An observational study in Lumbar Spinal Stenosis, Lumbar Disc Herniation With Radiculopathy and Lumbar Degenerative Spondylolisthesis, sponsored by Marmara University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-03-23.
Sponsored by Marmara University · Observational
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.
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.
458 studies on the registry are indexed under Spinal Stenosis; 105 are open to participants now.
This study's planned enrollment of 75 is below the median of 120 across 154 observational studies indexed under Spinal Stenosis.
Browse Spinal Stenosis studies →Marmara University is the lead sponsor of 599 studies on the registry; 138 are open to participants now.
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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.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients receiving intraoperative opioid-based analgesia without ESP or other truncal regional anesthesia techniques.
Drug: Opioid based Anesthesia · Device: Intraoperative ANI Monitoring · Device: Bispectral Index Monitoring
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.
Drug: Opioid-free Anesthesia · Procedure: Erector Spinae Plane Block · Device: Intraoperative ANI Monitoring · Device: Bispectral Index Monitoring
Patients receiving ultrasound-guided erector spinae plane (ESP) block plus intraoperative opioid analgesia such as remifentanil or morphine.
Procedure: Erector Spinae Plane Block · Drug: Opioid based Anesthesia · Device: Intraoperative ANI Monitoring · Device: Bispectral Index Monitoring
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)
Also known as: OFA
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)
Also known as: ESP, ESPB, L-ESPB, L-ESP
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)
Also known as: OBA, Conventional opioid anesthesia
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.
Also known as: ANI, ANI 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.
Also known as: BIS, BIS Monitoring
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.
Time frame: 0-48 hours after surgery
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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 frame: 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).
Time frame: Intraoperative period
Patient Satisfaction Score
Patient-reported satisfaction with postoperative analgesia evaluated on a 0-3 scale (poor, moderate, good, very good).
Time frame: At 48 hours postoperatively
Length of Post-operative Hospital Stay
Total duration of postoperative hospitalization measured in days.
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
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
Time frame: 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).
Time frame: Intraoperative Period
Intraoperative Oxygenation and Ventilation Parameters
Oxygen saturation (SpO₂) and end-tidal carbon dioxide (ETCO₂) values recorded at predefined intraoperative intervals.
Time frame: 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).
Time frame: 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.
Time frame: Intraoperative period (from induction of anesthesia, assessed every 30 minutes until the end of surgery)
Plan to share: No — 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.
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