ACUTE KIDNEY FAILURE

Specific causes of acute kidney failure

▪   Prerenal failure and acute tubular necrosis
▪   Vascular causes of acute kidney failure
▪   Nephrotoxic causes of acute kidney failure
▪   Glomerulonephritic and vasculitic causes of
    acute kidney failure
▪   Interstitial nephritis as a cause of acute
    kidney failure
▪   'Haematological' causes of acute kidney failure
▪   Hepatokidney Syndrome
▪   Tropical

Tropical

Acute kidney failure in the developing world, as elsewhere, is usually a consequence of acute tubular necrosis. The causes of hospital-acquired acute kidney failure are the same as in the developed world, with nephrotoxic drugs, major surgery, and hospital-acquired sepsis the dominant factors. By contrast, the causes of community-acquired acute kidney failure are very different.

The Chandigarh study showed that 30 years ago diarrhoeal disease and obstetric complications each accounted for about 25 per cent of cases of acute kidney failure in North India, but more recently each has accounted for about 10 per cent. Infections that often cause acute kidney failure in the developing world include falciparum malaria, leptospirosis, melioidosis, cholera, salmonellosis, and shigellosis. Intravascular haemolysis is a common feature of many cases, being found in over 20 per cent of 325 patients receiving dialysis for acute kidney failure in Chandigarh. This was most frequently seen in those with glucose-6-phosphate dehydrogenase deficiency, with copper sulphate poisoning and snake bite the next commonest causes. Poisoning by deliberate (occasionally accidental) ingestion of paraquat (herbicide) is not uncommon in agricultural communities: aside from kidney failure this can lead to inexorably progressive respiratory failure with an extremely high mortality. Treatment with corticosteroids and cyclophosphamide has been used in an attempt to prevent pulmonary fibrosis and may be of benefit. Heatstroke can cause acute kidney failure.

Snake bite

Acute kidney failure develops in 5 to 30 per cent of the victims of severe viper poisoning and is the cause of between 2 and 3 per cent of cases of acute kidney failure, but a very much higher proportion in some centres at some times of the year. It develops from a few hours to 72 h following the bite, and is non-oliguric in 50 per cent of cases. Hyperkalaemia may be prominent in bites associated with myonecrosis, such as those of sea-snakes. The usual kidney pathology is acute tubular necrosis, but acute cortical necrosis can occur. Kidney management is supportive.

Copper sulphate poisoning

Copper sulphate is extensively used in the leather industry and is a relatively common (although decreasing) cause of poisoning in India. Symptoms include nausea, vomiting, diarrhoea, epigastric pain, gastrointestinal bleeding, and coma. Signs include jaundice, hypotension, and shock. Investigation reveals intravascular haemolysis, methaemoglobinaemia, haemoglobinuria, haematuria, and kidney failure, the latter complicating 11 of 29 cases in one series.

Histological examination of the kidneys shows acute tubular necrosis with luminal haemoglobin casts, rupture of tubular basement membranes, and copper in degenerated tubules.

Aside from gastric lavage, management usually involves the administration (urine output permitting) of intravenous 0.9 per cent saline, mannitol, and/or diuretics to encourage copper elimination, intramuscular dimercaprol (but with extreme caution if kidney failure has developed), and dialysis.