Should dialysis be offered to cancer patients with acute kidney injury?

Objectives Cancer patients are at high risk for acute kidney injury (AKI), which is associated with high mortality when renal replacement therapy is required. Because physicians might be reluctant to offer dialysis to patients with malignancies, we sought to appraise outcomes in critically ill cancer patients (mainly with hematological malignancies) who received renal replacement therapy for AKI complicating cancer management. Design Cohort study including consecutive patients who received renal replacement therapy for AKI complicating cancer management, over a 42-month period. Their mortality was compared with that of non-cancer patients who received renal replacement therapy in the same center over the same study period (control group). Setting A 12-bed medical intensive care unit in a university hospital. Results 94 critically-ill cancer patients met the inclusion criteria. Median SAPS II was 53 (IQR 40–75) and median Logistic Organ Dysfunction score was 7 (IQR 5–10). The etiology of AKI was multiple in most patients (248 identified factors in 93 patients). Hospital mortality was 51.1%. Two variables were independently associated with hospital mortality: the severity of associated organ failures at ICU admission (OR, 1.33; 95% CI, 1.11–1.59; per point) and renal function deterioration after ICU admission (OR, 5.42; 95% CI, 1.62–18.11). Characteristics of the malignancy were not associated with hospital mortality. The presence of cancer had no detectable influence on hospital mortality after adjustment for gender, age, acute severity as assessed by the SAPS II score, and chronic health status [OR 1.2, 95% CI 0.63–2.27; p = 0.57]. Conclusion ICU admission should be considered in selected critically ill cancer patients with AKI requiring renal replacement therapy.     

多器官功能障碍综合征合并急性肾功能衰竭患者的病死危险因素分析

目的调查在ICU住院期间多器官功能障碍综合征(MODS)患者出现急性肾功能衰竭(ARF)的病死率及死亡危险因素。方法回顾性调查1998年至2002年住北京六家医院ICU的MODS患者共413例,采用流行病学研究方法对其中合并ARF患者死亡危险因素进行分析。结果413例MODS患者中,135例发生ARF,死亡77例,病死率57.03%。患者入院第一天平均APACHEⅡ评分(17.15±6.67)分。合并1个肾外器官功能衰竭者病死率28.00%,2个肾外器官功能衰竭者为58.62%,3个肾外器官功能衰竭者为61.29%,并发4个肾外器官功能衰竭者病死率达77.78%。单因素分析显示,机械通气、昏迷、低血压、少尿和器官衰竭的数目及血肌酐(Cr)峰值等因素均与ARF死亡关系显著(P<0.05)。对上述死亡危险因素进行Logistic回归分析,结果显示肿瘤术后、昏迷、严重代谢性酸中毒、应用肝素、制酸剂、机械通气等对死亡的影响有显著意义。结论在ICU的MODS患者中,出现ARF的死亡率很高,且与肾外器官衰竭的数目密切相关。     

Prognosis and 1-year mortality of intensive care unit patients with severe hepatic encephalopathy

Purpose

Data regarding outcome of patients with chronic liver disease with severe hepatic encephalopathy in intensive care unit are currently scarce.

Methods

This study is a retrospective observational case series in a medical intensive care unit (ICU) in a university hospital from 1995 to 2005. Patients with hepatic encephalopathy (HE) (admitted with or developing) were identified. Clinical and laboratory parameters were analyzed to determinate predictors of ICU and 1-year mortality.

Results

Seventy-one patients were included (53 male). Median Simplified Acute Physiology Score was 56 with Child-Pugh score 11 ± 2. Seventy-six percent of patients were admitted with coma (Glasgow Coma Scale, 7.7 ± 4). Eighty-two percent of patients required intubation, and 28% vasopressors. Thirty-five percent died during ICU stay. At 1 year, mortality was 54%. Univariate analysis identified arterial hypotension, mechanical ventilation, vasopressors at any time, acute renal failure, Simplified Acute Physiology Score, and sepsis associated with ICU mortality. In multivariate analysis, vasopressor use or acute renal failure was the main independent predictor of ICU death and 1-year mortality. Patients free of these risk factors, even requiring intubation, were identified as isolated HE, with lower mortality rates.

Conclusion

Predictors of outcome were similar to other groups of patients with liver disease admitted for other reasons. Intensive care unit mortality was lower than reported for other groups of patients with similar illness. Patients with severe HE admitted to ICU with no organ dysfunction other than mechanical ventilation had a better outcome and may require ICU admission.     

Acute renal failure in intensive care burn patients (ARF in burn patients).

The purpose of this study was to establish the incidence and mortality of burn patients with acute renal failure (ARF) at the Helsinki Burn Centre and to analyze the associated factors. The files of 238 intensive care (ICU) patients of a total of 1380 burn patients admitted to our institution between November 1988 and December 2001 were studied retrospectively. Of all admitted burn patients, 17.2% needed ICU. According to our criteria (S-Cr >120 micromol/l = 1.4 mg/dl), 39.1% of the ICU patients suffered from ARF and one in three of these required renal replacement therapy. The proportion of all admitted burn patients requiring renal replacement therapy was 2.3%. The mortality of ICU patients with ARF was 44.1% whereas that of patients without ARF was only 6.9%. Renal function recovered in all survivors. The nonsurvivors had a larger burned total body surface area, were older, and had more inhalation injuries and a higher abbreviated burn severity index score. The prognosis for patients with early ARF was worse than that for patients with late ARF. Rhabdomyolysis caused by flame injury was associated with high mortality. In this study we observed that ARF is associated with higher mortality even in minor burns when compared with patients without ARF. Flame burn with rhabdomyolysis and subsequent ARF predicts very poor survival. If a patient with severe ARF survives, the renal failure recovers over time.     

Daily evaluation of organ function during renal replacement therapy in intensive care unit patients with acute renal failure

PurposeThe aim of this study was to assess changes in organ function in acute renal failure patients during renal replacement therapy and relate them to outcome.Materials and MethodsMedical and nursing charts from 111 patients with acute renal failure who underwent renal replacement therapy (hemodialysis or hemofiltration) from July 2000 until July 2002 on a 31-bed medicosurgical intensive care unit (ICU) at a university hospital in Belgium and in whom the Sequential Organ Failure Assessment (SOFA) score was calculated daily before the start of therapy until the seventh day, or the end of therapy, were analyzed. Changes in SOFA score over time (Δ SOFA) were calculated.ResultsOf 111 patients, 63 (57%) died in the ICU. Nonsurvivors were older (68 [52-76] vs 59 [48-70] years, P = .017) and had initially higher respiratory, cardiovascular, and total SOFA scores compared with survivors. A greater Δ renal SOFA at 24 hours was associated univariantly with a higher risk of ICU mortality (odds ratio, 1.7; 95% confidence interval, 1.2-2.6; P = .013). In a multivariate analysis with ICU outcome as the dependent variable, only age, cardiovascular SOFA score on admission, and the change in total SOFA score over the first 24 hours were independently associated with a greater risk of death.ConclusionsAssessment of these factors in the first 24 hours of renal replacement therapy could help identify patients at higher risk of mortality early during their ICU admission.     

The epidemiology of acute renal failure in the world

PURPOSE OF REVIEW: The aim of this article is to describe our current understanding of the epidemiology of acute renal failure, especially in severe cases requiring renal replacement therapy. Some data from an international observational study (the Beginning and Ending Supportive Therapy (BEST) for the kidney study) are also presented. RECENT FINDINGS: Multiple epidemiological studies for acute renal failure have been conducted in different populations using various criteria and reported a wide range of incidence and mortality. In several multicenter studies reporting the incidence of renal replacement therapy requirement in a general intensive care unit population, however, renal replacement therapy requirement and hospital mortality was quite similar among the studies, approximately 4% and 60%, respectively. In North and South America, nephrologists typically manage acute renal failure patients with intermittent renal replacement therapy. On the other hand, in Asia, Australia and Europe, intensivists are commonly responsible for managing these patients with continuous renal replacement therapy. SUMMARY: Although the epidemiology of acute renal failure is varied among regions and centers, the average incidence of renal replacement therapy requirement and hospital mortality in critical illness are similar in multicenter studies. Continuous renal replacement therapy is gaining popularity and intensivists are becoming responsible for managing patients with it. More studies are needed to understand acute renal failure epidemiology worldwide. To conduct such studies, consensus criteria for acute renal failure and a well performed acute renal failure-specific severity score will be required.     

重症医学科患者急性肾损伤的发病率及危险因素的分析

目的:探讨重症监护病房(intensive care unit,ICU)收治患者急性肾损伤(acute kidney injury,AKI)的发病率以及相关危险因素。方法:回顾分析ICU 1443例患者的临床资料,按照AKI临床诊断标准筛选AKI患者,进行病因分析,检测AKI患者的实验室指标,记录尿量、住ICU时间等用Logistic回归分析影响预后的危险因素。结果:1443例ICU患者中符合2012年KDIGO-AKI诊断标准的患者98例(6.7%),其中病死32例(32.65%),需肾替代治疗50例(51.02%),随着AKI患者年龄和分期的增大,病死率越高;病因构成中脓毒症性AKI患者48例(48.98%),非脓毒症性AKI患者50例(51.02%),脓毒症性AKI患者住ICU时间和住院时间均较非脓毒症性AKI患者长(t=2.292,P=0.024;t=2.083,P=0.040),且行肾替代治疗比率较高(χ2=4.083,P=0.043)。Logistic回归分析显示老年、少尿、休克、酸中毒、AKI 3期、升压药物、感染和需肾替代治疗是AKI预后不良的危险因素。结论:ICU中AKI患者的发病率和病死率均较高,AKI的预后与多种因素有关,及早发现并干预治疗对降低AKI病死率具有重要意义。     

急性肾功能衰竭96例临床研究

目的研究急性肾功能衰竭(ARF)患者的病因、预后和影响预后的因素。方法回顾性研究我院2004年6月至2008年6月住院ARF患者的临床资料。结果观察期间住院患者共34 622例次,其中ARF患者96例,占同期住院患者的0.28%。ARF主要病因为感染、心力衰竭和药物。ARF患者病死率为30.2%,进行肾替代治疗者病死率(24.1%)低于保守治疗者(35.8%),二者比较差异有统计学意义(P0.01)。结论住院ARF患者的主要病因是感染、心力衰竭和药物,ARF的发病率和病死率较高,肾替代治疗预后较好。     

Epidemiology of acute renal failure and outcome of haemodiafiltration in intensive care

Objective: To examine the epidemiology of acute renal failure (ARF) and to identify predictors of mortality in patients treated by continuous venovenous haemodiafiltration (CVVHDF). Design: Uncontrolled observational study. Setting: One intensive care unit (ICU) at a surgical and trauma centre. Patients: A consecutive sample of 3591 ICU treatments. Measurements and results: Demographic data, indications for ICU admission, severity scores and organ system failure at the beginning of CVVHDF were set against the occurrence of ARF and ICU mortality. 154 (4.3 % of ICU patients and 0.6 % of the hospital population) developed ARF and were treated with CVVHDF. Higher American Society of Anesthesiologists (ASA) status and higher Apache II score were associated with ICU incidence of ARF. However, these criteria were not able to predict outcome in ARF. A simplified predictive model was derived using multivariate logistic regression modelling. The mortality rates were 12 % with one failing organ system (OSF), 38 % with two OSF, 72 % with three OSF, 90 % with four OSF and 100 % with five OSF. The adjusted odds ratio (OR) of death was 7.7 for cardiovascular failure, 6.3 for hepatic failure, 3.6 for respiratory failure, 3.0 for neurologic failure, 5.3 for massive transfusion and 3.7 for age of 60 years or more. Conclusion: General measures of severity are not useful in predicting the outcome of ARF. Only the nature and number of dysfunctioning organ systems and massive transfusion at the beginning of CVVHDF and the age of the patients gave a reliable prognosis in this group of patients. Received: 8 July 1996 Accepted: 21 August 1997     

The attributable mortality of acute renal failure in critically ill patients with liver cirrhosis

Objective To determine outcome and mortality risk related to acute renal failure (ARF) in critically ill patients with cirrhosis.Design and setting A retrospective cohort analysis and two independent case-control analyses in a medical ICU.Patients 41 and 32 patients who developed mild and severe ARF, respectively, matched (1:2 ratio) with cirrhotic patients without ARF during their ICU stay.Measurements and results Cirrhotic patients with ARF had higher MELD, APACHE II, and SOFA scores at baseline that those without ARF. They had more respiratory failure and cardiovascular failure during ICU stay, longer stay in ICU, and a greater crude hospital mortality rate (65% vs. 32%). Multivariate survival analysis identified ARF (hazard ratio, HR, 4.1), alcohol abuse or dependency, and severe sepsis or septic shock as independent predictors of death. In case-control studies both mild and severe ARF were independently associated with mortality (HR, 2.6, and 4.2, respectively). Cirrhotic patients with mild ARF patients had a higher risk of death than those without ARF (relative risk, RR, 2.0). Severe ARF was associated with an increase matched risk of death (RR 2.6), higher mortality of 51%, and higher risk-adjusted mortality rate (2.1 vs. 0.9).Conclusions ICU patients with liver cirrhosis still have a high crude mortality. In this specific population ARF is associated with an excess mortality, depending on the severity of renal dysfunction.Electronic Supplementary Material Electronic supplementary material to this paper can be obtained by using the Springer Link server located at     

Continuous venovenous haemofiltration in cancer patients with renal failure: a single-centre experience

Objective To assess the effect of continuous venovenous hemodiafiltration (CVVHDF) in cancer patients with acute renal failure.Patients and methods Retrospective study of all patients with acute renal failure requiring dialysis and treated with CVVHDF in a medical intensive care unit (ICU) from a cancer hospital.Results From January 1997 until December 2002, 32 cancer patients were treated with CVVHDF for acute renal failure. Their characteristics were: male/female 23/9, median age 61 years, haematological/solid tumours 16/16, and median APACHE II and IGS II scores 31/67. The number of organ failures was 1/2/3/4 in respectively 10/6/13/2 patients. Complete, partial or absence of resolution of acute renal failure was noted in 13, 8 and 11 patients. Sixteen patients (50%) died in the ICU and 15 (47%) were discharged alive from the hospital. In univariate analysis, variables statistically significantly adversely associated with hospital mortality were renal failure of renal origin, bone marrow transplant, increasing number of organ failures, reduced lymphocyte count, elevated bilirubin and lower creatinine levels, increased thromboplastin time, younger age, increased APACHE II and IGS II, ARDS and mechanical ventilation. In multivariate analysis, two models were used including either APACHE II or IGS II. The number of organ failures was found as the only significant prognostic factor in both models (p=0.01). Elevated phosphate level was a poor prognostic factor for hospital mortality (p=0.04) in the model including APACHE II.Conclusions In the experience of a single centre, CVVHDF is effective in the treatment of acute renal failure in cancer patients. The increasing number of organ failures was the single independent poor predictive factor for hospital mortality. Cancer characteristics and general gravity scores were not predictive factors.     

Acute kidney injury in the intensive care unit according to RIFLE

OBJECTIVES: To apply the RIFLE criteria "risk," "injury," and "failure" for severity of acute kidney injury to patients admitted to the intensive care unit and to evaluate the significance of other prognostic factors. DESIGN: Retrospective analysis of the Riyadh Intensive Care Program database. SETTING: Riyadh Intensive Care Unit Program database of 41,972 patients admitted to 22 intensive care units in the United Kingdom and Germany between 1989 and 1999. PATIENTS: Acute kidney injury as defined by the RIFLE classification occurred in 15,019 (35.8%) patients; 7,207 (17.2%) patients were at risk, 4,613 (11%) had injury, and 3,199 (7.6%) had failure. It was found that 797 (2.3%) patients had end-stage dialysis-dependent renal failure when admitted to an intensive care unit. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS:: Patients with risk, injury, and failure classifications had hospital mortality rates of 20.9%, 45.6%, and 56.8%, respectively, compared with 8.4% among patients without acute kidney injury. Independent risk factors for hospital mortality were age (odds ratio 1.02); Acute Physiology and Chronic Health Evaluation II score on admission to intensive care unit (odds ratio 1.10); presence of preexisting end-stage disease (odds ratio 1.17); mechanical ventilation (odds ratio 1.52); RIFLE categories risk (odds ratio 1.40), injury (odds ratio 1.96), and failure (odds ratio 1.59); maximum number of failed organs (odds ratio 2.13); admission after emergency surgery (odds ratio 3.08); and nonsurgical admission (odds ratio 3.92). Renal replacement therapy for acute kidney injury was not an independent risk factor for hospital mortality. CONCLUSIONS: The RIFLE classification was suitable for the definition of acute kidney injury in intensive care units. There was an association between acute kidney injury and hospital outcome, but associated organ failure, nonsurgical admission, and admission after emergency surgery had a greater impact on prognosis than severity of acute kidney injury.     

连续性肾脏替代与间歇性血液透析治疗重症急性肾衰的比较研究

目的：回顾性对比研究连续性肾脏替代治疗与间歇性血液透析治疗重症急性肾衰的疗效。方法：重症急性肾衰患者85例，其中45例行肾脏替代，40例行血液透析，对比分析两组患者的临床资料、疗效和预后。结果：肾脏替代组病情明显重于血液透析组（P〈0．01）。肾脏替代组血流动力学稳定。对氮质血症和水电解质控制优于血液透析组（P〈0．05）。肾脏替代组存活35例（77.8％），死亡10例（22．2％）；血液透析组存活21例（52．5％），死亡19例（47．5％）。两组存活率比较差异有显著性（P〈0．05）。结论：肾脏替代治疗重症急性肾衰的疗效优于血液透析，能提高重症急性肾衰患者的存活率，改善预后。     

Acute respiratory failure in immunosuppressed patients admitted to ICU

IntroductionThe number of hospitalized immunosuppressed adults is a growing and often develop severe complications that require admission to an Intensive Care Unit (ICU). The main cause of admission is acute respiratory failure (ARF). The goal of the study was to determine if ARF represents an independent risk factor for hospital mortality and in particular, we sought to ascertain if any risk factors were independently and identifiably associated with a bad outcome.MethodsWe perform a retrospective study of a prospectively collected data from patients admitted to an ICU. Adult patients with known immunosuppressive condition admitted to ICU were included.ResultsA total of 248 patients were included. Of 248 patients, 117 (47.2%) had a diagnosis of ARF at the time of ICU admission. Patients with ARF had a significantly higher in-hospital mortality (53.4% vs. 28.2% p = 0.001). Factors independently associated with hospital mortality were diagnosis of ARF at ICU admission, the presence of septic shock, use of continuous renal replacement therapy and failure of high-flow nasal canula(HFNC)/non-invasive (NIV) respiratory therapies.ConclusionWe identified ARF on admission and failure of HFNC/NIV to be independently associated with increased hospital mortality in immunosuppressed patients.     

An assessment of the RIFLE criteria for acute renal failure in hospitalized patients

OBJECTIVE: The Acute Dialysis Quality Initiative (ADQI) Group published a consensus definition (the RIFLE criteria) for acute renal failure. We sought to assess the ability of the RIFLE criteria to predict mortality in hospital patients. DESIGN: Retrospective single-center study. SETTING: University-affiliated hospital. PATIENTS: All patients admitted to the study hospital between January 2000 and December 2002. Patients were excluded if they were younger than 15 yrs old, were on chronic dialysis, or had kidney transplant or if their length of hospital stay was <24 hrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We included 20,126 patients. Mean age was 64 yrs, 14.7% of patients required intensive care unit admission, and hospital mortality was 8.0%. According to the RIFLE criteria, 9.1% of all patients were in the Risk category for acute renal failure, 5.2% were in the Injury category, and 3.7% were in the Failure category. There was an almost linear increase in hospital mortality from Normal to Failure (Normal, 4.4%; Risk, 15.1%; Injury, 29.2%; and Failure, 41.1%). Multivariate logistic regression analysis showed that all RIFLE criteria were significantly predictive factors for hospital mortality, with an almost linear increase in odds ratios from Risk to Failure (odds ratios, Risk 2.5, Injury 5.4, Failure 10.1). CONCLUSIONS: The RIFLE criteria for acute renal failure classified close to 20% of our study patients as having some degrees of acute impairment in renal function and were useful in predicting their hospital mortality.     

Correlation between the AKI classification and outcome

Introduction

The Acute Kidney Injury Network proposed a new classification for acute kidney injury (AKI) distinguishing between three stages. We applied the criteria to a large intensive care unit (ICU) population and evaluated the impact of AKI in the context of other risk factors.

Methods

Using the Riyadh Intensive Care Program database, we applied the AKI classification to 22,303 adult patients admitted to 22 ICUs in the UK and Germany between 1989 and 1999, who stayed in the ICU for 24 hours or longer and did not have end-stage dialysis dependent renal failure.

Results

Of the patients, 7898 (35.4%) fulfilled the criteria for AKI (19.1% had AKI I 3.8% had AKI II and 12.5% had AKI III). Mortality in the ICU was 10.7% in patients with no AKI, 20.1% in AKI I, 25.9% in AKI II and 49.6% in AKI III. Multivariate analysis confirmed that AKI III, but not AKI I and AKI II, were independently associated with ICU mortality (odds ratio (OR) = 2.27). Other independent risk factors for ICU mortality were age (OR = 1.03), sequential organ failure assessment (SOFA) score on admission to the ICU (OR = 1.11), pre-existing end-stage chronic health (OR = 1.65), emergency surgery (OR = 2.33), mechanical ventilation (OR = 2.83), maximum number of failed organ systems (OR = 2.80) and non-surgical admission (OR = 3.57). Cardiac surgery, AKI I and renal replacement therapy were associated with a reduced risk of dying in the ICU. AKI II was not an independent risk factor for ICU mortality. Without renal replacement therapy as a criterion, 21% of patients classified as AKI III would have been classified as AKI II or AKI I. Renal replacement therapy as a criterion for AKI III may inadvertently diminish the predictive power of the classification.

Conclusions

The proposed AKI classification correlated with ICU outcome but only AKI III was an independent risk factor for ICU mortality. The use of renal replacement therapy as a criterion for AKI III may have a confounding effect on the predictive power of the classification system as a whole.     

Effect of acute renal failure requiring renal replacement therapy on outcome in critically ill patients

OBJECTIVES: Acute renal failure is a complication in critically ill patients that has been associated with an excess risk of hospital mortality. Whether this reflects the severity of the disease or whether acute renal failure is an independent risk factor is unknown. The aim of this study was to analyze severity of illness and mortality in a group of critically ill patients with acute renal failure requiring renal replacement therapy in a number of Austrian intensive care units. DESIGN: Prospective, multicenter cohort study. PATIENTS AND SETTING: A total of 17,126 patients admitted consecutively to 30 medical, surgical, and mixed intensive care units in Austria over a period of 2 yrs. MEASUREMENTS AND MAIN RESULTS: Analyzed data included admission data, Simplified Acute Physiology Score, Logistic Organ Dysfunction system, Simplified Therapeutic Intervention Scoring System, length of intensive care unit stay, intensive care unit mortality, and hospital mortality. Of the admitted patients, 4.9% (n = 839) underwent renal replacement therapy because of acute renal failure (renal replacement therapy patients). These patients had a significantly higher hospital mortality (62.8% vs. 15.6%, p<.001), which remained significantly higher even when renal replacement therapy patients were matched with control subjects for age, severity of illness, and treatment center. Since univariate analysis demonstrated further intensity of treatment to be an additional predictor for outcome, a multivariate model including therapeutic interventions was developed. Five interventions were associated with nonsurvival (mechanical ventilation, single vasoactive medication, multiple vasoactive medication, cardiopulmonary resuscitation, and treatment of complicated metabolic acidosis/alkalosis). In contrast, the use of enteral nutrition predicted a favorable outcome. CONCLUSIONS: The results of our study suggest that acute renal failure in patients undergoing renal replacement therapy presents an excess risk of in-hospital death. This increased risk cannot be explained solely by a more pronounced severity of illness. Our results provide strong evidence that acute renal failure presents a specific and independent risk factor for poor prognosis.     

The cost of an intensive care unit: A prospective study

The cost of intensive care for patients admitted to the ICU were estimated. Patients suffering from severe combined acute respiratory and renal failure who required mechanical ventilation and renal replacement therapy (SCARRF-D) cost per day significantly more than non-renal patients (£ 938 compared to £ 653 per patient respectively) and their average length of stay in hospital is nearly 4 times as long (28.8 compared to 7.6 days respectively). Approximately 44% of the total cost was staff related (28% for the provision of nurses and 16% for the rest). Retrieving information related to cost was difficult, time consuming and labour intensive.     

RIFLE classification in patients with acute kidney injury in need of renal replacement therapy

OBJECTIVES: To evaluate the association of RIFLE classification with the outcomes of critically ill patients with acute kidney injury (AKI) who require renal replacement therapy (RRT). DESIGN AND SETTING: Prospective cohort study in the medical-surgical ICUs at three tertiary hospitals. PATIENTS: 214 patients over 1 year (mean age 71.4+/-15.8 years). Continuous RRT was used in 179 (84%); patients were classified as risk (25%), injury (27%), or failure (48%). Overall mortality was 76%. MEASUREMENTS AND RESULTS: There were no significant differences according to RIFLE classification (risk 72%, injury 79%, failure 76%). Variables selected in multivariate analysis were: older age (OR 1.03, 95% CI 1.01-1.06), presence of comorbidity (3.15, 1.10-9.02), poor chronic health status (6.51, 1.95-21.71), number of associated organ dysfunctions (patients with one or two organ dysfunctions 5.93, 2.03-17.33; patients with three or more organ dysfunctions 26.76, 6.28-114.11), and start of RRT after the first day of ICU (2.46, 1.09-5.53). RIFLE classification was forced into the model and was not selected. However, a subgroup analysis of 150 patients who received mechanical ventilation and vasopressors found failure to be associated with increased mortality (3.58, 1.08-11.80). CONCLUSIONS: Older age, number of organ dysfunctions, presence of comorbidities, and reduced functional capacity were the main prognostic factors. Patients who required RRT after the first day of ICU had a worse outcome. The RIFLE classification did not discriminate the prognosis in patients with AKI in need for RRT.