To compare the efficacy and characteristics of equipotent doses of intrathecal levobupivacaine with ropivacaine.
Sixty ASA grade I/II patients of 18–60 years, either sex posted for lower limb orthopaedic surgery under spinal anaesthesia were randomly given either 15 mg levobupivacaine or 22.5 mg ropivacaine. Sensory and motor block, haemodynamic characteristics, as well as any side effects, were recorded.
Onset of sensory block to T10 was more rapid in group R than group L, p < 0.0001. The median (range) height achieved in group R was T7 (T5–T10) while in group L was T7 (T4–T10). Time to reach maximum height and time to modified Bromage grade 3 was shorter in group R as compared to group L, p < 0.0001. Levobupivacaine produced significantly longer (290.50 ± 34.67) duration of motor block compared to ropivacaine (222.50 ± 23.00). Duration of analgesia was significantly longer in group L (309.83 ± 36.45) than group R (249.50 ± 22.83). No serious adverse effects were recorded.
Levobupivacaine produces significantly longer duration of analgesia than ropivacaine when used in a ratio of 0.6:1. Efficacy, toxicity and haemodynamic profile make ropivacaine suitable agent for surgeries with low threshold for hypotension.