Hyperkalaemia — ECG & emergency management
What it means
ECG progression: tall tented T waves → flattened/absent P → broad QRS → sinusoidal → VF/asystole. Emergency Mx (UK Renal Association): IV calcium gluconate (cardiac-membrane stabilisation, doesn't lower K), then insulin (10 units) + 25 g glucose ± nebulised salbutamol to shift K intracellularly; treat the cause and remove K (e.g. potassium binders, dialysis).
Worked example
K 6.9 with tented T waves and broadening QRS → calcium gluconate first, then insulin–dextrose.
In the exam
A patient in AKI has K 7.0 with peaked T waves and a widening QRS; the priority drug protects the myocardium without lowering the potassium.
What settles it
Calcium gluconate STABILISES the myocardium (no K-lowering); insulin–dextrose and salbutamol SHIFT K into cells; binders/dialysis REMOVE it.
Classically confused with
Hyponatraemia — the volume-status approach
Source: UK Renal Association / Resus Council