[Thermographic assessments of the sympathetic blockade after stellate ganglion block (no. 3)--the block at the base of the 6th cervical transverse process].

We attempted to define effects of stellate ganglion block (SGB) at the base of 6th cervical transverse process by evaluating extent and degree of sympathetic blockade after SGB using the infrared thermography. Ten healthy volunteers (7 females, 3 males, age 26.0 years) were subjects of this study. Two different volumes (5 or 10 ml) of 1% plain mepivacaine were used (B5 group and B10 group). We performed SGB twice using two different volumes in all subjects on different day. Thermography was performed before and 30 minutes after SGB. On thenar and hypothenar, change of skin temperature in the B10 group tended to be higher compared with the B5 group. There were no significant differences in forehead or cheek temperature between the two groups. The thermographic whole hot area pattern on the ipsilateral hand after SGB in B10 group (60%) tended to be more frequent compared with the B5 group (40%). All subjects showed Horner's sign. No severe side-effect occurred in either group, but complaints of dysphagia appeared more frequently in the B10 group (80%) than in B5 group (40%). The change of skin temperature on thenar and hypothenar after B5 was significantly larger than that after the SGB at the top of the anterior tubercle of 6th cervical transverse process (P less than 0.05). In conclusion, B10 had more effect on lower cervical and upper thoracic sympathetic nerves than B5, but it also had a significant incidence of dysphagia feeling. Concerning the effect of the lower cervical and upper thoracic sympathetic block, B5 was superior to the SGB at the top of the anterior tubercle of 6th cervical transverse process.