***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: BACKGROUND Renal replacement therapy ( RRT ) for acute renal failure ( ARF ) may be provided in many setting s within the hospital . Such patients require a high level of care and often have a poor prognosis . No prospect i ve studies have accurately defined this population , making the prediction of necessary re sources and the planning of services difficult . AIM To ascertain the incidence , causes and outcomes of  acute renal failure requiring renal replacement therapy in Scotl and . DESIGN A prospect i ve observational census of all clinical areas providing renal replacement therapy in three Scottish health boards ( Grampian , Highl and , Tayside ) . METHODS Patients were identified by liaison with each unit providing RRT . Factors precipitating renal failure and reasons for RRT were recorded at the time of initiation . Comorbid disease burden was scored using the Charlson index . Patient status at 90 days was assessed from case-notes , contacting general practitioners where necessary . RESULTS 375 patients per million population per year received RRT ; 203 per million per year for either ARF or acute-on-chronic renal failure . 73.5 % of patients receiving RRT for ARF died within 90 days , 23.5 % became independent of RRT . The median duration of hospital admission was 19 days . DISCUSSION The annual incidence of ARF requiring RRT is just over 200 per million population , almost twice that of end-stage renal disease requiring RRT . Such treatment places high dem and s upon health care re sources BACKGROUND Continuous veno-venous haemofiltration is increasingly used to treat acute renal failure in critically ill patients , but a clear definition of an adequate treatment dose has not been established . We undertook a prospect i ve r and omised study of the impact different ultrafiltration doses in continuous renal replacement therapy on survival . METHODS We enrolled 425 patients , with a mean age of 61 years , in intensive care who had acute renal failure . Patients were r and omly assigned ultrafiltration at 20 mL h(-1 ) kg(-1 ) ( group 1 , n=146 ) , 35 mL h(-1 ) kg(-1 ) ( group 2 , n=139 ) , or 45 mL h(-1 ) kg(-1 ) ( group 3 , n=140 ) . The primary endpoint was survival at 15 days after stopping haemofiltration . We also assessed recovery of renal function and frequency of complications during treatment . Analysis was by intention to treat . RESULTS Survival in group 1 was significantly lower than in groups 2 ( p=0.0007 ) and 3 ( p=0.0013 ) . Survival in groups 2 and 3 did not differ significantly ( p=0.87 ) . Adjustment for possible confounding factors did not change the pattern of differences among the groups . Survivors in all groups had lower concentrations of blood urea nitrogen before continuous haemofiltration was started than non-survivors . 95 % , 92 % , and 90 % of survivors in groups 1 , 2 , and 3 , respectively , had full recovery of renal function . The frequency of complications was similarly low in all groups . INTERPRETATION Mortality among these critically ill patients was high , but increase in the rate of ultrafiltration improved survival significantly . We recommend that ultrafiltration should be prescribed according to patient 's bodyweight and should reach at least 35 mL h(-1 ) kg(-1 ) BACKGROUND Despite the widespread use of continuous renal replacement therapy in critically ill patients with acute renal failure ( ARF ) , there are few data supporting its benefits over conventional intermittent hemodialysis ( IHD ) . We sought to analyze differences in survival between modalities in a study that compared continuous venovenous hemodialysis ( CVVHD ) with IHD . METHODS Eighty critically ill patients with ARF requiring dialysis were r and omized after stratification by severity of illness to treatment with CVVHD or IHD .  RESULTS There were no differences in survival or renal recovery between groups . In patients who died , mean survival time was 10.7 + /- 11.2 days for the IHD group versus 14.3 + /- 16.1 days for the CVVHD group ( P = not significant ) . There was greater net volume removal in the CVVHD group during 72 hours . Declines in urine output during 72 hours were similar between groups . Mean arterial pressure off and on dialysis therapy was analyzed retrospectively . There was a significant decrease in mean arterial pressure for patients on IHD therapy not seen in those on CVVHD therapy , but this did not lead to a survival advantage . CONCLUSION Despite greater volume control , CVVHD did not lead to an improvement in survival , preservation of urine output , or renal recovery compared with IHD in patients with ARF Among critically ill patients , acute kidney injury ( AKI ) requiring dialysis is associated with mortality rates generally in excess of 50 % . Continuous renal replacement therapies ( CRRT ) often are recommended and widely used , although data to support its superiority over intermittent hemodialysis ( IHD ) are lacking . Data from the Program to Improve Care in Acute Renal Disease ( PICARD ) , a multicenter observational study of AKI , were analyzed . Among 398 patients who required dialysis  , the risk for death within 60 d was examined by assigned initial dialysis modality ( CRRT [ n = 206 ] versus IHD [ n = 192 ] ) using st and ard Kaplan-Meier product limit estimates , proportional hazards ( " Cox " ) regression methods , and a propensity score approach to account for selection effects . Crude survival rates were lower for patients who were treated with CRRT than IHD ( survival at 30 d 45 versus 58 % ; P = 0.006 ) . Adjusted for age , hepatic failure , sepsis , thrombocytopenia , blood urea nitrogen , and serum creatinine and stratified by site , the relative risk for death associated with CRRT was 1.82 ( 95 % confidence interval 1.26 to 2.62 ) . Further adjustment for the propensity score did not material ly alter the association ( relative risk 1.92 ; 95 % confidence interval 1.28 to 2.89 ) . Among critically ill patients with AKI , CRRT was associated with increased mortality . Although the results could reflect residual confounding by severity of illness , these data provide no evidence for a survival benefit afforded by CRRT . Larger , prospect i ve , r and omized clinical trials to compare CRRT and IHD in severe AKI are needed BACKGROUND Acute renal failure ( ARF ) requiring dialysis in critically ill patients is associated with an in-hospital mortality rate of 50 to 80 % . The worldwide st and ard for renal replacement therapy is intermittent hemodialysis ( IHD ) . Continuous hemodialysis and hemofiltration techniques have recently emerged as alternative modalities . These two therapies have not been directly compared . METHODS A multicenter , r and omized , controlled trial was conducted comparing two dialysis modalities ( IHD vs. continuous hemodiafiltration ) for the treatment of ARF in the intensive care unit ( ICU ) . One hundred sixty-six patients were r and omized . Principal outcome measures were ICU and hospital mortality , length of stay , and recovery of renal function . RESULTS Using intention-to-treat analysis , the overall ICU and in-hospital mortalities were 50.6 and 56.6 % , respectively . Continuous therapy was associated with an increase in ICU ( 59.5 vs. 41.5 % , P < 0.02 ) and in-hospital ( 65.5 vs. 47.6 % , P < 0.02 ) mortality relative to intermittent dialysis .  Median ICU length of stay from the time of nephrology consultation was 16.5 days , and complete recovery of renal function was observed in 34.9 % of patients , with no significant group differences . Despite r and omization , there were significant differences between the groups in several covariates independently associated with mortality , including gender , hepatic failure , APACHE II and III scores , and the number of failed organ systems , in each instance biased in favor of the intermittent dialysis group . Using logistic regression to adjust for the imbalances in group assignment , the odds of death associated with continuous therapy was 1.3 ( 95 % CI , 0.6 to 2.7 , P = NS ) . A detailed investigation of the r and omization process failed to explain the marked differences in patient assignment . CONCLUSIONS A r and omized controlled trial of alternative dialysis modalities in ARF is feasible . Despite the potential advantages of continuous techniques , this study provides no evidence of a survival benefit of continuous hemodiafiltration compared with IHD . This study did not control for other major clinical decisions or other supportive management strategies that are widely variable ( for example , nutrition support , hemodynamic support , timing of initiation , and dose of dialysis ) and might material ly influence outcomes in ARF . St and ardization of several aspects of care or extremely large sample sizes will be required to answer optimally the questions originally posed by this investigation Objective . To describe long-term quality of life , intensive care , and hospital mortality in patients with acute renal and respiratory failure treated with one of two methods of renal replacement therapy ( RRT ) .  Design . Cross-sectional survey of long-term survivors from a prospect i ve observational study of two methods of RRT . Setting . A combined surgical and medical intensive care unit in a university hospital . Patients and participants . One hundred and twenty-six patients with acute renal and respiratory failure who required treatment with RRT and mechanical ventilation .  Interventions . 1 . RRT for acute renal failure was with either continuous hemodialysis with ultrafiltration using biocompatible membranes and prostacyclin and heparin anticoagulation ( CHDF ) or intermittent hemodialysis using cuprophane membranes and heparin anticoagulation ( IHD ) ; 2 . Health-related quality of life in long-term survivors was assessed with the SF-36 ( HRQL ) question naire . Measurements and main results . 1 . There was no difference in ICU mortality ( 73.5%[39/53 ] IHD vs. 71.8%[46/64 ] CHDF , P = NS ) or hospital mortality ( 83%[44/53 ] IHD vs. 76.5 % [ 49/64 ] CHDF , P = NS ) between the two RRT treatment groups . By 1999 , there were 16 surviving patients ; 2 . Twelve of these survivors completed SF-36 forms ( 10 CHDF vs. 2 IHD ) . The overall physical health summary score and scores for seven of the health domains were significantly reduced . The mental health summary score and the domain mental health score did not differ from the general population . Conclusions . 1 . The method of RRT used in ICU patients with ARF had no influence on survival ; 2 . The long-term survivors of multi-organ failure have poor physical health Two hundred and fifty consecutive patients with acute renal failure treated by continuous haemofiltration on one intensive care unit ( ICU ) were studied prospect ively to investigate the possibility of predicting outcome at the time of referral . Logistic regression analysis was used to identify important prognostic factors and the regression coefficients were used to weight a scoring system for the severity of illness of patients with acute renal failure .  Overall survival was 53 % with improvement over the course of the study . Multivariate analysis showed that outcome was related to age , need for artificial ventilation , use of inotropes , urine volume , serum bilirubin , arterial base deficit and serum creatinine . The scoring system based on the first five of these variables had a specificity of predicting death of 67 % and a sensitivity of 76 % BACKGROUND Mortality rates of critically ill patients with acute renal failure ( ARF ) requiring renal replacement therapy ( RRT ) are high . Intermittent and continuous RRT are available for these patients on the intensive care units ( ICUs ) . It is unknown which technique is superior with respect to patient outcome . METHODS We r and omized 125 patients to treatment with either continuous venovenous haemodiafiltration ( CVVHDF ) or intermittent haemodialysis ( IHD ) from a total of 191 patients with ARF in a tertiary-care university hospital ICU . The primary end-point was ICU and in-hospital mortality , while recovery of renal function and hospital length of stay were secondary end-points . RESULTS During 30 months , no patient escaped r and omization for medical reasons . Sixty-six patients were not r and omized for non-medical reasons . Of the 125 r and omized patients , 70 were treated with CVVHDF and 55 with IHD . The two groups were comparable at the start of RRT with respect to age ( 62+/-15 vs 62+/-15 years , CVVHDF vs IHD ) , gender ( 66 vs 73 % male sex ) , number of failed organ systems ( 2.4+/-1.5 vs 2.5+/-1.6 ) , Simplified Acute Physiology Scores ( 57+/-17 vs 58+/-23 ) , septicaemia ( 43 vs 51 % ) , shock ( 59 vs 58 % ) or previous surgery ( 53 vs 45 % ) . Mortality rates in the hospital ( 47 vs 51 % , CVVHDF vs IHD , P = 0.72 ) or in the ICU ( 34 vs 38 % , P = 0.71 ) were independent of the technique of RRT applied . Hospital length of stay in the survivors was comparable in patients on CVVHDF [ median ( range ) 20 ( 6 - 71 ) days , n = 36 ] and in those on I 
    Output:
    
In patients who are haemodynamically stable , the RRT modality does not appear to influence important patient outcomes , and therefore the preference for CRRT over IRRT in such patients does not appear justified in the light of available evidence .
CRRT was shown to achieve better haemodynamic parameters such as MAP .