The effect of buffered lidocaine in local anesthesia: a prospective, randomized, double-blind study.

PURPOSE: Open carpal tunnel decompression under local anesthesia is routinely done by many surgeons. However, patients complain of pain during the injection of local anesthesia. This prospective, double-blind, randomized study was to compare the pain visual analog scale (VAS) scores of local anesthesia using lidocaine with and without sodium bicarbonate in patients with bilateral carpal tunnel syndrome.

METHODS

Twenty-five patients underwent bilateral simultaneous carpal tunnel decompression. All had topical anesthetic cream applied on the palm and wrist before the lidocaine block. In a randomized manner, half of the hands were blocked with nonbuffered lidocaine and half were blocked with buffered lidocaine. Pain was evaluated on a VAS score.

RESULTS

The mean pain VAS score in the hand with buffered lidocaine was 4.6 ± 1.5 and 6.5 ± 1.5 for the hand with nonbuffered lidocaine. After adjustment for individual threshold of the pain, the mean pain VAS score changed into 4.6 ± 1.3 with buffered lidocaine and 6.6 ± 1.7 without buffered lidocaine.

CONCLUSIONS

In open carpal tunnel surgery, the use of buffered lidocaine for local anesthesia reduces the anesthetic pain effectively.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.