Registered Cardiovascular Invasive Specialist (RCIS) Practice Test

What is the primary function of low dose dopamine (1-5 mcg/kg/min)?

1. To decrease heart rate

2. To improve renal function and urine output

3. To act as a strong vasoconstrictor

4. To increase blood pressure

The correct answer is: To improve renal function and urine output

The primary function of low-dose dopamine at a dosage of 1-5 mcg/kg/min is to improve renal function and increase urine output. This effect is primarily mediated through its action on the dopaminergic receptors in the kidneys, which leads to vasodilation of the renal vasculature. This vasodilation results in increased blood flow to the kidneys, enhancing glomerular filtration and subsequently promoting urine production. Low-dose dopamine is often used in clinical settings, particularly in situations such as acute kidney injury or during certain types of shock, to maintain renal perfusion and protect kidney function while ensuring adequate diuresis. By stimulating these receptors, dopamine can help prevent further damage to the kidneys during periods of low perfusion. Understanding the physiological impact of low-dose dopamine is crucial for its appropriate clinical application, especially in critical care and cardiology contexts. Other potential effects of dopamine, such as increased heart rate or changes in blood pressure, generally occur at higher dosages and are not the primary actions associated with the low-dose range.