Ultrasound-Guided Ilioinguinal-Iliohypogastric Nerve Block Following Spinal Anesthesia Comparing Dexmedetomidine Versus Nalbuphine as Adjuvants to Bupivacaine in Unilateral Inguinal Hernia Repair

September 18, 2026 updated by: Mohammed Ayman Abd El-khaleq, Assiut University

Ultrasound-Guided Ilioinguinal-Iliohypogastric Nerve Block Following Spinal Anesthesia Comparing Dexmedetomidine Versus Nalbuphine as Adjuvants to Bupivacaine in Unilateral Inguinal Hernia Repair: A Prospective, Randomized, Double-Blind Controlled Study

This study evaluates and compares the pain-relieving efficacy and safety of adding either dexmedetomidine or nalbuphine to bupivacaine in an ultrasound-guided ilioinguinal-iliohypogastric nerve block for patients undergoing elective unilateral inguinal hernia repair under spinal anesthesia.

While spinal anesthesia provides effective surgical anesthesia, postoperative pain often increases as the block recedes. Supplementing spinal anesthesia with an ultrasound-guided peripheral nerve block targeting the ilioinguinal and iliohypogastric nerves provides localized pain relief. Adding adjuvant medications to the local anesthetic may extend the duration of pain control and reduce systemic analgesic requirements.

Participants are randomly allocated to one of three groups:

  • Control Group: Receives bupivacaine with normal saline.
  • Nalbuphine Group: Receives bupivacaine combined with nalbuphine.
  • Dexmedetomidine Group: Receives bupivacaine combined with dexmedetomidine.

The primary objective is to assess the duration of analgesia by measuring the time from the regression of spinal sensory anesthesia until the first request for rescue pain medication. Secondary objectives include evaluating total 24-hour pain medication consumption, postoperative pain scores, vital signs, sedation scores, patient satisfaction, and side effects.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

102

Phase

  • Phase 4

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Age 18 to 65 years
  • American Society of Anesthesiologists (ASA) physical status I or II
  • Scheduled for elective unilateral primary inguinal hernia repair under spinal anesthesia supplemented with ilioinguinal-iliohypogastric nerve block
  • Body weight between 45 and 100 kg and body mass index (BMI) <= 35 kg/m^2
  • Ability to understand the study protocol, comply with study requirements, and communicate pain intensity using the Visual Analog Scale (VAS)

Exclusion Criteria:

  • Known allergy or hypersensitivity to amide-type local anesthetics, dexmedetomidine, or nalbuphine
  • Contraindications to spinal anesthesia (e.g., severe hypovolemia, elevated intracranial pressure, active infection at the lumbar puncture site, severe spinal deformity)
  • History of neurological disorders (e.g., peripheral neuropathy, myopathy, seizure disorders, or cognitive impairment)
  • Coagulopathy, concurrent anticoagulant therapy, or local infection at the block site contraindicating regional anesthesia
  • Severe hepatic, renal, or cardiovascular disease (e.g., heart block, uncontrolled hypertension, ischemic heart disease, severe valvular disease, chronic renal failure, or liver cirrhosis)
  • History of opioid or substance abuse
  • Emergency surgical procedures
  • Procedures expected to exceed 3 hours or requiring conversion to general anesthesia

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Group C: Bupivacaine Control

Patients undergo ultrasound-guided ilioinguinal-iliohypogastric nerve block immediately following spinal anesthesia with a total injectate volume of 10 mL consisting of 8 mL 0.5% bupivacaine (40 mg) and 2 mL sterile normal saline (final bupivacaine concentration 0.4%).
Drug: Bupivacaine

Single-injection ultrasound-guided ilioinguinal-iliohypogastric (IIIH) nerve block administered immediately after spinal anesthesia. The injectate consists of 8 mL 0.5% bupivacaine (40 mg) combined with 2 mL sterile 0.9% normal saline to achieve a total volume of 10 mL (final bupivacaine concentration 0.4%).
Experimental: Group N: Nalbuphine Adjuvant

Patients undergo ultrasound-guided ilioinguinal-iliohypogastric nerve block immediately following spinal anesthesia with a total injectate volume of 10 mL consisting of 8 mL 0.5% bupivacaine (40 mg) and nalbuphine 10 mg diluted with sterile normal saline to 10 mL (final bupivacaine concentration 0.4%).
Drug: Bupivacaine

Single-injection ultrasound-guided ilioinguinal-iliohypogastric (IIIH) nerve block administered immediately after spinal anesthesia. The injectate consists of 8 mL 0.5% bupivacaine (40 mg) combined with 2 mL sterile 0.9% normal saline to achieve a total volume of 10 mL (final bupivacaine concentration 0.4%).

Drug: Nalbuphine

Single-injection ultrasound-guided ilioinguinal-iliohypogastric (IIIH) nerve block administered immediately after spinal anesthesia. The injectate consists of 8 mL 0.5% bupivacaine (40 mg) combined with nalbuphine 10 mg, diluted with sterile 0.9% normal saline to achieve a total volume of 10 mL (final bupivacaine concentration 0.4%).
Experimental: Group D: Dexmedetomidine Adjuvant

Patients undergo ultrasound-guided ilioinguinal-iliohypogastric nerve block immediately following spinal anesthesia with a total injectate volume of 10 mL consisting of 8 mL 0.5% bupivacaine (40 mg) and dexmedetomidine 1 µg/kg diluted with sterile normal saline to 10 mL (final bupivacaine concentration 0.4%).
Drug: Bupivacaine

Single-injection ultrasound-guided ilioinguinal-iliohypogastric (IIIH) nerve block administered immediately after spinal anesthesia. The injectate consists of 8 mL 0.5% bupivacaine (40 mg) combined with 2 mL sterile 0.9% normal saline to achieve a total volume of 10 mL (final bupivacaine concentration 0.4%).

Drug: Dexmedetomidine

Single-injection ultrasound-guided ilioinguinal-iliohypogastric (IIIH) nerve block administered immediately after spinal anesthesia. The injectate consists of 8 mL 0.5% bupivacaine (40 mg) combined with dexmedetomidine 1 µg/kg, diluted with sterile 0.9% normal saline to achieve a total volume of 10 mL (final bupivacaine concentration 0.4%).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to First Rescue Analgesia
Time Frame: Up to 24 hours postoperatively

Time in minutes from the documented regression of spinal sensory block to the T12 dermatome until the patient's first request for rescue analgesia, administered when the Visual Analog Scale (VAS) pain score is 4 or greater (scale of 0 = no pain to 10 = worst imaginable pain).
Up to 24 hours postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assiut University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

November 1, 2027

Study Registration Dates

First Submitted

September 18, 2026

First Submitted That Met QC Criteria

September 18, 2026

First Posted (Actual)

September 23, 2026

Study Record Updates

Last Update Posted (Actual)

September 23, 2026

Last Update Submitted That Met QC Criteria

September 18, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Dex vs Nalbuphine: Nerve Block

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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