American Association of Critical-Care Nurses (AACN) Certification Practice Test

What condition is conivaptan used to treat?

1. Hypovolemic hyponatremia

2. Euvolemic and hypervolemic hyponatremia

3. Acute kidney injury

4. Chronic heart failure only

The correct answer is: Euvolemic and hypervolemic hyponatremia

Conivaptan is primarily used to treat euvolemic and hypervolemic hyponatremia, which are conditions characterized by low sodium levels in the blood while the body's volume status is normal or excessively high. This medication acts as a vasopressin antagonist, blocking the effects of antidiuretic hormone (ADH or vasopressin) in the kidneys, leading to increased excretion of free water and thereby raising serum sodium levels. In cases of euvolemic hyponatremia, patients may present with conditions such as syndrome of inappropriate antidiuretic hormone secretion (SIADH) where water retention can dilute sodium. Hypervolemic hyponatremia typically occurs in conditions like heart failure or liver cirrhosis, where excess fluid contributes to dilutional hyponatremia. Conivaptan's mechanism of action is particularly beneficial in such scenarios, helping to correct sodium levels by promoting aquaresis—removal of excess water without substantial sodium loss. The other options do not represent conditions for which conivaptan is indicated. For instance, hypovolemic hyponatremia results from a total body sodium deficit, and the treatment would focus on fluid