Comparison of 1% lignocaine with 0.5% bupivacaine in digital ring blocks

In a randomised double-blind trial comparing 1% lignocaine with 0.5% bupivacaine in digital ring block, the mean time of onset of complete anaesthesia was 5.8 minutes (range 5 to 10 minutes) for lignocaine and 11.2 minutes (range 8 to 20 minutes) for bupivacaine. The duration of action was 59.6 minutes (S.D. +/- 28.7 minutes) for lignocaine and 476 minutes (S.D. +/- 277 minutes) for bupivacaine. We describe how these differences can be exploited in clinical practice.