Comparative Dose-Response of Intrathecal Dexmedetomidine for Post-Spinal Shivering

NCT ID: NCT07327879

Last Updated: 2026-01-08

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: PHASE3
• Total Enrollment: 120 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-01-28
• Study Completion Date: 2026-12-30

Brief Summary

Dexmedetomidine, a highly selective α2-adrenergic agonist, when used intrathecally as an adjuvant to local anesthetics, prolongs sensory/motor block and may blunt thermoregulatory shivering mechanisms. Several randomized controlled trials and meta-analyses have demonstrated decreased shivering incidence with intrathecal dexmedetomidine, but reported doses vary (commonly 2.5, 5, and 10 µg, and in some trials up to 15-20 µg), and the balance between efficacy and adverse effects (sedation, bradycardia, and hypotension) is not fully established. Hence, a head-to-head randomized comparison of several low-to-moderate intrathecal doses is warranted.

Objective: to compare the safety and efficacy of three intrathecal dexmedetomidine doses (2.5 µg, 5 µg, 10 µg) versus placebo for the prevention of post-spinal shivering.

Conditions

Post-Spinal Shivering

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: DOUBLE

Study Groups

Group P

Patients in this group will receive the standard spinal anesthetic consisting of hyperbaric bupivacaine 0.5% (15 mg) combined with an equivalent volume of normal saline (0.9% NaCl), containing no active dexmedetomidine. The total intrathecal injection volume will be standardized to 3.5 mL across all groups by adjusting the volume of saline added.

Group Type: PLACEBO_COMPARATOR

Group P (Placebo Control Group)

Intervention Type: DRUG

Patients in this group will receive the standard spinal anesthetic consisting of hyperbaric bupivacaine 0.5% (15 mg) combined with an equivalent volume of normal saline (0.9% NaCl), containing no active dexmedetomidine. The total intrathecal injection volume will be standardized to 3.5 mL across all groups by adjusting the volume of saline added. This group serves as the control to establish the baseline incidence and characteristics of post-spinal shivering and block dynamics without the intervention of the α2-adrenergic agonist.

Group D2.5

Patients in this group will receive the standard spinal anesthetic (15 mg hyperbaric bupivacaine 0.5%) supplemented with a low dose of 2.5 µg of dexmedetomidine. Normal saline will be added to achieve the standardized total intrathecal volume of 3.5 mL.

Group Type: EXPERIMENTAL

Group D2.5 (Low-Dose Dexmedetomidine Group)

Intervention Type: DRUG

Patients in this group will receive the standard spinal anesthetic (15 mg hyperbaric bupivacaine 0.5%) supplemented with a low dose of 2.5 µg of dexmedetomidine. Normal saline will be added to achieve the standardized total intrathecal volume of 3.5 mL.

Group D5

Patients in this group will receive the standard spinal anesthetic combined with a moderate dose of 5 µg of dexmedetomidine. The total volume will be adjusted to 3.5 mL with normal saline.

Group Type: EXPERIMENTAL

Group D5 (Moderate-Dose Dexmedetomidine Group)

Intervention Type: DRUG

Patients in this group will receive the standard spinal anesthetic combined with a moderate dose of 5 µg of dexmedetomidine. The total volume will be adjusted to 3.5 mL with normal saline.

Group D10

Patients in this group will receive the standard spinal anesthetic supplemented with a higher dose of 10 µg of dexmedetomidine, with normal saline used to standardize the total volume to 3.5 mL.

Group Type: EXPERIMENTAL

Group D10 (Higher-Dose Dexmedetomidine Group)

Intervention Type: DRUG

Patients in this group will receive the standard spinal anesthetic supplemented with a higher dose of 10 µg of dexmedetomidine, with normal saline used to standardize the total volume to 3.5 mL.

Interventions

Group P (Placebo Control Group)

Patients in this group will receive the standard spinal anesthetic consisting of hyperbaric bupivacaine 0.5% (15 mg) combined with an equivalent volume of normal saline (0.9% NaCl), containing no active dexmedetomidine. The total intrathecal injection volume will be standardized to 3.5 mL across all groups by adjusting the volume of saline added. This group serves as the control to establish the baseline incidence and characteristics of post-spinal shivering and block dynamics without the intervention of the α2-adrenergic agonist.

Intervention Type: DRUG

Group D2.5 (Low-Dose Dexmedetomidine Group)

Patients in this group will receive the standard spinal anesthetic (15 mg hyperbaric bupivacaine 0.5%) supplemented with a low dose of 2.5 µg of dexmedetomidine. Normal saline will be added to achieve the standardized total intrathecal volume of 3.5 mL.

Intervention Type: DRUG

Group D5 (Moderate-Dose Dexmedetomidine Group)

Patients in this group will receive the standard spinal anesthetic combined with a moderate dose of 5 µg of dexmedetomidine. The total volume will be adjusted to 3.5 mL with normal saline.

Intervention Type: DRUG

Group D10 (Higher-Dose Dexmedetomidine Group)

Patients in this group will receive the standard spinal anesthetic supplemented with a higher dose of 10 µg of dexmedetomidine, with normal saline used to standardize the total volume to 3.5 mL.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Adult patients (age 18-75 years)
• Scheduled for ureteric stone removal surgery
• ASA(American Society of Anesthesiologists) physical status I, II, or III
• Able to provide informed consent

Exclusion Criteria

• Known allergy to dexmedetomidine, bupivacaine, or other study medications
• Preexisting bradycardia (heart rate <50 beats per minute)
• Second- or third-degree atrioventricular (AV) block without a pacemaker
• Severe hepatic dysfunction
• Uncontrolled hypotension
• Pregnancy
• Chronic use of α₂-agonists or antagonists (e.g., clonidine, tizanidine)
• Infection at the planned spinal puncture site
• Coagulopathy or bleeding disorder
• Inability to rate or communicate shivering (e.g., language barrier, cognitive impairment)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Benha University

OTHER

Sponsor Role: collaborator

Al-Azhar University

OTHER

Sponsor Role: lead

Responsible Party

Neveen Abd El Maksoad Kohaf

Lecturer of Clinical Pharmacy

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Al-Azhar University

Cairo, Egypt, Egypt

Countries

Egypt

Central Contacts

Neveen A Kohaf, Ph.D

Role: CONTACT

nevenabdo@azhar.edu.eg

+201060383012

Facility Contacts

Neveen A. Kohaf, PhD

Role: primary

nevenabdo@azhar.edu.eg

01060383012

Other Identifiers

RC. 2.12.2025

Identifier Type: -

Identifier Source: org_study_id