[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100658880":3},{"organization":4,"outcomesModule":7,"designInfo":59,"detailedDescription":72,"studyPopulation":58,"armGroups":73,"interventions":91,"overallOfficials":101,"centralContacts":106,"locations":115,"responsibleParty":134,"collaborators":58,"id":137,"slug":138,"hasResults":139,"nctId":140,"briefTitle":141,"officialTitle":142,"acronym":58,"eligibilityCriteria":143,"healthyVolunteers":139,"sex":144,"minAge":145,"maxAge":58,"enrollmentInfo":146,"targetDuration":58,"studyType":149,"phases":150,"briefSummary":152,"conditions":153,"keywords":156,"overallStatus":163,"whyStopped":58,"lastUpdateSubmitDate":164,"lastUpdatePostDateStruct":165,"startDateStruct":168,"completionDateStruct":169,"leadSponsor":171,"locationsCount":172},{"fullName":5,"class":6},"Istanbul University","OTHER",{"primaryOutcomes":8,"secondaryOutcomes":13,"otherOutcomes":58},[9],{"measure":10,"description":11,"timeFrame":12},"Bilateral Frontal Regional Cerebral Oxygen Saturation (rSO₂)","Regional cerebral oxygen saturation (rSO₂, %) will be measured bilaterally over the frontal cortex using near-infrared spectroscopy. Left and right rSO₂ values will be recorded at each prespecified assessment time point.","Before spinal anesthesia (baseline) and at 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 minutes after spinal anesthesia",[14,18,21,24,27,30,33,37,40,43,47,50,54],{"measure":15,"description":16,"timeFrame":17},"Incidence of Hypotension","Hypotension will be defined as a mean arterial pressure (MAP) below 65 mmHg and\u002For a reduction in systolic blood pressure of at least 30% from baseline.","During the first 60 minutes after spinal anesthesia",{"measure":19,"description":20,"timeFrame":17},"Time to First Hypotensive Episode","Time from completion of spinal anesthesia to the first episode meeting the predefined criteria for hypotension.",{"measure":22,"description":23,"timeFrame":17},"Requirement for Ephedrine","Proportion of participants requiring intravenous ephedrine for treatment of hypotension.",{"measure":25,"description":26,"timeFrame":17},"Total Ephedrine Dose","Total cumulative dose of intravenous ephedrine administered for treatment of hypotension, measured in milligrams.",{"measure":28,"description":29,"timeFrame":17},"Incidence of Bradycardia","Bradycardia will be defined as a heart rate below 45 beats per minute.",{"measure":31,"description":32,"timeFrame":17},"Requirement for Atropine","Proportion of participants requiring intravenous atropine for treatment of bradycardia.",{"measure":34,"description":35,"timeFrame":36},"Minimum Regional Cerebral Oxygen Saturation","The lowest recorded frontal regional cerebral oxygen saturation (rSO₂, %) value during the observation period will be determined from the prespecified bilateral NIRS measurements.","From baseline to 60 minutes after spinal anesthesia",{"measure":38,"description":39,"timeFrame":36},"Maximum Relative Decrease in Regional Cerebral Oxygen Saturation","Maximum percentage decrease in frontal regional cerebral oxygen saturation (rSO₂) from the corresponding pre-spinal baseline value.",{"measure":41,"description":42,"timeFrame":36},"Incidence of Cerebral Desaturation","Cerebral desaturation will be defined as a decrease in frontal regional cerebral oxygen saturation (rSO₂) of at least 20% from the corresponding pre-spinal baseline value at any prespecified measurement time point.",{"measure":44,"description":45,"timeFrame":46},"Postoperative Nausea Severity","Postoperative nausea severity will be assessed using a numeric rating scale (NRS), with higher scores indicating greater nausea severity.","From the end of surgery through the first postoperative day",{"measure":48,"description":49,"timeFrame":46},"Requirement for Rescue Antiemetic Treatment","Proportion of participants requiring rescue antiemetic medication for postoperative nausea or vomiting.",{"measure":51,"description":52,"timeFrame":53},"Post-Spinal Headache Severity","Severity of post-spinal headache assessed using a numeric rating scale (NRS).","During the first postoperative day",{"measure":55,"description":56,"timeFrame":57},"Incidence of Postoperative Delirium","Postoperative delirium will be assessed using the 4AT. A 4AT score of 4 or greater will be considered positive for delirium.","In the post-anesthesia care unit, approximately 12 hours after surgery, and on the first postoperative day",null,{"allocation":60,"interventionModel":61,"interventionModelDescription":62,"primaryPurpose":63,"observationalModel":58,"timePerspective":58,"maskingInfo":64},"RANDOMIZED","PARALLEL","Participants will be assigned to one of three parallel groups: ondansetron administered before spinal anesthesia, ondansetron administered after spinal anesthesia, or placebo.","PREVENTION",{"masking":65,"maskingDescription":66,"whoMasked":67},"QUADRUPLE","tudy solutions will be prepared in identical volumes and appearance by personnel not involved in clinical care or outcome assessment. Treatment allocation will remain concealed from participants, care providers, investigators involved in data collection, and outcome assessors.",[68,69,70,71],"PARTICIPANT","CARE_PROVIDER","INVESTIGATOR","OUTCOMES_ASSESSOR","This is a single-center, prospective, randomized, double-blind, placebo-controlled, three-arm parallel-group clinical trial in adults aged 65 years or older undergoing endoscopic urologic surgery under spinal anesthesia.\n\nSpinal anesthesia may cause hypotension and bradycardia because of sympathetic blockade, reduced venous return, and activation of reflex mechanisms including the Bezold-Jarisch reflex. Ondansetron is a 5-hydroxytryptamine type 3 (5-HT₃) receptor antagonist that may attenuate these hemodynamic changes.\n\nParticipants will be randomized to receive one of three study strategies: intravenous ondansetron 8 mg before spinal anesthesia, intravenous ondansetron 8 mg after spinal anesthesia, or placebo. Study solutions will be prepared in a blinded manner so that participants and relevant clinical and outcome-assessment personnel remain unaware of treatment allocation.\n\nCerebral oxygenation will be assessed using bilateral frontal near-infrared spectroscopy. Left and right regional cerebral oxygen saturation (rSO₂) values will be recorded before spinal anesthesia and at 5-minute intervals during the first 60 minutes following spinal anesthesia.\n\nHemodynamic variables, including blood pressure and heart rate, will be monitored throughout the study period. The need for vasopressor treatment, total vasopressor dose, bradycardia, and atropine use will also be recorded. Postoperative outcomes will include nausea and vomiting, rescue antiemetic use, post-spinal headache, and postoperative delirium assessed using the 4AT.\n\nThe study is designed to compare the effects of different timings of ondansetron administration on cerebral oxygenation and hemodynamic stability during the early period after spinal anesthesia.",[74,81,86],{"label":75,"type":76,"description":77,"interventionNames":78},"Early Ondansetron","EXPERIMENTAL","Participants will receive ondansetron 8 mg intravenously approximately 10 minutes before completion of the intrathecal injection.",[79,80],"Drug: Ondansetron 8 mg","Drug: 0.9 % sodium chloride",{"label":82,"type":83,"description":84,"interventionNames":85},"Late Ondansetron","ACTIVE_COMPARATOR","Participants will receive ondansetron 8 mg intravenously approximately 5 minutes after completion of the intrathecal injection.",[79,80],{"label":87,"type":88,"description":89,"interventionNames":90},"Placebo","PLACEBO_COMPARATOR","Participants will receive placebo according to the blinded study protocol at the corresponding study time points.",[80],[92,97],{"type":93,"name":94,"description":95,"armGroupLabels":96,"otherNames":58},"DRUG","Ondansetron 8 mg","Ondansetron 8 mg will be administered intravenously according to the assigned study arm. In the early ondansetron arm, the drug will be administered approximately 10 minutes before completion of the intrathecal injection. In the late ondansetron arm, the drug will be administered approximately 5 minutes after completion of the intrathecal injection.",[75,82],{"type":93,"name":98,"description":99,"armGroupLabels":100,"otherNames":58},"0.9 % sodium chloride","Placebo will be administered intravenously in the same volume and appearance as the active study drug according to the blinded study protocol.",[75,82,87],[102],{"name":103,"affiliation":104,"role":105},"Ezgi Budak Ozyalcin, Anesthesiology Specialist","Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Department of Anesthesiology and Reanimation","PRINCIPAL_INVESTIGATOR",[107,111],{"name":103,"role":108,"phone":109,"phoneExt":58,"email":110},"CONTACT","+905056043177","budakezgi@gmail.com",{"name":112,"role":108,"phone":113,"phoneExt":58,"email":114},"Fatiş Altındaş, Professor of Anesthesiology","+905337785278","fatisaltintas@hotmail.com",[116],{"facility":117,"status":58,"city":118,"state":119,"zip":120,"country":121,"countryCode":58,"cosmosGeoPoint":122,"geoPoint":127,"contacts":128},"Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine","Fatih","Istanbul","34360","Turkey (Türkiye)",{"type":123,"coordinates":124},"Point",[125,126],28.94083,41.0225,{"lat":126,"lon":125},[129,132],{"name":130,"role":108,"phone":131,"phoneExt":58,"email":110},"Ezi Budak Özyalçın, Anesthesiology Specialist","05056043177",{"name":112,"role":108,"phone":133,"phoneExt":58,"email":114},"+905537785278",{"type":105,"investigatorFullName":135,"investigatorTitle":136,"investigatorAffiliation":5,"oldNameTitle":58,"oldOrganization":58},"Ezgi Budak Ozyalcın","Anesthesiology Specialist","100658880","phase-4-effects-of-ondansetron-timing-during-spinal-anesthesia-for-urologic-surgery-100658880",false,"NCT07858149","Effects of Ondansetron Timing During Spinal Anesthesia for Urologic Surgery","Clinical Effects of Ondansetron Administration in Patients Undergoing Urologic Surgery Under Spinal Anesthesia","Inclusion Criteria:\n\n* Male sex.\n* Age 65 years or older.\n* ASA physical status I-III.\n* Scheduled for elective transurethral resection of the prostate (TUR-P) or transurethral resection of bladder tumor (TUR-BT) under spinal anesthesia.\n* Ability to provide written informed consent.\n\nExclusion Criteria:\n\n* Known hypersensitivity or contraindication to ondansetron.\n* Corrected QT interval (QTc) \\>480 ms.\n* Significant cardiac conduction abnormality.\n* Concomitant use of medications known to prolong the QT interval.\n* Severe ischemic heart disease.\n* Severe chronic obstructive pulmonary disease.\n* Skin lesion, wound, or other condition preventing placement of frontal NIRS sensors.\n* Contraindication to spinal anesthesia.","MALE","65 Years",{"count":147,"type":148},99,"ESTIMATED","INTERVENTIONAL",[151],"PHASE4","This study will evaluate whether the timing of intravenous ondansetron administration affects cerebral oxygenation and hemodynamic stability in older adults undergoing endoscopic urologic surgery under spinal anesthesia.\n\nParticipants aged 65 years or older will be randomly assigned to one of three groups: ondansetron administered before spinal anesthesia, ondansetron administered after spinal anesthesia, or placebo. Ondansetron will be administered intravenously at a dose of 8 mg.\n\nCerebral oxygenation will be assessed using bilateral frontal near-infrared spectroscopy (NIRS). Regional cerebral oxygen saturation (rSO₂) will be recorded before spinal anesthesia and at 5-minute intervals during the first 60 minutes after spinal anesthesia.\n\nThe study will also evaluate blood pressure, heart rate, vasopressor requirements, bradycardia, postoperative nausea and vomiting, post-spinal headache, and postoperative delirium.\n\nThe aim is to determine whether the timing of ondansetron administration influences cerebral oxygenation and hemodynamic stability after spinal anesthesia.",[154,155],"Spinal Anesthesia-Induced Hypotension","Cerebral Oxygenation",[157,158,159,160,161,162],"Ondansetron","Spinal anesthesia","Regional cerebral oxygen saturation","Near-infrared spectroscopy","Urologic surgery","Older adults","NOT_YET_RECRUITING","2026-09-30",{"date":166,"type":167},"2026-10-05","ACTUAL",{"date":164,"type":148},{"date":170,"type":148},"2027-01-22",{"name":5,"class":6},1]