A COMPARATIVE STUDY OF INTRATHECAL HYPERBARIC BUPIVACAINE 0.5% & INTRATHECAL ISOBARIC ROPIVACAINE 0.5% FOR QUALITY AND DURATION OF ANAESTHESIA AND POST - OPERATIVE ANALGESIA IN PATIENTS UNDERGOING LOWER LIMB SURGERIES

Abstract

BACKGROUND: Spinal anaesthesia is the standard technique for lower limb surgeries. Ropivacaine, a long acting amide type of local anaesthetic reduces potential toxicity, improves relative sensory and motor blockade and has higher threshold for cardiotoxicity and neurotoxicity. AIM: To compare the efficacy and advantages of isobaric Ropivacaine over hyperbaric Bupivacaine. DESIGN: Randomized double-blinded trial. METHODS: Sixty patients were randomly allocated to receive intrathecally either 3ml of 0.5% hyperbaric bupivacaine (Group C) or 3ml of 0.5% isobaric ropivacaine (Group B). RESULTS: Both the groups were demographically statistically insignificant. Onset of sensory block at L1 (p=0.000) and the median time of onset of sensory block at T10 (p<0.01) was statistically significant. Group B achieved lower levels of peak sensory block compared to group C (p<0.0001). The time taken to achieve maximum motor blockade (group B 9±2.03 min and group C 5±1.55 min) and the time of onset of maximum motor block were delayed with group B compared to group C (p=0.000). The mean duration of analgesia (p<0.05) and the mean duration of motor blockade (p<0.05), return of Bromage to zero (P=0.000) with group B was less when compared to group C and was statistically significant. CONCLUSION: Isobaric Ropivacaine 0.5% (study group B) provides lesser grade of motor blockade and shorter duration of both sensory and motor blockade for short duration orthopaedic surgeries where prolonged motor blockade is quite undesirable and early mobilization can be planned.