56 - 60 SBAs for the Final FRCA
Question 56
A 19 year old woman has just finished her first ultramarathon and is celebrating with her family at the finish line when she collapses, followed by a 10 second generalised seizure.
Her numbers are as follows:
- Sodium - 123 mmol/L
- Plasma osmolality - 230 mOsm/L
- Urine sodium - 14 mmol/L
- Urine osmolality - 260 mOsm/L
Which of the following is false?
- Demyelination can cause confusion
- The patient has drunk too much water
- This could be SIADH
- Hyponatraemia should be corrected slowly
- The seizures are likely due to brain swelling
Answer
- This could be SIADH
Well I suppose it always 'could' be anything, but the point here is the numbers and history don't support the suggestion of SIADH.
SIADH requires a high urinary sodium (>20) and osmolality (>300 ish).
All of the others are true.