What is the recommended approach to anesthesia and pain management for endoscopic spine surgery?

Anesthesia and Pain Management for Endoscopic Spine Surgery

For endoscopic spine surgery, use local anesthesia with conscious sedation as the primary anesthetic approach, combined with multimodal opioid-sparing analgesia including bilateral erector spinae plane (ESP) blocks, NSAIDs, acetaminophen, and adjunctive agents like ketamine or dexmedetomidine. 1, 2, 3

Anesthetic Approach

Primary Recommendation: Local Anesthesia with Conscious Sedation

• Local anesthesia with or without conscious sedation is safe and effective for endoscopic spine procedures, with 96% of patients reporting excellent to good postoperative satisfaction. 3
• This approach reduces the risk of major surgical and medical complications compared to general anesthesia, while slightly increasing minor medical complications. 3
• Length of hospital stay is shorter with local anesthesia compared to general anesthesia. 3
• Patients maintain the ability to provide neurological feedback during the procedure, enhancing safety. 3

When General Anesthesia is Required

If general anesthesia is necessary for patient or surgical factors, proceed with the multimodal pain management strategy below. 1

Multimodal Pain Management Protocol

Baseline Therapy for All Patients

• Scheduled acetaminophen 1g every 6 hours 1, 2
• NSAIDs or COX-2 inhibitors on a scheduled basis 1
• Gabapentinoids (gabapentin or pregabalin) started preoperatively and continued postoperatively to reduce pain scores, opioid consumption, and improve long-term functional outcomes 1

Regional Anesthesia: Erector Spinae Plane (ESP) Blocks

Bilateral ESP blocks at the appropriate thoracic level provide superior opioid-sparing analgesia for spine surgery. 2, 4, 5, 6

Technical Details:

• For lumbar/lumbosacral procedures: Perform bilateral ESP blocks at T10 or T12 level 4, 6
• For cervical procedures: Perform bilateral ESP blocks at T1 level 5
• Dosing: 15-20 mL of 0.25% bupivacaine per side, with optional addition of 8 mg dexamethasone 2, 5
• Timing: Perform after induction of general anesthesia (if used) and positioning 2, 5
• Single-injection vs. continuous: Either single-injection or continuous catheter techniques are effective 4

Evidence for ESP Blocks:

• ESP blocks eliminate or dramatically reduce postoperative opioid requirements in spine surgery 2, 4
• Intraoperative opioid consumption is reduced by approximately 60% (119.53 mcg vs. 308.6 mcg fentanyl equivalents) 5
• Postoperative pain scores are significantly lower throughout the recovery period 5, 6
• No interference with intraoperative neuromonitoring (somatosensory evoked potentials) 4
• No motor or sensory blockade that would impair neurological assessment 4
• Earlier mobilization (sitting/walking achieved 2-3 hours sooner) 5

Intraoperative Adjunctive Agents

Ketamine

• Low-dose ketamine infusion as a co-analgesic reduces postoperative pain and opioid requirements 1, 7, 2
• Particularly effective when combined with ESP blocks in an opioid-free regimen 2
• Monitor for emergence reactions and hemodynamic effects 7

Dexmedetomidine

• Dexmedetomidine infusion provides sedation and analgesia with opioid-sparing effects 1, 2
• Can be used as part of multimodal anesthesia during the procedure 2
• Caution: May cause bradycardia and hypotension; monitor vital signs closely 8

Intravenous Lidocaine

• Lidocaine infusion decreases intraoperative anesthetic requirements, lowers postoperative pain scores, reduces analgesic requirements, and improves return of bowel function 9
• Continue throughout the procedure; unclear benefit of postoperative continuation 9
• Critical safety requirement: Continuous ECG monitoring mandatory during infusion 9
• Watch for systemic toxicity symptoms: blurred vision, dizziness, tinnitus, perioral anesthesia, tongue paresthesia 9

Local Wound Infiltration

• Infiltrate surgical incision sites with long-acting local anesthetic (bupivacaine) for immediate postoperative pain relief 1
• This is particularly important if regional blocks are not performed 1

Postoperative Pain Management

PACU (Recovery Room):

• Intravenous fentanyl or short-acting opioid for breakthrough pain only 9
• Continue scheduled acetaminophen and NSAIDs 1

Ward Management:

• Continue scheduled acetaminophen and NSAIDs throughout the postoperative period 1
• Oral tramadol or other suitable opioid as rescue medication only 9
• Limit opioid prescriptions to no more than 7 days to minimize complications and addiction risk 1
• Baclofen 10 mg every 8 hours may be added for muscle spasm management 2
• Transition to oral medications as soon as possible 9

Critical Pitfalls and Caveats

Opioid-Related Concerns

• Preoperative opioid use of any dose is strongly associated with longer duration of postoperative opioid use and worse clinical outcomes 1
• Opioid tolerance and opioid-induced hyperalgesia may develop in as little as 4 weeks of therapy 9
• Up to 75% of people entering treatment for heroin addiction report their first opioids were prescription drugs 1
• Overreliance on opioids leads to respiratory depression, nausea, vomiting, delayed mobilization, and prolonged ileus 1

Regional Anesthesia Safety

• ESP blocks must be performed under ultrasound guidance for safety 9
• ESP blocks do not cause motor blockade or interfere with neurological assessment, making them ideal for spine surgery 4
• Unlike epidural analgesia (which is effective for open lumbar surgery but not feasible for cervical procedures), ESP blocks can be safely used at any spinal level 9, 2, 4, 5

Anticholinergic Use

• Do not administer anticholinergic agents simultaneously with or after dexmedetomidine, as this can cause secondary tachycardia, prolonged hypertension, and cardiac arrhythmias 8
• If needed, anticholinergics may be given at least 10 minutes before dexmedetomidine 8

Monitoring Requirements

• Regular pain score assessment using validated tools is essential to evaluate treatment response 1
• Maintain normothermia during and after surgery 9
• For patients receiving spinal morphine (if used), close monitoring for 24 hours is required due to risk of delayed respiratory depression 9

Algorithm Summary

Step 1: Consider local anesthesia with conscious sedation as first-line approach for endoscopic spine surgery 3

Step 2: If general anesthesia required, perform bilateral ESP blocks at appropriate level (T10-T12 for lumbar, T1 for cervical) with 15-20 mL 0.25% bupivacaine per side 2, 4, 5

Step 3: Administer baseline multimodal analgesia: scheduled acetaminophen, NSAIDs, and gabapentinoids 1

Step 4: Add intraoperative adjuncts: low-dose ketamine and/or dexmedetomidine infusions, consider IV lidocaine with continuous ECG monitoring 9, 1, 7, 2

Step 5: Perform local wound infiltration with long-acting local anesthetic 1

Step 6: Postoperatively, continue scheduled non-opioid analgesics, use short-acting opioids for breakthrough pain only, limit opioid duration to ≤7 days 1