NCLEX-PN® ExaminationPhysiological AdaptationHard
The nurse is caring for a client with a new diagnosis of diabetes insipidus (DI). Which of the following findings would the nurse anticipate?
- ASpecific gravity of urine 1.002, serum osmolality 305 mOsm/kg, increased thirst.
- BSpecific gravity of urine 1.010, serum osmolality 275 mOsm/kg, decreased urine output.
- CSpecific gravity of urine 1.020, serum osmolality 295 mOsm/kg, normal urine output.
- DSpecific gravity of urine 1.030, serum osmolality 280 mOsm/kg, decreased thirst.
Show answer & explanationAnswer & explanation
Correct answer: A. Specific gravity of urine 1.002, serum osmolality 305 mOsm/kg, increased thirst.
Diabetes insipidus (DI) is characterized by a deficiency of antidiuretic hormone (ADH) or the kidneys' inability to respond to ADH. This leads to the excretion of large amounts of dilute urine, resulting in a very low urine specific gravity (<1.005). The excessive water loss causes dehydration, leading to increased serum osmolality (>295 mOsm/kg) and intense thirst (polydipsia) as the body tries to compensate.
Why the other options are wrong
- B. Normal urine specific gravity and low serum osmolality with decreased urine output are inconsistent with DI.
- C. Normal urine specific gravity, serum osmolality, and urine output are inconsistent with DI.
- D. High urine specific gravity and normal serum osmolality with decreased thirst are inconsistent with DI.
Diabetes Insipidus (DI) Diagnostics
A disorder caused by ADH deficiency or renal insensitivity to ADH, leading to excessive excretion of dilute urine and profound thirst.
- Cardinal symptoms: polyuria (up to 20 L/day) and polydipsia.
- Urine specific gravity is very low (<1.005).
- Serum osmolality is high (>295 mOsm/kg) due to dehydration.
- Serum sodium is often high (hypernatremia).
Memory trick: DI = Dry Inside, Dilute Out!