The Change in Regional Cerebral Oxygen Saturation after Stellate Ganglion Block

BACKGROUND Stellate ganglion block (SGB) is known to increase blood flow to the innervations area of the stellate ganglion. Near infrared spectroscopy reflects an increased blood volume and allows continuous, non-invasive, and bedside monitoring of regional cerebral oxygen saturation (rSO(2)). We investigated the influence of SGB on bilateral cerebral oxygenation using a near infrared spectroscopy. METHODS SGB was performed on 30 patients with 1% lidocaine 10 ml using a paratracheal technique at the C6 level and confirmed by the presence of Horner's syndrome. The blood pressure (BP), heart rate (HR) and rSO(2) were measured before SGB and 5, 10, 15 and 20 minutes after SGB. Tympanic temperature of each ear was measured prior to SGB and 20 minutes after SGB. RESULTS The increments of the rSO(2) on the block side from the baseline were statistically significant at 5, 10, 15 and 20 minutes. The rSO(2) on the non-block side compared with the baseline, however, decreased at 15 and 20 minutes. The difference between the block and the non-block sides was significant at 15 and 20 minutes. The BP at 10, 15 and 20 minutes was increased and the HR was increased at 10 and 15 minutes. CONCLUSIONS We observed an increment of the rSO(2) on the block side from the baseline; however, the rSO(2) on the non-block side decreased.