Treat this as a life-threatening hyperkalaemic emergency and involve senior ED/critical-care and renal teams immediately, while arranging urgent haemodialysis. In a dialysis-dependent patient who has missed dialysis, hyperkalaemia with metabolic acidosis and possible fluid overload/pulmonary oedema requires immediate medical stabilisation plus definitive potassium removal by dialysis; urgent renal replacement therapy is indicated when hyperkalaemia, metabolic acidosis, fluid overload or pulmonary oedema do not respond to medical treatment, and refractory severe hyperkalaemia is an indication for RRT NICE CKS.
- Immediate assessment and monitoring: Use continuous cardiac monitoring, obtain a 12-lead ECG, secure IV access, repeat potassium urgently to confirm the result if this does not delay treatment, and repeat blood gas/glucose and serial serum potassium measurements during treatment. Hyperkalaemia can cause ECG changes, arrhythmias, heart block and cardiac arrest SmPC Potassium,SmPC Potassium.
- Stabilise the myocardium: If there are ECG changes or peri-arrest arrhythmia, give IV 10% calcium gluconate 10–20 mL over 1–5 minutes with ECG monitoring; its effect may be transient, so repeat dosing may be needed if ECG abnormalities persist SmPC Potassium,SmPC Potassium.
- Temporise by shifting potassium intracellularly: Give IV insulin with glucose, with bedside glucose monitoring and glucose administration to prevent hypoglycaemia; insulin and glucose promote cellular potassium uptake SmPC Potassium,SmPC Potassium.
- Address acidaemia: Consider IV sodium bicarbonate as an adjunct in metabolic acidosis, recognising that it is a temporising measure rather than definitive potassium removal SmPC Potassium,SmPC Potassium.
- Definitive treatment: Contact nephrology/renal dialysis services urgently and arrange emergency haemodialysis, which may be required in renal insufficiency and is the appropriate means of potassium removal in this anuric or dialysis-dependent context SmPC Potassium,SmPC Potassium,NICE CKS.
- Breathlessness and chest pain: Assess for pulmonary oedema/fluid overload and concurrent acute coronary syndrome, including oxygenation assessment, chest examination, ECG and appropriate cardiac investigations; escalation to critical care is appropriate if there is respiratory compromise, refractory hyperkalaemia, haemodynamic instability or evolving ECG abnormalities. Fluid overload and pulmonary oedema are complications for which urgent RRT may be indicated when medical management is inadequate NICE CKS.
Do not allow temporising treatment to delay dialysis. Calcium protects against potassium cardiotoxicity but does not lower serum potassium, whereas insulin/glucose and bicarbonate shift potassium intracellularly; haemodialysis provides definitive potassium removal in renal failure SmPC Potassium,SmPC Potassium.