ACCS Respiratory Practice Exam 2026 - Free Advanced Respiratory Care Practice Questions and Study Guide

Ketamine has a unique effect on the brain: it dilates cerebral vessels, which increases cerebral blood flow and raises the brain’s metabolic activity. This combination drives up intracranial pressure and cerebral perfusion pressure, and it also raises cerebral oxygen consumption. At the same time, it tends to spare respiration, preserving spontaneous breathing, and it does not cause the same level of cardiovascular depression as some other agents (even though it can raise heart rate and blood pressure via sympathetic stimulation, it doesn’t suppress cardiovascular function). This mix—increasing ICP, CPP, and CMRO2 while leaving respiration largely unaffected and not depressing circulation—fits ketamine best. Other induction agents tend to lower cerebral metabolism or depress respiration or cardiovascular function, making them less consistent with the described effects.