Despite its extensive use in clinical practice, there is uncertainty about the optimal time and indications for initiation of RRT in the ICU [6]. Clearly, the process involved in deciding when to initiate RRT in critically ill adult patients is complex and can be influenced by numerous factors, including patient-specific and clinician-specific http://www.selleckchem.com/products/Rapamycin.html factors and those related to organizational/logistical issues (Table (Table1).1). Indeed, studies have shown marked variation of practice between clinicians, and across institutions and countries [7,8].Table 1Summary of selected factors potentially influencing the decision to initiate renal replacement therapy in critically ill patientsAn evaluation of timing of RRT initiation has been the focus of a number of clinical studies.

These have recently been summarized in a systematic review and meta-analysis [6,9-13]. Most of these studies have been small, retrospective or secondary analyses, and have arbitrarily dichotomized the study population into ‘early’ or ‘late’ RRT initiation based on biochemical criteria, urine output criteria, or by ‘door-to-dialysis’ time [14]. The meta-analysis by Seabra and colleagues [12] also included five randomized trials. A pooled analysis from these trials showed a non-statistically significant trend towards reduced mortality with earlier initiation of RRT (relative risk 0.64; 95% confidence interval (CI), 0.40 to 1.05, P = 0.08). However, this pooled analysis only included data from 270 patients, thus limiting its statistical power.

Accordingly, this limits the inferences about timing of RRT initiation and prohibits a simple translation of such data easily to the bedside to guide clinical management. While large prospective studies are urgently needed, the currently available data would indicate a potential benefit associated with earlier initiation of RRT for those patients where RRT is likely to be needed in terms of both survival and recovery of kidney function [12,15].Currently, there exists no broad consensus to guide clinicians on this important issue. In fact, RRT initiation has been repeatedly identified as a research priority [16-18]. Accordingly, we have developed an opinion-based clinical algorithm to aid in the decision on when to consider initiation of RRT in critically ill patients (Figure (Figure1).1).

The algorithm gives a more quantitative characterization of ‘timing’ and incorporates several patient-specific factors, based on clinical evidence when available, that may influence when to initiate RRT. We adapt the terminology proposed by the Acute Kidney Injury Network (AKIN): ‘illness trajectory’ refers Carfilzomib to the pace of clinical evolution of the patient, and AKI ‘trend’ refers to the rate of clinical and/or biochemical changes (including urea and creatinine) [16].