Diabetes Insipidus Flashcards
What are the two types of DI
Cranial (low ADH secretion)
Nephrogenic (low ADH reaction)
What are the characteristics of DI
>3 litres of dilute urine in 24hrs (low osmolality <300) High serum osmolality Nocturia Polydipsia Polyuria
What are the causes of Cranial Diabetes Insipidus
Idiopathic
Head trauma
ADH gene mutation
Pituitary adenoma
What are the causes of nephrogenic Diabetes Insipidus
ADH-R mutation Lithium Hyperglycemia Chronic kidney disease Hypercalcemia
What should you rule out first with Diabetes insipidus
Diabtes Mellitus by doing Blood glucose and electrolytes and U/E
What is the initial Investigation of DI
Rule out DM
Urine dipstick - glycosuria
Serum osmolality = high
Urine osmolality = low
What is the Gold Standard test for DI
Water deprivation with desmopressin stimulation (No water for 8 hours)
Results for Cranial DI with desmopressin
urine osmolality rises to normal
Results for Nephrogenic DI with desmopressin
Urine osmolality stays low
What is the management of Cranial DI
Desmopressin
Manage hyponatremia
What is the management of Nephrogenic DI
Correct hypokalemia and hypercalcemia
High dose Desmopressin
Thiazide diuretics and NSAID (Polydipsia)
