A Comparative Study of Intrathecal Isobaric (0.75%) Ropivacaine with Isobaric (0.5%) Bupivacaine for Elective Lower Abdominal/limb Surgeries – A Clinical Study

Objective: To compare the clinical effects of 2.2ml of 0.75% intrathecal isobaric Ropivacaine with 2.2ml of 0.5% isobaric Bupivacaine for elective lower abdominal/limb surgeries. Materials and methods: A prospective randomized controlled double blind study. 60 patients were randomly selected for the study and are divided into two groups of 30 each. Group B patients received 2.2ml of 0.5% isobaric Bupivacaine intrathecally. Group R patients received 2.2ml of 0.75% isobaric Ropivacaine intrathecally. Onset, maximum level and duration of sensory block. Onset and maximum duration of motor block, hemodynamic parameters and adverse effects if any were studied. Results: There was significant difference between the two groups in mean time to onset of sensory block at L1, 158.40±41.89sec with Bupivacaine and 174.00±44.12sec with Ropivacaine, (P 0.073+). Maximum sensory height attained was comparable in both the groups being T8. Total duration of sensory block was 182.67±20.29 min in group B and 190.33±9.3min in group R, which is significant.(P). Mean time of onset of complete motor block was 3 min in group B and 10-15 min group R (p<0.001). Duration of motor block was 218.50±19.17min in group B and 149.00±3.81 min in group R which is clinically and statistically significant (P<0.001). Hemodynamic parameters and side effects were comparable in both groups. Conclusion: Ropivacaine 16.5 mg (2.2 ml of 0.75% isobaric Ropivacaine) provides comparable quality of sensory block but has slower onset and significantly shorter duration of motor block and better hemodynamic stability compared to Bupivacaine.