A Randomized Controlled Study of 0.5% Bupivacaine, 0.5% Ropivacaine and 0.75% Ropivacaine for Supraclavicular Brachial Plexus Block.

INTRODUCTION: For any surgery in the upper extremity that does not involve the shoulder, a supraclavicular block is preferred, as it is a safe procedure associated with rapid onset and reliable anaesthesia. Although ropivacaine has been extensively studied for epidural anaesthesia, very few reports exist on its use in supraclavicular brachial plexus block.

AIM: This study was conducted to investigate and compare the effectiveness of supraclavicular brachial plexus anaesthesia with two different concentrations of ropivacaine (0.5% and 0.75%) and to compare them with the standard 0.5% bupivacaine.

MATERIALS AND METHODS: Ninety patients of age 18 to 60 years belonging to American Society of Anaesthesiologists (ASA) status 1 or 2, admitted to Pondicherry Institute of Medical Sciences were chosen for the study and were divided into three groups. Group A received 30 ml of 0.5% bupivacaine, group B received 30 ml of 0.5% ropivacaine and group C received 30 ml of 0.75% ropivacaine into the supraclavicular region, by a nerve-stimulator technique. Onset time of each of the drug was recorded both for the sensory and motor block. Duration of sensory and motor block was recorded along with peri-operative haemodynamic monitoring.

RESULTS: The onset of complete sensory and motor block observed with both ropivacaine groups and bupivacaine was similar (16.85±6.67 min in group A, 17.79±5.03 min in group B and 18.48±6.14 in group C, p>0.05); onset of motor block (21.45±4.45 min in group A, 22.23±4.05 min in group B and 22.33±5.17 in group C, p < 0.05). The duration of sensory block with 0.5% bupivacaine was 11.58 hours, with 0.5% ropivacaine was 9.02 hours with 0.75% ropivacaine was 8.87 hours (p<0.001). The duration of motor block with 0.5% bupivacaine was 12.94 hours, with 0.5% ropivacaine was 8.29 hours with 0.75% ropivacaine was 7.89 hours (p<0.001). Multiple comparison test with Bonferroni correction showed there was statistically significant difference in mean duration of sensory block between Group A (0.5% bupivacaine) and Group B (0.5% ropivacaine) and also between Group A (0.5% bupivacaine) and Group C (0.75% ropivacaine). However, there were no statistically significant difference in mean duration of sensory block between Group B (0.5% ropivacaine) and Group C (0.75% ropivacaine). The preoperative, intra operative and postoperative heart rate, systolic & diastolic blood pressure and oxygen saturation were comparable among the three study groups (p>0.05). No side effects were recorded in the study.

CONCLUSION: The onset of sensory and motor block was similar in all the three groups. However, when compared to bupivacaine group, recovery of motor functions was faster in both the ropivacaine groups. Patients in all the 3 groups did not experience any adverse effects.