SIADH

Question 1

concentrated urine in the presence of hyponatraemia and low plasma osmolality points to which diagnosis?

Answer 1

SIADH

Question 2

which type of lung cancer is linked to SIADH?

Answer 2

small cell lung carcinoma

Question 3

Which common drugs are linked to SIADH?

Answer 3

SSRIs
NSAIDs
chemotherapeutic agents

Question 4

What usually causes SIADH?

Answer 4

excessive vasopressin release

Question 5

what does vasopressin do?

Answer 5

Stimulates collecting reabsorption of water from collecting ducts into blood

Question 6

what are classic clinical features of SIADH?

Answer 6

nausea
vomiting
confusion
no history of recent diuretic use
euvolaemic hyponatraemia

Question 7

what are the key investigations for SIADH?

Answer 7

serum sodium (low)
serum osmolality (low)
serum urea (low)
urine osmolality (high)

Question 8

what is the management of acute SIADH?

Answer 8

treat underlying cause
fluid restriction.
If severe: IV hypertonic saline and furosemide

Question 9

what is the management of chronic SIADH?

Answer 9

treat underlying cause
fluid restriction
selective V2 receptor antagonist or sodium chloride +furosemide (loop diuretic)