Therapeutic targets
- Correction of hyperkalemia, i.e., promotion of excretion and infiltration of potassium into cells
- Correction of the disturbed acid-base balance.
- Avoidance of cardiac arrhythmias
Therapy recommendations
- Acute hyperkalemia (potassium value: > 6.5 mmol/l) and/or previous cardiac damage or ECG changes represent an emergency situation → intensive medical monitoring required!
- Discontinuation of causative drugs (see below medical history).
- Causal therapy of causative diseases (see under the respective disease).
- Restriction of enteral (“via the intestine”) potassium intake.
- Stabilization of the resting membrane potential of the heart muscle cells and the conduction system to prevent cardiac arrhythmias: Calcium i.v. (= intravenously, i.e. into the vein); available for i.v. use in Germany:
- Calcium gluconate 10% (2.26 mmol Ca 2+ in 10-ml amp.) [less tissue toxic].
- Calcium chloride 10% (6.8 mmol Ca 2+ in 10-ml amp).
Minimum dose: 6.8 mmol Ca 2+ (≡ 30 ml calcium gluconate 10 % or 10 ml calcium chloride 10 %).
- Infiltration of potassium into the cells:
- Combined administration of alt-insulin: 20 I.U. alt-insulin in 20 min i.v.) and glucose (250 ml glucose 20% or 10 IU insulin + 50 g glucose as a bolus or 20 IU insulin with 60 g glucose/h Effect: insulin induces simultaneous shift of glucose and potassium to intracellular; onset of action after 30 min, duration of action 4-6 h.
- Administration of sympathomimetics (drugs that enhance the action of the sympathetic nervous system; shift of potassium to intracellular) – inhalation with β2-mimetics, e.g., salbutamol, 2 times 0.2 mg multiple inhalation.
- Administration of sodium bicarbonate to correct acidosis: 100-200 ml sodium bicarbonate 8.4% i.v.Effect: correction of disturbed acid-base balance: alkalosis → sodium proton exchanger (NHE) active → shift of sodium to intracellular → increased activity of the sodium-potassium pump → potassium lowering extracellular; onset of action after about 10 min, duration of action 2 h.
- Promotion of diuresis:
- Loop diuretics (diuretic medications), e.g., fuosemide, i.v. + 0.9% NaCl solution (physiologic saline)
- Cation exchangers (oral or rectal/via the rectum): ion exchange resins that exchange K +- for Na +-ions in the intestine (not suitable as acute therapy, as elimination is insufficient).
- If necessary, also passive hemodialysis (blood washing) (target clinic should be selected accordingly).
- Prophylaxis or secondary prevention of hyperkalemia (impaired renal function and potassium value approaches 5 mmol/l): administration of cation exchangers (eg, sodium salt of polystyrene sulfonate (NaPSS), calcium salt of polystyrene sulfonate (CaPSS), Patiromer (Patiromersorbitx calcium)).
- Measures in mild hyperglycemia: see under “Further therapy“.