Magnesium vs. Dexmedetomidine in TURBT Under Spinal Anesthesia (TURBT)

A Randomized Controlled Trial of the Analgesic, Hemodynamic, and Respiratory Effects of Intravenous Magnesium Sulfate and Dexmedetomidine Infusions During Transurethral Bladder Tumor Resection Under Spinal Anesthesia

This randomized controlled trial evaluated the effects of intraoperative intravenous magnesium sulfate versus dexmedetomidine on postoperative pain, analgesic consumption, hemodynamic stability, and respiratory function in patients undergoing elective transurethral resection of bladder tumor (TUR-M) under spinal anesthesia. Magnesium sulfate significantly reduced postoperative pain scores, delayed the time to first analgesic request, and decreased total analgesic consumption compared to dexmedetomidine and control groups, while both agents were hemodynamically and respiratorily safe.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain; Spinal Anesthesia; Dexmedetomidine; Magnesium Sulfate; Bladder Tumors; Hemodynamic and Respiratory Monitoring
• Intervention / Treatment: Drug: magnesium sulfate; Drug: Dexmedetomidine; Drug: Normal Saline

Detailed Description

This study is a prospective, randomized, controlled trial designed to evaluate the effects of intraoperative intravenous magnesium sulfate versus dexmedetomidine infusions in patients undergoing elective transurethral resection of bladder tumor (TUR-M) under spinal anesthesia. Adult patients (age 18-85 years) with ASA physical status I-III scheduled for TUR-M were enrolled. Participants were randomly assigned to receive either magnesium sulfate, dexmedetomidine, or saline infusion during surgery. All patients received standardized spinal anesthesia. The study assesses postoperative pain, analgesic consumption, hemodynamic and respiratory parameters, and side effects. The trial aims to determine which agent provides better postoperative analgesia while maintaining cardiovascular and respiratory safety.

• Study Type: Interventional
• Enrollment (Actual): 93
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • SBÜ Kartal Dr. Lütfi Kırday City Hospital, İstanbul

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Age between 18 and 85 years. Classified as ASA physical status I, II, or III according to the American Society of Anesthesiologists.

Patients scheduled for elective transurethral resection of bladder tumor (TUR-M) under spinal anesthesia.

Exclusion Criteria:

Patients under 18 years or over 85 years of age. Contraindications to spinal anesthesia (e.g., infection at puncture site, coagulopathy).

History or current diagnosis of significant cardiac arrhythmia. Known allergy or contraindication to the study drugs (magnesium sulfate or dexmedetomidine).

Patients requiring conversion to general anesthesia due to inadequate spinal anesthesia intraoperatively.

Mental retardation, cognitive impairment, or communication difficulties that prevent understanding of study procedures or pain assessment.

Patients who refuse to participate in the study.

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Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Magnesium Sulfate Infusion Group; Patients receive intravenous magnesium sulfate at 15 mg/kg/hour during TUR-M surgery under spinal anesthesia. Infusion solution is prepared aseptically by diluting the calculated dose in 50 mL of 0.9% NaCl. Postoperative analgesia is administered as rescue treatment based on VAS scores.	Drug: magnesium sulfate; Patients receive intravenous magnesium sulfate at 15 mg/kg/hour during TUR-M surgery under spinal anesthesia. The calculated dose is diluted in 50 mL of 0.9% sodium chloride and infused intravenously throughout the surgery. Postoperative analgesia is provided as rescue treatment based on VAS scores.
Experimental: Dexmedetomidine Infusion Group; Patients receive intravenous dexmedetomidine at 0.5 µg/kg/hour during TUR-M surgery under spinal anesthesia. The calculated dose is diluted in 50 mL of 0.9% NaCl and infused intravenously. Postoperative analgesia is given as rescue treatment according to VAS scores.	Drug: Dexmedetomidine; Patients receive intravenous dexmedetomidine at 0.5 µg/kg/hour during TUR-M surgery under spinal anesthesia. The calculated dose is diluted in 50 mL of 0.9% sodium chloride and infused intravenously throughout the surgery. Postoperative analgesia is provided as rescue treatment based on VAS scores.
Active Comparator: Control Group (Saline Infusion); Patients receive intravenous normal saline at 15 mL/kg/hour during TUR-M surgery under spinal anesthesia. Infusion is administered with the same protocol and devices as the experimental arms to maintain blinding. Postoperative analgesia is provided as rescue treatment based on VAS scores.	Drug: Normal Saline; Patients receive 15 mL/kg/hour of 0.9% sodium chloride without active pharmacological agents during TUR-M surgery under spinal anesthesia. Infusion is administered using the same protocol and devices as the experimental arms to maintain blinding. Postoperative analgesia is provided as rescue treatment based on VAS scores.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to First Analgesic Request	Time (in minutes) from the end of surgery until the patient first requests postoperative analgesia.	Postoperative period up to 24 hours
Total Postoperative Analgesic Consumption	Total amount of analgesics (paracetamol and tramadol) administered within 24 hours after surgery.	24 hours postoperative
Postoperative Pain Scores	Pain intensity measured using the Visual Analog Scale (VAS) at the end of surgery, 60 minutes, 6 hours, and 24 hours after surgery.	24 hours postoperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Integrated Pulmonary Index (IPI)	Respiratory effort and ventilatory adequacy measured intraoperatively.	During surgery
Intraoperative heart rate	Heart rate will be continuously monitored intraoperatively using standard anesthesia monitoring. Mean intraoperative heart rate will be recorded and reported in beats per minute (bpm).	During surgery
Intraoperative systolic blood pressure	Systolic blood pressure will be continuously monitored intraoperatively using standard anesthesia monitoring. Mean intraoperative systolic blood pressure will be recorded and reported in millimeters of mercury (mmHg).	During surgery
Intraoperative diastolic blood pressure	Diastolic blood pressure will be continuously monitored intraoperatively using standard anesthesia monitoring. Mean intraoperative diastolic blood pressure will be recorded and reported in millimeters of mercury (mmHg).	During surgery
Intraoperative mean arterial pressure	Mean arterial pressure will be continuously monitored intraoperatively using standard anesthesia monitoring. Mean intraoperative MAP values will be recorded and reported in millimeters of mercury (mmHg).	During surgery
Adverse Effects	Incidence of hypotension, bradycardia, desaturation, postoperative nausea and vomiting, and other side effects.	Intraoperative and 24 hours postoperative

Collaborators and Investigators

• Sponsor: Dr. Lutfi Kirdar Kartal Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 15, 2024
• Primary Completion (Actual): September 1, 2025
• Study Completion (Actual): December 15, 2025

Study Registration Dates

• First Submitted: February 16, 2026
• First Submitted That Met QC Criteria: February 25, 2026
• First Posted (Actual): March 3, 2026

Study Record Updates

• Last Update Posted (Actual): March 3, 2026
• Last Update Submitted That Met QC Criteria: February 25, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: postoperative analgesia; TURBT; Integrated Pulmonary Index
• Additional Relevant MeSH Terms: Urogenital Diseases; Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urologic Neoplasms; Urinary Bladder Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Urinary Bladder Neoplasms; Sulfur Compounds; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Pharmaceutical Preparations; Azoles; Imidazoles; Inorganic Chemicals; Crystalloid Solutions; Isotonic Solutions; Solutions; Sulfur Acids; Sulfates; Sulfuric Acids; Magnesium Compounds; Dexmedetomidine; Magnesium Sulfate; Saline Solution
• Other Study ID Numbers: DrLutfiKirdarTRH-ANES-HY-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The individual participant data (IPD) will not be shared publicy due to local data privacy regulations and institutional policy. Aggregate results will be available in published form.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No