Back Pain Lower Back Chronic, Lumbar Surgery, Opioid Analgesia, Postoperative Pain, Regional Anaesthesia
Conditions
Keywords
retrolaminar block, regional anesthesia, lumbar spine surgery, Multimodal analgesia, opioid consumption, Ultrasound-guided nerve block
Brief summary
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
PROCEDUREUltrasound-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.
OTHERStandard Analgesia
Patients receive standard multimodal analgesia without regional anesthesia block.
Sponsors
Universidad de los Andes, Chile
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
Outcomes assessors (including pain evaluators and data collectors) will be blinded to group allocation. The anesthesiologist performing the intervention and the patient cannot be blinded due to the nature of the procedure (performance of nerve block). Postoperative care providers will also be blinded to treatment allocation.
Intervention model description
Randomized, Parallel Assignment, Blinded outcome assessment
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total postoperative opioid consumption | 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
| Measure | Time frame | Description |
|---|---|---|
| Pain Intensity | 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 |
| Duration of Sensory Block | From block performance up to 72 hours | Duration in hours from block performance until complete sensory recovery assessed by thermal and tactile testing |
| Time to First Rescue Analgesia | From end of surgery up to 24 hours | Time in minutes from end of surgery until first request for rescue analgesia |
| Incidence of PONV | First 24 hours postoperatively | Incidence of postoperative nausea and vomiting (PONV) requiring antiemetic rescue medication |
| Length of hospital stay | From admission to discharge, assessed up to 30 days | Total number of days from hospital admission to discharge |
Countries
Chile
Contacts
CONTACTRoberto Coloma, MD
CONTACTNicolás Valls, MD, PhD
STUDY_DIRECTORNicolas J Valls, M.D, Ph.D
Anesthesiologyst, Clinica Universidad de los Andes
Outcome results
None listed