The nurse is caring for a 10-year-old client diagnosed with diabetes insipidus. Which finding would be least expected in this condition?

Diabetes insipidus (DI) is characterized by a deficiency of antidiuretic hormone (ADH) or resistance to its effects, resulting in the kidneys' inability to concentrate urine. The hallmark manifestations include extreme thirst (polydipsia), markedly increased urine output (polyuria), and low urine specific gravity (typically below 1.005) because the kidneys excrete large amounts of dilute urine. These three findings are all expected and consistent with the pathophysiology of DI. Peripheral edema, however, is the least expected finding. Edema results from fluid accumulation in the tissues, which is associated with conditions causing fluid retention such as heart failure, nephrotic syndrome, or hypoalbuminemia. In diabetes insipidus, the problem is the opposite — excessive fluid loss through urine — which leads to dehydration and hypernatremia if fluid intake is inadequate. Therefore, a child with DI would not typically present with peripheral edema. Students often confuse DI with diabetes mellitus or SIADH; in SIADH, fluid retention and hyponatremia occur, which could lead to edema, but this is a distinct and opposite condition from DI.