Renal replacement therapy is a method of removing plasma waste products and excess fluid and maintaining normal electrolyte concentrations. It is used when the kidneys are unable to perform this function. It may be used temporarily in acute kidney injury or long-term in chronic kidney disease.

Indications

Acute kidney injury

Refractory – AEIOU 

• Acidosis
• Electrolyte abnormalities (hyperkalaemia, hyponatraemia, hypercalcaemia)
• Intoxicants (methanol, lithium, salicylates)
• Overload 
• Uraemia

Chronic kidney disease

In chronic kidney disease, renal replacement therapy is generally required when the GFR is <15ml/minute, and there are symptoms or complications of kidney disease.

Types of renal replacement therapy

NB: ‘Haemodiafiltration’ combines haemodialysis and haemofiltration. It may be used for chronic kidney disease (haemodiafiltration) or acute kidney injury (continuous venovenous haemodiafiltration). It has a theoretical advantage over haemodialysis because it also allows removal of some larger molecules (e.g. β2 microglobulin).

Questions