Opioid Free and Opioid Based Anesthesia in Elective Lumbar Spine Surgery

Official title

Prospective Comparative Evaluation of Intra-operative and Postoperative Outcomes Associated With Opioid Free Versus Opioid Based Anesthesia Techniques in Patients Undergoing Elective Lumbar Spinal Surgery

Overview

This prospective, observational, non-randomized clinical study aims to evaluate the intraoperative and postoperative effects of opioid-free multimodal anesthesia compared with opioid-containing anesthesia methods in adult patients undergoing lumbar spinal surgery. Patients will be managed according to routine clinical practice and assigned to one of three groups based on the analgesic strategy used by the attending anesthesiologist: (1) opioid-free anesthesia using multimodal agents and/or erector spinae plane (ESP) block; (2) ESP block plus intraoperative opioids; or (3) opioid-based anesthesia without regional blocks. The primary objective is to compare postoperative pain control and opioid requirements within the first 48 hours after surgery. Secondary objectives include evaluating opioid-related side effects such as nausea, vomiting, pruritus, constipation, delayed mobilization, urinary retention, and postoperative complications classified according to the Clavien-Dindo system. Standard postoperative analgesia, including intravenous morphine patient-controlled analgesia (PCA), acetaminophen, and NSAIDs, will be provided for all patients. The study aims to determine whether an opioid-free multimodal analgesic approach can reduce opioid consumption and related adverse effects while maintaining adequate analgesia in patients undergoing lumbar spinal surgery.

Detailed description

Lumbar spinal surgery, including lumbar canal stenosis and lumbar disc herniation procedures, is frequently associated with significant postoperative pain. Opioids are commonly used for perioperative analgesia; however, they may lead to several adverse effects such as nausea, vomiting, pruritus, constipation, urinary retention, delayed mobilization, and, less commonly, respiratory depression. In recent years, opioid-sparing and opioid-free multimodal analgesia strategies have gained increasing interest in an effort to minimize these side effects while maintaining effective pain control.

This prospective, observational, non-randomized study will evaluate the intraoperative and postoperative outcomes of three different anesthetic approaches routinely used in clinical practice for adult patients undergoing lumbar spinal surgery. Patients will be allocated into groups based on the independent decision of the attending anesthesiologist; the research team will not influence the anesthesia plan.

Group 1 (Opioid-free anesthesia): Patients receive multimodal analgesia (including agents such as acetaminophen, lidocaine, magnesium sulfate, ketamine, esmolol, and dexmedetomidine) and may undergo an erector spinae plane (ESP) block or other trunk blocks. No intraoperative opioids are administered.

Group 2 (ESP + opioid group): Patients receive an ESP block and multimodal analgesia, with the addition of intraoperative opioids such as remifentanil or morphine, as determined by the anesthesiologist.

Group 3 (Opioid-based anesthesia): Patients receive opioid-containing analgesia without the use of ESP or other truncal regional blocks.

All patients will receive standardized postoperative analgesia according to institutional guidelines, including intravenous morphine via patient-controlled analgesia (PCA), acetaminophen, and NSAIDs. Rescue analgesia will be provided as needed with intravenous morphine, acetaminophen, or tramadol.

Data will be collected regarding demographics, intraoperative hemodynamic parameters, anesthesia medications, intraoperative opioid and non-opioid consumption, urine output, depth of anesthesia (BIS), and surgery duration. Postoperative assessments will include pain scores (VAS and NRS at 0, 3, 6, 12, 24, and 48 hours), total opioid consumption, time to first analgesic request, patient satisfaction, postoperative complications, bowel function, mobilization time, urine output, vital signs, and length of stay. Complications will be classified using the Clavien-Dindo system to allow standardized comparison of postoperative morbidity across groups.

The primary objective of the study is to determine whether an opioid-free multimodal analgesia regimen provides effective postoperative pain control and reduces opioid requirements compared with opioid-containing strategies. Secondary objectives include evaluating the incidence of opioid-related adverse effects and the overall quality of recovery. By systematically comparing these three routinely used anesthetic approaches, the study aims to clarify the potential benefits of opioid-free anesthesia in lumbar spine surgery and support evidence-based perioperative analgesia strategies.

Interventions

• Drug Opioid-free Anesthesia
  A multimodal opioid-free anesthetic regimen including ESP block and agents such as acetaminophen, lidocaine, dexmedetomidine, ketamine, magnesium sulfate, and esmolol. No intraoperative opioids are given. Applies to Groups:Group 1 (Opioid-Free Anesthesia Group)
• Procedure Erector Spinae Plane Block
  Before surgery, after endotracheal intubation of the patient in the prone position, a bilateral ultrasound-guided erector spinae plane block was performed at the vertebral level above the surgical site, using 20 mL of 0.25% bupivacaine per side in the lumbar region." Applies to Groups: * Group 2 (for patients who receive ESP) * Group 3 (ESP + Opioid Group)
• Drug Opioid based Anesthesia
  Intraoperative opioid analgesia (e.g., remifentanil infusion and/or morphine) administered according to standard clinical practice. Applies to Groups: * Group 3 (ESP + Opioid Group) * Group 1 (Opioid-Based Anesthesia Group)
• Device Intraoperative ANI Monitoring
  The Analgesia Nociception Index (ANI) device is used intraoperatively to continuously assess autonomic nervous system responses to nociceptive stimuli. ANI values are recorded in all participants and compared across anesthetic cohorts for evaluation of intraoperative analgesic adequacy.
• Device Bispectral Index Monitoring
  Continuous intraoperative depth of anesthesia monitoring using the Bispectral Index (BIS) device. BIS values are recorded throughout the procedure to assist in titration of anesthetic agents and to standardize anesthesia depth across study cohorts. The BIS device is used for monitoring only, and no device-related investigational procedures are performed.

Primary outcome measures

• Postoperative Opioid Consumption in the First 48 Hours [Time frame: 0-48 hours after surgery]

Secondary outcome measures (12)

• Postoperative Pain Intensity Assessed by Numerical Rating Scale (NRS) [Time frame: 0, 3, 6, 12, 24, and 48 hours postoperatively]
• Incidence of Opioid-Related Adverse Effects [Time frame: 0-48 hours]
• Postoperative Complications According to the Clavien-Dindo Classification [Time frame: Within 30 days after surgery]
• Time to First Analgesic Request [Time frame: Postoperative period (assessed every 6 hours during the first 48 hours after arrival in the recovery unit)]
• Total Non-Opioid Analgesic Consumption [Time frame: 0-48 hours]
• Time to First Mobilization [Time frame: From the end of surgery until the first documented ambulation, assessed within the first 48 postoperative hours]
• Return of Bowel Function [Time frame: Time from the end of surgery to the first documented bowel movement, assessed within the first 48 postoperative hours]
• Intraoperative Heart Rate [Time frame: Intraoperative period]
• Patient Satisfaction Score [Time frame: At 48 hours postoperatively]
• Length of Post-operative Hospital Stay [Time frame: Length of postoperative hospital stay, defined as the time from the end of surgery to hospital discharge, assessed up to 30 days postoperatively]
• Intraoperative Analgesia Nociception Index (ANI) Values [Time frame: hroughout the intraoperative period]
• Intraoperative Blood Pressure [Time frame: Intraoperative Period]

Eligibility criteria

Inclusion criteria

• Adults aged 18 to 75 years
• Elective surgery only
• Scheduled for elective lumbar spinal surgery (lumbar spinal stenosis and/or lumbar disc herniation)
• ASA physical status I-III
• No previous lumbar spine surgery
• Able to provide written informed consent
• BIS monitoring available and recorded
• Ability to comply with postoperative pain assessment (NRS/VAS)
• Stable hemodynamic status preoperatively

Exclusion criteria

• Age younger than 18 or older than 75
• Inability or unwillingness to provide informed consent
• Severe psychiatric disease or cognitive impairment
• Emergency surgery cases
• BMI > 40 kg/m²
• Pregnancy
• Uncontrolled hypertension, arrhythmia, or severe cardiac disease
• Renal failure
• Chronic beta-blocker use
• Coagulation disorders
• Chronic alcohol dependence or substance use
• Neurological deficits affecting perception of pain
• Chronic pain syndrome (fibromyalgia, chronic LBP > 3 months)
• Chronic gabapentinoid use
• Anemia
• Known allergy to any anesthetic or analgesic agents used in the study
• Local infection at the intended ESP block injection site
• Intraoperative change in anesthetic technique that deviates from initial planned management
• Pediatric patients (<18 years)

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

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Turkey (Türkiye) · 1 center

• Marmara university hospital — Istanbul

Identifiers

NCT: NCT07489001 · 09.2025.403

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗