Which induction agent is associated with increased cerebral blood flow and intracranial pressure?

Which induction agent is associated with increased cerebral blood flow and intracranial pressure?

• A. Ketamine
• B. Propofol
• C. Thiopental
• D. Isoflurane

Answer: (A)

Ketamine increases cerebral blood flow by both raising cerebral metabolic rate for oxygen and causing cerebral vasodilation, and its sympathomimetic effects raise systemic blood pressure. This combination raises cerebral perfusion pressure and increases cerebral blood volume, leading to higher intracranial pressure. That is why it is classically associated with increased CBF and ICP, particularly in patients with potential intracranial pathology. In contrast, propofol and thiopental reduce cerebral blood flow and intracranial pressure by lowering cerebral metabolic rate and causing cerebral vasoconstriction. Isoflurane can increase cerebral blood flow through vasodilation and may raise ICP at higher concentrations, though its effects on CMRO2 can complicate the balance. Overall, ketamine is the induction agent most consistently linked with increased CBF and ICP.

Ketamine increases cerebral blood flow by both raising cerebral metabolic rate for oxygen and causing cerebral vasodilation, and its sympathomimetic effects raise systemic blood pressure. This combination raises cerebral perfusion pressure and increases cerebral blood volume, leading to higher intracranial pressure. That is why it is classically associated with increased CBF and ICP, particularly in patients with potential intracranial pathology.

In contrast, propofol and thiopental reduce cerebral blood flow and intracranial pressure by lowering cerebral metabolic rate and causing cerebral vasoconstriction. Isoflurane can increase cerebral blood flow through vasodilation and may raise ICP at higher concentrations, though its effects on CMRO2 can complicate the balance. Overall, ketamine is the induction agent most consistently linked with increased CBF and ICP.