INS and cardiac arrhythmia: Understandably, the ECG can be normal in severe hyperkalaemia as the association of hyperkalaemia with arrythmias is dependent on factors including the rate of rise of serum potassium, red blood cell concentration (reflecting level of potassium at tissues), pH and calcium concentration, all of which can be difficult to appreciate in the acute setting, potentially leading to physician uncertainty and tendencies to prescribe insulin/dextrose.11