A Comparative Study of Intrathecal 0.5% Hyperbaric Bupivacaine & Intrathecal 0.75% Isobaric Ropivacaine in Lower Abdominal Surgeries

BACKGROUNDRopivacaine, a long acting amide local anaesthetic, has reduced potential for neurotoxicity and cardiotoxicity and is considered to block sensory nerves to a greater degree than motor nerves.In today's world, faster recovery along with minimal side effects and early ambulation after surgeries under spinal anaesthesia are very important.So, this prospective randomized study was aimed at evaluating and comparing the efficacy and safety of intrathecally injected isobaric ropivacaine and intrathecally injected hyperbaric bupivacaine in patients posted for lower abdominal surgeries under spinal anaesthesia. METHODS90 patients belonging to ASA physical status I & II scheduled for lower abdomen surgeries were randomly selected for the study and were divided into two groups of 45 each.Group B received 3 ml of 0.5% hyperbaric (15 mg) bupivacaine intrathecally.Group R received 3 ml of 0.75% isobaric (22.5 mg) ropivacaine intrathecally.Onset and extent of sensory block, onset and duration of motor block, maximum height of sensory block, duration of analgesia, hemodynamic parameters and adverse effects if any were studied.SPSS 20.0 and GraphPad Prism 6.0 were used for the analysis of the data. RESULTSThe mean time for onset of sensory block was significantly faster in group B as compared to group R (8.28±2.2min v/s 7.98±2.2min).There was no significant difference between the groups regarding the time for two segment regression.Mean time of onset of motor block was significantly faster in group B. The mean duration of motor blockade was 146.89±14.11min in group R and 208.91±14.62min in group B. The mean duration of analgesia was comparable in both the groups.Hemodynamic parameters and side effects were comparable in both the groups.CONCLUSIONS 0.75% isobaric ropivacaine provided similar duration of analgesia with a shorter duration of motor block as compared to hyperbaric 0.5% bupivacaine and it also provided adequate level of sensory block for the surgery with minimal intraoperative and postoperative side effects and stable haemodynamics throughout the surgery.