Propofol can cause hypotension through which mechanism?

• A. Venous dilation.
• B. Arterial vasodilation.
• C. Direct myocardial depression.
• D. Increased heart rate.

Answer: (B)

Propofol lowers blood pressure mainly by causing arterial vasodilation, which reduces systemic vascular resistance (afterload). This relaxation of arterial smooth muscle drops arterial pressure quickly. Venous dilation can also occur and decrease venous return, contributing to lower preload, but the dominant factor is arterial dilation. Propofol can also have some direct depressive effects on the heart and may cause bradycardia, which can further reduce blood pressure, but increased heart rate would not explain the hypotension.