The aim of this study is to evaluate the effects of local anesthetic distribution on symptoms using ultrasound image after C6 stellate ganglion block (SGB).

Twenty-six patients underwent SGB via an anterior paratracheal approach at the sixth cervical level using 6 ml of 1% mepivacaine. We divided the patients into two groups by local anesthetic distribution using ultrasound image after SGB. In the group 'sub', injected local anesthetic was beneath the prevertebral fascia. In the group 'supra', some of injected local anesthetic was above the prevertebral fascia. The occurrence of Horner's syndrome, warm sensation on the face and hand, brachial plexus block, hoarseness, and foreign body sensation in the throat were evaluated. The skin temperature of the bilateral thumbs was measured pre and post SGB.

The occurrence of hoarseness and the foreign body sensation in the throat was significantly reduced in the group 'sub' than the group 'supra' (P < 0.05). The skin temperature of the ipsilateral thumb significantly increased in both groups compared to the pre SGB values, and the change of the skin temperature significantly increased in the group 'sub' than the group 'supra' (P < 0.05).

Subfascial distribution of local anesthetic under ultrasound image after SGB reduces the typical complications. It is more effective in the sympathetic block than suprafascial distribution.