{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,14]],"date-time":"2026-02-14T20:56:52Z","timestamp":1771102612955,"version":"3.50.1"},"reference-count":27,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,5,27]],"date-time":"2025-05-27T00:00:00Z","timestamp":1748304000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,5,27]],"date-time":"2025-05-27T00:00:00Z","timestamp":1748304000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/100016027","name":"NYU Grossman School of Medicine","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100016027","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000925","name":"John Templeton Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000925","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J Cardiothorac Surg"],"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>Studies have not explored consciousness during deep hypothermic circulatory arrest (DHCA). However, as studies in cardiac arrest have identified a spectrum of consciousness, we sought to establish the feasibility of studying consciousness during DHCA.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods<\/jats:title>\n            <jats:p>This was a prospective study across 10 hospitals with 36 DHCA patients undergoing thoracic aortic aneurysm repair or pulmonary endarterectomy. A tablet computer delivered audiovisual stimuli (images and names of three fruits) using headphones during each procedure as a potential test of implicit learning and explicit recall. We also established electroencephalography (EEG) and near-infrared spectroscopy (NIRS) to measure electrocortical markers of consciousness and cerebral oxygenation. Post-procedure interviews were carried out to test patients\u2019 ability to recall the audiovisual stimuli as well other explicit memories. Primary outcomes: 1) Feasibility of establishing tests of explicit recall and implicit learning, 2) Electroencephalography testing during DHCA. Secondary outcomes: 1) Signs of explicit recall of memories or implicit learning, and 2) identification of electrocortical biomarkers of consciousness during DHCA.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>Overall, 29\/36 (81%) had the tablet set up. All 36 had NIRS and EEG set up, but 9 (25%) had useable EEG data, and 23 (66%) NIRS data. Delta EEG waves were observed during circulatory arrest in 3\/9 (33%) patients, while 1\/9 (11%) had theta waves just prior to circulatory arrest. All others showed isoelectric pattern. 35\/36 (97%) agreed to follow up interviews. None had explicit recall of the names of the three fruits, but 3\/36 (9%) correctly guessed them as a potential sign of implicit learning and 3 (9%) recalled other memories including events around the procedure and themes consistent with a recalled experience of death.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusions<\/jats:title>\n            <jats:p>A spectrum of consciousness and awareness, including signs of implicit learning and electrocortical biomarkers of consciousness may be present during DHCA, despite absence of visible signs of consciousness.\u00a0This can be further used to help explain the negative psychological outcomes that cardiac arrest survivors face.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/s13019-025-03484-w","type":"journal-article","created":{"date-parts":[[2025,5,27]],"date-time":"2025-05-27T21:20:21Z","timestamp":1748380821000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Consciousness in deep hypothermic circulatory arrest: a feasibility study"],"prefix":"10.1186","volume":"20","author":[{"given":"Joshua","family":"Ross","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas","family":"Jan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Deane","family":"Smith","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anelly","family":"Gonzales","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aubrey","family":"Galloway","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Natalia","family":"Leontovich","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tara","family":"Keshavarz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Analise","family":"Dickinson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David","family":"Friedman","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Emmeline","family":"Koopman","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Elise","family":"Huppert","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ian","family":"Jaffe","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christopher","family":"Burke","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John","family":"Kern","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paul","family":"Stelzer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ashraf","family":"Sabe","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rebecca","family":"Spiegel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew","family":"Klein","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arvind","family":"Rajagopal","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gage","family":"Parr","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Charles","family":"Deakin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sam","family":"Parnia","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2025,5,27]]},"reference":[{"key":"3484_CR1","unstructured":"American Heart Association. CPR Facts & Stats. Available from: https:\/\/cpr.heart.org\/en\/resources\/cpr-facts-and-stats\/."},{"issue":"2","key":"3484_CR2","doi-asserted-by":"publisher","first-page":"215","DOI":"10.1016\/j.resuscitation.2007.01.020","volume":"74","author":"S Parnia","year":"2007","unstructured":"Parnia S, Spearpoint K, Fenwick PB. Near death experiences, cognitive function and psychological outcomes of surviving cardiac arrest. Resuscitation. 2007;74(2):215\u201321.","journal-title":"Resuscitation"},{"issue":"7","key":"3484_CR3","doi-asserted-by":"publisher","first-page":"873","DOI":"10.1016\/j.resuscitation.2012.11.021","volume":"84","author":"KP Wilder Schaaf","year":"2013","unstructured":"Wilder Schaaf KP, Artman LK, Peberdy MA, Walker WC, Ornato JP, Gossip MR, et al. Anxiety, depression, and PTSD following cardiac arrest: A systematic review of the literature. Resuscitation. 2013;84(7):873\u20137.","journal-title":"Resuscitation"},{"issue":"12","key":"3484_CR4","doi-asserted-by":"publisher","first-page":"1799","DOI":"10.1016\/j.resuscitation.2014.09.004","volume":"85","author":"S Parnia","year":"2014","unstructured":"Parnia S, Spearpoint K, De Vos G, Fenwick P, Goldberg D, Yang J, et al. AWARE\u2014AWAreness during REsuscitation\u2014A prospective study. Resuscitation. 2014;85(12):1799\u2013805.","journal-title":"Resuscitation"},{"issue":"1","key":"3484_CR5","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1111\/nyas.14740","volume":"1511","author":"S Parnia","year":"2022","unstructured":"Parnia S, Post SG, Lee MT, Lyubomirsky S, Aufderheide TP, Deakin CD, et al. Guidelines and standards for the study of death and recalled experiences of death\u2013a multidisciplinary consensus statement and proposed future directions. Ann N Y Acad Sci. 2022;1511(1):5\u201321.","journal-title":"Ann N Y Acad Sci"},{"key":"3484_CR6","doi-asserted-by":"publisher","first-page":"229","DOI":"10.1016\/j.resuscitation.2021.10.040","volume":"169","author":"MH Wyckoff","year":"2021","unstructured":"Wyckoff MH, Singletary EM, Soar J, Olasveengen TM, Greif R, Liley HG, et al. 2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group. Resuscitation. 2021;169:229\u2013311.","journal-title":"Resuscitation"},{"key":"3484_CR7","unstructured":"Wyckoff MH, Greif R, Morley PT, Ng KC, Olasveengen TM, Singletary EM, et al. 2022 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces. Circulation. 2022 Dec 20 [cited 2024 May 5];146(25). Available from: https:\/\/www.ahajournals.org\/doi\/10.1161\/CIR.0000000000001095."},{"issue":"9298","key":"3484_CR8","doi-asserted-by":"publisher","first-page":"2039","DOI":"10.1016\/S0140-6736(01)07100-8","volume":"358","author":"P Van Lommel","year":"2001","unstructured":"Van Lommel P, Van Wees R, Meyers V, Elfferich I. Near-death experience in survivors of cardiac arrest: a prospective study in the Netherlands. The Lancet. 2001;358(9298):2039\u201345.","journal-title":"The Lancet"},{"key":"3484_CR9","doi-asserted-by":"publisher","first-page":"109903","DOI":"10.1016\/j.resuscitation.2023.109903","volume":"191","author":"S Parnia","year":"2023","unstructured":"Parnia S, Keshavarz Shirazi T, Patel J, Tran L, Sinha N, O\u2019Neill C, et al. AWAreness during REsuscitation - II: A multi-center study of consciousness and awareness in cardiac arrest. Resuscitation. 2023;191:109903.","journal-title":"Resuscitation"},{"issue":"2","key":"3484_CR10","doi-asserted-by":"publisher","first-page":"387","DOI":"10.1097\/00000542-199708000-00027","volume":"87","author":"MM Ghoneim","year":"1997","unstructured":"Ghoneim MM, Block R. Learning and Memory during General Anesthesia. Anesthesiology. 1997;87(2):387\u2013410.","journal-title":"Anesthesiology"},{"issue":"4","key":"3484_CR11","doi-asserted-by":"publisher","first-page":"479","DOI":"10.1111\/j.2044-8295.1995.tb02566.x","volume":"86","author":"J Andrade","year":"1995","unstructured":"Andrade J. Learning during anaesthesia: A review. British J of Psychology. 1995;86(4):479\u2013506.","journal-title":"British J of Psychology"},{"issue":"1","key":"3484_CR12","first-page":"139","volume":"13","author":"Y Gidron","year":"2002","unstructured":"Gidron Y, Barak T, Henik A, Gurman G, Stiener O. Implicit learning of emotional information under anesthesia: Neuroreport. 2002;13(1):139\u201342.","journal-title":"Implicit learning of emotional information under anesthesia: Neuroreport"},{"issue":"35","key":"3484_CR13","doi-asserted-by":"publisher","first-page":"14432","DOI":"10.1073\/pnas.1308285110","volume":"110","author":"J Borjigin","year":"2013","unstructured":"Borjigin J, Lee U, Liu T, Pal D, Huff S, Klarr D, et al. Surge of neurophysiological coherence and connectivity in the dying brain. Proc Natl Acad Sci USA. 2013;110(35):14432\u20137.","journal-title":"Proc Natl Acad Sci USA"},{"issue":"12","key":"3484_CR14","doi-asserted-by":"publisher","first-page":"1095","DOI":"10.1089\/jpm.2009.0159","volume":"12","author":"LS Chawla","year":"2009","unstructured":"Chawla LS, Akst S, Junker C, Jacobs B, Seneff MG. Surges of Electroencephalogram Activity at the Time of Death: A Case Series. J Palliat Med. 2009;12(12):1095\u2013100.","journal-title":"J Palliat Med"},{"issue":"19","key":"3484_CR15","doi-asserted-by":"publisher","first-page":"e2216268120","DOI":"10.1073\/pnas.2216268120","volume":"120","author":"G Xu","year":"2023","unstructured":"Xu G, Mihaylova T, Li D, Tian F, Farrehi PM, Parent JM, et al. Surge of neurophysiological coupling and connectivity of gamma oscillations in the dying human brain. Proc Natl Acad Sci USA. 2023;120(19):e2216268120.","journal-title":"Proc Natl Acad Sci USA"},{"issue":"14","key":"3484_CR16","doi-asserted-by":"publisher","first-page":"813531","DOI":"10.3389\/fnagi.2022.813531","volume":"22","author":"R Vicente","year":"2022","unstructured":"Vicente R, Rizzuto M, Sarica C, Yamamoto K, Sadr M, Khajuria T, et al. Enhanced Interplay of Neuronal Coherence and Coupling in the Dying Human Brain. Front Aging Neurosci. 2022;22(14):813531.","journal-title":"Front Aging Neurosci"},{"issue":"1_suppl","key":"3484_CR17","first-page":"27","volume":"26","author":"EM Elmistekawy","year":"2011","unstructured":"Elmistekawy EM, Rubens FD. Deep hypothermic circulatory arrest: Alternative strategies for cerebral perfusion. A review article Perfusion. 2011;26(1_suppl):27\u201334.","journal-title":"A review article. Perfusion."},{"issue":"1","key":"3484_CR18","doi-asserted-by":"publisher","first-page":"e19","DOI":"10.1016\/j.resuscitation.2011.09.027","volume":"83","author":"M Beauregard","year":"2012","unstructured":"Beauregard M, St-Pierre \u00c9L, Rayburn G, Demers P. Conscious mental activity during a deep hypothermic cardiocirculatory arrest? Resuscitation. 2012;83(1):e19.","journal-title":"Resuscitation"},{"issue":"2","key":"3484_CR19","doi-asserted-by":"publisher","first-page":"235","DOI":"10.1586\/17434440.3.2.235","volume":"3","author":"JD Tobias","year":"2006","unstructured":"Tobias JD. Cerebral oxygenation monitoring: near-infrared spectroscopy. Expert Rev Med Devices. 2006;3(2):235\u201343.","journal-title":"Expert Rev Med Devices"},{"issue":"8","key":"3484_CR20","doi-asserted-by":"publisher","first-page":"779","DOI":"10.1016\/j.hlc.2016.12.010","volume":"26","author":"B Indja","year":"2017","unstructured":"Indja B, Seco M, Seamark R, Kaplan J, Bannon PG, Grieve SM, et al. Neurocognitive and Psychiatric Issues Post Cardiac Surgery. Heart Lung Circ. 2017;26(8):779\u201385.","journal-title":"Heart Lung Circ"},{"issue":"4","key":"3484_CR21","doi-asserted-by":"publisher","first-page":"224","DOI":"10.1177\/014107688808100413","volume":"81","author":"L Goldmann","year":"1988","unstructured":"Goldmann L. Information-Processing under General Anaesthesia: A Review. J R Soc Med. 1988;81(4):224\u20137.","journal-title":"J R Soc Med"},{"issue":"2","key":"3484_CR22","doi-asserted-by":"publisher","first-page":"171","DOI":"10.1093\/bja\/aeh054","volume":"92","author":"C Deeprose","year":"2004","unstructured":"Deeprose C, Andrade J, Varma S, Edwards N. Unconscious learning during surgery with propofol anaesthesia \u2020 \u2020This article is accompanied by Editorial II. Br J Anaesth. 2004;92(2):171\u20137.","journal-title":"Br J Anaesth"},{"issue":"1","key":"3484_CR23","doi-asserted-by":"publisher","first-page":"19","DOI":"10.1007\/s44192-024-00072-7","volume":"4","author":"JG Kovoor","year":"2024","unstructured":"Kovoor JG, Santhosh S, Stretton B, Tan S, Gouldooz H, Moorthy S, et al. Near-death experiences after cardiac arrest: a scoping review. Discov Ment Health. 2024;4(1):19.","journal-title":"Discov Ment Health"},{"issue":"2","key":"3484_CR24","first-page":"148","volume":"53","author":"K Sandhu","year":"2009","unstructured":"Sandhu K, Dash H. Awareness during anaesthesia. Indian J Anaesth. 2009;53(2):148\u201357.","journal-title":"Indian J Anaesth"},{"issue":"4","key":"3484_CR25","doi-asserted-by":"publisher","first-page":"269","DOI":"10.1016\/S0163-8343(03)00042-2","volume":"25","author":"B Greyson","year":"2003","unstructured":"Greyson B. Incidence and correlates of near-death experiences in a cardiac care unit. Gen Hosp Psychiatry. 2003;25(4):269\u201376.","journal-title":"Gen Hosp Psychiatry"},{"issue":"8","key":"3484_CR26","doi-asserted-by":"publisher","first-page":"2257","DOI":"10.1093\/brain\/awab095","volume":"144","author":"J Frohlich","year":"2021","unstructured":"Frohlich J, Toker D, Monti MM. Consciousness among delta waves: a paradox? Brain. 2021;144(8):2257\u201377.","journal-title":"Brain"},{"issue":"2","key":"3484_CR27","doi-asserted-by":"publisher","first-page":"1248","DOI":"10.1152\/jn.00249.2015","volume":"114","author":"RNS Sachdev","year":"2015","unstructured":"Sachdev RNS, Gaspard N, Gerrard JL, Hirsch LJ, Spencer DD, Zaveri HP. Delta rhythm in wakefulness: evidence from intracranial recordings in human beings. J Neurophysiol. 2015;114(2):1248\u201354.","journal-title":"J Neurophysiol"}],"container-title":["Journal of Cardiothoracic Surgery"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s13019-025-03484-w.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s13019-025-03484-w\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s13019-025-03484-w.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,5,27]],"date-time":"2025-05-27T21:20:23Z","timestamp":1748380823000},"score":1,"resource":{"primary":{"URL":"https:\/\/cardiothoracicsurgery.biomedcentral.com\/articles\/10.1186\/s13019-025-03484-w"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,5,27]]},"references-count":27,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["3484"],"URL":"https:\/\/doi.org\/10.1186\/s13019-025-03484-w","relation":{},"ISSN":["1749-8090"],"issn-type":[{"value":"1749-8090","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5,27]]},"assertion":[{"value":"27 May 2024","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"18 May 2025","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"27 May 2025","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Protocol received ethics committee approval from all sites prior to enrolling the first participant at each site. IRB approval was obtained by committee at NYU Langone Health.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"242"}}