Although it is possible these patients may have had a degree of pre-existing chronic kidney disease, it is also possible that they had AKI without the necessary www.selleckchem.com/products/Calcitriol-(Rocaltrol).html changes in serum creatinine within the required time period. Using the RIFLE classification that suggested a 1-week timeframe instead of the 48-hour timeframe proposed for the AKIN scale, Ostermann and colleagues found a higher incidence of AKI (39.5% instead of 34.4%; AKI I, 19.3%; AKI II, 6.7%; AKI III, 13.5%). The ICU mortality would have altered only slightly with the change of timeframe (AKI I, 21.0%; AKI II, 24.9%; AKI III, 49.0%). Furthermore, the authors suggested that utilization of RRT as a criterion for AKI III might not be objective and may have had a confounding effect on the predictive power of the classification system as a whole.

It must be said that this effect might be due to a particularly aggressive strategy of the authors, who probably treated AKI with RRT at very early stages of the disease: the protective effect of RRT on mortality found by Ostermann and colleagues on multivariate analysis interestingly confirms this assumption.As already reported last year [10], a large retrospective analysis of the Australian and New Zealand Intensive Care Society database [11] compared RIFLE and AKIN classification in the first 24 hours after admission to the ICU. Even if these classifications were not conceived to be used only in the first 24 hours of admission, the authors found that estimates of prevalence and crude mortality were very similar between the two classification schemes, and concluded that – compared with the RIFLE criteria – the AKIN criteria did not substantially improve the sensitivity, robustness and predictive ability of the definition and classification of AKI.

Lopes and coauthors also evaluated the incidence of AKI and compared the ability of the maximum RIFLE and of the maximum AKIN within ICU hospitalization in predicting inhospital mortality of critically ill patients [12]. Critically ill patients admitted between January 2003 and December 2006 were retrospectively evaluated. Chronic kidney disease patients undergoing dialysis or renal transplant patients were excluded from the analysis. In total, 662 patients (mean age, 58.6 �� 19.2 years; 40% females) were evaluated. Different from Ostermann and colleagues, the AKIN criteria allowed the identification of more AKI patients than the RIFLE criteria (50.

4% vs. 43.8%, P = 0.018) and classified more patients with Stage 1 (Risk in RIFLE) (21.1% vs. 14.7%, P = 0.003), but no differences were observed for Stage 2 (Injury in RIFLE) (10.1% vs. 11%, P = 0.655) and for Stage 3 (Failure in RIFLE) (19.2% vs. 18.1%, P = 0.672). Mortality was significantly Batimastat higher for AKI patients defined by any of the RIFLE criteria (41.3% vs. 11%, P < 0.0001; OR = 2.