Which patient is at the greatest risk for developing fluid volume excess?

A. A patient with hyperthyroidism: Hyperthyroidism involves a hypermetabolic state that often leads to increased diaphoresis, tachypnea, and potential diarrhea, which increase insensible and sensible fluid loss. Patients with this condition are more susceptible to fluid volume deficit rather than excess. Their elevated metabolic rate generally prevents the accumulation of excess intravascular fluid. B. A patient with congestive heart failure: In this condition, the heart cannot pump blood efficiently, leading to decreased renal perfusion and the activation of the renin-angiotensin-aldosterone system. This results in the pathological retention of sodium and water by the kidneys, causing systemic and pulmonary edema. It is a primary risk factor for hypervolemia and fluid overload. C. A patient receiving loop diuretics: Loop diuretics increase the excretion of water and electrolytes by inhibiting reabsorption in the renal tubules. The primary therapeutic effect and common side effect of these medications is the reduction of total body fluid. This places the patient at a high risk for fluid volume deficit. D. A patient with diabetic ketoacidosis: This acute metabolic complication causes profound osmotic diuresis due to extreme hyperglycemia. The high glucose concentration in the renal filtrate pulls water with it, leading to severe cellular and intravascular dehydration. Patients in this state require aggressive fluid resuscitation to correct a massive volume deficit.