EPIDEMIOLOGY OF ACUTE-RENAL-FAILURE - A PROSPECTIVE, MULTICENTER, COMMUNITY-BASED STUDY

There are very limited data on overall epidemiology of ARF. It is cruc ial to know the incidence, etiology and clinical features of ARF to pr omote prevention strategies and to implement adequate resources for th e management of this entity. During a nine month period, a collaborati ve prospective protocol with 98 variables was developed to assess all ARF episodes encountered in the 13 tertiary-care hospitals in Madrid, Spain (covering 4.2 million people of over 14 years of age). ARF was c onsidered when a sudden rise in serum creatinine concentration (S-Cr) to more than 177 mu mol/liter was found in patients with normal renal function, or when the sudden rise (50% or more) was observed in patien ts with previous mild-to-moderate chronic renal failure (S-Cr < 264 mu mol/liter). Of the 748 cases of ARF studied, 665 episodes presented i n inhabitans from the Madrid area. This gives an overall incidence of ARF of 209 cases per million population (p.m.p.; 95% Ci 195 to 223). T he incidence of acute tubular necrosis (ATN) was 88 cases p.m.p. (95% CI 79 to 97), prerenal ARF 36 p.m.p (95% CI 40 to 52), acute-onset chr onic ARF 29 p.m.p. (95% CI 24 to 34), and obstructive ARF 13 p.m.p. (9 5% CI 19 to 27). The mean age was 63 +/- 17 years. The most frequent c auses of ARF were ATN (45%), prerenal (21%), acute-onset chronic renal failure (12.7%) and obstructive ARF (10%). Renal function was normal at admission in 48% of patients who later developed ARF. Mortality (35 %) was much higher than that of the other patients admitted (5.4%, P < 0.001). This real outcome correlated extremely well with the expected outcome calculated through out the severity index of ARF (SI) 0.433 /- 0.246 (mean +/- SD). In 187 cases, mortality was attributed to unde rlying disease, thus corrected mortality due to ARF was 26.7%. Dialysi s was required in 36% of patients. and was associated with a significa ntly higher SI of ARF (0.57 +/- 0.23 vs. 0.35 +/- 0.19, P < 0.001) and mortality (65.9 vs. 33.2%, P < 0.001). Mortality in patients hemodial yzed with biocompatible synthetic membranes (N = 50) was similar to th at observed with cellulosic ones (N = 84; 66% vs. 59.5%, NS). Mortalit y was higher in patients with coma, assisted respiration, hypotension, jaundice (all P < 0.001) and oliguria (P < 0.02). This study gives, f or the first time, the incidence of all forms of ARF in a developed co untry. ARF is iatrogenically induced at a high rate by modern medicine . Prevention strategies, particularly in the perioperative period, are needed to decrease its impact.