Opioid Free and Opioid Based Anesthesia in Elective Lumbar Spine Surgery

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

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.

Study Overview

• Status: Recruiting
• Conditions: Lumbar Spinal Stenosis; Lumbar Disc Degeneration; Lumbar Degenerative Spondylolisthesis; Lumbar Disc Herniation With Radiculopathy
• Intervention / Treatment: Drug: Opioid based Anesthesia; Device: Intraoperative ANI Monitoring; Device: Bispectral Index Monitoring; Drug: Opioid-free Anesthesia; Procedure: Erector Spinae Plane Block

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.

• Study Type: Observational
• Enrollment (Estimated): 75

Contacts and Locations

• Study Contact: Name: Burcu Akyüz Irfanoğlu, MD; Phone Number: 900-555-725-9649; Email: brcakyz1@gmail.com
• Study Contact Backup: Name: Seniyye Ulgen zengin, MD; Phone Number: 900-505-714-2443; Email: ulgen_t@yahoo.com

Study Locations

• Turkey (Türkiye)
  • Maltepe
    • Istanbul, Maltepe, Turkey (Türkiye), 34722
      • Recruiting
      • Marmara University Hospital
      • Contact: BURCU Akyüz İrfanoğlu, MD; Phone Number: 900-505-714-2443; Email: brcakyz1@gmail.com
      • Contact: Seniyye Ulgen zengin, MD; Phone Number: 900-505-714-24-43; Email: ulgen_t@yahoo.com
      • Sub-Investigator: Meliha Orhon Ergün, MD
      • Sub-Investigator: Burcu Akyüz Irfanoğlu, MD
      • Principal Investigator: Seniyye Ulgen Zengin, MD

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Adult patients aged 18 to 75 years undergoing elective lumbar spine surgery for conditions such as lumbar spinal stenosis, lumbar disc herniation, degenerative spondylolisthesis, or lumbar disc degeneration at Marmara University Pendik Training and Research Hospital. All participants are surgical patients who meet the clinical indication for lumbar spinal procedures. No healthy volunteers are included. Patients are assigned to one of three observational cohorts based on the anesthesia technique chosen by the attending anesthesiologist in routine clinical practice.

Description

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)

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group 1- Opioid-Based Anesthesia Group; Patients receiving intraoperative opioid-based analgesia without ESP or other truncal regional anesthesia techniques.	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); Other Names: OBA; Conventional opioid anesthesia; 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.; Other Names: ANI; ANI monitoring; 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.; Other Names: BIS Monitoring; BIS
Group 2- Opioid-Free Anesthesia Group; Patients receiving opioid-free multimodal anesthesia, with or without ESP block, and non-opioid agents such as acetaminophen, lidocaine, ketamine, dexmedetomidine, magnesium sulfate, and esmolol.	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.; Other Names: ANI; ANI monitoring; 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.; Other Names: BIS Monitoring; BIS; 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); Other Names: OFA; 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); Other Names: ESPB; ESP; L-ESPB; L-ESP
Group 3- ESP Block + Opioid Group; Patients receiving ultrasound-guided erector spinae plane (ESP) block plus intraoperative opioid analgesia such as remifentanil or morphine.	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); Other Names: OBA; Conventional opioid anesthesia; 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.; Other Names: ANI; ANI monitoring; 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.; Other Names: BIS Monitoring; BIS; 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); Other Names: ESPB; ESP; L-ESPB; L-ESP

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Opioid Consumption in the First 48 Hours	Total cumulative opioid consumption (morphine equivalents) within the first 48 postoperative hours, recorded via intravenous patient-controlled analgesia (PCA) and rescue opioid boluses. This measure evaluates the analgesic effectiveness of opioid-free versus opioid-containing intraoperative anesthesia strategies.	0-48 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain Intensity Assessed by Numerical Rating Scale (NRS)	Pain intensity will be measured using the Numerical Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain). Assessments will be recorded at predefined postoperative time points.	0, 3, 6, 12, 24, and 48 hours postoperatively
Incidence of Opioid-Related Adverse Effects	Presence of nausea, vomiting, pruritus, constipation, urinary retention, sedation, and respiratory depression. Adverse effects will be compared among the three anesthesia groups.	0-48 hours
Postoperative Complications According to the Clavien-Dindo Classification	Postoperative complications will be graded according to the Clavien-Dindo classification system (Grade I-V). Any deviation from the normal postoperative course will be recorded and classified, and the highest Clavien-Dindo grade observed during the follow-up period will be used for analysis.Complications were prospectively recorded and classified according to the Clavien-Dindo classification.	Within 30 days after surgery
Time to First Analgesic Request	Time elapsed from arrival in the recovery unit to the first patient request for additional analgesia, with analgesic requests recorded at 6-hour intervals over a 48-hour postoperative period.	Postoperative period (assessed every 6 hours during the first 48 hours after arrival in the recovery unit)
Total Non-Opioid Analgesic Consumption	Total amount of non-opioid analgesics administered postoperatively (e.g., acetaminophen, NSAIDs), including rescue doses.	0-48 hours
Time to First Mobilization	Time from the end of surgery to the patient's first ambulation, as documented by the clinical team, measured in postoperative hours.	From the end of surgery until the first documented ambulation, assessed within the first 48 postoperative hours
Return of Bowel Function	Time to the first documented bowel movement measured in postoperative hours and the presence or absence of constipation during the postoperative period.	Time from the end of surgery to the first documented bowel movement, assessed within the first 48 postoperative hours
Intraoperative Heart Rate	Heart rate measured in beats per minute (bpm), recorded at predefined intraoperative intervals (baseline before induction, after induction, after intubation and every 30 minutes thereafter until the end of surgery).	Intraoperative period
Patient Satisfaction Score	Patient-reported satisfaction with postoperative analgesia evaluated on a 0-3 scale (poor, moderate, good, very good).	At 48 hours postoperatively
Length of Post-operative Hospital Stay	Total duration of postoperative hospitalization measured in days.	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	Analgesia Nociception Index (ANI) values recorded intraoperatively to assess autonomic response to nociceptive stimuli. ANI values will be compared between groups and correlated with intraoperative hemodynamic parameters and postoperative pain scores (NRS/VAS). This outcome evaluates the potential predictive value of ANI monitoring in differentiating analgesic effectiveness across anesthesia strategies.T	hroughout the intraoperative period
Intraoperative Blood Pressure	Systolic, diastolic, and mean arterial blood pressure measured in mmHg, recorded at predefined intraoperative intervals (baseline before induction,after induction, after intubation, and every 30 minutes thereafter until the end of surgery).	Intraoperative Period
Intraoperative Oxygenation and Ventilation Parameters	Oxygen saturation (SpO₂) and end-tidal carbon dioxide (ETCO₂) values recorded at predefined intraoperative intervals.	Intraoperative period
Intraoperative Bispectral Index (BIS) Values	BIS values recorded at predefined intraoperative intervals.(baseline before induction, after induction, after intubation, and every 30 minutes thereafter until the end of surgery).	Intraoperative period
Intraoperative Urine Output	Urine output measured in milliliters (mL) at predefined 30-minute intraoperative intervals following induction of anesthesia, as an indicator of intraoperative renal perfusion and fluid balance.	Intraoperative period (from induction of anesthesia, assessed every 30 minutes until the end of surgery)

Collaborators and Investigators

• Sponsor: Marmara University
• Investigators: Principal Investigator: burcu Akyüz irfanoğlu, MD, Marmara University Hospital; Study Chair: seniyye ülgen zengin, MD, Marmara University Hospital; Study Director: meliha orhon ergün, MD, Marmara University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 9, 2025
• Primary Completion (Estimated): December 9, 2026
• Study Completion (Estimated): December 10, 2026

Study Registration Dates

• First Submitted: December 11, 2025
• First Submitted That Met QC Criteria: March 18, 2026
• First Posted (Actual): March 23, 2026

Study Record Updates

• Last Update Posted (Actual): March 23, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Postoperative Pain; Regional Anesthesia; Opioid Consumption; Lumbar Spine Surgery; Erector Spinae Plane Block; ESP Block; Multimodal Analgesia; Opioid-Free Anesthesia; Opioid-Related Adverse Effects
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Bone Diseases; Musculoskeletal Diseases; Postoperative Complications; Pathologic Processes; Spinal Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Spinal Stenosis; Intervertebral Disc Degeneration
• Other Study ID Numbers: 09.2025.403

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared. The study involves clinical information collected under institutional ethical approval, and no consent was obtained for external sharing of identifiable or de-identified participant-level data.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes