Comparing Doses of Intrathecal Dexmedetomidine

Comparing Doses of Intrathecal Dexmedetomidine Along With Bupivacaine for Cesarean Section: A Double-Blind Randomized Clinical Trial

To compare the duration of sensory and motor blockade produced by two different intrathecal doses of dexmedetomidine (5 µg and 10 µg) when added to hyperbaric bupivacaine in patients undergoing elective cesarean section

Study Overview

• Status: Completed
• Conditions: Dexmedetomidine
• Intervention / Treatment: Drug: Dexmedetomidine 5 mcg; Drug: Dexmedetomidine 10 mcg

Detailed Description

Cesarean section remains one of the most commonly performed surgical procedures worldwide, serving as a critical intervention to reduce maternal and neonatal morbidity when vaginal delivery poses increased risks. Global cesarean delivery rates have risen steadily, from approximately 7% in 1990 to around 21% in recent years, with projections indicating that by 2030, nearly one in three births may occur via cesarean section .This trend is particularly pronounced in regions like Latin America and the Caribbean (over 40%) and varies significantly by socioeconomic factors, healthcare access, and clinical indications . In Pakistan and similar settings, rates continue to increase, underscoring the need for optimized anesthetic techniques that prioritize maternal safety, fetal well-being, rapid recovery, and effective postoperative pain control.

Regional anesthesia, specifically spinal anesthesia, is the preferred method for elective cesarean sections due to its rapid onset, avoidance of airway complications associated with general anesthesia, minimal placental transfer of drugs, and enhanced maternal satisfaction. Hyperbaric bupivacaine is the most widely used local anesthetic for this purpose, providing reliable sensory and motor blockade. However, when used alone, bupivacaine offers relatively short-duration postoperative analgesia, which can delay ambulation, hinder early mother-infant bonding, and increase the need for systemic analgesics6. To address these limitations, various intrathecal adjuvants have been investigated to enhance block quality, prolong analgesia, and improve overall outcomes.

Dexmedetomidine, a highly selective α2-adrenergic agonist, exhibits sedative, anxiolytic, and analgesic properties without significant respiratory depression. When administered intrathecally, it inhibits nociceptive transmission through presynaptic C-fibers and postsynaptic dorsal horn neurons, resulting in prolonged sensory and motor blockade compared to bupivacaine alone8,9 . Multiple recent studies and meta-analyses have confirmed its efficacy as an adjuvant in obstetric spinal anesthesia, demonstrating extended analgesia duration, reduced shivering, and fewer side effects (e.g., pruritus, nausea) than opioids like fentanyl . However, the optimal intrathecal dose remains controversial: lower doses (e.g., 3-5 µg) may offer a favorable benefit-risk profile with minimal hemodynamic impact, while higher doses (e.g., 10 µg) provide greater prolongation but raise concerns about potential bradycardia or hypotension in parturient.

This prospective, double-blind, randomized clinical trial compares the effects of two commonly used doses of intrathecal dexmedetomidine-5 µg and 10 µg-when added to a standard dose of hyperbaric bupivacaine (12.5 mg) for elective cesarean section. The primary aim is to determine which dose yields superior prolongation of sensory and motor blockade while maintaining maternal hemodynamic stability and safety.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Phase 4

Contacts and Locations

Study Locations

• Pakistan
  • Punjab Province
    • Rawalpindi, Punjab Province, Pakistan, 46220
      • Bahria International Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Parturients aged 20-40 years
• ASA physical status II
• Scheduled for elective cesarean section
• Ability to provide informed written consent

Exclusion Criteria:

• ASA physical status III or higher
• Emergency cesarean section
• Previous labor analgesia
• History of cardiovascular, neurological, or systemic disease
• Contraindications to spinal anesthesia
• Surgery duration exceeding 60 minutes

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Group A; Dexmedetomidine 5 mcg	Drug: Dexmedetomidine 5 mcg; 12.5 mg (2.5 mL) of 0.5% hyperbaric bupivacaine + 5 µg dexmedetomidine; Other Names: Dexmedetomidine 5mcg
Active Comparator: Group B; Dexmedetomidine 10 mcg	Drug: Dexmedetomidine 10 mcg; 12.5 mg (2.5 mL) of 0.5% hyperbaric bupivacaine + 10 µg dexmedetomidine; Other Names: Dexmedetomidine 10mcg

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of sensory blockade	Visual Analouge Scale (0 to 10)	6 hrs
Duration of motor blockade	Bromage Scale (1 to 5)	6 hrs

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hemodynamic parameters	Heart rate per minute	Till end of surgery
Hemodynamic parameters	Mean arterial pressure in millimeters of mercury	Till end of surgery

Collaborators and Investigators

• Sponsor: Bahria International Hospital
• Investigators: Principal Investigator: azher munir, mbbs, Bahria International Hospital

Publications and helpful links

General Publications

• Mowar A, Singh V, Pahade A, Karki G. Effect of three different doses of intrathecal dexmedetomidine on subarachnoid block: a prospective randomized double-blind trial. Anaesth. pain intensive care 2021;26(1):8-13; DOI:10.35975/apic.v26i1.1759

Study record dates

Study Major Dates

• Study Start (Actual): October 22, 2025
• Primary Completion (Actual): January 21, 2026
• Study Completion (Actual): January 21, 2026

Study Registration Dates

• First Submitted: January 23, 2026
• First Submitted That Met QC Criteria: January 31, 2026
• First Posted (Actual): February 9, 2026

Study Record Updates

• Last Update Posted (Actual): February 9, 2026
• Last Update Submitted That Met QC Criteria: January 31, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: cesarean section; spinal anesthesia; Dexmedetomidine; bupivacaine; motor block; sensory block
• Additional Relevant MeSH Terms: Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Imidazoles; Dexmedetomidine
• Other Study ID Numbers: 2021-6907

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No