Water Deprivation Test

Indication: Diagnose diabetes insipidus.

Procedure:

1. Patient to fast, no food or water from 12AM, midnight.
2. Insert saline lock into peripheral vein to obtain blood samples.
3. Begin test at 8AM.
4. Obtain serum sodium and urine osmolarity levels stat hourly.
5. Discuss laboratory studies with prescribing physican to determine progression of test.
6. It may be necessary to administrate vasopressin 5 units subcutaneously during the test.
7. If the physician requests vasopressin, obtain serum sodium and urine osmolarity levels every 30 minutes.
8. Continue collection of serum sodium and urine osmolarity levels until physician orders the test to stop.
9. Remove saline lock from peripheral vein after completion of deprivation test.

Interpretation: Highly dependent on physician experience and preference.