CCP Vasoactive Drug Pharmacology 2

Question 1

Which receptor subtype mediates the positive inotropic effect of dopamine at doses of 5–10 mcg/kg/min?

Accepted Answer

Beta-1

Answer

At intermediate doses (5–10 mcg/kg/min), dopamine primarily stimulates beta-1 adrenergic receptors, increasing cardiac contractility and heart rate.

Question 2

Milrinone exerts its positive inotropic effect by inhibiting which enzyme?

Accepted Answer

Phosphodiesterase III

Answer

Milrinone inhibits phosphodiesterase III, preventing cAMP breakdown and increasing intracellular calcium availability for myocardial contraction.

Question 3

A patient on cardiopulmonary bypass develops hypotension with low SVR. Which vasopressor acts primarily on V1 receptors to increase SVR without affecting heart rate?

Accepted Answer

Vasopressin

Answer

Vasopressin acts on V1 receptors in vascular smooth muscle to cause vasoconstriction independent of adrenergic pathways, with minimal chronotropic effect.

Question 4

During weaning from CPB, dobutamine is preferred over dopamine primarily because dobutamine:

Accepted Answer

Causes less tachycardia and fewer dysrhythmias at equivalent inotropic doses

Answer

Dobutamine produces strong beta-1 inotropic effects with less chronotropy and dysrhythmia risk compared to dopamine at comparable inotropic doses.

Question 5

Which pharmacologic property of nitroprusside requires co-administration of thiosulfate during prolonged infusions?

Accepted Answer

Cyanide ion accumulation

Answer

Nitroprusside releases cyanide ions during metabolism; thiosulfate acts as a sulfur donor to convert cyanide to the less toxic thiocyanate.

(CCP) Certified Clinical Perfusionist Practice Test

(CCP) Certified Clinical Perfusionist Practice Test

CCP Vasoactive Drug Pharmacology 2