Kidney replacement therapy and dialysis in children: Viva

Branch 1: Recognising the need for kidney replacement therapy

The candidate should recognise that this post-cardiac surgery girl has severe acute kidney injury with several of the AEIOU indications for urgent dialysis. She has refractory hyperkalaemia with widening of the QRS complex, an emergency, and fluid overload with rising ventilator pressures that signals early pulmonary oedema. A strong candidate should state that the hyperkalaemia is life-threatening and needs immediate calcium gluconate to stabilise the myocardium while definitive removal by dialysis is arranged, because the medical therapies of insulin-dextrose, salbutamol, and bicarbonate only shift potassium and do not remove it. ^[1]

If the examiner asks how common this scenario is, the candidate should cite the AWARE study finding that acute kidney injury develops in roughly 27 percent of critically ill children within the first week and severe AKI in about 12 percent, with post-cardiac surgery being a classic trigger because cardiopulmonary bypass and low cardiac output injure the kidney. The candidate should explain that the decision to dialyse rests on whether the disturbances are refractory and progressive with end-organ effects, which this child clearly has. ^[1]