A nurse administers desmopressin to a client who has a diagnosis of diabetes insipidus. The nurse recognizes that which the following laboratory findings indicate a therapeutic effect of the medication?

A. Blood urea nitrogen (BUN) 15 mg/dL: BUN levels are not a direct indicator of the therapeutic effect of desmopressin in diabetes insipidus. While BUN can indicate hydration status, it does not specifically reflect the effectiveness of desmopressin. B. Urine specific gravity 1.015: A urine specific gravity of 1.015 indicates that the kidneys are concentrating urine appropriately, which is the desired effect of desmopressin in diabetes insipidus. This shows that the medication is improving the kidney's ability to retain water. C. Serum sodium 146 mEq/L: A serum sodium of 146 mEq/L is elevated, indicating dehydration or hypernatremia, which is a common concern in diabetes insipidus. Desmopressin should help lower sodium levels by promoting water retention, so this value suggests inadequate therapeutic effect. D. Blood glucose 80 mg/dL: Blood glucose levels are not directly affected by desmopressin, which is used to treat the symptoms of diabetes insipidus. While normal blood glucose levels are important, they do not indicate the success of desmopressin therapy for this condition.