Lower Limb Amputation, Neuropathic Pain, Phantom Limb Pain
Conditions
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.
Interventions
DRUGHyperbaric Bupivacaine plus Saline
Hyperbaric bupivacaine 0.5% 11 mg plus saline 0.9% 0.1 ml administered intrathecally. Total volume 2.3 ml.
DRUGHyperbaric Bupivacaine plus Dexmedetomidine
Hyperbaric bupivacaine 0.5% 11 mg plus dexmedetomidine 10 µg administered intrathecally. Total volume 2.3 ml.
Sponsors
Universidad Juárez Autónoma de Tabasco
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* 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
Exclusion criteria
* 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time to First Analgesic Rescue | 48 hours postoperatively | Time in hours from spinal block to first postoperative analgesic rescue request. |
| Proportion Requiring Analgesic Rescue | 48 hours postoperatively | Proportion of patients requiring at least one analgesic rescue dose during the postoperative period. |
| Heart Rate | 4 hours postoperatively | Heart rate measured in beats per minute during the first 4 hours post-block. |
| Duration of Motor Block | 48 hours postoperatively | 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. |
| Duration of Sensory Block | 48 hours postoperatively | Duration of sensory block assessed by Hollmen scale. Measured at multiple timepoints through 48 hours postoperatively. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Acute Neuropathic Pain | 48 hours postoperatively | Incidence of acute neuropathic pain assessed by DN4 screening tool (0-10, score ≥4 indicates neuropathic pain component). Reported as exploratory secondary outcome. |
Countries
Mexico
Contacts
PRINCIPAL_INVESTIGATORGabriel López-Ramírez, PhD
Universidad Juárez Autónoma de Tabasco
Outcome results
None listed