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NCT Number: NCT07334288

Retrolaminar Analgesia for LuMbar Surgery

This randomized controlled trial evaluates the effectiveness of ultrasound-guided retrolaminar nerve block in addition to standard multimodal analgesia for postoperative pain management in patients undergoing lumbar spine surgery. Fifty patients will be randomly assigned to receive either the retrolaminar block combined with standard pain management or standard pain management alone. The primary outcome is total opioid consumption in the first 24 hours after surgery. Secondary outcomes include pain intensity at multiple time points, time to first rescue analgesia, duration of sensory block, incidence of postoperative nausea and vomiting, length of hospital stay, patient satisfaction, and chronic pain development at 3 and 6 months follow-up.

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Key information

Conditions

Postoperative Pain Back Pain Lower Back Chronic Lumbar Surgery Neurologic Manifestations Opioid Analgesia Pain Pain, Postoperative Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Regional Anaesthesia Signs and Symptoms

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Clínica Universidad de los Andes, Chile

Santiago, Santiago Metropolitan, 171571, Chile

Location status: Recruiting

Location contact

Roberto Coloma, MD

CONTACT

[email protected]

+56 22 618 3100

About this study

BACKGROUND: Lumbar spine surgery is associated with significant postoperative pain, which can delay recovery and increase complications. Regional anesthesia techniques, specifically retrolaminar blocks, may provide superior analgesia compared to systemic opioids alone.

STUDY DESIGN: This is a prospective, randomized, controlled trial conducted at Clínica Universidad de Los Andes, Chile. Patients will be allocated using variable block randomization (block sizes 4 and 6) in a 1:1 ratio.

INTERVENTIONS: All patients will receive standardized general anesthesia (Propofol, Remifentanil, Rocuronium) and multimodal analgesia including paracetamol, metamizol, ketorolac, morphine, and pregabalin. The intervention group will additionally receive bilateral ultrasound-guided retrolaminar blocks with ropivacaine 0.5% (20 ml per side) at the end of surgery.

OUTCOMES: Primary outcome is cumulative morphine consumption via patient-controlled analgesia (PCA) during the first 24 postoperative hours. Secondary outcomes include pain scores (VAS 0-10) at 0, 6, 12, 24, 48, and 72 hours; time to first rescue analgesia; duration of sensory block; incidence of nausea/vomiting; hospital length of stay; time to ambulation; sleep quality; patient satisfaction; adverse events; and development of chronic pain at 3 and 6 months.

SAMPLE SIZE: 50 patients (25 per group) provides 80% power to detect a clinically significant difference in opioid consumption.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult patients aged 18-80 years
  • Scheduled for elective lumbar spine surgery (with instrumentation)
  • American Society of Anesthesiologists (ASA) physical status I-III
  • Willing and able to provide written informed consent
  • Able to use patient-controlled analgesia (PCA) device

Exclusion criteria

  • Refusal to participate in the study
  • Known allergy to local anesthetics (bupivacaine - levobupivacaine - lidocaine) or any study medication
  • Contraindication to regional anesthesia (infection at injection site, coagulopathy)
  • Chronic opioid use (daily use for >3 months prior to surgery)
  • Severe psychiatric disorder that precludes informed consent
  • Emergency surgery
  • Diabetes mellitus with preoperative glucose >180 mg/dl
  • Pregnancy or breastfeeding
  • Body mass index (BMI) >40 kg/m²
  • Reoperation or revision of the same level of previous spinal surgery

Treatment and study plan

Ultrasound-Guided Retrolaminar Block

Procedure

Patients will receive bilateral ultrasound-guided retrolaminar blocks with Bupivacaine 0.25% and Epinephrine 50mcg (15 ml total volume per side) before surgery. The block will be performed by an experienced anesthesiologist using real-time ultrasound guidance.

Standard Analgesia

Other

Patients receive standard multimodal analgesia without regional anesthesia block.

Primary outcomes

  1. Total postoperative opioid consumption

    Time frame: First 24 hours after surgery

    Cumulative morphine consumption (in mg morphine equivalents) delivered via patient-controlled analgesia (PCA) pump during the first 24 postoperative hours

Secondary outcomes

  1. Pain Intensity

    Time frame: Time in minutes from end of surgery until first request for rescue analgesia Time Frame: From end of surgery up to 72 hours

    Pain intensity measured using Visual Analog Scale (VAS, 0-10 where 0=no pain and 10=worst imaginable pain) Time Frame: 0, 6, 12, 24, 48, and 72 hours postoperatively

  2. Duration of Sensory Block

    Time frame: From block performance up to 72 hours

    Duration in hours from block performance until complete sensory recovery assessed by thermal and tactile testing

  3. Time to First Rescue Analgesia

    Time frame: From end of surgery up to 24 hours

    Time in minutes from end of surgery until first request for rescue analgesia

  4. Incidence of PONV

    Time frame: First 24 hours postoperatively

    Incidence of postoperative nausea and vomiting (PONV) requiring antiemetic rescue medication

  5. Length of hospital stay

    Time frame: From admission to discharge, assessed up to 30 days

    Total number of days from hospital admission to discharge

Other outcomes

  1. Patient satisfaction

    Time frame: 72 hours postoperatively

    Patient satisfaction with pain management measured using 5-point Likert scale (1=very dissatisfied to 5=very satisfied)

  2. Chronic Pain Development

    Time frame: 3 months and 6 months postoperatively

    Incidence of chronic pain defined as VAS > 3 at surgical site

Study contacts

Contact information is provided by the study sponsor or research team.

Nicolás Valls, MD, PhD

CONTACT

[email protected]

+56 9 33741332

Roberto Coloma, MD

CONTACT

[email protected]

(56) 22 618 3100

Sponsors and collaborators

Lead sponsor

Universidad de los Andes, Chile

Other

Registry information

Official study title

Efficacy of Ultrasound-Guided Retrolaminar Block Combined With Standard Multimodal Analgesia for Postoperative Pain Management in Lumbar Spine Surgery: A Randomized Controlled Trial

Acronym: REALM

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Jan 12, 2026
Registry last updated
Apr 13, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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