Controversies in Regional Anesthesia

1. Controversies in Regional Anesthesia R3 김 세 희

2. Two controversies in regional anesthesia • spinal lidocaine neurotoxicity • spinal hematoma

3. The spinal lidocaine controversy • Since 1993 : report of Transient radiculating back pain after single dose lidocaine. • Abandoning lidocaine single dose spinal anesthetic.

4. Transient neurologic symptom. • Dysthesia radiating into one or both buttocks and post. Leg. • With or without back pain, presenting after recovery from spinal anesthesia. • Greater than incisional pain. • Physical and diagnostic study : no abnormalities • Resolve with time or NSAID, trigger-point injections

5. Major risk factor of TNS • lidocaine ; disproportionately associated • positioning (sciatic stretch) ; relative risk 2.6 lithotomy, knee arthroscopy • ambulatory status ; 3.6 compared inpatient increased risk • obesity ;body mass index greater than 30 relative risk

6. Unrelated Factors • Concentration ; hyperbaric spinal lidocaine at 5,2,1,or 0.5% - same incidence of TNS • Dose : no link between TNS & wide range(<50mg to >75mg) of clinically relevant lidocaine dose, • Spinal adjuncts • Sex, age, surgical case length, spinal needle tip design, careless patient handling.

7. Speculative factor • unclear neurotoxicity • musculoskeletal straine • Other as-yet-undefined factors

8. Final recommendation • Avoid spinal lidocaine in position causing sciatic stretch (lithotomy, knee arthroscopy) • For ambulatory spinal anesthesia ( lithotomy position or knee arthroscopy), : low dose of bupivacaine(5-6mg) with fentanyl(10- 20 ug). • Continue use spinal lidocaine supine in position • If TNS dose occur : reassure the patient its temporary nature, NSAID, follow up if symptom persistent beyond 24hours or neurologic symptom.

9. The Low Molecular weight heparin controversy • The background of controversy • Anesthetic consideration • Guideline for treating patient. • Alternatives

10. The background • LMWH :thromboembolic prophylaxis inpatient surgery, with cancer, treatment of DVT • Inappropriate concurrent use and central neuraxis regional aneshthesia : worrisome incidence of spinal hematoma.

11. Anesthetic consideration • Pharmacology of Enoxaparin • Anesthetic risk factors • Diagnosis and treatment of spinal hematoma

12. Pharmacoloy of Enoxaparin • LMWH compound : enoxaparin, dalteparin • not alter routine tests pf coagulation (aPTT, PT, ACT) • half life 3-4hrs, antothrombotic activerty 12hrs, baseline levels returning at 24hrs.

13. Anesthetic risk factors • Central neuraxis during peak LMWH activity • Epidural catheter removal • Concurrent administration of antiplatelet(aspirin, NSAID,ticlopidine, clopidogrel), heparin, wafarin,dextran • Traumatic or prolonged attempts at needle placement. • Advanced patient age. • Renal failure • Coagulation disorder

14. Diagnostic and treatment • Diagnosis • local anesthetic block; recede more slowly • neurologic sign develop after block dissipated • median time-3days • progressive weakness, sensory changes, bowel or bladder symptoms. • Tx • rapid diagnosis and central neuraxis imaging • decompressive laminectomy (within 8hrs)

15. Guide line • Received LMWH • spinal or epidural anesthesia , diagnostic lumbar puncture : delay 12hrs, after 24hrs appropriate. • Epidural catheter and will receive LMWH • remove after 12-24hrs, after 2hrs delay : initial LMWH dose. • Receiving LMWH and indwelling epidural catheter. ; great risk of spinal hematoma. ; limit epidural infusion, short-acting local anesthetics, opioid alone. ; at least 12hr(conservatively 24hrs) from last LMWH – remove catheter.

16. Alternatives. • Combination of regional anesthesia and delayed LMWH ; regional anesthesia - reduced thromboembolic complication - improved postoperative analgesia - earlier mobilization and improved rehabilitation ; for TKR -spinal anestheisa & femoral nerve block, eliminating indwelling epicatheters. • Combination of intermittent compression stocking, low-dose wafarin, aspirin