Use of the AKIN criteria to assess the incidence of acute renal injury, outcome and prognostic factors of ICU mortality in critically ill patients

Abstract

To evaluate the value of the AKIN criteria of acute kidney injury (AKI) in the incidence and prognoses in critically ill patients, and to further identify risk factors associated with the prognoses of the critically ill patients. We retrospectively studied 544 adult patients hospitalized for ≥24 h to a comprehensive ICU with 16 beds in teaching hospital from January 2008 to December 2009. Based on AKIN criteria, these patients were classified into four groups: NAKI (no AKI), AKII, AKIII, and AKIIII respectively. (1) Of the patients, 191 (35.5%) fulfilled the criteria for AKI (14.8% had AKI I 8.2% had AKI II and 11.9% had AKIIII). (2) Mortality in the ICU was much higher in patients with AKI than in patients with no AKI (48% vs 11%, OR 7.48, 95%CI 4.831-11.587, P<0.001). The mortality rate was 37% for AKII group, 51% for AKIII group and 60% for AKIIII group. (3) In multivariate analysis, each AKIN category was independently associated with ICU mortality. The other independent risk factors for ICU mortality included internal medical diseases, septic shock, pre-existing chronic illness, APACHEII score, the number of failed organs, mechanical ventilation and CRRT. The AKIN category closely relates to the prognoses in critically ill patients, even the mild degree of AKI with a much higher mortality rate than the patients without AKI. The AKIN criteria has some direction significance to the early detection and classification of AKI and to the prediction of clinical outcomes in critically ill patients.