Comparison of 0.5% Bupivacaine and 0.5% Ropivacaine epidurally in lower limb orthopaedic surgeries

Abstract

INTRODUCTIONThe recognition of acute life-threatening cardiotoxicity of bupivacaine lead to the search for a local anaesthetic agent comparable with bupivacaine but with lower cardiotoxicity resulting in development of a relatively new amide, ropivacaine. Ropivacaine is produced as pure 'S' enantiomer with lower lipid solubility, easier reversibility after inadvertent intravascular injection, significant reduction in central nervous system toxicity, lesser motor block and greater differentiation of sensory and motor block. 1,2,3 In equi-potent concentrations the degree of motor blockade is less pronounced with ropivacaine, and there is a greater propensity for blocking pain transmitting A-delta and C fibres rather than A-α motor fibres. Ropivacaine has enormous potential as a local anaesthetic agent. 4,5,6 It appears to have most of the blocking characteristics of bupivacaine. These findings created interest to study this new anaesthetic agent for block characteristics and safety profile and to compare this drug with commonly used drug bupivacaine and to know whether it can replace this older anaesthetic agent in future. So we have undertaken the study to compare ropivacaine 0.5% (20ml) and bupivacaine 0.5% (20ml) for epidural anaesthesia in patients undergoing lower limb orthopaedic surgeries. METHODSA randomized prospective clinical study of patients undergoing elective lower limb orthopaedic surgeries receiving either epidural ropivacaine or bupivacaine was undertaken after obtaining written informed consent and institutional approval. Sixty patients divided into two groups of 30 each by computer generated random number, Group R to receive 20 ml of 0.5% ropivacaine ABSTRACT Background: Ropivacaine in equi-potent concentrations with bupivacaine, the degree of motor blockade is less pronounced with ropivacaine, and there is a greater propensity for blocking pain transmitting A-delta and C fibres rather than A-α motor fibres. It appears to have most of the blocking characteristics of bupivacaine. So we have undertaken the study to compare ropivacaine 0.5% (20ml) and bupivacaine 0.5% (20ml) for epidural anaesthesia in patients undergoing lower limb orthopaedic surgeries. Methods: This double-blind, randomized study involves 60 patients who were undergone orthopaedic surgery, having ASA-I or ASA-II physical status. Out of 60, 30 patients received 20 ml of 0.5% ropivacaine and 30 patients received 20 ml of 0.5% bupivacaine at the L3, 4 interspace. Parameters measured were the onset time, duration and spread of sensory block, the onset time, peak time, duration and degree of motor block, the quality of anaesthesia and the heart rate and blood pressure profile during block onset. Results: Epidurally, Ropivacaine in comparison to Bupivacaine provides quicker onset, early peak effect and prolonged duration of sensory block and shorter duration of motor block. Ropivacaine provides prolonged effective analgesia. It reduces requirement of rescue analgesics and related side effects. Conclusions: Ropivacaine 0.5% is safer a...