A nurse is caring for a patient with heart failure who is receiving a combination of medications, including an ACE inhibitor and a diuretic. The nurse should monitor for which of the following potential complications?

Choice A rationale Hyperglycemia is not a typical complication of combining ACE inhibitors and diuretics, although some diuretics like thiazides can slightly affect glucose levels. Hypokalemia is a common side effect of loop or thiazide diuretics, but ACE inhibitors actually promote potassium retention. Therefore, the risk of hypokalemia is often mitigated when these two drugs are used together. This choice does not represent the most significant or common combined risk associated with this specific drug pairing in heart failure. Choice B rationale ACE inhibitors and diuretics both lower blood pressure, which can lead to profound hypotension, especially during the initiation of therapy. Additionally, ACE inhibitors block the secretion of aldosterone, which normally promotes potassium excretion; this results in a risk of hyperkalemia. While some diuretics waste potassium, the potassium-retaining effect of the ACE inhibitor is a critical monitoring point. The combination of reduced vascular resistance and decreased fluid volume makes hypotension a primary concern for patient safety. Choice C rationale Hypertension is unlikely when a patient is taking two different types of antihypertensive medications. Both ACE inhibitors and diuretics are intended to lower blood pressure by reducing systemic vascular resistance and blood volume, respectively. Furthermore, while diuretics can cause hypokalemia, the presence of an ACE inhibitor makes hyperkalemia a more significant concern due to its effect on the renin-angiotensin-aldosterone system. This option incorrectly identifies both the blood pressure trend and the electrolyte risk. Choice D rationale Hypoglycemia is not a recognized side effect of ACE inhibitors or diuretics. Hyponatremia can occur with diuretic use due to the inhibition of sodium reabsorption in the renal tubules, but it is not the most common or characteristic complication when paired specifically with an ACE inhibitor. The most significant and immediate risks involve the regulation of potassium and the maintenance of adequate systemic perfusion pressure, making the monitoring of blood pressure and potassium levels the nursing priority.