Management: Myocardial Stabilisation

In patients with cardiac arrhythmias or conduction abnormalities, the first step is to stabilise the myocardium.

Calcium does not lower the serum potassium level, but should be used when the ECG shows a widened QRS, sine wave pattern, arrhythmias, or in hyperkalaemic cardiac arrest, in order to stabilise the myocardium.

Either calcium chloride or calcium gluconate can be used and are widely available. Due to the greater potency of calcium chloride, larger doses of calcium gluconate can be needed if this is used in preference. Calcium gluconate is less irritating to veins and therefore a preferable choice if given peripherally.

Calcium chloride 10%

Dose: 5-10ml over 10 minutes

Complications: Thrombophlebitis

Calcium gluconate 10%

Dose: 10-20ml over 5-10 minutes

Further doses can be given until the ECG normalises, and calcium levels should be monitored on blood gases.

Hypertonic (3%) saline has been shown to reverse ECG changes in patients with hyperkalaemia and concurrent hyponatraemia. There is no evidence that its administration benefits eunatraemic patients, and so use of hypertonic saline should be restricted to hyponatraemic hyperkalaemic patients with an awareness of the potential volume overload it may cause. The dose is a 50ml push [8].