Ropivacaine versus lidocaine in digital nerve blocks: a prospective study.

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.