Supraclavicular versus Infraclavicular Approach to Brachial Plexus Block under Ultrasound Guidance for Elective Surgeries of the Upper Limb: A Randomised Controlled Trial

Introduction: Ultrasonography has revived the infraclavicular approach to brachial plexus block resulting in many studies available in the literature. However, very few studies have assessed the sensory block characteristics of individual nerve territories by this approach. Aim: To compare the supraclavicular with the infraclavicular approach with special emphasis on the assessment of block characteristics of each nerve domain. Materials and Methods: This randomised controlled trial was conducted on 40 patients of American Society of Anesthesiologists (ASA) physical status I and II, aged between 20-60 years of age undergoing elective surgical procedures of the upper limb. They were randomly allocated into either group Supraclavicular (SC group) or Infraclavicular (IC group). Ultrasound-guided block was performed using 30 mL of 0.25% bupivacaine. The primary outcome measure was the efficacy of block, and the secondary outcome was the time taken for performance of block. Categorical variables were compared with the Chi-square test or Fisher's-exact test. Continuous variables were analysed using the unpaired t-test. The p-value <0.05 was considered significant. Results: Sensory block was complete in radial, median, and musculocutaneous nerve territories in both groups. All patients in the IC group had a complete sensory block in the ulnar nerve territory, compared to 80% patients in the SC group (p=0.036). Patients in the IC group had higher motor block scores in the shoulder joint (p=0.016), elbow, and wrist joints (p=0.036) and finger joints (p= 0.038). Block performance time was significantly longer in the IC group (p<0.001). Conclusion: Infraclavicular approach provides better motor block and more complete sensory block of the upper limb. However, the time taken for performing the block was longer.