Final answer:
The statement that the use of dobutamine can increase oxygen demand of the heart is true; dobutamine functions as a positive inotrope, enhancing the strength of the heart's contractions and therefore its oxygen needs.
Step-by-step explanation:
The use of dobutamine is associated with an increase in the oxygen demand of the heart, so the accurate answer to the student's question is A) True. Dobutamine is a medication known as a positive inotrope, which means it increases the force of the heart's contractions. This enhancement in contractility raises the demand for oxygen by the cardiac muscle. It is often used in the treatment of acute heart failure or in cardiac stress tests to mimic the effect of exercise on the heart.
Contrary to adrenaline, which also raises heart rate and can increase oxygen demand, β-blockers generally have the opposite effect. They reduce heart rate and decrease the heart's demand for oxygen. In this context, it's important to understand that during hyperpnea, the increased rate and depth of ventilation are a response to an increase in oxygen demand, but this physiological response does not significantly alter blood oxygen or carbon dioxide levels.