A client with central diabetes insipidus receives desmopressin. Which finding best indicates the intended response to therapy?
1Urine output is 360 mL/hr, and urine specific gravity is 1.001
2Urine output is 200 mL/hr, and serum sodium is 153 mEq/L
3Urine output is 75 mL/hr, and urine specific gravity is 1.015✓ Correct answer
4Urine output is 25 mL/hr, and serum sodium is 128 mEq/L with headache
Explanation
Desmopressin replaces antidiuretic activity, so effective therapy decreases excessive urine volume and produces more concentrated urine. Very low output with hyponatremia and headache suggests excessive water retention rather than the intended balanced response.
Quick answer A lower, adequate urine output with increased urine concentration shows the intended antidiuretic response.
Why this is correct Central diabetes insipidus causes large amounts of dilute urine because antidiuretic hormone activity is deficient. Desmopressin should reduce urine volume and increase urine osmolality or specific gravity while maintaining safe fluid and sodium balance.
Easy analogy or mental picture Desmopressin partly closes a drain that was letting too much dilute water escape. The desired result is controlled flow, not a blocked drain, and the analogy does not replace sodium and neurologic monitoring.
Memory hook Effective desmopressin makes urine less excessive and more concentrated without water intoxication.
NCLEX decision rule Evaluate antidiuretic replacement by pairing urine volume with urine concentration and sodium status. Continued dilute polyuria means inadequate effect, while oliguria with hyponatremic symptoms suggests excessive effect.
Why the other choices are wrong High dilute output shows persistent diabetes insipidus. Continued high sodium with polyuria is inadequate response, and very low output with low sodium and headache signals water intoxication.
References
[1]
NCSBN: 2026 NCLEX-RN Test PlanNational Council of State Boards of Nursing
[2]
DailyMed: Desmopressin Acetate Oral SolutionU.S. National Library of Medicine