Hyponatraemia
- Hypo: D&V, diuretics → 0.9% NaCl
- Eu: SIADH → restrict 800 mL
- Hyper: CHF, cirrhosis → restrict + diuretic
Hyperkalaemia
- ≥6.5 or ECG: 10 mL Ca gluconate IV
- 10 U insulin + 50 mL 50% dextrose
- Salbutamol 10–20 mg neb
- Resonium / dialysis
Hypocalcaemia
- Symptoms: paraesthesia, Chvostek, Trousseau, tetany
- 10 mL Ca gluconate IV slow
- Check Mg, vit D, PTH
Hypomagnesaemia
- Often with hypoK
- MgSO₄ 2 g IV over 1 h
