Introduction

Despite advances in the understanding, diagnosis and treatment of acute renal failure, many aspects remain unresolved. Modern technology has provided different modalities to perform extracorporeal renal support, but it is not clear which is superior in terms of efficacy and outcome. Moreover, evidence-based medicine has not yet defined when to start and when to wean off renal replacement therapy (RRT).

Starting renal replacement therapy

Renal replacement is indicated when renal dysfunction leads to one or more of the following:

1. • severe fluid overload;

2. • pulmonary oedema;

3. • hyperkalemia; and

4. • metabolic acidosis.

Renal replacement therapy is traditionally considered when all medical treatment (diuretics, bicarbonate administration, fluid restriction and nutritional restriction) have failed. However, greater ease of use and a low associated morbidity has led to RRT being considered earlier in the disease process. This may be related to the perception that maintenance of homeostasis and prevention of complications is increasingly important. There is also some evidence that RRT has some role to play in the management of sepsis and multiple organ dysfunction syndromes, before acute renal failure has ensued. Recent algorithms have placed more emphasis on prevention.