Diabetes Insipidus Flashcards
1
Q
Describe the difference between Cranial and Nephrogenic Diabetes insipidus
A
Cranial - decreased secretion of antidiuretic hormone (ADH) from the pituitary
Nephrogenic - insensitivity to ADH
2
Q
Causes of cranial DI
A
- idiopathic
- post head injury
- pituitary surgery
- craniopharyngiomas
- infiltrative cause e.g. sarcoid
- haemochromatosis
3
Q
Causes of nephrogenic DI
A
- genetic
- hypercalcaemia
- hypokalaemia
- lithium
- demeclocycline
- tubulo-interstitial disease: obstruction, sickle-cell, pyelonephritis
4
Q
Main presenting features
A
polyuria
polydipsia
5
Q
Investigation findings which indicate DI
A
- high plasma osmolality, low urine osmolality
- urine osmolality of >700 excludes DI
- water deprivation test
6
Q
Management of DI
A
Cranial - desmopressin
Nephrogenic
- thiazides
- low salt/protein diet
7
Q
A
