Quadro-Iliac Plane Block for Analgesia After Lumbar Microdiscectomy (QIPB RCT)

Effect of Ultrasound-Guided Quadro-Iliac Plane Block Compared With Local Infiltration Analgesia After Single-Level Lumbar Microdiscectomy: A Prospective, Double-Blind, Controlled, Multicenter Randomized Trial

This study will evaluate whether ultrasound-guided quadro-iliac plane block provides better postoperative pain control than local infiltration analgesia in patients undergoing single-level lumbar microdiscectomy.

Adult patients scheduled for elective single-level lumbar microdiscectomy will be randomly assigned to receive either bilateral quadro-iliac plane block plus patient-controlled analgesia or local infiltration analgesia plus patient-controlled analgesia. The main outcome of the study will be total fentanyl consumption during the first 24 hours after surgery. Pain scores, need for rescue analgesia, opioid-related side effects, patient satisfaction, and recovery quality will also be evaluated.

Study Overview

• Status: Not yet recruiting
• Conditions: Pain Management
• Intervention / Treatment: Procedure: Ultrasound-Guided Quadro-Iliac Plane Block; Procedure: Local Infiltration Analgesia (LIA)

Detailed Description

This is a prospective, randomized, double-blind, controlled, multicenter clinical trial designed to assess the analgesic efficacy of ultrasound-guided quadro-iliac plane block in patients undergoing elective single-level lumbar microdiscectomy.

Patients aged 18-75 years with American Society of Anesthesiologists physical status I-III who are scheduled for elective single-level lumbar microdiscectomy under general anesthesia will be included. Participants will be randomized into two groups. The intervention group will receive bilateral ultrasound-guided quadro-iliac plane block before emergence from anesthesia, followed by postoperative patient-controlled analgesia. The control group will receive local infiltration analgesia performed by the surgeon, followed by postoperative patient-controlled analgesia.

All patients will receive a standardized general anesthesia protocol. Postoperative analgesia will be provided using a fentanyl-based patient-controlled analgesia device. The primary outcome will be total fentanyl consumption during the first postoperative 24 hours. Secondary outcomes will include numerical rating scale pain scores at predefined postoperative time points, rescue analgesic requirement, opioid-related adverse effects such as nausea, vomiting, pruritus and respiratory depression, dermatomal sensory spread, and patient-reported recovery quality using the QoR-15 questionnaire.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Engin ihsan Turan, principal investigator; Phone Number: +905382431114; Email: drenginihsan@gmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 34303
      • Health Science University İstanbul Kanuni Sultan Süleyman Education and Training Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 to 75 years
• American Society of Anesthesiologists physical status I to III
• Scheduled for elective single-level lumbar microdiscectomy, such as L4-L5 or L5-S1 disc herniation
• Planned surgery under general anesthesia
• Able to provide written informed consent

Exclusion Criteria:

• Allergy or hypersensitivity to local anesthetics
• Coagulopathy or active anticoagulant use
• Infection, scar tissue, or skin lesion at the injection site
• Pregnancy or breastfeeding
• Chronic pain syndrome or regular opioid use
• American Society of Anesthesiologists physical status IV or higher
• Planned surgery for two or more levels of disc herniation

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Quadro-Iliac Plane Block Group; Participants in this group will receive bilateral ultrasound-guided quadro-iliac plane block before emergence from general anesthesia, followed by postoperative fentanyl-based patient-controlled analgesia.	Procedure: Ultrasound-Guided Quadro-Iliac Plane Block; Bilateral ultrasound-guided quadro-iliac plane block will be performed before emergence from general anesthesia in the prone position. After visualization of the quadratus lumborum muscle and iliac crest at the L3 level, 30 mL of 0.167% bupivacaine will be injected into the interfascial plane on each side. All participants will receive postoperative fentanyl-based patient-controlled analgesia.
Active Comparator: Local Infiltration Analgesia Group; Participants in this group will receive surgeon-performed local infiltration analgesia, followed by postoperative fentanyl-based patient-controlled analgesia.	Procedure: Local Infiltration Analgesia (LIA); Local infiltration analgesia will be performed by the surgeon before the end of surgery. A total dose of 50 mg of 0.25% bupivacaine will be infiltrated into the subcutaneous tissue. All participants will receive postoperative fentanyl-based patient-controlled analgesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Fentanyl Consumption During the First 24 Hours After Surgery	Total postoperative fentanyl consumption administered via patient-controlled analgesia will be recorded during the first 24 hours after surgery.	Postoperative 0-24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain Scores at Rest and During Movement	Pain intensity will be assessed using the Numerical Rating Scale at rest and during movement. The scale ranges from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain.	Postoperative 0, 1, 6, 12, and 24 hours
Rescue Analgesic Requirement	The need for rescue analgesia with intravenous tenoxicam will be recorded during the postoperative follow-up period.	Postoperative 0-24 hours
Opioid-Related Adverse Effects	Opioid-related adverse effects, including nausea, vomiting, pruritus, and respiratory depression, will be recorded.	Postoperative 0-24 hours
Quality of Recovery Score	Patient-reported recovery quality will be assessed using the Quality of Recovery-15 questionnaire.	Postoperative 24 hours
Dermatomal Sensory Spread	Dermatomal sensory spread of the block will be evaluated using a cold test.	Postoperative 2 hours

Collaborators and Investigators

• Sponsor: Kanuni Sultan Suleyman Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): July 10, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 2, 2026

Study Registration Dates

• First Submitted: July 6, 2026
• First Submitted That Met QC Criteria: July 6, 2026
• First Posted (Actual): July 10, 2026

Study Record Updates

• Last Update Posted (Actual): July 10, 2026
• Last Update Submitted That Met QC Criteria: July 6, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neurobehavioral Manifestations; Perceptual Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Agnosia
• Other Study ID Numbers: Quadroiliac plane block RCT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No