hyponatraemia

Question 1

what Na level are you worried about

Answer 1

• Rate of change – if Na has dropped suddenly more concerning than chronic
• But if certain level doesn’t matter if chronic
• <110/115 – risk of symptomatic high – risk of complication eg seizures is very common
• 120-130 – if gradual – needs managing but less serious
• Need to think about sx – headache, vomiting, confusion – need admission

Question 2

what are the causes of low Na

Answer 2

• SIADH – syndrome so need to think of the causes of it
  
  • Drugs
  • Things in lung – chest infection, TB, cancer
  • Brain – mets, stroke, subdurals
• Addisons adrenal failure – malignant disease, TB – have to affect both adrenal glands
• Euvolaemic, hypo or hypervolaemic
  
  • Hypervolaemic – too much water
  • Eu – more water than salt but not overloaded

Question 3

drugs that cause hyponatraemia

Answer 3

• thiazide diuretics - indapamide - most common cause of very low
• loop diuretics - furosemide
• ACEi - ramipril
• PPIs - omeprazole
• SSRIs - sertraline
• anticonvulsants - carbamazepine
• human analogues - desmopressin
• recreational drugs - ecstasy

all with acute illness/stresses