Water deprivation test is used in the diagnosis of:
a. Anterior pituitary disease.
b. Posterior pituitary disease.
c. Hypothyroidism.
a. Anterior pituitary disease.
b. Posterior pituitary disease.
c. Hypothyroidism.
(b) Water intake is restricted the patient loses 3-5% of body weight or until 3 consecutive hourly determination of urine osmolarity are within 10% of each other. Measure urine osmolality, plasma vasopressin and increased urine osmolality with exogenous vasopressin.
|
|
Urine osmol
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Pl. VP
|
After VP
|
|
Normal
|
>800
|
>2
|
↑
|
|
DI
|
<300 o:p="">
|
Undetectable
↑
Nephrogenic DI
<300 o:p="">
>5
No change
Labels
Clinical Chemistry