[Brain blood volume measured with near infrared spectroscopy increased after stellate ganglion block].

There are many controversies whether the brain blood flow increases or not after stellate ganglion block (SGB). We found in 10 outpatients that the brain blood volume increased after SGB using near infrared spectroscopy (NIRO500, Hamamatsu Photonics, Inc.). HbO2 showed peak level of 3.6 mumol.l-1 at 30 min and 2.2 mumol.l-1 at 40 min. Peak level of Hb was 5.6 mumol.l-1 at 40 min. These values indicated increased brain blood flow after SGB.