{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T01:15:08Z","timestamp":1783646108310,"version":"3.55.0"},"reference-count":25,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T00:00:00Z","timestamp":1779062400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T00:00:00Z","timestamp":1783641600000},"content-version":"vor","delay-in-days":53,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["22K10909"],"award-info":[{"award-number":["22K10909"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Anesthesiol"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Automated infrared pupillometry (AIP) provides a quantitative, non-invasive, and reproducible method for assessing the pupillary light reflex, which is mediated by brainstem pathways. Although AIP has been increasingly used in critical care settings, interpretation of pupillary parameters may be confounded by the administration of sedatives and analgesics. However, the influence of these medications on individual AIP parameters in postoperative intensive care unit patients remains insufficiently characterized. This proof-of-concept pilot study aimed to identify pupillometric parameters that remain relatively stable under routine sedative and analgesic exposure following elective cardiovascular surgery.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This prospective observational study included 10 patients admitted to the coronary care unit (CCU) after elective open-heart surgery. AIP parameters and bispectral index (BIS) values were measured postoperatively at predefined time points from CCU admission to extubation. Temporal changes in each parameter were analyzed descriptively using within-patient comparisons over the postoperative course.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The Neurological Pupil Index (NPi) and latency (LAT) showed minimal temporal variation throughout the observation period. In contrast, BIS values increased progressively after surgery, accompanied by gradual increases in constriction percentage (CH), mean contraction velocity (CV), and maximum contraction velocity, whereas mean dilation velocity remained relatively unchanged over time. When comparing predefined postoperative time points immediately after CCU admission and after extubation, only CH showed an increase (median [interquartile range]: 0.45 [0.38\u20130.52] vs. 0.68 [0.60\u20130.73];\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.02).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In this small postoperative cohort, NPi and LAT were relatively more stable than other pupillometric parameters under routine sedative and analgesic exposure. However, given the limited sample size and the absence of neurological complications, these findings should be interpreted as descriptive and hypothesis-generating, and no conclusions can be drawn regarding clinical utility for neurological monitoring or prognostication. In contrast, CH and CV require cautious interpretation, as they may be influenced by pharmacological agents rather than by the underlying neurological status.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s12871-026-03889-7","type":"journal-article","created":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T03:24:58Z","timestamp":1779074698000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Exploring the relative stability of automated infrared pupillometry parameters under sedative and analgesic exposure after cardiac surgery"],"prefix":"10.1186","volume":"26","author":[{"given":"Saiko","family":"Okamoto","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hideaki","family":"Sakuramoto","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sayaka","family":"Hosoi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kanji","family":"Matsuzaki","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akira","family":"Ouchi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nobutake","family":"Shimojo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoshiaki","family":"Inoue","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,5,18]]},"reference":[{"key":"3889_CR1","doi-asserted-by":"publisher","first-page":"121E","DOI":"10.1136\/bjo.85.1.121e","volume":"85","author":"JP Diamond","year":"2001","unstructured":"Diamond JP. The pupil. Anatomy, physiology and clinical applications. Br J Ophthalmol. 2001;85:121E.","journal-title":"Br J Ophthalmol"},{"key":"3889_CR2","doi-asserted-by":"publisher","first-page":"e629","DOI":"10.1212\/WNL.0000000000012984","volume":"97","author":"P Opic","year":"2021","unstructured":"Opic P, R\u00fcegg S, Marsch S, Gut SS, Sutter R. Automated quantitative pupillometry in the critically ill: A systematic review of the literature. Neurology. 2021;97:e629\u201342.","journal-title":"Neurology"},{"key":"3889_CR3","doi-asserted-by":"publisher","first-page":"180","DOI":"10.1016\/j.jocn.2022.04.023","volume":"100","author":"S Stutzman","year":"2022","unstructured":"Stutzman S, Iype P, Marshall J, Speir K, Schneider N, Tran C, et al. Inter-device reliability of the NPi-200 and NPi-300 pupillometers. J Clin Neurosci. 2022;100:180\u20133.","journal-title":"J Clin Neurosci"},{"key":"3889_CR4","doi-asserted-by":"publisher","first-page":"1603033","DOI":"10.3389\/fneur.2025.1603033","volume":"16","author":"J Nakao","year":"2025","unstructured":"Nakao J, Muroi A, Marushima A, Tasaki K, Inoue Y, Matsumaru Y, et al. Assessment of the brain impact of soccer heading using pupillary light reflex. Front Neurol. 2025;16:1603033.","journal-title":"Front Neurol"},{"key":"3889_CR5","doi-asserted-by":"publisher","first-page":"383","DOI":"10.1177\/0885066619881124","volume":"36","author":"MM Bower","year":"2021","unstructured":"Bower MM, Sweidan AJ, Xu JC, Stern-Neze S, Yu W, Groysman LI. Quantitative pupillometry in the Intensive Care Unit. J Intensive Care Med. 2021;36:383\u201391.","journal-title":"J Intensive Care Med"},{"key":"3889_CR6","doi-asserted-by":"publisher","first-page":"205","DOI":"10.3171\/jns.2003.98.1.0205","volume":"98","author":"WR Taylor","year":"2003","unstructured":"Taylor WR, Chen JW, Meltzer H, Gennarelli TA, Kelbch C, Knowlton S, et al. Quantitative pupillometry, a new technology: normative data and preliminary observations in patients with acute head injury. Technical note. J Neurosurg. 2003;98:205\u201313.","journal-title":"J Neurosurg"},{"key":"3889_CR7","doi-asserted-by":"publisher","first-page":"609","DOI":"10.3390\/brainsci12050609","volume":"12","author":"F Romagnosi","year":"2022","unstructured":"Romagnosi F, Bernini A, Bongiovanni F, Iaquaniello C, Miroz JP, Citerio G, et al. Neurological pupil index for the early prediction of outcome in severe acute brain injury patients. Brain Sci. 2022;12:609.","journal-title":"Brain Sci"},{"key":"3889_CR8","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1016\/j.resuscitation.2020.06.002","volume":"154","author":"H Obinata","year":"2020","unstructured":"Obinata H, Yokobori S, Shibata Y, Takiguchi T, Nakae R, Igarashi Y, et al. Early automated infrared pupillometry is superior to auditory brainstem response in predicting neurological outcome after cardiac arrest. Resuscitation. 2020;154:7\u201384.","journal-title":"Resuscitation"},{"key":"3889_CR9","doi-asserted-by":"publisher","first-page":"e0316358","DOI":"10.1371\/journal.pone.0316358","volume":"20","author":"C Park","year":"2025","unstructured":"Park C, Park SY, Kim M, Park B, Hong JM. Automated quantitative pupillometry as a predictor for transtentorial brain herniation in patients with malignant acute ischemic stroke. PLoS ONE. 2025;20:e0316358.","journal-title":"PLoS ONE"},{"issue":"Suppl 1","key":"3889_CR10","doi-asserted-by":"publisher","first-page":"i95","DOI":"10.1093\/bja\/aev072","volume":"115","author":"PJ Schuller","year":"2015","unstructured":"Schuller PJ, Newell S, Strickland PA, Barry JJ. Response of bispectral index to neuromuscular block in awake volunteers. Br J Anaesth. 2015;115(Suppl 1):i95\u2013103.","journal-title":"Br J Anaesth"},{"key":"3889_CR11","doi-asserted-by":"publisher","first-page":"1338","DOI":"10.1164\/rccm.2107138","volume":"166","author":"CN Sessler","year":"2002","unstructured":"Sessler CN, Gosnell MS, Grap MJ, Brophy GM, O\u2019Neal PV, Keane KA, et al. The Richmond Agitation-Sedation Scale: validity and reliability in adult intensive care unit patients. Am J Respir Crit Care Med. 2002;166:1338\u201344.","journal-title":"Am J Respir Crit Care Med"},{"key":"3889_CR12","doi-asserted-by":"publisher","first-page":"291","DOI":"10.1007\/s10877-016-9839-3","volume":"31","author":"K Shirozu","year":"2017","unstructured":"Shirozu K, Setoguchi H, Tokuda K, Karashima Y, Ikeda M, Kubo M, et al. The effects of anesthetic agents on pupillary function during general anesthesia using the automated infrared quantitative pupillometer. J Clin Monit Comput. 2017;31:291\u20136.","journal-title":"J Clin Monit Comput"},{"key":"3889_CR13","doi-asserted-by":"publisher","first-page":"818","DOI":"10.1097\/00003246-198510000-00009","volume":"13","author":"WA Knaus","year":"1985","unstructured":"Knaus WA, Draper EA, Wagner DP, Zimmerman JE. Apache II: A severity of disease classification system. Crit Care Med. 1985;13:818\u201329.","journal-title":"Crit Care Med"},{"key":"3889_CR14","doi-asserted-by":"publisher","first-page":"145","DOI":"10.1016\/S1386-5056(02)00014-X","volume":"65","author":"A Junger","year":"2002","unstructured":"Junger A, B\u00f6ttger S, Engel J, Benson M, Michel A, R\u00f6hrig R, et al. Automatic calculation of a modified Apache II score using a patient data management system (PDMS). Int J Med Inf. 2002;65:145\u201357.","journal-title":"Int J Med Inf"},{"key":"3889_CR15","doi-asserted-by":"publisher","first-page":"15964","DOI":"10.1038\/s41598-018-34367-x","volume":"8","author":"S Yokobori","year":"2018","unstructured":"Yokobori S, Wang KKK, Yang Z, Zhu T, Tyndall JA, Mondello S, et al. Quantitative pupillometry and neuron-specific enolase independently predict return of spontaneous circulation following cardiogenic out-of-hospital cardiac arrest: a prospective pilot study. Sci Rep. 2018;8:15964.","journal-title":"Sci Rep"},{"key":"3889_CR16","doi-asserted-by":"publisher","first-page":"100287","DOI":"10.1016\/j.bjao.2024.100287","volume":"10","author":"C Kaye","year":"2024","unstructured":"Kaye C, Rhodes J, Austin P, Casey M, Gould R, Sira J, et al. Assessment of depth of sedation using bispectral Index\u2122 monitoring in patients with severe traumatic brain injury in UK intensive care units. BJA Open. 2024;10:100287.","journal-title":"BJA Open"},{"key":"3889_CR17","doi-asserted-by":"publisher","first-page":"877","DOI":"10.1016\/j.bja.2024.02.001","volume":"132","author":"L Shi","year":"2024","unstructured":"Shi L, Jin DN, Cao XJ, Liu H, Gu WJ, Zhang M, et al. Assessment of sedation by automated pupillometry in critically ill patients: a prospective observational study. Br J Anaesth. 2024;132:877\u201385.","journal-title":"Br J Anaesth"},{"key":"3889_CR18","doi-asserted-by":"publisher","first-page":"1546","DOI":"10.1167\/iovs.02-0468","volume":"44","author":"O Bergamin","year":"2003","unstructured":"Bergamin O, Kardon RH. Latency of the pupil light reflex: sample rate, stimulus intensity, and variation in normal subjects. Invest Ophthalmol Vis Sci. 2003;44:1546\u201354.","journal-title":"Invest Ophthalmol Vis Sci"},{"key":"3889_CR19","doi-asserted-by":"publisher","first-page":"975","DOI":"10.1007\/s10877-025-01293-z","volume":"39","author":"S Holmsk\u00e4r","year":"2025","unstructured":"Holmsk\u00e4r S, \u00d6hrn M, Furudahl M, Kesti J, Pansell J. Is quantitative pupillometry affected by ambient light? A prospective crossover study. J Clin Monit Comput. 2025;39:975\u201386.","journal-title":"J Clin Monit Comput"},{"key":"3889_CR20","doi-asserted-by":"publisher","first-page":"e12825","DOI":"10.1002\/emp2.12825","volume":"3","author":"EL Jolkovsky","year":"2022","unstructured":"Jolkovsky EL, Fernandez-Penny FE, Alexis M, Benson LN, Wang BH, Abella BS. Impact of acute intoxication on quantitative pupillometry assessment in the emergency department. J Am Coll Emerg Physicians Open. 2022;3:e12825.","journal-title":"J Am Coll Emerg Physicians Open"},{"key":"3889_CR21","doi-asserted-by":"publisher","first-page":"609","DOI":"10.3390\/brainsci12050609","volume":"12","author":"F Romagnosi","year":"2022","unstructured":"Romagnosi F, Bernini A, Bongiovanni F, Iaquaniello C, Miroz JP, Citerio G, et al. Neurological pupil index for the early prediction of outcome in severe acute brain injury patients. Brain Sci. 2022;12:609.","journal-title":"Brain Sci"},{"key":"3889_CR22","doi-asserted-by":"publisher","first-page":"925","DOI":"10.1016\/S1474-4422(23)00271-5","volume":"22","author":"M Oddo","year":"2023","unstructured":"Oddo M, Taccone FS, Petrosino M, Badenes R, Blandino-Ortiz A, Bouzat P, et al. The Neurological Pupil index for outcome prognostication in people with acute brain injury (Orange): a prospective, observational, multicentre cohort study. Lancet Neurol. 2023;22:925\u201333.","journal-title":"Lancet Neurol"},{"key":"3889_CR23","doi-asserted-by":"publisher","first-page":"e0153566","DOI":"10.1371\/journal.pone.0153566","volume":"11","author":"Y Wang","year":"2016","unstructured":"Wang Y, Zekveld AA, Naylor G, Ohlenforst B, Jansma EP, Lorens A, et al. Parasympathetic nervous system dysfunction, as identified by pupil light reflex, and its possible connection to hearing impairment. PLoS ONE. 2016;11:e0153566.","journal-title":"PLoS ONE"},{"key":"3889_CR24","doi-asserted-by":"publisher","first-page":"1037","DOI":"10.1097\/ALN.0000000000000384","volume":"121","author":"MD Rollins","year":"2014","unstructured":"Rollins MD, Feiner JR, Lee JM, Shah S, Larson M. Pupillary effects of high-dose opioid quantified with infrared pupillometry. Anesthesiology. 2014;121:1037\u201344.","journal-title":"Anesthesiology"},{"key":"3889_CR25","doi-asserted-by":"publisher","first-page":"27","DOI":"10.1046\/j.1365-2125.2001.01311.x","volume":"51","author":"MD Larson","year":"2001","unstructured":"Larson MD, Talke PO. Effect of dexmedetomidine, an alpha2-adrenoceptor agonist, on human pupillary reflexes during general anaesthesia. Br J Clin Pharmacol. 2001;51:27\u201333.","journal-title":"Br J Clin Pharmacol"}],"container-title":["BMC Anesthesiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s12871-026-03889-7","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12871-026-03889-7.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12871-026-03889-7.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T01:05:23Z","timestamp":1783645523000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1186\/s12871-026-03889-7"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,18]]},"references-count":25,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,12]]}},"alternative-id":["3889"],"URL":"https:\/\/doi.org\/10.1186\/s12871-026-03889-7","relation":{},"ISSN":["1471-2253"],"issn-type":[{"value":"1471-2253","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,18]]},"assertion":[{"value":"5 August 2025","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"4 May 2026","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"18 May 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"This study was approved by the Ethics Committees of the University of Tsukuba Hospital (Notification No. 1832) and Hitachi General Hospital (Approval No. 2022-38), and was registered with the University Hospital Medical Information Network (UMIN; ID: 000049165). Written informed consent was obtained from all participants upon hospital admission.","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":"417"}}