What is the symptom of phrenic nerve block puncture needle

Hello, phophrenic nerve block can be caused by cephalic diffusion of local anesthems involving more proximal nerve roots (Ca, C4, and C5) or by incorrect manipulation causing local anesthems to accumulate outside the sheath of the brachial plexus and in front of the anterior scalene muscle. Ultrasound or conventional X-ray techniques can be used for diagnosis. Chest radiographs can be taken in the inspiratory and exhalatory positions and compared with changes in diaphragm position. Little or no diaphragm movement between exhalation and inspiration suggests a brisket nerve block. I hope my reply is helpful to you.