Relative potencies of bupivacaine, levobupivacaine, and ropivacaine for neonatal spinal anaesthesia

– Comparing the relative potency of new local anaesthetics such as levobupivacaine and ropivacaine with bupivacaine by the minimum local analgesic concentration model has not been described for neonatal spinal anaesthesia. This information is important to compare agents and to determine the most effective spinal dose. Appropriate doses for infant spinal anaesthesia are 1 mg kg^–1 of isobaric 0.5% bupivacaine and ropivacaine and 1.2 mg kg^–1 of isobaric 0.5% levobupivacaine.