Discussion
critically ill, failure of three organs in most patients., RIFLE, septic shock, AKI
CRITICALLY ILL, ACUTE RENAL FAILURE, SEPTIC SHOCK
To the best of our knowledge, this is the first study based on a randomized clinical trial to find a differential impact on outcome of the timing of RRT initiation, according to the diagnostic criteria used to define AKI. Our results indicate that patients in the failure category of the RIFLE classification (corresponding to KDIGO stage 3) are a heterogeneous group, whereby those diagnosed on the basis of creatinine elevation alone do not appear to benefit from early initiation of RRT, but on the contrary, may actually be at risk for increased mortality with such a strategy. Conversely, patients diagnosed on the basis of reduced urine output only had a numerically, albeit non-statistically significantly higher mortality rate with delayed RRT initiation.At the time the IDEAL-ICU study was designed, in the absence of consensual criteria for RRT initiation, the definition of “early” versus “delayed” or “late” initiation of RRT was arbitrary. Thus, we chose the RIFLE criteria for the early-strategy group of IDEAL-ICU [The decision to initiate RRT is usually made in a wider clinical context that takes account of the patient’s comorbidities and other organ dysfunctions. Clinicians do not decide solely on the basis of RIFLE/KDIGO criteria, and it is important to stress that our results concern a population with septic shock and acute renal failure, with invasive mechanical ventilation in over 85% of cases, and therefore with failure of three organs in most patients. Nevertheless, the RIFLE/KDIGO criteria remain major determinants of the decision to initiate RRT in critically ill patients in routine practice [In fact, the RIFLE and KDIGO scores are both based on an increase in serum creatinine and a reduction in urine output [This is not the first time that an increase in mortality has been observed with early RRT when initiation is based on creatinine level alone. In a prospective multicenter observational study [A further possible interpretation of our results is that the IDEAL-ICU trial [An important strength of our study is that the data stem from a multicenter randomized controlled trial, in a large population of patients in the acute phase of septic shock. Second, the groups included in this analysis are fine-tuned, with specific criteria, providing a level of nuance not present in other studies on this topic. However, this study also has some limitations. Firstly, this is a 