A nurse is caring for a client who is postoperative and has a history of Addison's disease. For which of the following manifestations should the nurse monitor?

Choice A rationale Addison's disease is characterized by an insufficiency of adrenal corticosteroids, specifically cortisol and aldosterone. Aldosterone is responsible for sodium and water retention in the kidneys. When levels are low, the body excretes excessive sodium and water, leading to hypovolemia and a significant drop in blood pressure. Postoperative stress increases the body's demand for these hormones, and a lack of adequate replacement can lead to an Addisonian crisis, manifested primarily by profound hypotension. Choice B rationale In the context of adrenal insufficiency and the resulting hypovolemia, the body typically attempts to compensate for low cardiac output by increasing the heart rate. Therefore, tachycardia is a more common finding than bradycardia in a client with Addison's disease experiencing a crisis. Bradycardia would suggest a different underlying pathology, such as a primary cardiac conduction issue or certain drug toxicities, rather than the volume depletion and electrolyte imbalances typically seen with adrenal failure. Choice C rationale Hyperkalemia, rather than hypokalemia, is the classic electrolyte imbalance seen in Addison's disease. Aldosterone normally promotes the excretion of potassium in exchange for sodium. In its absence, the kidneys retain potassium, leading to serum levels above the normal range of 3.5 to 5.0 mEq/L. High potassium levels can lead to cardiac dysrhythmias and muscle weakness. The nurse must monitor for signs of elevated potassium to prevent lethal cardiac events during the postoperative recovery period. Choice D rationale Hyponatremia occurs in Addison's disease because the lack of aldosterone prevents the kidneys from reabsorbing sodium. Serum sodium levels will often fall below the normal range of 135 to 145 mEq/L. This loss of sodium is accompanied by water loss, contributing to dehydration and low blood pressure. Hypernatremia would be more indicative of conditions like diabetes insipidus or excessive salt intake, which are not characteristic of the pathophysiology associated with primary adrenal insufficiency.