Comparative study of 0.5 percentage hyperbaric levobupivacaine, 0.75 percentage hyperbaric ropivacaine and 0.5 percentage hyperbaric bupivacaine with fentanyl in subarachnoid block for lower limb surgeries.

Bupivacaine is the most commonly used intrathecal local anaesthetic ,but due to CNS and CVS toxicity associated with it lead to research of better alternatives for spinal anaesthesia. Studies have reported that hyperbaric 0.5% ropivacaine produce reliable subarachnoid block but of shorter duration than 0.5 % hyperbaric bupivacaine and 0.5 % hyperbaric levobupivacaine.A prospective randomized double blind study is planned to be conducted on 195 adult ASA grade I, II, III patients posted for lower limb surgeries under spinal anaesthesia after taking a written informed consent. Enrolled patients will be randomly divided into three equal groups to receive either   2.5ml of 0.5% hyperbaric levobupivacaine with , 2.5ml  of 0.75% hyperbaric ropivacaine and 2.5ml of 0.5% hyperbaric bupivacaine with 25µg fentanyl (total volume-3ml) in subarachnoid block. Patient will be observed for duration of sensory block, time of onset of sensory and motor block, maximum sensory level, time to achieve maximum sensory level, time to complete motor block, time required for complete motor regression, duration of analgesia and hemodynamic parameters. This study will help us to compare 0.5% hyperbaric levobupivacaine, 0.75% hyperbaric ropivacaine and 0.5% hyperbaric bupivacaine in combination with fentanyl in terms of clinical efficacy and safety profile for use in lower limb surgeries under subarachnoid block