Intrathecal Dexmedetomidine and Acute Neuropathic Pain After Lower Limb Amputation

NCT07565662 | Completed

• 2 other identifiers: JI-PG348CEI/JGC/C02-25
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized controlled trial evaluated the effect of adding intrathecal dexmedetomidine (10 µg) to hyperbaric bupivacaine (11 mg) for spinal anesthesia in patients undergoing lower limb amputation. Thirty patients (ASA I-III) scheduled for elective supra- or infracondylar amputation were randomly allocated to two groups: Control Group (n=15) received hyperbaric bupivacaine 11 mg plus saline 0.9%, and Experimental Group (n=15) received hyperbaric bupivacaine 11 mg plus dexmedetomidine 10 µg. Primary outcomes were duration of motor and sensory neuraxial block and postoperative analgesia at 48 hours. As a prespecified exploratory secondary outcome, incidence of acute neuropathic pain was assessed using the DN4 screening tool at 48 hours. The study was conducted at the Hospital Regional de Alta Especialidad Dr. Juan Graham Casasus, Villahermosa, Tabasco, Mexico, from April to October 2025. Ethics approval was obtained from the Institutional Review Board (CEI/JGC/C02-25) prior to patient enrollment.

Conditions

Phantom Limb Pain; Neuropathic Pain; Lower Limb Amputation

Outcome Measures

Primary Outcomes (5)

• Time to First Analgesic Rescue

  Time in hours from spinal block to first postoperative analgesic rescue request.

  48 hours postoperatively

• Proportion Requiring Analgesic Rescue

  Proportion of patients requiring at least one analgesic rescue dose during the postoperative period.

  48 hours postoperatively

• Heart Rate

  Heart rate measured in beats per minute during the first 4 hours post-block.

  4 hours postoperatively

• Duration of Motor Block

  Duration of motor block assessed by modified Bromage scale (0-3, higher scores indicate greater motor block). Measured at multiple timepoints through 48 hours postoperatively.

  48 hours postoperatively

• Duration of Sensory Block

  Duration of sensory block assessed by Hollmen scale. Measured at multiple timepoints through 48 hours postoperatively.

  48 hours postoperatively

Secondary Outcomes (1)

• Incidence of Acute Neuropathic Pain

  48 hours postoperatively

Study Arms (2)

Control Group - Bupivacaine Alone

ACTIVE COMPARATOR

Patients in this arm received hyperbaric bupivacaine 0.5% 11 mg plus saline 0.9% 0.1 ml administered intrathecally via spinal injection at level L2-L3. Total volume: 2.3 ml.

Drug: Hyperbaric Bupivacaine plus Saline

Experimental Group - Bupivacaine plus Dexmedetomidine

EXPERIMENTAL

Patients in this arm received hyperbaric bupivacaine 0.5% 11 mg plus dexmedetomidine 10 µg administered intrathecally via spinal injection at level L2-L3. Total volume: 2.3 ml.

Drug: Hyperbaric Bupivacaine plus Dexmedetomidine

Interventions

Hyperbaric Bupivacaine plus Saline DRUG

Hyperbaric bupivacaine 0.5% 11 mg plus saline 0.9% 0.1 ml administered intrathecally. Total volume 2.3 ml.

Control Group - Bupivacaine Alone

Hyperbaric Bupivacaine plus Dexmedetomidine DRUG

Hyperbaric bupivacaine 0.5% 11 mg plus dexmedetomidine 10 µg administered intrathecally. Total volume 2.3 ml.

Experimental Group - Bupivacaine plus Dexmedetomidine

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients scheduled for elective supra- or infracondylar lower limb amputation
• Age 18 to 65 years
• ASA physical status I-III
• Acceptance of neuraxial anesthetic technique

You may not qualify if:

• Patient refusal of anesthetic procedure
• Prolonged coagulation times
• Anatomical abnormalities of the spine
• ASA IV classification
• Atrioventricular block grade 2 or 3 without pacemaker
• Neurological deterioration (Glasgow score less than 8)
• Hemodynamic instability

Sponsors & Collaborators

• Universidad Juárez Autónoma de Tabasco: lead

Study Sites (1)

Hospital Regional de Alta Especialidad Dr. Juan Graham Casasus

Villahermosa, Tabasco, 86126, Mexico

Location

MeSH Terms

Conditions

Phantom Limb; Neuralgia

Interventions

Sodium Chloride; Dexmedetomidine

Condition Hierarchy (Ancestors)

Perceptual Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Pain, Postoperative; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Peripheral Nervous System Diseases; Neuromuscular Diseases

Intervention Hierarchy (Ancestors)

Chlorides; Hydrochloric Acid; Chlorine Compounds; Inorganic Chemicals; Sodium Compounds; Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Gabriel López-Ramírez, PhD

  Universidad Juárez Autónoma de Tabasco

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor-Researcher, División Académica de Ciencias de la Salud

Study Record Dates

• First Submitted: April 23, 2026
• First Posted: May 4, 2026
• Study Start: April 1, 2025
• Primary Completion: October 31, 2025
• Study Completion: October 31, 2025
• Last Updated: May 4, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

ME (1)