To study the relation of volume of local anaesthetic and diaphragmatic motility in ultrasound guided supraclavicular brachial plexus block

Abstract

Supraclavicular brachial plexus block is a valuable technique for upper limb surgeries, but it carries the risk of hemi diaphragmatic paresis due to phrenic nerve involvement, which can limit its utility. Thirty-six patients undergoing forearm and hand surgery received ultrasound-guided supraclavicular brachial plexus blocks with varying volumes of 0.5% ropivacaine, determined by Dixon and Massey's up-and-down approach starting at 25 ml. We assessed diaphragmatic paralysis/paresis incidence and spirometry parameters across different volumes to optimize clinical outcomes. Among the patients, 15 ml of 0.5% ropivacaine consistently provided effective surgical anesthesia without causing diaphragmatic paralysis or paresis. The study showed no significant changes in spirometry parameters such as FEV1 and FVC with lower volumes, while higher volumes correlated with increased diaphragmatic impairment. Reducing the volume of 0.5% ropivacaine mitigates the risk of diaphragmatic paralysis associated with supraclavicular brachial plexus blocks, ensuring safe and effective anesthesia for upper limb surgeries.