1. Polyuria-polydipsia Central diabetes insipidus Nephrogenic diabetes insipidus Psychogenic water drinking Diabetes mellitus

2. Survey of diabetes insipidus History quantitation of daily fluid intake and output  noturia or enuresis detailed dietary history  avoid foods with a high protein content acuteness of onset drug growth and development

3. Survey of diabetes insipidus Lab 24h I/O Urine: specific gravity or osmo., glucose Serum sodium and osmo. definite diagnosis: water deprivation testwater deprivation test

4. Water deprivation test Prcedure morning: empty bladder & weigh pt NPO blood: Na, K, Ca, Crea, osmo., vasopressin q1h check:  BW  Urine: vol., specific gravity(sg), osmolality  Serum: Na, osmolality

5. Water deprivation test Ending (one of following) BW  > 3% serum Na > 150mmol/L or osmo. > 300 mmol/L U osmo reaches 850 mmol/kg for 2 consecutive tests U osmo stablized (  < 30mmol/kg between the last 2 collections) Empty bladder Blood: osmo., Na, and vasopressin DDAVP (2ug) s.c. or 10ug (0.1 ml) intranasal, and drink as desired U osmo and S osmo q30min x 2, (x4 if intranasal)

6. Interpretation Normal response Uosmo  to 500 – 1400 mosm/kg U/O decrease Sosmo: in normal range (< 295 mmol/kg)  U/P ratio > 2 ADH: no increase in Uosmo and no decreased U/O DI Uosmo: no increase, U/O: no decrease Sosmo increases (U/S ration < 2) ADH: CDI: U/O decrease, Uosmo increase NDI: no response

7. BWUrineSerum VolumeSpecific gravity OsomlarityNaOsmolarity Hr 0 13.550<1.005255152310 Hr 1 13.4401.005258155311 Goal 3%150305 Hr ’ 0 13.4311 Hr ’ 0.5 13.850<1.005234317 Hr ’ 1 13.8319 Hr ’ 1.5 13.830524314

8. Interpretation Max Uosm/Sosm before DDAVP Max Uosm/Sosm s/p DDAVP Uosm  s/p DDAVP Normal or PWD >1 < 9% Partial CDI >1 > 9% Complete CDI <1 1> 50% NDI <1 < 45% Patient 0.821.66123%

9. Central diabetes insipidus Cause brain tumor idiopathic neurosurgery head trauma HIE histiocytosis Survey: skull x-ray or head CT Tx: hormonal replacement

10. Nephrogenic diabetes insipidus Cause congenital acquired: chronic renal Dz e- disorder: hypokalemia, hypercalcemia sickle cell trait adrenal insufficiency drug  lithiium, colchicine, constrast, diuretics diet  protein starvation, chronic salt depletion, chronic high water intake

11. Nephrogenic diabetes insipidus Survey electrolyte renal echo Treatment low sodium diet (< 1mmol/kg/24h) adequate protein (2g/kg/day) 300-400 ml/kg water drug:  thiazide (hydrochlorothiazide 2-4mg/kg/d): 注意 hypokalemia, 可與 amiloride 併用  indocin (2mg/kg/d): 亦可與 thiazide 併用

12. Water deprivation test Prcedure morning: empty bladder & weigh pt NPO blood: Na, K, Ca, Crea, osmo., vasopressin q1h check:  BW  Urine: vol., specific gravity(sg), osmolality  Serum: Na, osmolality

13. Water deprivation test Ending (one of following) BW  > 5% (or 3%) serum Na > 150mmol/L and plasma osmo. > 305 mmol/kg U osmo reaches 850 mmol/kg for 2 consecutive tests U osmo stablized (  < 30mmol/kg between the last 2 collections) Empty bladder Blood: osmo., Na, and vasopressin DDAVP (2ug) use, and drink as desired U osmo and S osmo q30min x 2 