Classified on serum level
- Mild = 5.5 - 6.0mmol/l
- Moderate 6.1 - 6.9mmol/l
- Severe >7 mmol/l
Can cause cardiac standstill and VF
- Acute renal failure
- K+ sparing diuretics
- ACE inhibitors
- Adrenal insufficiency
- 10 - 20 ml of 10% Ca++ gluconate over 10 minutes
- Indicated when ECG changes present
- Antagonises cardiac excitability
- Does not affect plasma potassium level
- Duration of protection - minutes. Repeat as necessary.
- Slower (over 30 min) infusion in patients on digoxin.
Insulin with glucose
- Stimulates Na+ - K+ ATP pump and so intracellular uptake of K+.
- Dose = 10iu insulin in 50ml of 50% dextrose given as bolus.
- In children a glucose load of 0.5 g/kg/hr (2.5ml/kg/hr) should be given. If blood glucose rises above 10 mmol/l then insulin should be added at 0.05u/kg/hr.
- Onset of action 15 min, lasts about 1 hour.
- Binds B2, stimulates CAMP, which stimulates Na+-K+ ATP pump
- Give 0.5mg (4 µg/kg in children) slow IV
- 10mg nebulised Salbutamol (in children 2.5 mg if < 25kg, 5 mg if > 25 kg)
- Avoid IV administration in patients with ischaemic heart disease
- No effect on plasma level for at least 60 min
- No studies to demonstrate clear benefit
- May be considered in severe acidosis
Sodium polystyrene sulphonate
- Resin binds K+ in the intestine
- 50 grams polystyrene in 100-200ml 30% sorbitol or 10% glucose
- Given PR and left for at least 60 min
- Definitive hypokalaemic measure
- Rapid fall in plasma level in first hour
- Especially where hyperkalaemic arrest or other medications have failed.