Outcome from acute renal failure complicating critical illness is influenced by age

Acute renal failure is a common complication of critical illness. Renal replacement therapy with continuous venovenous haemofiltration (CVVH) is now a routine element of the organ support provided to these patients. The decision to initiate therapy is made on the basis of fluid balance, electrolytes, the degree of accumulation of urea and creatinine and, importantly, on the likely benefit to the patient.

In order to help inform this decision we conducted a retrospective audit of the outcome in terms of hospital mortality of patients receiving CVVH in our district hospital general intensive care unit.

Records were reviewed covering a period of 7 years; September 1995–November 2002. Over this period of time there was a total of 3848 admissions, with a mean APACHE II score of 16.2; these patients had a mean hospital mortality of 26%. Over the same period of time, 276 patients received CVVH. These patients had a mean APACHE II score of 24.8 and a mean hospital mortality of 53.3%. Examination of the data by age group showed that, up to the age of 75 years, the mortality rate was around the average. From 75 years onwards, however, mortality increased rapidly, with those aged 75–80 years having a mortality rate of 73%, and those older than 80 years having 100% mortality.

Intensivists require a performance audit of this kind if they are to establish reasonable limits to the extent of organ support. We contend that this provides valuable information for clinicians at the bedside and in discussions with patients and their relatives.

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