Calcium chloride

How it works

Calcium ions restore the transmembrane potential gradient at the myocyte membrane, stabilising cardiac cell excitability, and support normal cardiac and neuromuscular function.

Prescribing in practice

• It is highly irritant and extravasation causes severe tissue necrosis, so it should be given slowly through secure, ideally central, venous access with cardiac monitoring.
• Because it contains substantially more elemental calcium than the equivalent volume of calcium gluconate, the salt must never be assumed interchangeable without recalculation.
• Do not mix or co-administer with bicarbonate- or phosphate-containing solutions, which causes precipitation, and use caution in patients on digoxin where rapid calcium can precipitate arrhythmias.

Monitoring

Use continuous ECG monitoring with checks of serum calcium and potassium, observing the infusion site closely for extravasation.

Counselling the patient

• Flush lines and avoid bicarbonate or phosphate in the same line to prevent precipitation.
• Calcium provides only temporary cardiac protection in hyperkalaemia; treatments to shift and remove potassium must follow.
• Confirm which calcium salt and strength is intended before administration.

Evidence & guidelines

Intravenous calcium for myocardial protection in hyperkalaemia is standard in Resuscitation Council UK and UK renal hyperkalaemia guidance.