Increased Intracranial Pressure (ICP)

Control CO2 - CO2 is the fastest lever on cerebral blood volume; maintain normocarbia and reserve brief hyperventilation for acute herniation, not routine use.

Optimize venous drainage and positioning - Head-up, neutral neck, and avoid tight tube ties or anything obstructing jugular outflow.

Preserve perfusion pressure - Maintain blood pressure so cerebral perfusion pressure stays adequate as ICP rises; avoid hypotension.

Choose agents wisely - Blunt the ICP surge of laryngoscopy; high-dose volatile agents can raise ICP and uncouple flow, so titrate.

Avoid secondary insults - Prevent hypoxia, hypercarbia, hyperthermia, and hyperglycemia, and treat ICP surges promptly (hyperosmolar therapy, CSF drainage).

The skull is a fixed box holding brain, blood, and cerebrospinal fluid; once compensation is exhausted, any added volume (mass, edema, hemorrhage, hydrocephalus) raises intracranial pressure steeply.

Rising pressure reduces cerebral perfusion pressure and, at the extreme, causes herniation and death. The anesthetist's task is to lower or avoid raising ICP while preserving perfusion. Almost every anesthetic lever — CO2, positioning, venous drainage, blood pressure, and choice of agent — influences ICP.