***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: CONTEXT Although acute renal failure ( ARF ) is believed to be common in the setting of critical illness and is associated with a high risk of death , little is known about its epidemiology and outcome or how these vary in different regions of the world . OBJECTIVES To determine the period prevalence of ARF in intensive care unit ( ICU ) patients in multiple countries ; to characterize differences in etiology , illness severity , and clinical practice ; and to determine the impact of these differences on patient outcomes . DESIGN , SETTING , AND PATIENTS Prospect i ve observational study of ICU patients who either were treated with renal replacement therapy ( RRT ) or fulfilled at least 1 of the predefined criteria for ARF from September 2000 to December 2001 at 54 hospitals in 23 countries . MAIN OUTCOME MEASURES Occurrence of ARF , factors contributing to etiology , illness severity , treatment , need for renal support after hospital discharge , and hospital mortality . RESULTS Of 29 269 critically ill patients admitted during the study period , 1738 ( 5.7 % ; 95 % confidence interval [ CI ] , 5.5%-6.0 % ) had ARF during their ICU stay , including 1260 who were treated with RRT . The most common contributing factor to ARF was septic shock ( 47.5 % ; 95 % CI , 45.2%-49.5 % ) . Approximately 30 % of patients had preadmission renal dysfunction . Overall hospital mortality was 60.3 % ( 95 % CI , 58.0%-62.6 % ) . Dialysis dependence at hospital discharge was 13.8 % ( 95 % CI , 11.2%-16.3 % ) for survivors . Independent risk factors for hospital mortality included use of vasopressors ( odds ratio [ OR ] , 1.95 ; 95 % CI , 1.50 - 2.55 ; P<.001 ) , mechanical ventilation ( OR , 2.11 ; 95 % CI , 1.58 - 2.82 ; P<.001 ) , septic shock ( OR , 1.36 ; 95 % CI , 1.03 - 1.79 ; P = .03 ) , cardiogenic shock ( OR , 1.41 ; 95 % CI , 1.05 - 1.90 ; P = .02 ) , and hepatorenal syndrome ( OR , 1.87 ; 95 % CI , 1.07 - 3.28 ; P = .03 ) . CONCLUSION In this multinational study , the period prevalence of ARF requiring RRT in the ICU was between 5 % and 6 % and was associated with a high hospital mortality rate In patients with severe acute kidney injury ( AKI ) but no urgent indication for renal replacement therapy ( RRT ) , the optimal time to initiate RRT remains controversial . While starting RRT preemptively may have benefits , this may expose patients to unnecessary RRT . To study this , we conducted a 12-center open-label pilot trial of critically ill adults with volume replete severe AKI . Patients were r and omized to accelerated ( 12 h or less from eligibility ) or st and ard RRT initiation .  Outcomes were adherence to protocol -defined time windows for RRT initiation ( primary ) , proportion of eligible patients enrolled , follow-up to 90 days , and safety in 101 fully eligible patients ( 57 with sepsis ) with a mean age of 63 years . Median serum creatinine and urine output  at enrollment were 268 micromoles/l and 356 ml per 24 h , respectively . In the accelerated arm , all patients commenced RRT and 45/48 did so within 12 h from eligibility ( median 7.4 h ) . In the st and ard arm , 33 patients started RRT at a median of 31.6 h from eligibility , of which 19 did not receive RRT ( 6 died and 13 recovered kidney function ) . Clinical outcomes were available for all patients at 90 days following enrollment , with mortality 38 % in the accelerated and 37 % in the st and ard arm . Two surviving patients , both r and omized to st and ard RRT initiation , were still RRT dependent at day 90 . No safety signal was evident in either arm . Our findings can inform the design of a large-scale effectiveness r and omized control trial Purpose Septic shock is a leading cause of death among critically ill patients , in particular when complicated by acute kidney injury ( AKI ) . Small experimental and human clinical studies have suggested that high-volume haemofiltration ( HVHF ) may improve haemodynamic profile and mortality . We sought to determine the impact of HVHF on 28-day mortality in critically ill patients with septic shock and AKI . Methods This was a prospect i ve , r and omized , open , multicentre clinical trial conducted at 18 intensive care units in France , Belgium and the Netherl and s. A total of 140 critically ill patients with septic shock and AKI for less than 24 h were enrolled from October 2005 through March 2010 . Patients were r and omized to either HVHF at 70 mL/kg/h or st and ard-volume haemofiltration ( SVHF ) at 35 mL/kg/h , for a 96-h period . Results Primary endpoint was 28-day mortality . The trial was stopped prematurely after enrolment of 140 patients because of slow patient accrual and re sources no longer being available . A total of 137 patients were analysed ( two withdrew consent , one was excluded ) ; 66 patients in the HVHF group and 71 in the SVHF group . Mortality at 28 days was lower than expected but not different between groups ( HVHF 37.9 % vs. SVHF 40.8 % , log-rank test p = 0.94 ) . There were no statistically significant differences in any of the secondary endpoints between treatment groups . Conclusions In the IVOIRE trial , there was no evidence that HVHF at 70 mL/kg/h , when compared with contemporary SVHF at 35 mL/kg/h , leads to a reduction of 28-day mortality or contributes to early improvements in haemodynamic profile or organ function . HVHF , as applied in this trial , can not be recommended for treatment of septic shock complicated by AKI Introduction Abdominal surgery is probably associated with more likelihood to cause acute kidney injury ( AKI ) . The aim of this study was to evaluate whether early or late start of renal replacement therapy ( RRT ) defined by simplified RIFLE ( sRIFLE ) classification in AKI patients after major abdominal surgery  will affect outcome . Methods A multicenter prospect i ve observational study based on the NSARF ( N ational Taiwan University S urgical ICU A ssociated R enal F ailure ) Study Group data base . 98 patients ( 41 female , mean age 66.4 ± 13.9 years ) who underwent acute RRT according to local indications for post-major abdominal surgery AKI between 1 January , 2002 and 31 December , 2005 were enrolled The demographic data , comorbid diseases , types of surgery and RRT , as well as the indications for RRT were documented . The patients were divided into early dialysis ( sRIFLE-0 or Risk ) and late dialysis ( LD , sRIFLE -Injury or Failure ) groups . Then we measured and recorded patients ' outcome including in-hospital mortality and RRT wean-off until 30 June , 2006 . Results The in-hospital mortality was compared as endpoint . Fifty-seven patients ( 58.2 % ) died during hospitalization . LD ( hazard ratio ( HR ) 1.846 ; P = 0.027 ) , old age ( HR 2.090 ; P = 0.010 ) , cardiac failure ( HR 4.620 ; P < 0.001 ) , pre-RRT SOFA score ( HR 1.152 ; P < 0.001 ) were independent indicators for in-hospital mortality . Conclusions The findings of this study support earlier initiation of acute RRT , and also underscore the importance of predicting prognoses of major abdominal surgical patients with AKI by using RIFLE classification Background Acute kidney injury is a common and devastating complication of critical illness , for which renal replacement therapy is frequently needed to manage severe cases . While a recent systematic review suggested that “ earlier ” initiation of renal replacement therapy improves survival , completed trials are limited due to small size , single-centre status , and use of variable definitions to define “ early ” renal replacement therapy initiation . Methods / design This is an open-label pilot r and omized controlled trial . One hundred critically ill patients with severe acute kidney injury will be r and omly allocated 1:1 to receive “ accelerated ” initiation of renal replacement therapy or “ st and ard ” initiation at 12 centers across Canada . In the accelerated arm , participants will have a venous catheter placed and renal replacement therapy will be initiated within 12 hours of fulfilling eligibility . In the st and ard initiation arm , participants will be monitored over 7 days to identify indications for renal replacement therapy . For participants in the st and ard arm with persistent acute kidney injury , defined as a serum creatinine not declining > 50 % from the value at the time of eligibility , the initiation of RRT will be discouraged unless one or more of the following criteria are fulfilled : serum potassium ≥6.0 mmol/L ; serum bicarbonate ≤10 mmol/L ; severe respiratory failure ( PaO2/FiO2<200 ) or persisting acute kidney injury for ≥72 hours after fulfilling eligibility . The inclusion criteria are design ed to identify a population of critically ill adults with severe acute kidney injury who are likely to need renal replacement therapy during their hospitalization , but not immediately . The primary outcome is protocol adherence ( > 90 % ) . Secondary outcomes include measures of feasibility ( proportion of eligible patients enrolled in the trial , proportion of enrolled patients followed to 90 days for assessment of vital status and the need for renal replacement therapy ) and safety ( occurrence of adverse events ) . Discussion The optimal timing of renal replacement therapy initiation in patients with severe acute kidney injury remains uncertain , representing an important knowledge gap and a priority for high- quality research . This pilot trial is necessary to establish protocol feasibility , confirm the safety of participants and obtain estimated events rates for design of a large definitive trial . Trial registration Objective : The impact of continuous venovenous hemofiltration on  sepsis-induced multiple organ failure  severity is controversial . We sought to assess the effect of early application of hemofiltration on the degree of organ dysfunction and plasma cytokine levels in patients with severe sepsis or septic shock . Design : Prospect i ve , r and omized , open , multicenter study setting , 12 French intensive care units . Patients : A total of 80 patients were enrolled within 24 hours of development of the first organ failure related to a new septic insult . Interventions : Patients were r and omized to group 1 ( HF ) , who received hemofiltration ( 25 mL/kg/hr ) for a 96-hour period , or group 2 ( C ) who  were managed conventionally . Measurements and Main Results : The primary end point was the number , severity , and duration of organ failures during 14 days , as evaluated by the Sepsis-Related Organ Failure Assessment score , on an intention-to-treat analysis . Strict guidelines were provided to perform continuous hemofiltration under the same conditions and bearing the same objectives in all centers . Because of inclusion stagnation , the trial was discontinued after an interim analysis by which time 76 patients had been r and omized . The number and severity of organ failures were significantly higher in the HF group ( p < 0.05 ) . No modifications in plasma cytokine levels could be detected . Conclusion : These data suggest that early application of st and ard continuous venovenous hemofiltration is deleterious in severe sepsis and septic shock . This study does not rule out an effect of high-volume hemofiltration ( > 35 mL/kg/hr ) on the course of sepsis BACKGROUND The timing of renal-replacement therapy in critically ill patients who have acute kidney injury but no potentially life-threatening complication directly related to renal failure is a subject of debate . METHODS In this multicenter r and omized trial , we assigned patients with severe acute kidney injury ( Kidney Disease : Improving Global Outcomes [ KDIGO ] classification , stage 3 [ stages range from 1 to 3 , with higher stages indicating more severe kidney injury ] ) who required mechanical ventilation , catecholamine infusion , or both and did not have a potentially life-threatening complication directly related to renal failure to either an  early or a delayed strategy of renal-replacement therapy .  With the early strategy , renal-replacement therapy was started immediately after r and omization . With the delayed strategy , renal-replacement therapy was initiated if at least one of the following criteria was met : severe hyperkalemia , metabolic acidosis , pulmonary edema , blood urea nitrogen level higher than 112 mg per deciliter , or oliguria for more than 72 hours after r and omization . The primary outcome was overall survival at day 60 . RESULTS A total of 620 patients underwent r and omization . The Kaplan-Meier estimates of mortality at day 60 did not differ significantly between the early and delayed strategies ; 15 
    Output:
    
Conclusions Early initiation of RRT for patients with AKI is not associated with decreased overall mortality or a delayed renal recovery rate .
The optimal time to initiate RRT remains uncertain .