Spinal anaesthesia with articaine 5% vs bupivacaine 0.5% for day-case lower limb surgery: a double-blind randomized clinical trial

Background. A local anaesthetic with fast onset and short reliable duration of anaesthesia may be preferable for out-patient lower limb surgery. Articaine is believed to act faster and to have a shorter duration of action than bupivacaine, but there are no conclusive data available. The purpose of this study was to compare articaine and bupivacaine for day-case lower limb surgery. Methods. Eighty patients planned for day-case lower limb surgery enrolled in this study. Patients were randomized to receive hyperbaric articaine 80 mg or plain bupivacaine 15 mg intrathecally. Primary outcome variable was recovery time from motor block. Secondary outcomes were: onset of sensory and motor block, maximum spread of sensory block, time to micturition, discharge from the hospital, and complications. Results. The groups were comparable for the medians and the range of the maximum blocks after 30 min. Median time to complete regression of motor block was 101 min (range 80-129) for articaine compared with 307 min (range 225-350) for bupivacaine (P < 0.0005). First spontaneous micturition occurred after 257 min (210-293) in the articaine group and after 350 min (304-370) in the bupivacaine group (P < 0.0005). In the articaine and bupivacaine groups, patients were discharged after 300 min (273-347) and 380 min (332-431), respectively (P < 0.0005). There was no significant difference in the occurrence of complications between the groups. Conclusions. Spinal anaesthesia with 80 mg of hyperbaric articaine has a shorter duration than a spinal anaesthesia with 15 mg of plain bupivacaine in lower limb surgery of approximately 1 h duration