SIADH Flashcards
1
Q
what is SIADH
A
- syndrome of inappropriate ADH
- abnormally high ADH causing excessive water reabsorption in CDs
- hyponatraemia, hyperosmolar urine, plasma hypo-osmolarity occur in absence of other endocrine abnormalities (result of excess ADH)
2
Q
what can cause SIADH
A
- malignancy
- -> ectopic ADH prod. by neoplastic cells
- -> commonly assc. w/ small cell lung cancer
- meds
- injury
- post-op
- infection e.g. meningitis
3
Q
describe presentation of Px w/ SIADH
A
non specific symptoms
- fatigue
- headache
- muscle aches
- confusion
- nausea
- seizures/ reduced consciousness if severe hyponatraemia
4
Q
what is a more common cause of hyponatraemia than SIADH
A
excessive hydration
5
Q
what investigations can be done in suspected SIADH
A
- diagnosis of exclusion
- serum sodium levels; Px euvolaemic and hyponatraemic
- urine osmolality and urinary sodium
- exclude other causes e.g. excessive hydration, diuretic use, kidney disease
6
Q
outline management of SIADH
A
- discontinue any causative medications
- fluid restriction
- ADH receptor blockers (very potent so need to be monitored carefully)
7
Q
why is oedema not common with water retention due to SIADH
A
b/c of urinary loss of sodium
