{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T05:09:31Z","timestamp":1775797771410,"version":"3.50.1"},"reference-count":51,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T00:00:00Z","timestamp":1775779200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:p>Painless gastroscopy demonstrates significant improvement in patient comfort and examination compliance, which might indicate that the procedure has become commonly used in clinical practice. However, the critical step of accurately determining insertion timing could present challenges, given that unified standards and objective criteria appear to be lacking. Moreover, improper timing of insertion may increase patient discomfort and the risk of procedural complications while potentially affecting diagnostic accuracy. Traditionally, the eyelash reflex, respiratory patterns, blood pressure, heart rate, and other vital sign changes have been observed by clinicians to assist in judging optimal insertion time. Nevertheless, these indicators show limitations in sensitivity and specificity. Given that rapid advances in anesthesia monitoring technologies have occurred, advanced tools such as the Bispectral Index (BIS), capnography, perfusion index (PI), and ultrasound measurement of vocal cord angles could demonstrate gradual application in assessing insertion timing for painless gastroscopy. Thus, relevant literature may be systematically reviewed in this article. Furthermore, the theoretical foundations and clinical applications of these monitoring indicators might be deeply analyzed. Therefore, the findings could provide clinicians with scientific, objective, and effective methods for evaluating insertion timing, which may enhance safety and efficacy of painless gastroscopy procedures.<\/jats:p>","DOI":"10.3389\/fmed.2026.1809637","type":"journal-article","created":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T04:27:38Z","timestamp":1775795258000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Optimizing the timing of painless gastroscope insertion: integrating advanced monitoring tools to enhance safety and efficacy: a narrative review"],"prefix":"10.3389","volume":"13","author":[{"given":"Chunyan","family":"Li","sequence":"first","affiliation":[{"name":"Department of Anesthesiology, The Second Affiliated Hospital of Jiaxing University","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hongmei","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, The Second Affiliated Hospital of Jiaxing University","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shuai","family":"Kang","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, The Second Affiliated Hospital of Jiaxing University","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yipan","family":"Wu","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, The Second Affiliated Hospital of Jiaxing University","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li","family":"Hu","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, The Second Affiliated Hospital of Jiaxing University","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yun","family":"Xiong","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, The Second Affiliated Hospital of Jiaxing University","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,10]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1156","DOI":"10.1186\/s12885-023-11531-9","article-title":"Regular gastroscopy and colonoscopy during the evaluation of urachal Cancer: do we really need them?","volume":"23","author":"Luo","year":"2023","journal-title":"BMC Cancer"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"e2121403","DOI":"10.1001\/jamanetworkopen.2021.21403","article-title":"Estimated cost-effectiveness of endoscopic screening for upper gastrointestinal tract Cancer in high-risk areas in China","volume":"4","author":"Xia","year":"2021","journal-title":"JAMA Netw Open"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"102936","DOI":"10.1016\/j.ctim.2023.102936","article-title":"Effect of Electroacupuncture on discomfort during gastroscopy: a randomised controlled trial","volume":"73","author":"Yin","year":"2023","journal-title":"Complement Ther Med"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"855892","DOI":"10.3389\/fmed.2022.855892","article-title":"Alleviating Pregastroscopy anxiety using Mobile social media application","volume":"9","author":"Lu","year":"2022","journal-title":"Front Med"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1266","DOI":"10.1016\/j.dld.2024.11.029","article-title":"Deep sedation for gastrointestinal endoscopy in elderly patients. Subgroup analysis","volume":"57","author":"Martinez-Gonzalez","year":"2024","journal-title":"Dig Liver Dis"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"111042","DOI":"10.1016\/j.jclinane.2022.111042","article-title":"Bilevel positive airway pressure for gastroscopy with sedation in patients at risk of hypoxemia: a prospective randomized controlled study","volume":"85","author":"Wang","year":"2023","journal-title":"J Clin Anesth"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"604","DOI":"10.29271\/jcpsp.2019.07.604","article-title":"Propofol target-controlled infusion in anesthesia induction during painless gastroscopy","volume":"29","author":"Li","year":"2019","journal-title":"J Coll Physicians Surg Pak"},{"key":"ref8","first-page":"8390","article-title":"Predicting the best fit based on the synergistic interaction of remifentanil and propofol at the corrected dose in elderly patients undergoing painless gastroscopy","volume":"14","author":"Wang","year":"2022","journal-title":"Am J Transl Res"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1186\/s13741-024-00370-2","article-title":"Effect of intravenous lidocaine on the Ed50 of Propofol induction dose in elderly patients undergoing painless gastroscopy: a prospective, randomized, double-blinded, controlled study","volume":"13","author":"Tang","year":"2024","journal-title":"Perioper Med"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"56","DOI":"10.4253\/wjge.v15.i2.56","article-title":"Study of wrist-ankle acupuncture therapy for optimizing anaesthesia scheme of painless gastroscopy and improving painless gastroscopy related complications","volume":"15","author":"Zheng","year":"2023","journal-title":"World J Gastrointest Endosc"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"2550","DOI":"10.1016\/j.asjsur.2022.12.113","article-title":"Lidocaine spray anesthesia with a disposable laryngeal anesthetic tube for gastroscopy","volume":"46","author":"Dai","year":"2023","journal-title":"Asian J Surg"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"10850","DOI":"10.1038\/s41598-021-90342-z","article-title":"Deceleration capacity of heart rate variability as a predictor of sedation related hypotension","volume":"11","author":"Tsai","year":"2021","journal-title":"Sci Rep"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"739552","DOI":"10.3389\/fphar.2022.739552","article-title":"The impact of age on Propofol requirement for inducing loss of consciousness in elderly surgical patients","volume":"13","author":"Yang","year":"2022","journal-title":"Front Pharmacol"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"e29925","DOI":"10.1097\/MD.0000000000029925","article-title":"Usefulness of Bispectral index and patient state index during sevoflurane anesthesia in children: a prospective observational study","volume":"101","author":"Jang","year":"2022","journal-title":"Medicine"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"744169","DOI":"10.1016\/j.bjane.2021.04.030","article-title":"Using the perfusion index to predict changes in the depth of anesthesia in children compared with the a-line autoregression index: an observational study","volume":"74","author":"Abdel-Ghaffar","year":"2024","journal-title":"Braz J Anesthesiol"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"419","DOI":"10.1007\/s12028-019-00687-7","article-title":"The ascending reticular activating system","volume":"31","author":"Wijdicks","year":"2019","journal-title":"Neurocrit Care"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"194","DOI":"10.1016\/j.clinph.2013.06.024","article-title":"Simultaneous Bicoherence analysis of occipital and frontal electroencephalograms in awake and anesthetized subjects","volume":"125","author":"Hayashi","year":"2014","journal-title":"Clin Neurophysiol"},{"key":"ref18","volume-title":"Effect of Late Sleep on Effect-Site Concentration during Loss of Eyelash Reflex Induced by Target-Controlled Infusion of Propofol [Doctor]","author":"Che","year":"2025"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"1392141","DOI":"10.3389\/fmed.2024.1392141","article-title":"Optimizing sedation in gastroscopy: a study on the etomidate\/Propofol mixture ratio","volume":"11","author":"Tang","year":"2024","journal-title":"Front Med"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"1606134","DOI":"10.3389\/fmed.2025.1606134","article-title":"Safety and efficacy evaluation of low-dose of esketamine combined with propofol for painless gastroscopy: a single-center, randomized, double-blind, parallel controlled clinical trial","volume":"12","author":"Gu","year":"2025","journal-title":"Front Med"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"494","DOI":"10.11569\/wcjd.v26.i8.494","article-title":"Impact of timing of gastroscope insertion on anesthetic effect of intravenous propofol and sufentanil for painless gastroscopy","volume":"26","author":"Yuan","year":"2018","journal-title":"World Chin J Digestol"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"3324","DOI":"10.12659\/msm.907484","article-title":"Development of a hemodynamic model using routine monitoring parameters for nociceptive responses evaluation during surgery under general anesthesia","volume":"24","author":"Hirose","year":"2018","journal-title":"Med Sci Monit"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"3245","DOI":"10.2147\/jpr.S231596","article-title":"Prediction of hemodynamic reactivity by electroencephalographically derived pain threshold index in children undergoing general anesthesia: a prospective observational study","volume":"12","author":"Wu","year":"2019","journal-title":"J Pain Res"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"e4067","DOI":"10.7717\/peerj.4067","article-title":"Hrv-derived data similarity and distribution index based on ensemble neural network for measuring depth of Anaesthesia","volume":"5","author":"Liu","year":"2017","journal-title":"PeerJ"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"1060","DOI":"10.1097\/hjh.0000000000002760","article-title":"Elevated heart rate and cardiovascular risk in hypertension","volume":"39","author":"Mancia","year":"2021","journal-title":"J Hypertens"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1080\/08037050902812648","article-title":"Personality characteristics influencing determinacy of day and night blood pressure and heart rate","volume":"18","author":"Pavek","year":"2009","journal-title":"Blood Press"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"1228","DOI":"10.2130\/JIM.0b013e318230239e","article-title":"Relationship of blood pressure to heart rate in isolated systolic hypertension","volume":"59","author":"Goldberger","year":"2011","journal-title":"J Investig Med"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"142","DOI":"10.1007\/s11325-025-03305-3","article-title":"Home sleep study nasal airflow patterns and Epiglottic collapse during drug induced sleep endoscopy","volume":"29","author":"Sharma","year":"2025","journal-title":"Sleep Breath"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"814","DOI":"10.1007\/s10620-015-3945-9","article-title":"Bispectral index versus standard monitoring in sedation for endoscopic procedures: a systematic review and Meta-analysis","volume":"61","author":"Park","year":"2016","journal-title":"Dig Dis Sci"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"412","DOI":"10.23736\/s0375-9393.18.13227-5","article-title":"Bispectral index monitoring of sedation depth during endoscopy: a meta-analysis with trial sequential analysis of randomized controlled trials","volume":"85","author":"Zhang","year":"2019","journal-title":"Minerva Anestesiol"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"1189","DOI":"10.1111\/jgh.14943","article-title":"Target-controlled propofol infusion with or without bispectral index monitoring of sedation during advanced gastrointestinal endoscopy","volume":"35","author":"Lin","year":"2020","journal-title":"J Gastroenterol Hepatol"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"166","DOI":"10.1159\/000448433","article-title":"Bispectral index monitoring reduces the dosage of propofol and adverse events in sedation for endobronchial ultrasound","volume":"92","author":"Quesada","year":"2016","journal-title":"Respiration"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"1421","DOI":"10.3349\/ymj.2014.55.5.1421","article-title":"Bispectral index monitoring during anesthesiologist-directed Propofol and remifentanil sedation for endoscopic submucosal dissection: a prospective randomized controlled trial","volume":"55","author":"Park","year":"2014","journal-title":"Yonsei Med J"},{"key":"ref34","doi-asserted-by":"publisher","first-page":"e27","DOI":"10.1056\/NEJMvcm1105237","article-title":"Monitoring ventilation with capnography","volume":"367","author":"Ortega","year":"2012","journal-title":"N Engl J Med"},{"key":"ref35","doi-asserted-by":"publisher","first-page":"844","DOI":"10.1111\/j.1365-2044.2011.06808.x","article-title":"The use of capnography to confirm tracheal intubation during cardiac arrest","volume":"66","author":"Edwards","year":"2011","journal-title":"Anaesthesia"},{"key":"ref36","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1097\/sga.0000000000000426","article-title":"Capnography monitoring for patients undergoing moderate sedation: an Sgna fellowship project","volume":"42","author":"Kummer","year":"2019","journal-title":"Gastroenterol Nurs"},{"key":"ref37","doi-asserted-by":"publisher","first-page":"040201","DOI":"10.1088\/1752-7163\/ac2723","article-title":"Rationale for developing tunable laser spectroscopy (Tls) technology for high resolution real-time carbon dioxide monitoring (capnography) in human breath","volume":"15","author":"Pleil","year":"2021","journal-title":"J Breath Res"},{"key":"ref38","doi-asserted-by":"publisher","first-page":"100964","DOI":"10.1016\/j.accpm.2021.100964","article-title":"Perfusion index: physical principles, physiological meanings and clinical implications in Anaesthesia and critical care","volume":"40","author":"Coutrot","year":"2021","journal-title":"Anaesth Crit Care Pain Med"},{"key":"ref39","doi-asserted-by":"publisher","first-page":"242","DOI":"10.1186\/s12871-019-0917-1","article-title":"Evaluation of peripheral perfusion index and heart rate variability as early predictors for intradialytic hypotension in critically ill patients","volume":"19","author":"Mostafa","year":"2019","journal-title":"BMC Anesthesiol"},{"key":"ref40","doi-asserted-by":"publisher","first-page":"1185","DOI":"10.1007\/s10877-019-00443-4","article-title":"The ability of perfusion index to detect segmental ulnar nerve sparing after supraclavicular nerve block","volume":"34","author":"Abdelhamid","year":"2020","journal-title":"J Clin Monit Comput"},{"key":"ref41","doi-asserted-by":"publisher","first-page":"1106","DOI":"10.1111\/pan.13000","article-title":"Using a pulse oximeter to determine clinical depth of anesthesia-investigation of the utility of the perfusion index","volume":"26","author":"Krishnamohan","year":"2016","journal-title":"Paediatr Anaesth"},{"key":"ref42","doi-asserted-by":"publisher","first-page":"156","DOI":"10.1186\/s12871-025-03024-y","article-title":"Feasibility study of using perfusion index to predict the timing of laryngeal mask insertion: an observational study","volume":"25","author":"Cai","year":"2025","journal-title":"BMC Anesthesiol"},{"key":"ref43","doi-asserted-by":"publisher","first-page":"281","DOI":"10.1111\/pan.13324","article-title":"The prediction probabilities for emergence from sevoflurane anesthesia in children: a comparison of the perfusion index and the Bispectral index","volume":"28","author":"Liu","year":"2018","journal-title":"Paediatr Anaesth"},{"key":"ref44","doi-asserted-by":"publisher","first-page":"318","DOI":"10.1016\/j.jclinane.2016.05.012","article-title":"Pulse oximetry-derived Pleth variability index can predict Dexmedetomidine-induced changes in blood pressure in spontaneously breathing patients","volume":"34","author":"Sato","year":"2016","journal-title":"J Clin Anesth"},{"key":"ref45","doi-asserted-by":"publisher","first-page":"276","DOI":"10.1093\/bja\/aex166","article-title":"Predicting successful supraclavicular brachial plexus block using pulse oximeter perfusion index","volume":"119","author":"Abdelnasser","year":"2017","journal-title":"Br J Anaesth"},{"key":"ref46","doi-asserted-by":"publisher","first-page":"433","DOI":"10.21037\/gs.2018.07.09","article-title":"Validation of ultrasound as a diagnostic tool to assess vocal cord motion in an animal feasibility study","volume":"7","author":"Dewan","year":"2018","journal-title":"Gland Surg"},{"key":"ref47","doi-asserted-by":"publisher","first-page":"1010","DOI":"10.1111\/anae.15786","article-title":"Facemask ventilation and vocal cord angle following neuromuscular blockade: a prospective observational study()","volume":"77","author":"Lee","year":"2022","journal-title":"Anaesthesia"},{"key":"ref48","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1016\/j.surg.2021.05.062","article-title":"Intraoperative trans-laryngeal ultrasound (Lusg) of the vocal cord is a novel method of confirming the recurrent laryngeal nerve (Rln) integrity during thyroid and neck surgery","volume":"171","author":"Fung","year":"2022","journal-title":"Surgery"},{"key":"ref49","doi-asserted-by":"publisher","first-page":"1239","DOI":"10.23736\/s0375-9393.17.11755-4","article-title":"Accuracy of transcutaneous laryngeal ultrasound for detecting vocal cord paralysis in the immediate postoperative period after Total thyroidectomy","volume":"83","author":"de Miguel","year":"2017","journal-title":"Minerva Anestesiol"},{"key":"ref50","doi-asserted-by":"publisher","first-page":"885","DOI":"10.1007\/s13304-020-00728-3","article-title":"Transcutaneous laryngeal ultrasonography: a reliable, non-invasive and inexpensive preoperative method in the evaluation of vocal cords motility-a prospective multicentric analysis on a large series and a literature review","volume":"72","author":"Gambardella","year":"2020","journal-title":"Updat Surg"},{"key":"ref51","doi-asserted-by":"publisher","first-page":"893","DOI":"10.1016\/j.amjsurg.2021.08.019","article-title":"Perioperative transcutaneous laryngeal ultrasonography to assess vocal cord function in thyroid surgery","volume":"223","author":"Kim","year":"2022","journal-title":"Am J Surg"}],"container-title":["Frontiers in Medicine"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1809637\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T04:27:39Z","timestamp":1775795259000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1809637\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,10]]},"references-count":51,"alternative-id":["10.3389\/fmed.2026.1809637"],"URL":"https:\/\/doi.org\/10.3389\/fmed.2026.1809637","relation":{},"ISSN":["2296-858X"],"issn-type":[{"value":"2296-858X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,10]]},"article-number":"1809637"}}