Prospective randomized, blind comparison of ropivacaine and levobupivacaine for superficial plexus anesthesia in carotid endoarterectomy.

Background. The authors performed a study to evaluate if the onset time, duration of sensory block, and quality of postoperative analgesia in superficial cervical plexus anesthesia with 0.5% levobupivacaine (1 mg/kg) was greater than 0.75% ropivacaine (1.5 mg/kg). Methods. Design: randomized, double-blind study. Setting: University teaching hospital. Participants: 28 consecutive patients undergoing elective carotid thromboendoarterectomy were randomized into two groups. Interventions: patients received either 1 mg/kg of 0.5% levobupivacaine (N.=15), or 1.5 mg/kg of 0.75% ropivacaine (N.=13). We assessed the onset time (pinprick test), duration of sensory block, and postoperative analgesia with the two drugs. Results. Onset time of sensory block was 20±6 min with ropivacaine and 29±8 min with levobupivacaine (P=0.003). Intraoperatively we used different total doses of lidocaine, with the median (interquartile range) dose of 50 (40-100) mg for ropivacaine and 130 (60-180) mg for levobupivacaine (P=0.05). The first pain medication was requested after 12±0.4 h by ropivacaine patients and after 11±1.6 h by levobupivacaine patients (P=0.5). Conclusion. No beneficial effect was noted in the quality of nerve block or patient's satisfaction for 0.5% levobupivacaine when compared to 0.75% ropivacaine.