A comparative study of 0.5% levobupivacaine with 0.5% bupivacaine in epidural anaesthesia for lower abdominal and lower limb surgeries

Background: Spinal and epidural anaesthesia are regional anaesthesia methods that are widely used, especially in lower abdominal and lower extremity operations. Bupivacaine is the widely used local anaesthetic in regional anaesthesia. Stereoisomers of the agent are being developed for use instead of the isomers, in order to avoid the toxic side effects of local anaesthetic agent. Bupivacaine is available in a commercial preparation as a racemic mixture (50:50) of its two enantiomers, Levo-Bupivacaine, S (-) isomer and Dextro-Bupivacaine, R (+) isomer. Several central nervous system and cardiovascular adverse reactions reported in the literature have been linked to the R (+) isomer of Bupivacaine. Aim : To evaluate the clinical efficacy of 0.5% Levobupivacaine with 0.5% Bupivacaine in epidural anaesthesia without adjuvant medication in patients undergoing elective for lower abdominal and lower limb surgeries with respect to onset of action of sensory block, duration of analgesia, onset of action and duration of motor block, hemodynamic changes and side effects. Materials and Methods: A prospective randomized clinical trial on 100 patients aged between 18-60 years scheduled for elective lower abdominal or lower limb surgery under epidural anesthesia belonging to ASA grade I and II were included in this study. All patients were randomly allocated into two groups. Group B (n=50) patients receiving 0.5% isobaric Bupivacaine 17 ml. Group L (n=50) patients receiving 0.5% isobaric Levobupivacaine 17ml. Following parameters observed - onset time of sensory block, highest level of sensory block, duration of sensory block, duration of sensory analgesia, onset time of motor block, degree of motor block, duration of motor block, hemodynamic changes and side effects such as hypotension, bradycardia, nausea, vomiting. Results: Both groups are comparable with respect to age, sex, weight and duration of surgery. Group-L has similar onset time of sensory block and highest level of sensory block reached as compared to Group-B. Group-L has a longer duration of sensory block as compared to Group-B. Mean Time to two segment regression / Duration of sensory block in Group-L being 132.46 minutes and Group-B being 89.28 minutes. P-value=0.000. Group-L has longer duration of sensory analgesia as compared to Group-B. Mean Time of sensory analgesia in block in Group-L is 326.5 min and in Group-B is 284.42 min. P-value= 0.000. Group-L has a slower onset of motor block as compared to Group-B. Mean Time to onset of motor block in Group-L is 19.6 min and in Group-B is 17.74 min. P-value= 0.000. Group-L has shorter duration of motor block as compared to Group-B .Mean Duration of motor block in Group-L is 197.4 min and in Group-B is 203.3 min. P-value= 0.017. Group L has similar degree of motor blockade as compared to Group B. No statistical difference was found between Group-L and Group-B with respect to variability in systolic blood pressure, diastolic blood pressure, heart rate and oxygen saturation at various time intervals. Conclusion: Levobupivacaine has a similar onset time and longer duration of sensory blockade and slower onset and shorter duration of motor blockade, with comparable quality of analgesia and hemodynamic parameters as compared with Bupivacaine. Owing to its better safety profile, Levobupivacaine is a good alternative to Bupivacaine.