Introduction

Acute renal failure is characterised by a rapid fall in glomerular filtration rate, clinically manifest as an abrupt and sustained rise in urea and creatinine. Life threatening consequences include volume overload, hyperkalaemia, and metabolic acidosis. Acute renal failure is both common and costly and carries a high morbidity and mortality. As it is often preventable, identification of patients at risk and institution of appropriate preventive measures are crucial. In incipient or established acute renal failure rapid recognition and treatment may prevent irreversible loss of nephrons.

In most cases of acute renal failure initial management is by non-specialist clinicians, often comparatively junior ones. All clinicians should therefore be able to recognise the symptoms and signs of acute renal failure, request and interpret initial investigations, initiate appropriate treatment, and know when, and how urgently, to consult a more experienced colleague or specialist. This review highlights the common causes of acute renal failure, defines the population at risk, evaluates established and newer strategies for prevention and treatment, and identifies those patients who warrant early referral.

Who gets acute renal failure?

Acute renal failure is increasingly common, particularly in elderly people, although reported incidences vary according to the definition used and the population studied. In 1993 a community based study found an incidence of severe acute renal failure (serum creatinine > 500 µmol/l) of 172 per million adults per year, of whom 72% were over 70.1 Age related incidence rose from 17 per million per year in adults under 50 to 949 per million per year in the 80-89 age group. More recent prospective studies report an overall incidence of acute renal failure of almost 500 per million per year2 3 and an incidence of acute renal failure needing dialysis of more than 200 per million per year.4 This is double the UK incidence of end …