diabetes Insipidus

Question 1

Pathophysiology of DI?

Answer 1

Opposite of SIADH

ADH doesn’t work

Question 2

Types of DI? And explain

Answer 2

1. central DI
2. nephrogenic DI
3. gestational GI
4. dipsogenic DI/psychogenic polydipsia

Question 3

Clinical features of DI?

Answer 3

Polyuria (daily uop 10-15 l)
Nocturia
Compensatory polydipsia

Question 4

Aetiolgy?

Answer 4

Cranial-
Familial
Idiopathic (autoimmune)
Tumours 
Infection (tb,meningitis,cerebral abcess)
Infiltration (sarcoidosis)
Post surgical 
Vascular (hemorrhage,sheehan’s xd)

Nephrogenic-
Familial 
Idiopathic 
Renal tubular acidosis 
Hypokalemia 
Hypercalcemia
Drugs
Sickle cell disease

Question 5

Ix of DI?

Answer 5

1.high plasma osmolality with low urine osmolality
2.high or high normal serum sodium
3.high 24 hr urine volume
4.water deprivation test (confirmatory)
Failure of urine consentration with fluid deprivation
In cranial ^ by 50% with vasopressin and not in nephrogenic

Question 6

Tx of DI?

Answer 6

Central and gestation -desmopressin
Nephrogenic-thiazide
Dipsogenic-behavioral