Lumbar Degenerative Diseases, Postoperative Acute Pain
Conditions
Keywords
Liposomal bupivacaine, Local infiltration analgesia, Posterior lumbar fusion, Postoperative pain, Randomized controlled trial, Opioid-sparing
Brief summary
Spine surgery often causes severe postoperative pain. Currently, our hospital routinely uses ropivacaine for local infiltration analgesia (lasting 6-8 hours). This study evaluates liposomal bupivacaine, a novel long-acting local anesthetic providing up to 72 hours of pain relief, in patients undergoing posterior lumbar spine surgery. Through a randomized controlled design, we will compare the two drugs' effects on pain control within 72 hours and opioid consumption. Both regimens are guideline-recommended and safe.
Interventions
DRUGLiposomal bupivacaine (local infiltration)
Patients will receive a pre-closure local infiltration of 266 mg liposomal bupivacaine (20 mL for single-level surgery; 30 mL for two-level surgery) combined with 25 mg bupivacaine hydrochloride (10 mL total volume). The drug will be injected bilateral into the paraspinal muscles and subcutaneous tissues prior to wound closure. This provides both immediate (bupivacaine HCl) and prolonged (liposomal) analgesia."
Patients will receive 120 mg ropivacaine diluted to 30 mL (single-level) or 40 mL (two-level) with normal saline. The solution will be infiltrated bilateral into the paraspinal muscles and subcutaneous tissues using the same technique as the experimental arm, ensuring consistent injection depth and distribution.
Sponsors
Min Li
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
All personnel responsible for short-term and long-term postoperative follow-up, completion of clinical observation forms, and data entry/verification are excluded from patient recruitment, randomization, and anesthesia management. These personnel remain blinded to patient group allocation and are prohibited from communicating with the study coordinator regarding any group assignment information.Statistical analysis is performed by dedicated statisticians not involved in clinical anesthesia procedures.Both patients and their family members remain blinded to group allocation throughout the study.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥18 years； * ASA physical status class I-III； * Scheduled for elective 1- or 2-level posterior lumbar surgery: Decompression (laminectomy/discectomy) and fusion with internal fixation
Exclusion criteria
* Chronic pain disorders requiring ≥30 mg oral morphine equivalents/day for \>3 months. * Pre-existing neurological deficits that may interfere with pain assessment. * Hypersensitivity to any component of multimodal analgesia or local anesthetics (e.g., bupivacaine, ropivacaine). * Acute systemic/local infection (e.g., surgical site infection, sepsis). * Metastatic spinal malignancies (confirmed by imaging/histopathology). * Pregnancy or lactation. * Patient refusal after detailed protocol explanation. * Other investigator-determined high-risk conditions.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total opioid consumption within 72 hours postoperatively (converted to morphine milligram equivalents, MME) | 72 hours postoperative | Opioid doses will be converted to MME using the CDC standard conversion table |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative pain intensity assessed by Numeric Rating Scale (NRS, 0-10) at rest and during movement (e.g., coughing/ambulation) at predefined timepoints: pre-PACU discharge, 4h, 8h, 24h, 48h, and 72h after surgery. | Immediately prior to PACU discharge，4 hours, 8 hours, 24 hours, 48 hours, and 72 hours after surgery. | NRS ranges from 0 (no pain) to 10 (worst imaginable pain). Movement-associated pain will be assessed during standardized activities (e.g., coughing on command or first ambulation).All assessors will be trained to ensure consistent NRS measurement across timepoints. Daytime assessments: Performed within ±30 minutes of scheduled timepoints Nighttime adjustments: Assessments falling between 21:00 (9:00 PM) and 07:00 (7:00 AM) will be deferred to 08:00 AM the following morning to avoid sleep disruption. Original timepoints documented with annotations (e.g., "Scheduled: 02:00; Assessed: 08:00+1") |
| Total postoperative morphine consumption via PCA | Cumulative consumption recorded at 4 hours, 8 hours, 24 hours, 48 hours, and 72 hours after surgery | PCA settings will be standardized across all patients: * Bolus dose: 1 mg morphine equivalent * Lockout interval:10 minutes * No background infusion. |
| Total Postoperative Rescue Tramadol Consumption | From PCA initiation until 72 hours (Day3) postoperatively. Rescue tramadol consumption will be recorded at 4hours, 8hour, 24hours, 48hours, 72hours after surgery. | Trigger Criteria: NRS \>3 at rest despite PCA morphine (1mg bolus, 10min lockout). Dosing Protocol: Tramadol 50mg IV/oral Data Collection: Cumulative tramadol consumption recorded at 4hours, 8hour, 24hours, 48hours, 72hours after surgery. Convert oral to IV equivalent for analysis |
| Sleep disturbance due to pain (binary scale) | Postoperative Days 1 (24 hours), 2 (48 hours), and 3 (72 hours), with daily assessment window: 8:00-9:00 AM | Patients will report whether pain interfered with sleep during the previous night using a standardized binary scale: * 0: No sleep disruption (pain did not awaken or prevent sleep) * 1: Sleep disrupted (pain caused awakening or difficulty falling asleep). Assessment Protocol: Evaluated each morning at 8:00 AM by trained research staff Covers sleep quality during the preceding night (20:00-07:59) Delayed assessment for nighttime surgeries: If surgery ends after 18:00, first assessment deferred to 8:00 AM on postoperative Day 1 |
| Time to first independent ambulation | From surgery completion until event occurs, assessed up to 72 hours postoperatively | Definition: Hours from surgery end to first unassisted walking \>5 meters |
| Immediate local anesthetic-related complications (0-2 hours) | From local anesthetic infiltration completion through 2 hours post-procedure. | All complications will be recorded and graded. Immediate events (0-2h): * Local anesthetic systemic toxicity (LAST): CNS/CV symptoms (e.g., seizures, arrhythmias) * Allergic reactions: urticaria, bronchospasm, anaphylaxis |
| Incidence of nausea/vomiting (PONV) | From surgery completion through 72 hours (Day 3) postoperatively, with interval reporting: 0-24 hours (Day 1), 24-48 hours (Day 2), 48-72 hours (Day 3). | Graded by severity: 1=Mild (no rescue), 2=Moderate (required 1 antiemetic), 3=Severe (≥2 antiemetics or prolonged NPO). Standardized Assessment Protocol at fixed timepoints: Day 1: 0-24 hours postoperatively Day 2: 24-48 hours postoperatively Day 3: 48-72 hours postoperatively Assessment window: Performed daily at 08:00 AM for previous 24-hour period Evening surgeries (end time \>18:00): First assessment at 08:00 AM on Day 1 Symptom tracking: Nursing staff document all emetic episodes and antiemetic administrations in real-time |
| Pruritus severity | From surgery completion through 72 hours (Day 3) postoperatively, with interval analyses: 0-24 hours (Day 1)，24-48 hours (Day 2)，48-72 hours (Day 3) | Rated by patients: 0=None, 1=Mild (no treatment), 2=Moderate (topical therapy), 3=Severe (systemic treatment). |
| Incidence of Postoperative Urinary Retention Requiring Catheterization | From surgery completion through 72 hours (Day 3) postoperatively, with planned intervals: 0-24 hours (Day 1), 24-48 hours (Day 2), 48-72 hours (Day 3). | Definition \& Assessment Protocol: Diagnostic Criteria: Bladder volume ≥600 mL (ultrasound-confirmed) + inability to void spontaneously. Catheterization threshold: Pain (VAS ≥4) with bladder volume ≥600 mL, OR No voiding for 8 hours + bladder volume ≥400 mL. Data Collection: Event-driven assessments: Triggered by patient-reported symptoms. Maximum observation period: 72 hours (Day 3). |
| Postoperative Sedation Levels Assessed by Ramsay Scale | From anesthesia emergence until 72 hours postoperatively, at Fixed timepoints: 4 hours, 8 hours, 24 hours, 48 hours and 72 hours after surgery. | Ramsay Scale: 1. Patient anxious/agitated 2. Cooperative/oriented 3. Responds to commands only 4. Asleep but brisk response to stimulus 5. Sluggish response 6. No response. Scoring Direction: Higher scores indicate deeper sedation (1=inadequate, 6=excessive). Clinical Thresholds: Target range: RSS 2-4 (ERAS-recommended optimal sedation) Intervention triggers: RSS ≥5 (reduce sedation), RSS ≤1 (rescue analgesia) Assessment Protocol Fixed Timepoints: 4 hours (Postoperative Day 0) 8 hours (Postoperative Day 0) 24 hours (Postoperative Day 1) 48 hours (Postoperative Day 2) 72 hours (Postoperative Day 3) Nighttime Adjustment: Assessments between 21:00-07:00 deferred to 08:00 next morning Data Collection Window: ±30 minutes at each timepoint Standardized Stimuli: Verbal: "Open your eyes" at 70 dB Tactile: Shoulder shaking with 500g pressure |
| Incidence of Postoperative Delirium Assessed by 3D-CAM (3-Minute Diagnostic Interview for CAM-Defined Delirium) | From anesthesia emergence through 72 hours postoperatively: Primary Assessment Points: 24 hours (Postoperative Day 1) 48 hours (Postoperative Day 2) 72 hours (Postoperative Day 3) | 3D-CAM assesses: 1) Acute onset, 2) Inattention, 3) Disorganized thinking, 4) Altered consciousness. Administered by trained research assistants blinded to group allocation. Primary Assessment Points: 24 hours (Postoperative Day 1) 48 hours (Postoperative Day 2) 72 hours (Postoperative Day 3) Evaluation Window: ± 30 min at each timepoint. Nighttime detections (21:00-07:00) formally assessed at 08:00 next morning |
| PCA demand attempts | Counted over consecutive intervals: 0-4 hours, 4-8 hours, 8-24 hours, 24-48 hours, and 48-72 hours postoperatively | Unit of Measure: Number of attempts |
| PCA delivery/demand ratio | Calculated for each interval: 0-4hours, 4-8hours, 8-24hours, 24-48hhours, 48-72hours after surgery. | Calculation: (Number of successful PCA deliveries / Number of PCA demand attempts) × 100 |
| Time to first PCA attempt | Recorded from end of surgery until first PCA button press | — |
| Time to first tolerated oral intake | From PACU discharge until event occurs, assessed up to 48 hours postoperatively | Definition: Hours from surgery end to first clear liquid intake (≥50 mL) without vomiting within 30 minutes |
| Time to first bowel movement | From surgery completion until event occurs, assessed up to 7 days postoperatively | Definition: Hours from surgery end to first flatus or defecation reported by patient |
| Postoperative length of stay | From surgery completion until discharge, assessed up to 14 days postoperatively | Definition: Days from surgery end to hospital discharge (excluding preoperative days) |
| Delayed local anesthetic-related complications (24-72 hours) | Any clinical suspicion triggers immediate evaluation from 24 hours (Day 1) through 72 hours (Day 3) postoperatively | Definition: Complications manifesting 24-72 hours postoperatively Subcategories: 1.Wound Complications: 1. Infection: CDC criteria (purulent drainage + ≥1: erythema, pain, swelling) 2. Hematoma: Ultrasound-confirmed collection \>5 mL + hemoglobin drop ≥1 g/dL 3. Neurological Injury 2.Persistent deficit: Sensory/motor dysfunction beyond 72 hours Confirmed by: Day 3: Nerve conduction studies (amplitude reduction \>50%). Day 7: EMG if symptoms persist Assessment Schedule: Fixed timepoints: 24h (Day 1), 48h (Day 2), 72h (Day 3) at 08:00 AM Symptom-driven: Any clinical suspicion triggers immediate evaluation |
Countries
China
Contacts
PRINCIPAL_INVESTIGATORMin Li
Peking University Third Hospital
Outcome results
None listed