Treatment of severe hypokalaemia (arrhythmia, marked muscular weakness,rhabdomyolysis or serum potassiumlevel ≤ 2.5 mmol/litre)
Forms and strengths, route of administration
Ampoule containing 10% potassium chloride hypertonic solution (100 mg/ml, 10 ml), i.e. 1 g of potassium chloride(KCl) per 10 ml ampoule
Ionic composition:
potassium (K+): 13.4 mmol per 10 ml ampoule (13.4 mEq)
chloride (Cl–): 13.4 mmol per10 ml ampoule (13.4 mEq)
Check concentration before use: potassium chloride also comes in ampoules containing 7.5%, 11.2%, 15% and 20% solutions.
NEVER USE BY IV OR IM OR SC INJECTION. Potassium chloride must always be administered by slow IV infusion, diluted in 0.9% sodium chloride.
For dilution:
The potassium concentration in the infusion fluid should not exceed 40 mmol/litre.
Mix thoroughly the potassium and the 0.9% sodium chloride solution by inverting at least 5 times the infusion bottle or bag.
Dosage and duration
Dosage depends on the severity of hypokalaemia and the patient’s underlying condition. For information:
Child over 1 month:0.2 mmol/kg/hour for 3 hours
Each mmol of potassium is diluted in 25 ml of 0.9% sodium chloride.
Examples:
10 kg
0.2 (mmol) x 10 (kg) = 2 mmol/hour x 3 hours =6 mmol
6 mmol (= 4.5 ml of 10% KCl solution) diluted in 150 ml ofNaCl 0.9% and administered over 3 hours
15 kg
0.2 (mmol) x 15 (kg) = 3 mmol/hour x 3 hours =9 mmol
9 mmol (= 6.5 ml of 10% KCl solution) diluted in 225 ml ofNaCl 0.9% and administered over 3 hours
Adult: 40 mmol (= 3ampoules of 10 ml of 10% KCl) in one litre of 0.9% sodium chloride, to be administered over 4 hours. Do not exceed 10 mmol/hour.
The infusion may be repeated if severe symptoms persist or if the serum potassium level remains < 3 mmol/litre.
Contra-indications, adverse effects, precautions
Administer with caution to elderly patients.
Administer with caution and reduce the dose in patients with renal impairment (increased risk of hyperkalaemia).
May cause:
in the event of rapid or excessive administration: hyperkalaemia, cardiac conduction and rhythm disorders, potentially fatal;
in the event of extravasation: necrosis.
Infusion must be constantly monitored.
Remarks
A 7.5% potassium solution contains 1 mmol of K+/ml; a 11.2% solution contains 1.5 mmol of K+/ml;a 15% solution contains 2 mmol of K+/ml; a 20% solution contains 2.68 mmol of K+/ml.
Moderate hypokalaemia is defined as a potassium level < 3.5 mmol/litre; severe hypo kalaemia as a potassium level ≤ 2.5 mmol/litre.