Diabetes Insipidus

Question 1

What is diabetes insipidus?

Answer 1

decreased ADH secretion from the posterior pituitary (cranial) or impaired kidney response to ADH (nephrogenic)
It results in the passage of large volumes of dilute urine.

Question 2

What are the symptoms of diabetes insipidus

Answer 2

Polyuria
polydipsia
dehydration
symptoms of hypokalaemia- muscle weakness, hypotonia, cramps, palpitations, light-headedness
Symptoms of hypernatraemia- lethargy, thirst, weakness, irritability, fits, confusion, coma

Question 3

What investigations would you do if you suspected diabetes insipidus?

Answer 3

Urine dip
Urea&Electrolytes
Blood glucose to rule out DM
measure urine and serum osmolarity

Question 4

How do you diagnose diabetes insipidus?

Answer 4

8hr water deprivation test

Question 5

How do you treat diabetes insipidus?

Answer 5

Treat the underlying cause. So if it is cranial DI you may need to treat a pituitary tumour, or disease of the hypothalamus. If it is nephrogenic DI you will need to treat the kidneys which may be affected by drugs, polycystic kidney disease of sickle cell disease