The Comparison of Two Different Volumes of 0.5% Ropivacaine in Ultrasound-Guided Supraclavicular Brachial Plexus Block Onset and Duration of Analgesia for Upper Limb Surgery: A Randomized Controlled Study

BACKGROUND: The study is based on the fact that a lower volume of local anesthetic drugs for ultrasound-guided supraclavicular brachial plexus block is useful for upper limb surgeries lasting for a shorter duration, and result in a lower incidence of complications. AIM: The aim of this study is to compare the effectiveness of 35 mL of 0.5% ropivacaine with 20 mL of 0.5% ropivacaine in ultrasound-guided supraclavicular brachial plexus block for upper limb surgery. SETTING: Patients undergoing upper limb surgery in an industry-based government hospital in New Delhi, India. Patients were followed in the operation theater and the recovery room. DESIGN: The study design involves a prospective, double-blind, randomized controlled trial. MATERIALS AND METHODS: A total of 40 participants were recruited for this study. Twenty participants in each group (referred to as group 20 and 30) received 20 mL and 35 mL of 0.5% ropivacaine, respectively, in ultrasound-guided supraclavicular brachial plexus block. STATISTICAL ANALYSIS: The statistical analysis was performed using the software SPSS version 15 and a value of P < 0.05% was considered statistically significant. The statistical tests used included Student's t-test to compare values between the two groups for the mean of parametric data, Mann–Whitney U-test for a median of nonparametric data, and Chi-square test or Fisher's exact test for the categorical data. RESULTS: The sensory and motor block onset in group 20 was 18.06 ± 3.04 and 23.89 ± 2.14 min, respectively. The sensory and motor block onset in group 30 was 17 ± 2.01 and 23.75 ± 2.22 min, respectively. The duration of analgesia in group 20 and 30 was 575.56 ± 104.39 and 730.75 ± 102.09 min, respectively (P < 0.001). CONCLUSION: The onset of sensory and motor block of 20 mL of 0.5% ropivacaine is comparable to 35 mL of 0.5% ropivacaine for supraclavicular brachial plexus block for upper limb surgery. There was a 21% decrease in the duration of analgesia with a decrease in volume of 0.5% ropivacaine from 35 mL to 20 mL.