Addition of dexmedetomidine to ropivacaine for lower limb orthopaedic surgery under spinal anaesthesia to study its effect on block characteristics- An observational study

Abstract

Spinal anaesthesia provides faster onset, effective sensory and motor block, adequate muscle relaxation and profound analgesia simply by injecting a small amount of local anaesthetic drug directly into CSF in subarachnoid space. This present study was conducted to assess the efficacy of Dexmedetomidine as an adjuvant to Ropivacaine in terms of duration of sensory and motor block, post-operative analgesia and side effects in lower limb orthopedic surgeries.: This prospective study was done on 50 ASA I/II patients of age 18-60 years undergoing spinal anaesthesia for lower limb orthopaedic surgery. In this study patients received an intrathecal injection of 22.5 mg Ropivacaine (3ml Ropivacaine 0.75%) & 5μg dexmedetomidine i.e. 0.5 ml. Onset of sensory/motor block, duration of sensory/motor block, duration of analgesia and side effects were noted. Post-hoc bonferroni test was used for intercomparison of mean HR and MAP and significant difference was observed between them. The mean onset of Sensory Block was 3.51±0.50, mean Time to achieve maximum height of block (Minutes)was 10.63±0.59, Time to onset of regression at the level of L1 (minutes) was 187.45±22.61, mean Motor Block-Time to modified Bromage score 3 was 6.12±0.84 and Motor Block - Time to complete recovery (minutes) was 173.14±34.26. The mean Time to complete analgesia (in minutes) was 401.06±16.91 and mean Time to effective analgesia (in minutes) was 415.25±16.70. The present study concludes that addition of dexmedetomidine with Ropivacaine provides faster onset of sensory/motor block.