Hyponatremia
1. Def: <135mmol/L
2. First DDx: rule out pseudo-hyponatremia
- Hypertonic: hyperglycemia?
Na在hyperglycemia時會降低，correct Na=Na + 1.4×(sugar－100)
- Isotonic : hyperlipidemia, hyperproteinemia?
- Another consideration: sample mixed with IV injection fluids?
3. Hypotonic :
- Too much water? (beware of fluid retention)à do not give N/S, but restrict Na+ and water intake
- Not enough solutes? (beware of poor intake)à may give N/S
4. Symptoms:
nausea and
vomiting, headache, confusion, loss of energy and fatigue,
restlessness and
irritability, muscle weakness, spasms or cramps, seizures, coma
5. Na supplement
if needed
- Rate of infusion is important
- 應補鈉總量（mmol）=[135-病人血Na+(mmol/L)]×體重(kg)×0.6~0.5
- 補鈉的速度不能超過4~6 mEq/L/hour，24 hrs內不能超過9 Eq/L
6. Monitoring
- Urine output
- Na recheck Q4H
