If history, physical examination, or neuroimaging suggest increased intracranial pressure, specific steps may be indicated to reduce or ameliorate any further rise in ICP. Any noxious stimulus including “bucking” the ventilator will increase ICP; paralysis and sedation should be liberally used. A general recommendation is to keep the head elevated about 30º and midline to aid in venous drainage. Osmotic diuretics such as mannitol (0.5 to 1 g/kg) will decrease intravascular volume and brain water and may transiently reduce ICP. In cases of brain edema associated with tumor, steroids such as dexamethasone will reduce edema over several hours. Hyperventilation with reduction of Paco2 will reduce cerebral blood volume and transiently lower ICP. Current recommendations are to avoid prophylactic hyperventilation (Paco2 ≤ 35 mmHg) during the first 24h after brain injury. Brief hyperventilation may be necessary for refractory intracranial hypertension. Data to recommend specific therapy is lacking and preferences among individuals and institutions vary greatly; early communication is encouraged with consultants and admitting physicians.