Which statement best describes the effect of present-day volatile anesthetics on systemic blood pressure as dose increases?

Which statement best describes the effect of present-day volatile anesthetics on systemic blood pressure as dose increases?

• A. A Blood pressure increases
• B. B Blood pressure decreases in a dose-dependent fashion
• C. C Blood pressure remains unchanged
• D. D Blood pressure decreases then increases

Answer: (B)

Inhaled volatile anesthetics tend to lower blood pressure in a dose-dependent way because they cause vasodilation of the systemic arterioles and can depress myocardial contractility at higher concentrations. As the inspired concentration rises, vascular smooth muscle relaxes, shrinking systemic vascular resistance and dropping arterial pressure. At higher doses, the direct depressive effects on the heart further reduce cardiac output, amplifying the blood pressure decline. In practice, at low concentrations the change may be small, but with increasing dose the hypotension becomes more pronounced. Some patients may exhibit a compensatory increase in heart rate, but the overall trend with increasing dose is a fall in systemic blood pressure.

Inhaled volatile anesthetics tend to lower blood pressure in a dose-dependent way because they cause vasodilation of the systemic arterioles and can depress myocardial contractility at higher concentrations. As the inspired concentration rises, vascular smooth muscle relaxes, shrinking systemic vascular resistance and dropping arterial pressure. At higher doses, the direct depressive effects on the heart further reduce cardiac output, amplifying the blood pressure decline. In practice, at low concentrations the change may be small, but with increasing dose the hypotension becomes more pronounced. Some patients may exhibit a compensatory increase in heart rate, but the overall trend with increasing dose is a fall in systemic blood pressure.