Buffered versus plain lidocaine for digital nerve blocks.

STUDY OBJECTIVES: To test whether buffered lidocaine is less painful to administer as a digital nerve block than plain lidocaine.

DESIGN: Randomized, double-blind, prospective clinical trial.

SETTING: University hospital emergency department.

PARTICIPANTS: Adults not allergic to lidocaine requiring a digital nerve block.

INTERVENTIONS: Subjects received digital nerve blocks by injection of buffered lidocaine on one side and plain lidocaine on the other in a predetermined, randomized order. Pain of infiltration was assessed. Scores were compared using a two-tailed t-test. Standard 1% lidocaine was used if additional anesthetic was required.

MEASUREMENTS AND MAIN RESULTS: Thirty-one patients were enrolled. Buffered lidocaine was significantly less painful to administer than plain lidocaine (P < .001; t = 4.21). Supplemental anesthesia was required less often for buffered lidocaine (two times) compared with plain lidocaine (six times), although this difference was not statistically significant.

CONCLUSION: Because it causes less pain and is equally efficacious, buffered lidocaine is preferable to plain lidocaine for digital nerve blocks in adults.