Incidence and clinical outcomes of acute kidney injury requiring renal replacement therapy in Japan.

No population-based studies have described the prevalence of acute kidney injury (AKI) treated with renal replacement therapy (RRT) in Japan. This study prospectively examined the incidence of AKI requiring RRT by surveying 16 hospitals in Shizuoka prefecture from January to October 2006. The subjects comprised 242 patients treated with RRT during the observation period. The estimated incidence of AKI requiring RRT was 13.3 cases/100,000 persons/year in this area. Major contributing factors for AKI were sepsis (34%), cardiac shock (23%), and major surgery (12%). The in-hospital mortality rate was 47.1%, paralleling the increased number of insufficient organs. Oliguria was a risk factor for in-hospital mortality. These findings suggest that the incidence of AKI treated with RRT in Japan is comparable to those in Western countries, and the prognosis of AKI patients requiring RRT is also poor in Japanese patients.