{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T15:32:47Z","timestamp":1789140767636,"version":"build-2803163510"},"reference-count":20,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,22]],"date-time":"2026-01-22T00:00:00Z","timestamp":1769040000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"crossref","award":["JP22hk0102081"],"award-info":[{"award-number":["JP22hk0102081"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"crossref","award":["24hk010281h003"],"award-info":[{"award-number":["24hk010281h003"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Japan Society for the Promotion of Science (JSPA) KAKENHI","award":["JP22K09091"],"award-info":[{"award-number":["JP22K09091"]}]},{"name":"Japan Society for the Promotion of Science (JSPA) KAKENHI","award":["JP16K10954"],"award-info":[{"award-number":["JP16K10954"]}]},{"name":"Japan Society for the Promotion of Science (JSPA) KAKENHI","award":["00206088"],"award-info":[{"award-number":["00206088"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Under general anesthesia, maintaining patients\u2019 blood pressure (BP) is important to prevent organ ischemia. When bleeding occurs, it is sometimes difficult to increase BP with boluses of fluids or transfusions, and vasoconstrictors must be administered. This study investigated circulatory dynamic changes in patients who bled during surgery and were administered phenylephrine, particularly left ventricular end-diastolic volume (EDV), effective arterial elastance (Ea), and left ventricular end-systolic elastance (Ees), calculating each value from the left ventricular\u2013arterial coupling (Ees\/Ea). Methods: We calculated Ees\/Ea using electrocardiograms, arterial pressure waveforms, and phonocardiograms using an esophageal stethoscope. We investigated the changes in patients\u2019 EDV, Ea, and Ees during two periods: phenylephrine administration and after BP elevation. Results: The seven participants comprised three men and four women. Between the two periods, linear mixed-model analysis revealed that mean arterial pressure (MAP), Ea, and Ees significantly increased over time (MAP; \u03b2 = 8.7, p &lt; 0.01, Ea; \u03b2 = 0.22, p &lt; 0.05, Ees; \u03b2 = 0.73, p &lt; 0.05), while no significant changes were observed in other parameters such as heart rate and EDV. Conventional parameters demonstrated that stroke volume variation significantly decreased (\u03b2 = \u22122.0, p = 0.01), systemic vascular resistance index significantly increased (\u03b2 = 200, p &lt; 0.01), while no significant change was observed in cardiac index (\u03b2 = \u22120.03, p = 0.7). In patients administered phenylephrine due to BP decrease from bleeding, significant changes in afterload and cardiac contractility occurred without changes in preload. Conclusions: Our noninvasive method for calculating EDV, Ea, and Ees can be valuable for monitoring hemodynamics under anesthesia.<\/jats:p>","DOI":"10.3390\/jcm15020905","type":"journal-article","created":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T09:21:40Z","timestamp":1769505700000},"page":"905","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Effects of Phenylephrine Administration on the Circulatory Dynamics of Patients with Hypotension Due to Bleeding During Surgery, Specifically Left Ventricular End-Diastolic Volume, Effective Arterial Elastance, and Left Ventricular End-Systolic Elastance"],"prefix":"10.3390","volume":"15","author":[{"given":"Takahiro","family":"Shiraishi","sequence":"first","affiliation":[{"name":"Department of Anesthesiology and Reanimatology, University of Fukui Hospital, Fukui 910-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mayuki","family":"Sato","sequence":"additional","affiliation":[{"name":"School of Medical Sciences, University of Fukui, Fukui 910-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rina","family":"Takagi","sequence":"additional","affiliation":[{"name":"School of Medical Sciences, University of Fukui, Fukui 910-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3281-4477","authenticated-orcid":false,"given":"Kenji","family":"Shigemi","sequence":"additional","affiliation":[{"name":"Maizuru Municipal Hospital, Kyoto 625-8555, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2949-2574","authenticated-orcid":false,"given":"Yuka","family":"Matsuki","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimatology, University of Fukui Hospital, Fukui 910-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"706","DOI":"10.1016\/j.bja.2018.04.036","article-title":"Intraoperative hypotension and the risk of postoperative adverse outcomes: A systematic review","volume":"121","author":"Wesselink","year":"2018","journal-title":"Br. J. Anaesth."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1346","DOI":"10.1001\/jama.2017.14172","article-title":"Effect of individualized vs standard blood pressure management strategies on postoperative organ dysfunction among high-risk patients undergoing major surgery: A randomized clinical trial","volume":"318","author":"Futier","year":"2017","journal-title":"JAMA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1097\/EJA.0b013e32832a3a9c","article-title":"Left ventricular end-diastolic area is a measure of cardiac preload in patients with early septic shock","volume":"26","author":"Scheuren","year":"2009","journal-title":"Eur. J. Anaesthesiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1186\/cc10291","article-title":"Update on hemodynamic monitoring: A consensus of 16","volume":"15","author":"Vincent","year":"2011","journal-title":"Crit. Care"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1769","DOI":"10.1097\/00000542-200006000-00037","article-title":"Single-beat estimation of ventricular end-systolic elastance-effective arterial elastance as an index of ventricular mechanoenergetic performance","volume":"92","author":"Hayashi","year":"2000","journal-title":"Anesthesiology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1001\/jama.2022.9792","article-title":"Effect of fluid bolus administration on cardiovascular collapse Among critically ill patients undergoing tracheal intubation: A randomized clinical trial","volume":"328","author":"Russell","year":"2022","journal-title":"JAMA"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.jsams.2012.05.003","article-title":"Validity of predicting left ventricular end systolic pressure changes following an acute bout of exercise","volume":"16","author":"Kappus","year":"2013","journal-title":"J. Sci. Med. Sport"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"49","DOI":"10.2147\/IBPC.S45292","article-title":"Optimal perioperative management of arterial blood pressure","volume":"7","author":"Lonjaret","year":"2014","journal-title":"Integr. Blood Press. Control"},{"key":"ref_9","first-page":"863","article-title":"A formula to estimate the approximate surface area if height and weight be known","volume":"17","year":"1916","journal-title":"Arch. Intern. Med."},{"key":"ref_10","unstructured":"Richards, E., Lopez, M.J., and Maani, C.V. (2023). Phenylephrine. StatPearls, StatPearls Publishing."},{"key":"ref_11","unstructured":"Hooper, N., and Armstrong, T.J. (2022). Hemorrhagic shock. StatPearls, StatPearls Publishing."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1152\/japplphysiol.00126.2012","article-title":"Effects of phenylephrine on cardiac output and venous return depend on the position of the heart on the Frank-Starling relationship","volume":"113","author":"Cannesson","year":"2012","journal-title":"J. Appl. Physiol. (1985)"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"997","DOI":"10.1007\/s10877-024-01186-7","article-title":"Vasoconstriction with phenylephrine increases cardiac output in preload dependent patients","volume":"38","author":"Cihoric","year":"2024","journal-title":"J. Clin. Monit. Comput."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"564","DOI":"10.1097\/TA.0000000000000409","article-title":"Impact of epinephrine and norepinephrine on two dynamic indices in a porcine hemorrhagic shock model","volume":"77","author":"Giraud","year":"2014","journal-title":"J. Trauma Acute Care Surg."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1204","DOI":"10.1016\/j.bja.2025.01.023","article-title":"The Anrep effect in septic shock: A mechanism of cardiac adaption","volume":"134","author":"Sequeira","year":"2025","journal-title":"Br. J. Anesth."},{"key":"ref_16","first-page":"254","article-title":"Minimally invasive intraoperative estimation of left-ventricular end-systolic elastance with phenylephrine as loading intervention","volume":"132","author":"Boly","year":"2013","journal-title":"Br. J. Anaesth."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1213\/ANE.0b013e31824e2b6c","article-title":"Multicenter study verifying a method of noninvasive continuous cardiac output measurement using pulse wave transit time: A comparison with intermittent bolus thermodilution cardiac output","volume":"115","author":"Yamada","year":"2012","journal-title":"Anesth. Analg."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1007\/s10877-014-9624-0","article-title":"Reliability of a new 4th generation FloTrac algorithm to track cardiac output changes in patients receiving phenylephrine","volume":"29","author":"Ji","year":"2014","journal-title":"J. Clin. Monit. Comput."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"S578","DOI":"10.1161\/CIR.0000000000001380","article-title":"Part 10: Adult and Pediatric Special Circumstances of Resuscitation: 2025 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care","volume":"152","author":"Cao","year":"2025","journal-title":"Circulation"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1111\/anae.16172","article-title":"Effects of phenylephrine on systemic and cerebral circulations in humans: A systematic review with mechanistic explanations","volume":"79","author":"Meng","year":"2024","journal-title":"Anesthesia"}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/2\/905\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T05:11:26Z","timestamp":1769577086000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/2\/905"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,22]]},"references-count":20,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["jcm15020905"],"URL":"https:\/\/doi.org\/10.3390\/jcm15020905","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,22]]}}}