Definition N2O increases CBF, CMR, and ICP. Mostly due to cerebral vasodilation, although partly due to sympathoadrenal stimulation. This effect is lessened by co-administration of IV anesthetics, but may be worsened by addition of volatile. CBF response to CO2 is preserved w/ N2O administration. According to Miller, “There is no uniform agreement about the effect of N2O on CMR… […]