Increasing the pH of lidocaine decreased pain on injection and augmented patient comfort and satisfaction.
Randomized trial of buffered versus plain lidocaine for local anaesthesia in open carpal tunnel decompression.
We performed a randomized double-blind case-control study in 64 consecutive patients undergoing open carpal tunnel decompression under local anaesthetic to assess the pain experienced on injection of plain lidocaine (pH 6.4) compared with lidocaine buffered with sodium bicarbonate (pH 7.4). The results showed no statistical difference in the pain scores reported by patients. The mean pain scores for all patients were low, and most patients reported that they were "not at all anxious" about receiving a similar injection in the future.