Inhalational agent
Most Inhalational agents reduce cerebral metabolism (except nitrous oxide) by suppressing neuronal activity. These agents disturb cerebral autoregulation and cause cerebral vasodilatation, which increases cerebral blood volume (CBV) and can increase ICP. With administration > 2 hrs they increase CSF volume, which can also potentially contribute to increased ICP. Most agents increase the CO2 reactivity of cerebral blood vessels. These agents affect intraoperative EP monitoring.