Retrolaminar Analgesia for LuMbar Surgery

Official title

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

Overview

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.

Detailed description

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.

Interventions

• Procedure Ultrasound-Guided Retrolaminar Block
  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.
• Other Standard Analgesia
  Patients receive standard multimodal analgesia without regional anesthesia block.

Primary outcome measures

• Total postoperative opioid consumption [Time frame: First 24 hours after surgery]

Secondary outcome measures (5)

• 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]
• Duration of Sensory Block [Time frame: From block performance up to 72 hours]
• Time to First Rescue Analgesia [Time frame: From end of surgery up to 24 hours]
• Incidence of PONV [Time frame: First 24 hours postoperatively]
• Length of hospital stay [Time frame: From admission to discharge, assessed up to 30 days]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Chile · 1 center

• Clínica Universidad de los Andes, Chile — Santiago

Publications

• Zeballos JL, Voscopoulos C, Kapottos M, Janfaza D, Vlassakov K. Ultrasound-guided retrolaminar paravertebral block. Anaesthesia. 2013 Jun;68(6):649-51. doi: 10.1111/anae.12296. No abstract available. PMID 23662765
• Ardon AE, Prasad A, McClain RL, Melton MS, Nielsen KC, Greengrass R. Regional Anesthesia for Ambulatory Anesthesiologists. Anesthesiol Clin. 2019 Jun;37(2):265-287. doi: 10.1016/j.anclin.2019.01.005. Epub 2019 Mar 15. PMID 31047129
• Batra RK, Krishnan K, Agarwal A. Paravertebral block. J Anaesthesiol Clin Pharmacol. 2011 Jan;27(1):5-11. No abstract available. PMID 21804697
• Gerbershagen HJ, Aduckathil S, van Wijck AJ, Peelen LM, Kalkman CJ, Meissner W. Pain intensity on the first day after surgery: a prospective cohort study comparing 179 surgical procedures. Anesthesiology. 2013 Apr;118(4):934-44. doi: 10.1097/ALN.0b013e31828866b3. PMID 23392233

Identifiers

NCT: NCT07334288 · CUA2025-42

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗