Sodium Flashcards
Management of ACUTE HYPOnatraemia with CNS dysfunction:
- Stop precipitants
- Stop fluids
- Nil by mouth
-
If gross hypovol: small 250-500ml fluid bolus
If gross hypervol: frusemide bolus -
3% hypertonic saline, 3ml/kg.
Up to 3 doses, over 30mins (10mins each)
—> Endpoint: symptom/ seizure resolution
1ml/kg/hr if less urgent
- Increase Na by 4-6mmol in 6 hours (or Na 130) THEN STOP FOR THE DAY.
- NBM, strict fluid balance
- Neuroprotective
___________
HypoNa = cerebral oedema
Rapid overcorrection = central pontine demyelination
Treatment of accidental rapid over correction in hyponatraemia:
DDAVP (ADH) or D5W
—> increase free water retention —> dilute
Causes of hyponatraemia:
Severity, acuity, volume status and urinary Na
________________
FICTITIOUS
- Glucose
- Lipids
- Protein
______
HYPOVOL
Urine Na high (renal loss)
- Renal failure (salt-losing nephropathy)
- Addison’s
- Diuresis (Thiazides, osmotic)
- Cerebral salt wasting (brain lesions)
Urine Na low (pre-renal fluid depletion)
- Sweating
- Burns
- Diarrhoea, stoma
______
EUVOL
Urine Na high
- SIADH
Urine Na low (free fluid excess, inadequate Na intake)
- Polydipsia
- Hypotonic fluids
- Tea and toast diet, Beer
______
HYPERVOL
Urine Na high
-
Urine Na low (overload dilution)
- Cirrhosis
- CCF
- Nephrotic syndrome
SIADH: Causes
Brain
- Tumours, abscess, bleed, meningitis
Drugs
- SSRI, TCA, MAOI
- NSAIDS
- ADH drugs (vasopressin, DDAVP)
Lungs
- Pneumonia, TB
…HIV.
SIADH: Criteria
1- HypoNa
2- Serum osmolaLity LOW (<275)
- Urine osmolaLity HIGHER
4- Urine Na >20
5- Euvolaemia
6- No other cause (renal, cardiac, pituitary, adrenal, thyroid)
7- Corrects with fluid restriction
