Pathophysiology of acute renal failure

Abstract

Acute renal failure (ARF) affects 5–7% of all hospitalized patients (1–3) and continues to be associated with poor outcomes (4–10). This syndrome is common in the intensive care unit (ICU), with a reported incidence of 1–25% (11, 12) depending on the population being studied and the criteria used to define its presence. Uncomplicated ARF can usually be managed outside the ICU setting and carries a good prognosis, with mortality rates less than 5–10% (2, 13). In contrast, ARF complicating non-renal organ system failure in the ICU setting is associated with mortality rates of 50–70%, which have remained relatively constant over recent decades (9, 14–19). It is generally accepted that ARF in the ICU setting is associated with a high mortality rate (20, 21), and that ICU patients who develop ARF have a higher mortality than those who do not (9, 11, 12, 22–24). Furthermore, evidence exists that ARF is a specific independent risk factor for poor prognosis in critically ill patients (12, 21). Table 1 summarizes some studies reporting the incidence of, and mortality from, ARF in ICU patients.