Aetiology, diagnosis, treatment and prognosis of acute renal failure in an intensive care unit.

Over a period of 2 years, 82 patients out of 2,390 (3.43%) admitted to an intensive care unit developed acute renal failure (ARF). The diagnosis of ARF was based on the usual criteria of oliguria, a rising blood urea nitrogen and creatinine, urine sodium concentration greater than 20 mmol/l and a U/P osmolality ratio less than 1.1. In 9.2% of patients the latter two criteria were misleading. Sepsis was the commonest cause of vasomotor nephropathy but in 20.7% potentially nephrotoxic agents had been administered before development of ARF. Overall mortality was 73.2%, with patients older than 50 years of age having the highest mortality. ARF is associated with prolonged bed occupancy--an average of 59.8 days for the dialysed patients with ARF versus an average length of stay of 8.4 days for the hospital overall.