Adult-Gerontology Clinical Nurse Specialist (CNS) Practice Exam

What is a primary symptom indicating that a patient is unable to regulate electrolytes in acute renal failure?

1. hypokalemia

2. hyponatremia

3. hypermagnesemia

4. hyperphosphatemia

The correct answer is: hyponatremia

In acute renal failure (also known as acute kidney injury), the kidneys lose their ability to excrete waste products and regulate electrolyte levels effectively. One of the primary symptoms indicating this disrupted regulation is hyperphosphatemia, which is characterized by elevated phosphate levels in the blood. When the kidneys are not functioning properly, they cannot adequately excrete phosphate, leading to its accumulation. As a result, hyperphosphatemia can occur, which has significant implications for other electrolytes and can contribute to complications such as calcifications in soft tissues and cardiovascular issues. In contrast, while hyponatremia (low sodium levels) can occur in various clinical scenarios, it is not as directly indicative of acute renal failure as hyperphosphatemia. The kidney’s role in electrolyte balance is essential, but the body's sodium regulation may also be affected by fluid balance and other factors that do not necessarily indicate acute renal failure. Hypermagnesemia is less common, as magnesium typically has other sources and is more likely to accumulate in chronic kidney disease. Hypokalemia can also happen due to specific conditions like excessive renal loss, but it is not a primary symptom of acute renal failure, where hyperkalemia (high potassium levels) is usually more prevalent due to