In a patient with adrenocortical insufficiency, which presenting symptom supports the diagnosis?

In cases of adrenocortical insufficiency, one of the hallmark symptoms is decreased cardiac output. This condition arises from insufficient production of adrenal hormones, particularly glucocorticoids like cortisol, which is essential for maintaining cardiovascular function, fluid balance, and electrolyte homeostasis. When cortisol levels are low, the body becomes less efficient at managing blood volume and pressure, often leading to a decreased volume state and consequently, lower cardiac output.

The other choices involve symptoms that are not typically associated with adrenocortical insufficiency. For instance, fluid volume excess is more characteristic of conditions like heart failure or renal failure rather than adrenal insufficiency. Hypokalemia, or low potassium levels, is generally linked to conditions that promote diuresis or the use of diuretics, rather than adrenocortical insufficiency, where hyperkalemia (elevated potassium) is more common due to decreased aldosterone action. Hypothermia is indicative of systemic issues and is not a typical presenting symptom of adrenal insufficiency. Therefore, decreased cardiac output is the symptom that strongly supports the diagnosis of adrenocortical insufficiency.