Final answer:
Nitroglycerin is the correct IV medication to use for a patient in a hypertensive crisis with a low heart rate of 50, as it safely lowers blood pressure without further reducing heart rate.
Step-by-step explanation:
In the case of a patient experiencing a hypertensive crisis with a heart rate of 50, the appropriate intravenous (IV) medication to use is nitroglycerin. Nitroglycerin is a vasodilator that helps to lower blood pressure and is often used in acute management if the patient is at risk for heart failure. It is preferred over dobutamine, insulin, and potassium in this situation, especially as potassium could further slow the heart rate which is already low.
It's important to note that other medications such as beta blockers may be typically used to treat hypertension, but they must be used cautiously if the patient already has a low heart rate (bradycardia), as they can potentially exacerbate it. Nitroglycerin does not have a negative effect on heart rate and is generally safer in this scenario. In any case, treatment for a hypertensive crisis should be managed by a medical professional who can monitor and adjust the treatment as needed.