Correct Answer: C

Rationale: Increases in extracellular fluid (ECF) can lead to swelling of cells in the central nervous system, initially causing confusion, which may progress to coma or seizures. Although skin turgor, capillary refill, and heart sounds also may be affected by increases in ECF, these are signs that do not have as immediate impact on patient outcomes as cerebral edema.

Correct Answer: C

Rationale: The decrease in peripheral edema indicates an improvement in the patient's protein status. Edema is caused by low oncotic pressure in individuals with low serum protein levels. Good skin turgor is an indicator of fluid balance, not protein status. A low hematocrit could be caused by poor protein intake. Blood pressure does not provide a useful clinical tool for monitoring protein status.

Correct Answer: D

Rationale: The correct answer is D. Spironolactone is a potassium-sparing diuretic, so patients should choose low-potassium foods. Apple juice is a better choice than orange juice in this case as it is lower in potassium. Option A is incorrect because increasing fluid intake excessively is not necessary. Option B is incorrect as salt substitutes are high in potassium, which should be avoided. Option C is incorrect because patients on spironolactone should avoid increasing their potassium intake.

Correct Answer: A

Rationale: The correct answer is A. An alert, older patient can self-assess for signs of dehydration like dry mouth. This instruction is appropriate as it encourages the patient to respond to early signs of dehydration. Choice B is incorrect because the thirst mechanism decreases with age and feeling thirsty may not accurately indicate the need for fluids. Choice C is incorrect as many older patients prefer to limit evening fluid intake to enhance sleep quality. Choice D is incorrect because an older adult who is lethargic or confused may not be able to accurately assess their need for fluids.

Correct Answer: C

Rationale: The correct answer is C. The elevated serum sodium level (154 mEq/L) is consistent with the patient's neurologic symptoms of restlessness, agitation, and weakness, indicating a need for immediate action to prevent complications like seizures. The potassium level (3.4 mEq/L) and calcium level (7.8 mg/dL) are slightly off from normal but do not require immediate action. The phosphate level (4.8 mg/dL) is normal and not related to the symptoms presented by the patient.