COMPUTERIZED AXIAL-TOMOGRAPHY TO DEFINE THE DISTRIBUTION OF SOLUTION AFTER STELLATE GANGLION NERVE BLOCK

Study Objective: To define the spread of local anesthetic after C-6 stellate ganglion nerve block using computerized axial tomography (CAT). Design: Prospective, open descriptive study. Setting: Outpatient pain consult center. Patients: 10 ASA status I patients undergoing stellate ganglion nerve blocks for; sympathetically maintained pain. Interventions: Radiocontrast and local anesthetic was given in 5 ml increments to 20 mi total volume for C-6 stellate ganglion nerve blocks in eight patients and C-7 in two patients. Measurements and Main Results: CAT scanning was performed at baseline and after 5, 10, 15, and 20 ml of injectate was administered. Cervical level and pattern of injectate spread war recorded after each increment. Neck pressure above C-6 did not promote caudal spread. One half of the injections were beneath prevertebral fascia. Injections on top of the fascia spread more diffusely around C-6. All injections in high volume reached the medial aspect of T-1 around the head, not neck, of the first rib. Conclusions: Solutions injected for C-6 stellate ganglion nerve block concentrate medial to the stellate ganglion at T-1. Thus, they must produce upper extremity sympathectomy by a mechanism other than direct contact with the ganglion.