Case 2 - Hyponatraemia Flashcards
How can hyponatraemia present?
- History of vomitting and diarrhoea
- Recent start to hyponatraemic medication
- Confused and drowsy
Clinical assessments helpful for managing hyponatraemia
- Fluid assessment - are they hypovolaemic or diluted?
- Osmolarity - urine and serum
Biochemical tests needed when hyponatraemic
- Urinarlysis - for protein and blood - is it a CKD problem?
- TFTs - hypothyroidism
- VBG - other electolyte abnormalities
- U&Es
- LFTs
Medications known to cause hyponatraemia
- Diuretics
- SSRIs
- Antipsychotics
- Carbamazepine
Others - opiods, ACEi, PPIs
Management of someone with hyponatraemia who is dehydrated
Restore intravascular volume with 0.9% saline
Reasses
Management of hyponatraemia if not volume deplete with moderate or severe symptoms
Hypertonic saline - emergency (1.8% or 3% from ITU)
If no symptoms - offending medication is stopped, underlying cause is treated
How quickly should we aim to increase serum sodium?
No more than 1mmol/L/hr if acute - less than 8-10mmol/L in 24hrs though
No more than 15mmol/L /day if chronic
Complication if treat hyponatraemia too fast
Central pontine demyelination - osmotic demyelination syndrome
Dehydrated and urine Na not more than 20mmol/L causes of hyponatraemia:
NOT KIDNEY PROBLEM - loss Na+ and water
* Diarrhoea
* VOmitting
* Burns
* Fistulae
* Small bowel obstruction
* Trauma
* CF
* Heat exposure
Dehdrated and urine Na+ more than 20mmol/L causes of hyponatraemia:
KIDNEY PROBLEM - loss Na+ and water
* Addisons
* Renal failure
* Osmolar diuresis - lots glucose/urea
* Diuretic excess
Patient not dehydrated and oedematous causes
- Nephrotic syndrome
- Cardiac failure
- Liver cirrhosis
- Renal failure
Patient not dehydrated and not odedmatous
SIADH - see if urine osmolarity more than 100mmol/L, if yes is this.
If no:
Water overload
Severe hypothyroidism
Glucocorticoid insufficiency
Options for treatment if hyponatraemic and fluid overload risk - ie not hypovolaemic
Consider using furosemide alongside 0.9% saline
