Is SPGB Have an Effect on ICP and Oxygenation of Cerebral Venous Outflow in Craniotomy for Cerebral Tumors?

Throughout this study, the efficacy of Sphenopalatine Ganglion Block as scalp block in craniotomy operation will be assessed, and the effect of SPGB on cerebral hemostasis during craniotomy will be evaluated by monitoring of both ICP, AJVDO2 and SjVO2.