{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,6,5]],"date-time":"2025-06-05T11:31:11Z","timestamp":1749123071658,"version":"3.37.3"},"reference-count":40,"publisher":"BMJ","issue":"10","funder":[{"DOI":"10.13039\/501100003130","name":"Fonds Wetenschappelijk Onderzoek","doi-asserted-by":"publisher","award":["12U5618N","1805116N"],"award-info":[{"award-number":["12U5618N","1805116N"]}],"id":[{"id":"10.13039\/501100003130","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"published-print":{"date-parts":[[2019,10]]},"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>In addition to the well-documented factors that contribute to weaning failure, increased energy demands of the respiratory muscles during spontaneous breathing trials (SBTs) might not be met by sufficient increases in energy supplies. This discrepancy may deprive blood and oxygen of other tissues. In this context, restrictions in perfusion of splanchnic organs and non-working muscles during SBT have been associated with weaning failure. However, alterations in perfusion of the brain during the weaning process are less well understood.<\/jats:p><\/jats:sec><jats:sec><jats:title>Objective and hypothesis<\/jats:title><jats:p>To investigate whether cerebral cortex perfusion evolves differentially during the transition from mechanical ventilation (MV) to spontaneous breathing between patients failing or succeeding the SBT. We hypothesise that patients failing the SBT will exhibit reduced cerebral cortex perfusion during the transition from MV to spontaneous breathing as compared with patients succeeding the SBT.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods and analysis<\/jats:title><jats:p>This single-centre, prospective, observational study will be conducted in a medical Intensive Care unit of University Hospital Leuven, Belgium in ready to wean patients. Blood flow index in the cerebral cortex (prefrontal area), inspiratory (scalene) and expiratory muscle (upper rectus abdominis) and a non-working muscle (thenar eminence) will be simultaneously assessed by near-infrared spectroscopy (NIRS) using the tracer indocyanine green dye. Measurements will be performed on the same day during MV and during SBT. NIRS-derived tissue oxygenation index and cardiac output (by pulse contour analyses) will be recorded continuously. Twenty patients failing an SBT are estimated to be sufficient for detecting a significant difference in the change of cerebral cortex perfusion from MV to SBT (primary outcome) between SBT failure and success patients.<\/jats:p><\/jats:sec><jats:sec><jats:title>Ethics and dissemination<\/jats:title><jats:p>Ethics approval was obtained from the local ethical committee (Ethische Commissie Onderzoek UZ\/KU Leuven protocol ID: S60516). Results from this study will be presented at scientific meetings and congresses and published in peer-reviewed journals.<\/jats:p><\/jats:sec><jats:sec><jats:title>Trial registration number<\/jats:title><jats:p><jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT03240263\">NCT03240263<\/jats:ext-link>.<\/jats:p><\/jats:sec>","DOI":"10.1136\/bmjopen-2019-031072","type":"journal-article","created":{"date-parts":[[2023,4,5]],"date-time":"2023-04-05T17:30:01Z","timestamp":1680715801000},"page":"e031072","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":3,"title":["Cerebral cortex and respiratory muscles perfusion during spontaneous breathing attempts in ventilated patients and its relation to weaning outcomes: a protocol for a prospective observational study"],"prefix":"10.1136","volume":"9","clinical-trial-number":[{"clinical-trial-number":"nct03240263","registry":"10.18810\/clinical-trials-gov"}],"author":[{"given":"Zafeiris","family":"Louvaris","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marine","family":"Van Hollebeke","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander","family":"Dhaenens","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maarten","family":"Vanhemelen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Philippe","family":"Meersseman","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joost","family":"Wauters","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rik","family":"Gosselink","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander","family":"Wilmer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Langer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Greet","family":"Hermans","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2019,10,31]]},"reference":[{"key":"2023040221301571000_9.10.e031072.1","doi-asserted-by":"publisher","DOI":"10.1164\/rccm.201602-0320OC"},{"key":"2023040221301571000_9.10.e031072.2","doi-asserted-by":"crossref","unstructured":"Heunks LM , van der Hoeven JG . Clinical review: the ABC of weaning failure--a structured approach. Crit Care 2010;14:245.doi:10.1186\/cc9296","DOI":"10.1186\/cc9296"},{"key":"2023040221301571000_9.10.e031072.3","doi-asserted-by":"publisher","DOI":"10.1016\/j.resp.2013.05.012"},{"key":"2023040221301571000_9.10.e031072.4","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.96.09112383"},{"key":"2023040221301571000_9.10.e031072.5","first-page":"9","article-title":"The oxygen cost of breathing in patients with cardiorespiratory disease","volume":"126","author":"Field","year":"1982","journal-title":"Am Rev Respir Dis"},{"key":"2023040221301571000_9.10.e031072.6","doi-asserted-by":"publisher","DOI":"10.1164\/ajrccm\/139.2.513"},{"key":"2023040221301571000_9.10.e031072.7","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.96.09091868"},{"key":"2023040221301571000_9.10.e031072.8","doi-asserted-by":"publisher","DOI":"10.1164\/ajrccm.160.5.9901018"},{"key":"2023040221301571000_9.10.e031072.9","doi-asserted-by":"publisher","DOI":"10.1097\/00003246-200101000-00017"},{"key":"2023040221301571000_9.10.e031072.10","first-page":"1188","article-title":"Peripheral microcirculatory exploration during mechanical ventilation weaning","volume":"80","author":"Margetis","year":"2014","journal-title":"Minerva Anestesiol"},{"key":"2023040221301571000_9.10.e031072.11","first-page":"666","article-title":"Changes in thenar muscle tissue oxygen saturation assessed by near-infrared spectroscopy during weaning from mechanical ventilation","volume":"80","author":"Poriazi","year":"2014","journal-title":"Minerva Anestesiol"},{"key":"2023040221301571000_9.10.e031072.12","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.00126312"},{"key":"2023040221301571000_9.10.e031072.13","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1152\/jappl.1989.66.1.184","article-title":"Cardiovascular failure and apnea in shock","volume":"66","author":"Nava","year":"1989","journal-title":"J Appl Physiol"},{"key":"2023040221301571000_9.10.e031072.14","doi-asserted-by":"publisher","DOI":"10.4037\/ajcc2011886"},{"key":"2023040221301571000_9.10.e031072.15","doi-asserted-by":"crossref","unstructured":"Barwood M , Burrows H , Cessford J , et al . Brain blood flow and hyperventilation on cold water immersion: can treading water help control these symptoms of cold shock? Extrem Physiol Med 2015;4:A40.doi:10.1186\/2046-7648-4-S1-A40","DOI":"10.1186\/2046-7648-4-S1-A40"},{"key":"2023040221301571000_9.10.e031072.16","doi-asserted-by":"publisher","DOI":"10.1164\/ajrccm\/141.5_Pt_1.1214"},{"key":"2023040221301571000_9.10.e031072.17","doi-asserted-by":"publisher","DOI":"10.1378\/chest.85.2.203"},{"key":"2023040221301571000_9.10.e031072.18","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00904.2006"},{"key":"2023040221301571000_9.10.e031072.19","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1097\/ALN.0000000000002256","article-title":"Respiratory muscle effort during expiration in successful and failed weaning from mechanical ventilation","volume":"129","author":"Doorduin","year":"2018","journal-title":"Anesthesiology"},{"key":"2023040221301571000_9.10.e031072.20","doi-asserted-by":"crossref","unstructured":"Hoffman M , Van Hollebeke M , Clerckx B , et al . Can inspiratory muscle training improve weaning outcomes in difficult to wean patients? A protocol for a randomised controlled trial (IMweanT study). BMJ Open 2018;8:e021091.doi:10.1136\/bmjopen-2017-021091","DOI":"10.1136\/bmjopen-2017-021091"},{"key":"2023040221301571000_9.10.e031072.21","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.00010206"},{"key":"2023040221301571000_9.10.e031072.22","doi-asserted-by":"publisher","DOI":"10.1097\/CCM.0b013e318236f27e"},{"key":"2023040221301571000_9.10.e031072.23","doi-asserted-by":"crossref","unstructured":"Louvaris Z , Zakynthinos S , Vogiatzis I . Respiratory muscle blood flow measured by near-infrared spectroscopy (NIRS) by indosyanine green dye. In: Mechanics of breathing. Springler-Verlag, Italy, 2014: 169\u201378.","DOI":"10.1007\/978-88-470-5647-3_12"},{"key":"2023040221301571000_9.10.e031072.24","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1016\/j.resp.2018.05.001","article-title":"Cerebral oxygen availability during exercise in COPD patients with cognitive impairment","volume":"254","author":"Andrianopoulos","year":"2018","journal-title":"Respir Physiol Neurobiol"},{"key":"2023040221301571000_9.10.e031072.25","doi-asserted-by":"publisher","DOI":"10.1097\/00004647-199804000-00013"},{"key":"2023040221301571000_9.10.e031072.26","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1007\/s00134-002-1592-z","article-title":"Reproducibility of the blood flow index as noninvasive, bedside estimation of cerebral blood flow","volume":"29","author":"Wagner","year":"2003","journal-title":"Intensive Care Med"},{"key":"2023040221301571000_9.10.e031072.27","first-page":"38","article-title":"Bedside assessment of cerebral perfusion reductions in patients with acute ischaemic stroke by near-infrared spectroscopy and indocyanine green","volume":"75","author":"Terborg","year":"2004","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"2023040221301571000_9.10.e031072.28","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1152\/japplphysiol.00959.2017","article-title":"Near-Infrared spectroscopy using indocyanine green dye for minimally invasive measurement of respiratory and leg muscle blood flow in patients with COPD","volume":"125","author":"Louvaris","year":"2018","journal-title":"J Appl Physiol"},{"key":"2023040221301571000_9.10.e031072.29","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.accpm.2015.06.006","article-title":"Current use and perspective of indocyanine green clearance in liver diseases","volume":"35","author":"Levesque","year":"2016","journal-title":"Anaesth Crit Care Pain Med"},{"key":"2023040221301571000_9.10.e031072.30","doi-asserted-by":"publisher","DOI":"10.1034\/j.1600-0838.2001.110404.x"},{"key":"2023040221301571000_9.10.e031072.31","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.resp.2016.12.013","article-title":"Heterogeneity of blood flow and metabolism during exercise in patients with chronic obstructive pulmonary disease","volume":"237","author":"Louvaris","year":"2017","journal-title":"Respir Physiol Neurobiol"},{"key":"2023040221301571000_9.10.e031072.32","doi-asserted-by":"crossref","unstructured":"Chamos C , Vele L , Hamilton M , et al . Less invasive methods of advanced hemodynamic monitoring: principles, devices, and their role in the perioperative hemodynamic optimization. Perioper Med 2013;2:19.doi:10.1186\/2047-0525-2-19","DOI":"10.1186\/2047-0525-2-19"},{"key":"2023040221301571000_9.10.e031072.33","doi-asserted-by":"publisher","DOI":"10.1053\/j.jvca.2007.01.001"},{"key":"2023040221301571000_9.10.e031072.34","doi-asserted-by":"publisher","DOI":"10.1007\/s00134-010-2098-8"},{"key":"2023040221301571000_9.10.e031072.35","doi-asserted-by":"publisher","DOI":"10.1093\/bja\/aep267"},{"key":"2023040221301571000_9.10.e031072.36","doi-asserted-by":"publisher","DOI":"10.1053\/j.jvca.2011.07.011"},{"key":"2023040221301571000_9.10.e031072.37","doi-asserted-by":"publisher","DOI":"10.1053\/j.jvca.2006.08.004"},{"key":"2023040221301571000_9.10.e031072.38","doi-asserted-by":"crossref","unstructured":"Salzwedel C , Puig J , Carstens A , et al . Perioperative goal-directed hemodynamic therapy based on radial arterial pulse pressure variation and continuous cardiac index trending reduces postoperative complications after major abdominal surgery: a multi-center, prospective, randomized study. Crit Care 2013;17.doi:10.1186\/cc12885","DOI":"10.1186\/cc12885"},{"key":"2023040221301571000_9.10.e031072.39","doi-asserted-by":"crossref","first-page":"415","DOI":"10.3233\/THC-1996-4406","article-title":"Validation and clinical application of a continuous P0.1 measurement using standard respiratory equipment","volume":"4","author":"Kuhlen","year":"1996","journal-title":"Technol Health Care"},{"key":"2023040221301571000_9.10.e031072.40","doi-asserted-by":"publisher","DOI":"10.1093\/jmt\/47.3.198"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2019-031072","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,4,5]],"date-time":"2023-04-05T17:30:24Z","timestamp":1680715824000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2019-031072"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,10]]},"references-count":40,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2019,10,31]]},"published-print":{"date-parts":[[2019,10]]}},"alternative-id":["10.1136\/bmjopen-2019-031072"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2019-031072","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"type":"print","value":"2044-6055"},{"type":"electronic","value":"2044-6055"}],"subject":[],"published":{"date-parts":[[2019,10]]}}}