Renal Replacement Therapy – Overview


Classification

Renal replacement therapy can be classified as intermittent, continuous, hybrid and kidney transplantation.

  • Intermittent renal replacement therapy can be applied as intermittent haemodialysis (IHD) or isolated ultrafiltration (IUD).
  • Continuous renal replacement therapy can be applied as veno-venous slow continuous ultrafiltration (VV-SCUF), continuous veno-venous haemofiltration (CVVH), continuous veno-venous haemodialysis (CVVHD), continuous veno-venous haemodiafiltration (CVVHD+F) or peritoneal dialysis (PD).
  • Hybrid options between intermittent and continuous renal replacement therapy are also available.
  • Should neither of these options be feasible, kidney transplantation may be performed.

Indications for RRT (Renal Replacement Therapy)

Absolute indications include

  • Volume overload that remains unresponsive to diuretic therapy
  • Persistent hyperkalaemia despite medical therapy and
  • Severe metabolic acidosis. Severe metabolic acidosis presents with
    • Overt uraemic symptoms: Encephalopathy, Pericarditis, and Uraemic bleeding diathesis.

Relative indications for renal replacement therapy include progressive azotaemia without uraemic manifestations and persistent oliguria.

Modality Selections

The selection of the modality depends on the resources of the healthcare institution in which the patient is treated, the technical expertise of physicians and nursing staff and, of course, the patient’s wishes.

It is notable that official recommendations are limited, but the main stray of renal replacement therapy in acute kidney injury remains intermittent haemodialysis. Here, dialysis treatments are performed for 3-5 hours 3x/week or more often. The frequency depends on the patient’s requirements.