Nerve Stimulator Versus Ultrasound-guided Infraclavicular Block

Patients received a standard single injection infraclavicular block using the lateral sagittal approach of Klaastad. The infraclavicular brachial plexus is identified using an insulated needle connected to a nerve stimulator. Placement of the needle is considered adequate if motor response of radial nerve in the hand or wrist is still present at 0.2 - 0.5mA. Ropivacaine 0.5% 35ml is used.

Infraclavicular block is performed under ultrasound guidance. Linear probe is placed in a parasagittal positon below the clavicle medial to the coracoid process and adjusted to achieve a cross-sectional image of the axillary artery. Using in-plane technique, an 22-gauge insulated needle is advanced caudally and posteriorly to the axillary artery. Subsequently, 35 ml of 0.5% ropivacaine is incrementally injected.