Ropivacaine versus Lidocaine in Digital Nerve Blocks: A Prospective Study

Abstract

Ropivacaine is a relatively new long-acting amide local anesthetic. Since its introduction in 1996, it has been used for subcutaneous infiltration; epidural, intrathecal, and peripheral nerve block surgery; and postoperative analgesia. However, it has never been used for digital blocks. This prospective, randomized, double-blind study compares the digital block results following the administration of 2.5 ml of 0.75% ropivacaine solution and 2.5 ml of 2% lidocaine solution. From March of 1999 to March of 2001, 70 adult patients who underwent immediate reconstruction for traumatic injuries of the digits were prospectively randomized into two groups. Group A (n = 35) received 2.5 ml 0.75% ropivacaine and group B (n = 35) received 2.5 ml of 2% lidocaine for digital anesthesia. Onset time of anesthetic action, duration of anesthesia, time until first postoperative requirement for pain medication, and digital-brachial artery systolic blood pressure index were recorded and evaluated. Local vascular effects were observed visually. No side effects were observed. Lidocaine had the quickest onset of anesthesia, with a mean time of 1.3 minutes (range, 1 to 2.7 minutes). Ropivacaine had a mean onset time of 4.5 minutes (range, 3.5 to 5.5 minutes). The mean duration of postoperative anesthesia for lidocaine was 2.4 hours (range, 1.4 to 4 hours), compared with 21.5 hours for ropivacaine and less requirement for analgesics during the first 24 postoperative hours (p < 0.05) (range, 19 to 23 hours). No significant difference was found between the digital-brachial artery systolic blood pressure index of group A compared with group B. Ropivacaine can be used effectively as a local anesthetic for digital nerve blocks. It can be used for prolonged operations (>1.5 hours) without additional injections and can provide long-lasting postoperative analgesia.