Comparison of Pain Relief Duration With Dexmedetomidine Versus Fentanyl Added to Spinal Anesthesia in Patients Undergoing Lower Limb Orthopedic Surgery

NCT07770542 | Completed Phase 4

• 1 other identifier: U1111-1345-0217
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this randomized clinical trial is to compare how long effective pain relief lasts when dexmedetomidine or fentanyl is added to hyperbaric bupivacaine during spinal anesthesia for lower limb orthopedic surgery. The main question the study aims to answer is: Does adding dexmedetomidine to hyperbaric bupivacaine provide longer-lasting effective pain relief after surgery than adding fentanyl? The study will include 60 adults aged 18-65 years who are classified as ASA Grade I or II and are undergoing lower limb orthopedic surgery under spinal anesthesia. Participants will be randomly assigned to one of two groups. Participants in the dexmedetomidine group will receive dexmedetomidine with hyperbaric bupivacaine. Participants in the fentanyl group will receive fentanyl with hyperbaric bupivacaine. After surgery, participants will be monitored for pain using a visual analogue scale (VAS), ranging from 0 (no pain) to 10 (severe pain). Pain will be assessed hourly during the first 12 hours and subsequently according to the study protocol. If the VAS pain score is greater than 3, nalbuphine will be given as rescue pain medicine. The study will measure the time from administration of spinal anesthesia until the participant first requires rescue pain medicine. The total amount of nalbuphine required after surgery will also be recorded. The study hypothesis is that adding dexmedetomidine to hyperbaric bupivacaine will provide a longer duration of effective pain relief than adding fentanyl.

Conditions

Postoperative Pain

Keywords

Dexmedetomidine; Fentanyl; Hyperbaric Bupivacaine; Intrathecal Analgesia; Lower Limb Orthopedic Surgery; Spinal Anesthesia; Postoperative Pain; Unilateral Spinal Anesthesia

Outcome Measures

Primary Outcomes (1)

• Duration of Effective Analgesia

  Time from administration of the intrathecal study medication to the first requirement for rescue analgesia, defined as a postoperative visual analogue scale (VAS) pain score \>3. Duration will be recorded in minutes.

  From administration of spinal anesthesia, till 24 hours after surgery

Other Outcomes (1)

• Total Amount of Nalbuphine Used

  From the end of surgery through 24 hours postoperatively

Study Arms (2)

Dexmedetomidine Group

EXPERIMENTAL

Participants will receive dexmedetomidine intrathecally

Drug: Dexmedetomidine & Bupivacaine.

Fentanyl Group

ACTIVE COMPARATOR

Participants will receive fentanyl intrathecally

Drug: fentanyl and bupivacaine

Interventions

Dexmedetomidine & Bupivacaine. DRUG

0.5 µg dexmedetomidine (0.5 mL) added to 3 mL of 0.5% bupivacaine and administered intrathecally for spinal anesthesia during lower limb orthopedic surgery

Also known as: Precedex

Dexmedetomidine Group

fentanyl and bupivacaine DRUG

25 µg fentanyl (0.5 mL) added to 3 mL of 0.5% bupivacaine and administered intrathecally for spinal anesthesia during lower limb orthopedic surgery.

Fentanyl Group

Eligibility Criteria

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

You may qualify if:

• ASA status I and II
• Orthopedic leg operations under spinal anesthesia

You may not qualify if:

• Spinal deformity
• Coagulopathy (INR \>1.5)
• Allergic reaction to local anesthetic
• Recent heart attack (≤3-months)
• With neurological diseases
• Pulmonary diseases
• Major liver or kidney disorders and infection of skin at the block site

Sponsors & Collaborators

• Allama Iqbal Teaching Hospital: lead

Study Sites (1)

Allama Iqbal Teaching Hospital

Dera Ghazi Khan, Punjab Province, 32200, Pakistan

Location

MeSH Terms

Conditions

Pain, Postoperative

Interventions

Dexmedetomidine; Bupivacaine; Fentanyl

Condition Hierarchy (Ancestors)

Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Pain; Neurologic Manifestations; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Anilides; Amides; Organic Chemicals; Aniline Compounds; Amines; Piperidines

Study Officials

• Aushtar A Naqvi, FCPS

  Allama Iqbal Teaching Hospital

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: August 13, 2026
• First Posted: August 18, 2026
• Study Start: August 1, 2025
• Primary Completion: January 30, 2026
• Study Completion: January 30, 2026
• Last Updated: August 18, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

PA (1)