Acute renal failure. Multivariate analysis of causes and risk factors.

Accepted causes (acute insults) and risk factors for the development of acute renal failure were defined, quantitatively assessed, and tested for statistical significance in 143 patients with acute tubular necrosis. Sixty-two percent of patients had more than one acute insult, and 48 percent had more than one suspected risk factor. Hypotension, excessive aminoglycoside exposure, pigmenturia, and dehydration were identified as highly significant acute insults, while it was concluded that sepsis and administration of radiocontrast material could not be incriminated as causes of acute tubular necrosis. An additive interaction between acute insults was demonstrated, and the severity of acute renal failure was related to the number and severity of acute insults. Patients with oliguric renal failure had more severe acute insults than patients with nonoliguric renal failure. Preexisting renal disease and chronic hypertension were significant risk factors, the latter only when hypotension had been one of the acute insults. An age of more than 59 years, gout and/or chronic hyperuricemia, diabetes, and long-term diuretic administration were not found to be significant risk factors.