":"e_1_3_4_9_2","doi-asserted-by":"publisher","DOI":"10.1186\/s13054-018-1990-4"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.annemergmed.2017.12.006"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.4187\/respcare.04317"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.3233\/NPM-1474113"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.1115\/1.4063061"},{"key":"e_1_3_4_14_2","doi-asserted-by":"publisher","DOI":"10.1115\/1.4063263"},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","unstructured":"Kacinski R Strasser W Leonard S. Characteristics of flow in the upper airway during high flow nasal cannula oxygen therapy. In: Proceeding of 8th Thermal and Fluids Engineering Conference (TFEC). Begell House: Danbury Connecticut; 2023; pp. 193\u2013201; doi: 10.1615\/tfec2023.cnm.046138","DOI":"10.1615\/tfec2023.cnm.046138"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.4172\/2161-105X.1000376"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10439-016-1604-8"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10586-024-04353-2"},{"key":"e_1_3_4_19_2","doi-asserted-by":"publisher","DOI":"10.1115\/1.4053786"},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.1213\/ANE.0000000000005002"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511840531"}],"container-title":["Respiratory Care"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/19433654251384230","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/19433654251384230","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/19433654251384230","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T11:02:32Z","timestamp":1787310152000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/19433654251384230"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,17]]},"references-count":20,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2026,3]]}},"alternative-id":["10.1177\/19433654251384230"],"URL":"https:\/\/doi.org\/10.1177\/19433654251384230","relation":{},"ISSN":["1943-3654","1943-3654"],"issn-type":[{"value":"1943-3654","type":"print"},{"value":"1943-3654","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,17]]}}}