ABSTRACT
OBJECTIVE: This study compared the efficacy in terms of pain of injection, time of onset and duration of action of digital blocks of bupivacaine 0.5% alone and lidocaine 1% with epinephrine (1:100,000). METHODS: A randomised double-blind prospective study was performed in a single self-controlled group of 12 healthy volunteers (4 women, 8 men). Each participant was randomised to receive either lidocaine 1% with epinephrine (1:100,000) or bupivacaine 0.5% in either the right or left middle finger. Pain of injection was measured as the primary outcome using a 0-100 mm visual analogue scale. The time before anaesthesia to pinpricks was recorded and the duration of anaesthesia was reported by all volunteers. Statistical analysis was conducted using the non-parametric Wilcoxon signed rank test. RESULTS: Median visual analogue scale scores were significantly different between the lidocaine + epinephrine and bupivacaine groups (26.00 mm (4-52) vs 40.50 mm (10-71), p<0.05). The median time before anaesthesia to pinpricks was not significantly different between the two drugs (3.45 min (3-8) vs 3.30 min (3-8), p = 0.84). The median time needed for return of pinpricks was significantly different between the two drugs (321 min (228-463) vs 701 min (245-913), p<0.05). Follow-up was completed at 24 h. CONCLUSION: Lidocaine (1%) with epinephrine (1:100 000) was significantly less painful and had a shorter duration of action than bupivacaine (0.5%), which had a similar onset of action for digital nerve block. TRIAL REGISTRATION NUMBER: ISRCTN45121950.
