A COMPARATIVE CLINICAL STUDY OF INTRATHECAL ROPIVACAINE AND ROPIVACAINE-CLONIDINE COMBINATION FOR LOWER LIMB ORTHOPAEDIC SURGERIES

Ropivacaine is a promising drug for subarachnoid block because of its lower cardiotoxic and neurotoxic potential, but onset and duration of anaesthesia is also low and motor block is often insufficient which may lead to use of its higher doses. The aim of this randomized double-blinded study was to see whether the addition of small dose clonidine to small dose ropivacaine for spinal anesthesia prolonged the duration of postoperative analgesia while minimizing the side effects associated with higher doses of ropivacaine. We randomized 60 patients to 2 groups receiving intrathecal isobaric ropivacaine 18 mg (2.4 ml) combined with normal saline (Group R) or clonidine 30 μg (Group RC); all solutions were diluted with saline to 2.6 ml. We compared block characterstics, hemodynamic changes, post-operative analgesia and adverse effects of both the groups. Results showed that clonidine not only significantly reduced the onset time both of sensory and motor block, but also prolonged the duration. Hypotension and bradycardia was more with clonidine group during first hour. The addition of clonidine prolonged time to first analgesic request and decreased postoperative pain with minimal risk of delayed hypotension. Level of sedation and other side effects were comparable in both the groups. We concluded that addition of clonidine 30 μg to ropivacaine 18 mg produced an early and prolonged spinal anaesthesia and decrease the dose of post-operative analgesic requirement