Diaetes Insipidus Flashcards
(19 cards)
What is the purpose of the water deprivation test?
To evaluate patients who have polydipsia
Polydipsia refers to excessive thirst, which can be a symptom of various medical conditions.
What is the first step in conducting the water deprivation test?
Prevent patient from drinking water
What should be done after preventing water intake during the water deprivation test?
Ask the patient to empty their bladder
How frequently are urine and plasma osmolalities measured during the water deprivation test?
Hourly
What is the expected result of the water deprivation test in a normal individual?
Normal starting plasma osmolality with high urine osmolarity; unchanged urine osmolality post deprivation
What starting plasma osmolality and final urine osmolality results are expected in nephrogenic diabetes insipidus?
High starting plasma osmolality; final urine osmolality is low (less than 300)
What happens to urine osmolality post deprivation test in nephrogenic diabetes insipidus?
Urine osmolality is unchanged and still low
What are the initial plasma and urine osmolality results in central diabetes?
High starting plasma osmolality; final urine osmolality is low (less than 300)
What is the change in urine osmolality post deprivation test in central diabetes?
Urine osmolality increases
What does central diabetes indicate regarding ADH levels?
It is a disorder of low ADH
What are the initial osmolality results in psychogenic polydipsia?
Low starting plasma osmolality; high urine osmolality
What happens to urine osmolality post deprivation test in psychogenic polydipsia?
Urine osmolality is still high
What is nephrogenic diabetes insipidus?
A condition where the kidneys are unable to concentrate urine, leading to excessive urination and thirst.
What class of medication can be used to treat nephrogenic diabetes insipidus?
Thiazides
What dietary adjustments are recommended for managing nephrogenic diabetes insipidus?
Low salt/protein diet
Can central diabetes insipidus be treated with desmopressin?
True
Fill in the blank: Central diabetes insipidus can be treated with _______.
desmopressin
What are the causes of nephrogenic DI?
Haemochromatotis
Tuberointersitital disease from sickle cell, pyelonephritis and obstruction
Lithium
Genetic mutation of vasopressin receptor
What are the causes of cranial diabetes insipidus?
infiltrative
histiocytosis X
sarcoidosis
post head injury
pituitary surgery
craniopharyngiomas
