Peripheral nerve blocks have certain advantages over central neuraxial anaesthesia and general anaesthesia, hence they have become increasingly popular for the management of pain during surgery. The development of ultrasonography in regional anaesthesia made it possible to confirm precise needle placement and appropriate local anaesthetic administration. Furthermore, it is possible to prevent problems such as intravascular and intraneuronal injections. Real-time ultrasound not only lowers the amount of local anaesthetic needed for a successful nerve block but also enhances the quality of the block. Ultrasonographic guidance is beneficial in reducing intra neural injection and targets the neural sheath where drug can be deposited and block can be achieved with minimum possible volume. This study attempts to determine minimum possible volume of bupivacaine 0.5% to achieve adequate motor and sensory blockade by using ultrasound guided brachial plexus block. Methodology: The study was conducted in Department of Anaesthesiology, Gandhi Medical College and associated Hamidia Hospital, Bhopal during August 2022 to December 2023 after approval from institutional ethics committee. It was an Observational hospital-based study. The study was an observational study comprising of 75 patients between age group 18-60 years of either sex belonging to ASA grade I or II, scheduled for elective upper limb surgery. Patients with neurologic deficit in upper limb, Diaphragm palsy, Respiratory distress and Allergy to the local anaesthetics were excluded. Under all aseptic precautions ultrasonography was done at the level of supraclavicular region and structures traced from cephalic to caudal direction. the probe was placed in the coronal plane to visualize the subclavian artery and the brachial plexus in a transverse sectional view. Once the needle penetrated the brachial plexus, the bupivacaine 0.5% was injected after negative aspiration for blood or air just next to the artery, then the needle was repositioned to inject on the upper pole of the artery. Twenty five patients received 10 ml Drug (group A), next 25 patients received 15 ml Drug (group B) and next 25 patients received 20 ml Drug (group C) each. Result: Based on our findings, we determined that a volume of 15 ml of bupivacaine 0.5% reliably achieves effective sensory and motor blockade in the patients undergoing upper limb surgeries. This volume provides adequate anaesthesia while potentially reducing the risk of systemic toxicity associated with higher volume
Kewalramani et al. (Tue,) studied this question.