Ultrasound-Guided Erectro Spinae Plane Block Versus Stellate Ganglion Block for Patients With Upper Limb Acute Herpes Zoster Pain.

high frequency (6 to 13 MHz) linear transducer will be placed perpendicular to the tracheal axis at the cricoid cartilage and will be moved inferiorly until the superior aspect of the thyroid gland is visualized. Later, the transducer should be relocated laterally to visualize the anterior aspect of the Chassaignac's tubercle on \[\]the C6 transverse process. The carotid artery, internal jugular vein, thyroid gland, trachea, Longus colli, and Longus capitis muscle, prevertebral fascia, the root of C6 spinal nerve, and transverse process of C6 can be identified. Color Doppler will be used to detect the position of the vessels. With an in-plane approach, 22 to 25 gauge echo-enhanced needle is placed beside the trachea with a lateral to medial direction.

We will count the laminae in the cephaled-to-caudal direction, starting from the C7 using the US to determine the exact vertebral level where the needle will be inserted. A linear high-frequency ultrasound probe will be used to perform the blocks. After the determination of the needle insertion site, the US probe was placed over the spinous processes of the vertebrae at the midline in the longitudinal plane. The US probe will then slid laterally from the spinous processes to visualize the transverse process. The needle will be advanced posterior-to-anteriorly, in the caudal to cephalic direction using the in-plane orientation within paraspinal muscles, targeting the transverse process. When the tip of the needle reaches and contact the transverse process, the local anesthetic drugs(0.2-0.3ml/kg(11) of bupivacaine 0.25% 8mg Dexamethazone) will be administered