Which agent is known to increase intracranial pressure?

Which agent is known to increase intracranial pressure?

• A. Thiopental
• B. Diazepam
• C. Etomidate
• D. Ketamine

Answer: (D)

Intracranial pressure changes with how an agent affects cerebral blood flow and brain metabolism. Ketamine tends to raise ICP because it causes cerebral vasodilation and increased cerebral blood flow, which increases the volume of brain tissue within the skull. This effect is more noticeable in patients with existing intracranial pathology or impaired CSF drainage, which is why ketamine has historically been avoided in head injury or raised ICP scenarios. In contrast, the other common induction agents usually lower ICP by reducing cerebral metabolic rate and cerebral blood flow: thiopental, etomidate, and benzodiazepines like diazepam all tend to decrease cerebral activity and vasoconstrict cerebral vessels, thereby reducing ICP.

Intracranial pressure changes with how an agent affects cerebral blood flow and brain metabolism. Ketamine tends to raise ICP because it causes cerebral vasodilation and increased cerebral blood flow, which increases the volume of brain tissue within the skull. This effect is more noticeable in patients with existing intracranial pathology or impaired CSF drainage, which is why ketamine has historically been avoided in head injury or raised ICP scenarios. In contrast, the other common induction agents usually lower ICP by reducing cerebral metabolic rate and cerebral blood flow: thiopental, etomidate, and benzodiazepines like diazepam all tend to decrease cerebral activity and vasoconstrict cerebral vessels, thereby reducing ICP.