Cervical plexus anesthesia for carotid endarterectomy: comparison of ropivacaine and mepivacaine

Purpose: To evaluate the effectiveness of cervical plexus block performed with ropivacaine 0.75% or 1%, or mepivacaine 2%, Methods: In a prospective randomized, double-blind study, 60 patients received deep cervical plexus block with 0.2 ml.kg(-1) divided among C-2-C-4 injections using ropivacaine 0.75% and 1% or mepivacaine 2%, A blinded observer recorded loss of pin-prick sensation every minute in the C-2-C-4 dermatomes unlit readiness for surgery, Then, a superficial cervical block was performed with 0.15 ml.kg(-1) lidocaine 1%. The need for intraoperative supplemental analgesia and degree of pain and time of first postoperative pain medication were also recorded. Results: General anesthesia was not required to complete surgery in any case, No differences in the need for intraoperative supplemental analgesia was observed (7, 6, and 9 patients with ropivacaine 0.75% and 1% or mepivacaine 2%, respectively). Readiness to surgery required 15 (10 - 25) min with ropivacaine 0.75%, 18 (8 - 20) min with ropivacaine 1%, and 15 (5 - 20) min with mepivacaine 2% (P = NS); while patients asked for first postoperative pain medication after 10 (4 - 13) hr and 9 (6.5 - 11) hr with ropivacaine 0.75% and 1% compared with 5 (0 - 8) hr with mepivacaine 2% (P < 0.05), Conclusion: Ropivacaine 0.75% or 1% are appropriate choices when performing cervical plexus anesthesia for carotid endarterectomy, providing nerve block characteristics similar to those of mepivacaine 2%, but with the advantage of longer postoperative pain relief.