Diabetes insipidus Flashcards
diabetes insipidus has deficiency or insensitivity to what hormone?
ADH
what is DI?
passage of large amounts of diluted urine
criteria for DI
- QUANTITY- 2-3L/24hr of urine
2. CONCENTRATION- less than 300mOsm/kg
Which type of diabetes insidious is caused by decreased ADH production
central DI
most common type of DI
Central DI
primary causes of central DI
main one is ideopathic
also hypothalamic damage and hereditary
secondary causes of central DI
brain/pituitary tumors, cranial surgery, transphenoidal adenectomyx, head trauma
what is nephrogenic DI
Partial or complete insensitivity to ADH
kidney resistance to ADH is what type of DI
nephrogenic
sickle cell, lithium meds
hypercalcemia and hypokalemia
canc ause
nephrogenic DI
when does DI pt usually become symptomatic
when there is decreased water intake
DI presents like DM, except what levels are normal?
glucose
symptoms of DI
POLYURIA, POLYDIPSIA, NOCTURIA (ENURESIS-in kids)
hypernatremia- due to decreased water intake (weakness, seizures, ataxia, coma)
dehydration, hypotension, rapid vascular collapse
Diagnosis of DI
Water deprivation test UA: dilute urine/specific gravity 24 hr urine collection= less than 2L rules out DI CHEMISTIRES, ELECTROLYES, GLUCOSE LEVELS elevated URIC acid MRI of brain= no ADH so should not be lit up if pt has DI PLASMA ADH level VASOPRESSIN challenge test
in water deprivation test, if it gets more concentrated after given ADH then it is ____.
normal pt
