Buffered versus plain lidocaine for digital nerve blocks

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

Randomized, double-blind, prospective clinical trial.

University hospital emergency department.

Adults not allergic to lidocaine requiring a digital nerve block.

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.

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.

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