Select the false statement about isoflurane at or below 1 MAC.

Select the false statement about isoflurane at or below 1 MAC.

• A. A May attenuate bronchospasm
• B. B Produces a 2- to 3-fold increase in skeletal muscle blood flow
• C. C Decreases mean arterial pressure
• D. D Decreases cardiac output

Answer: (D)

At or below 1 MAC, isoflurane primarily causes vasodilation, which lowers systemic vascular resistance and arterial pressure, while the heart rate often rises or stays the same to help preserve cardiac output. It also has bronchodilating properties and tends to increase blood flow in skeletal muscle due to the generalized vasodilation. Isoflurane may attenuate bronchospasm because of its bronchodilating effect. It increases skeletal muscle blood flow because of vasodilation in those vascular beds, though the exact magnitude can vary. It decreases mean arterial pressure due to reduced systemic vascular resistance. However, cardiac output is not typically decreased at this concentration; despite some myocardial depression, the drop in afterload and possible reflex tachycardia usually preserve or modestly increase forward flow. Therefore, the statement claiming a decrease in cardiac output is not correct.

At or below 1 MAC, isoflurane primarily causes vasodilation, which lowers systemic vascular resistance and arterial pressure, while the heart rate often rises or stays the same to help preserve cardiac output. It also has bronchodilating properties and tends to increase blood flow in skeletal muscle due to the generalized vasodilation.

Isoflurane may attenuate bronchospasm because of its bronchodilating effect. It increases skeletal muscle blood flow because of vasodilation in those vascular beds, though the exact magnitude can vary. It decreases mean arterial pressure due to reduced systemic vascular resistance. However, cardiac output is not typically decreased at this concentration; despite some myocardial depression, the drop in afterload and possible reflex tachycardia usually preserve or modestly increase forward flow. Therefore, the statement claiming a decrease in cardiac output is not correct.