A postoperative patient is diagnosed with fluid volume overload. What should the nurse expect to assess in this patient?

Choice A Reason: This is incorrect because phosphorus is not the most affected electrolyte by acute renal failure. Phosphorus is a mineral that is involved in bone formation, energy metabolism, and acid-base balance. Acute renal failure can cause hyperphosphatemia, which is a high level of phosphorus in the blood, due to impaired excretion by the kidneys. However, hyperphosphatemia is usually asymptomatic and can be treated with phosphate binders and dietary restriction.

Choice B Reason: This is incorrect because magnesium is not the most affected electrolyte by acute renal failure. Magnesium is a mineral that is essential for nerve and muscle function, blood pressure regulation, and bone health. Acute renal failure can cause hypermagnesemia, which is a high level of magnesium in the blood, due to impaired excretion by the kidneys. However, hypermagnesemia is rare and usually occurs in patients who receive excessive magnesium supplementation or antacids.

Choice C Reason: This is correct because potassium is the most affected electrolyte by acute renal failure. Potassium is a mineral that is vital for nerve and muscle function, especially for the heart. Acute renal failure can cause hyperkalemia, which is a high level of potassium in the blood, due to impaired excretion by the kidneys. Hyperkalemia can cause muscle weakness, cardiac arrhythmias, and cardiac arrest. The nurse should monitor the patient's vital signs, electrocardiogram, and serum potassium level, and administer medications or dialysis as ordered.

Choice D Reason: This is incorrect because calcium is not the most affected electrolyte by acute renal failure. Calcium is a mineral that is essential for muscle contraction, nerve transmission, and blood clotting. Acute renal failure can cause hypocalcemia, which is a low level of calcium in the blood, due to decreased production of active vitamin D by the kidneys. Hypocalcemia can cause tetany, seizures, and cardiac arrhythmias. The nurse should monitor the patient's vital signs, electrocardiogram, and Chvostek's and Trousseau's signs, and administer calcium and vitamin D supplements as ordered.

Choice E Reason: This is incorrect because sodium is not the most affected electrolyte by acute renal failure. Sodium is a mineral that regulates fluid balance, blood pressure, and nerve impulses. Acute renal failure can cause hyponatremia or hypernatremia, which are low or high levels of sodium in the blood, due to impaired regulation of water intake and output by the kidneys. Hyponatremia can cause confusion, seizures, and coma. Hypernatremia can cause thirst, agitation, and restlessness. The nurse should monitor the patient's fluid balance, vital signs, and serum sodium level, and administer fluids or diuretics as ordered.

Choice A: Corticosteroid is incorrect because it does not directly affect the potassium level in the blood, although it can cause sodium and water retention, which can dilute the potassium concentration. Corticosteroid is a type of anti- inflammatory medication that can be used to treat conditions such as asthma, arthritis, or allergic reactions.

Choice B: Narcotic is incorrect because it does not directly affect the potassium level in the blood, although it can cause respiratory depression, which can lead to respiratory acidosis and hyperkalemia, or high potassium level. Narcotic is a type of analgesic medication that can be used to treat moderate to severe pain.

Choice C: Thiazide diuretic is correct because it is a type of medication that increases urine output and sodium excretion, but also causes potassium loss in the urine. Thiazide diuretic can be used to treat conditions such as hypertension, edema, or heart failure.

Choice D: Muscle relaxer is incorrect because it does not directly affect the potassium level in the blood, although it can cause muscle weakness, which can mimic the symptoms of hypokalemia. Muscle relaxer is a type of medication that can be used to treat conditions such as muscle spasms, back pain, or fibromyalgia.