Fig. 8. (A–F ) The ultrasound-guided needle advancement technique, showing one hand holding the probe and one hand holding the insulated needle in the interscalene location (A ) (CH = clavicular head of sternocleidomastoid muscle; SH = sternal head), the supraclavicular location (B ), and the axillary location (C ). In all cases, the needle is positioned at one end of the ultrasound probe and passed in-line with the ultrasound beam i.e. , in the same plane. Sonogram of the needle (arrows ) in contact with the brachial plexus in the interscalene (D ), supraclavicular (E ), and axillary (F ) locations. AA = axillary artery; SA = subclavian artery; SAM = scalenus anterior muscle; SCM = sternocleidomastoid muscle.