[Changes of tympanic temperature by stellate ganglion block]

The effects of stellate ganglion block (SGB) on the temperature of tympanic membrane were determined clinically. Thirty patients received SGB with 8 ml of 1 % mepivacaine. The tympanic temperature was measured using radiation non-contact tympanic membrane thermometer before and after administration of SGB for 30 min on the side where SGB was given. Before SGB the tympanic temperature was 37.29 +/- 0.08 degrees C, and there was no difference in the readings between the two sides. The tympanic temperature dropped significantly 5 min after SGB and reached its lowest value of 36.90 +/- 0.08 degrees C 15 min later. This drop persisted for more than 30 min after SGB. The fact that therapeutic effect of SGB is partly due to vasodilation and improvement in blood flow to the affected region was demonstrated, but these effects in internal carotid arterial system have not yet been studied in detail. Tympanic temperature has been proposed as a valid index of brain temperature in man. The mechanism of brain cooling has been suggested that countercurrent heat exchange takes place between carotid and jugular blood flow. Therefore the result of the study suggests that SGB could enhance an increase in the brain blood flow.