Ultrasound-guided stellate ganglion block. The red arrow: the puncture path; the white arrows: the stellate ganglion; S = Sternocleidomastoid muscle, JU = jugular vein, CA = common carotid artery, TH = thyroid, CL = longus cervicis muscle, VA = vertebral artery, VV = Vertebral vein, C7 = The seventh cervical vertebra.