Etomidate does all of the following EXCEPT which statement?

Etomidate does all of the following EXCEPT which statement?

• A. Abolishes CO2 reactivity
• B. Reduces CMRO2
• C. Produces direct cerebral vasoconstrictor
• D. Reduces CBF

Answer: (A)

Etomidate decreases brain metabolic activity while keeping cerebral blood flow in balance with the reduced metabolism. This drug lowers the brain’s oxygen consumption (CMRO2), and as CMRO2 falls, cerebral blood flow (CBF) also decreases in step with metabolic demand. Importantly, CO2 reactivity—the ability of cerebral vessels to dilate with higher CO2 (and constrict with lower CO2)—is preserved with etomidate; it does not abolish this response. Therefore, the statement claiming that etomidate abolishes CO2 reactivity is not true. The other effects described—reduced CMRO2 and reduced CBF—fit with etomidate’s profile, and the reduction in CBF is a secondary effect from lower metabolic demand rather than a direct vasoconstrictor action.

Etomidate decreases brain metabolic activity while keeping cerebral blood flow in balance with the reduced metabolism. This drug lowers the brain’s oxygen consumption (CMRO2), and as CMRO2 falls, cerebral blood flow (CBF) also decreases in step with metabolic demand. Importantly, CO2 reactivity—the ability of cerebral vessels to dilate with higher CO2 (and constrict with lower CO2)—is preserved with etomidate; it does not abolish this response. Therefore, the statement claiming that etomidate abolishes CO2 reactivity is not true. The other effects described—reduced CMRO2 and reduced CBF—fit with etomidate’s profile, and the reduction in CBF is a secondary effect from lower metabolic demand rather than a direct vasoconstrictor action.