Changes of etiology, incidence and outcomes of severe acute kidney injury during a 12-year period (2001-2012) in large university hospital

Abstract

Background: Despite improvement in the quality of critical care, the incidence and mortality of acute kidney injury (AKI) continues to rise. The aim of our study was to analyze the changes during a 12-year period in etiology, incidence and outcomes of severe AKI, which required dialysis, in a large single centre.

Methods: We performed retrospective analysis of all the patients (n=3215) with severe AKI hospitalized and dialysed in the hospital of Lithuanian university of health sciences Kauno Klinikos (HLUHS KK) during the period of 2001-2012.

Results: During a 12-year period, the incidence of severe AKI increased from 154 to 597 cases/p.m.p. The mean age of the patients increased from 58.2±19.2 years in 2001 to 65.7±17 years in 2012 (P<0.001). The number of men (n=2012; 62.6%) was significantly higher than that of women (n=1201; 37.4%; P<0.001). The causes of severe AKI were renal (n=1128; 35.1%), prerenal (n=642; 20%), obstructive (n=310; 9.6%) and in 12.7% of the patients-multifactorial. Overall, the most frequent cause of AKI was acute tubular necrosis (n=1069; 33.2%). The renal replacement therapy (RRT) was discontinued due to improved kidney function in 45.3% of cases. 8.1% of the patients remained dialysis dependent. The mortality rate was 44%.

Conclusions: During a 12-year period, the number of the patients with severe AKI increased three times with the predominance of men and elderly people. There was an observed increase in multifactorial causes of severe AKI; however, ATN remained dominant over the decade. The mortality rate remained high, almost half of the patients died, less than 10% remained dialysis dependent, the rest had the improvement of renal function.

Keywords: Acute kidney injury; Acute tubular necrosis; Epidemiology; Hemodialysis; Outcomes.