Thus, only creatinine criteria of the RIFLE consensus definition of AKI were used to define outcome. Where pre-morbid biochemical data was not available, a baseline sCr was estimated assuming a GFR of 75 ml/min Bicalutamide mw as previously described [9]. One patient received renal replacement therapy (RRT) for ongoing anuria prior to meeting biochemical criteria for RIFLE-I and was analyzed as developing AKI-Cr. Data were collected until the occurrence of AKI-Cr defined as RIFLE I[Cr] or greater or ICU discharge, oliguria during days in ICU after the occurrence of AKI-Cr were not included. Episodes of oliguria during each 24-hour period were correlated with the occurrence of new RIFLE I[Cr] or greater on routine morning bloods the next day.

We considered that more sustained oliguria may reflect extended periods of renal hemodynamic compromise and might better predict biochemically evident renal dysfunction. Thus, we sought to correlate the maximum duration of consecutive oliguria on any given ICU day with the occurrence of new RIFLE I[Cr] or greater on routine bloods the next morning. We secondarily assessed the predictive ability of oliguria in each of the two days preceding AKI-Cr and repeated our original analysis limiting data to that collected on the first three ICU days only.For each individual episode of oliguria basic hemodynamic variables at the beginning of the episode and any clinician response to oliguria (fluid, vasoactive drug, or diuretic prescription) were recorded and comparison was made between episodes of oliguria that were and were not associated with progression to RIFLE I[Cr] the next day.

In this analysis individual episodes of oliguria were treated as discrete events. This is because two different episodes of oliguria occurring on the same day might have occurred in different hemodynamic contexts and prompted different interventions. Clinical interventions were deemed to be associated with oliguria if they occurred during or within one hour of the end of a period of oliguria.Data handing and statistical analysisData were collected and collated using Microsoft Excel (Microsoft Corp, Redmond, WA, USA). Categorical variables were compared using Fisher’s exact test, continuous data were reported as median with inter-quartile range (IQR) and compared using the Mann-Whitney U test.

Receiver-operator characteristic (ROC) curve analysis was used to assess the ability of varying duration of the longest period of oliguria to predict the occurrence of RIFLE I[Cr] or greater the next day. Univariate statistics, ROC curve analysis and area under curve (AUC) calculation Cilengitide was carried out using GraphPad Prism version 5.0 d for Mac OS (GraphPad Software, La Jolla, CA) [10] additionally binomially fitted ROC curves and asymmetric 95% confidence intervals were prepared using ROC analysis: web-based calculator for ROC curves [11]. We defined an ROCAUC of 0.5 to 0.6 as showing no predictive ability, an ROCAUC of 0.