A nurse is caring for a client who receives furosemide to treat heart failure. Which of the following laboratory values should the nurse monitor for this client due to this medication?

A. Cortisol levels are not affected by furosemide, a loop diuretic. B. Furosemide can cause hypokalemia (low potassium) by increasing urinary excretion of potassium. Monitoring serum potassium levels is essential to prevent complications such as arrhythmias. C. Bicarbonate is not directly affected by furosemide, although metabolic alkalosis can occur secondarily. However, potassium is the primary concern. D. Albumin is related to nutritional status and liver function, but it is not significantly influenced by furosemide.