A randomized clinical trial of continuous versus intermittent dialysis for acute renal failure

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 standard 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, randomized, 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 randomized. 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 randomization, 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 randomization process failed to explain the marked differences in patient assignment. CONCLUSIONS: A randomized 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 materially influence outcomes in ARF. Standardization of several aspects of care or extremely large sample sizes will be required to answer optimally the questions originally posed by this investigation.     

IONIZED SERUM CALCIUM LEVELS DURING ACUTE RENAL FAILURE: INTERMITTENT HEMODIALYSIS VS. CONTINUOUS HEMODIAFILTRATION

Background: Achieving “adequacy of dialysis” includes the maintenance of normal serum ionized calcium concentrations and is an important therapeutic goal in the treatment of acute renal failure (ARF). It is unknown whether this goal is best achieved with intermittent or continuous renal replacement therapy. Methods: We compared the effects of continuous veno–venous hemodiafiltration (CVVHDF) and intermittent hemodialysis (IHD) on serum ionized calcium concentrations using daily morning blood tests in 88 consecutive intensive care patients of which half were treated with IHD and half with CRRT. Results: Mean patient age was 54 ± 14 years for IHD and 60 ± 14 years for CVVHDF (NS). However, patients who received CVVHDF were significantly more critically ill (mean APACHE II scores: 24.4 ± 5.1 for IHD vs. 29.2 ± 5.7 for CVVHDF, p<0.003). Before treatment, the mean ionized calcium concentration was 1.177 ± 0.03 mmol/l for IHD and 1.172 ± 0.04 mmol/l for CVVHDF (NS), with abnormal values in 51.6% of IHD patients and in 68% of CVVHDF patients (NS). During treatment, hypocalcemia was significantly more common among CVVHDF patients (24.5% vs. 14.9%; p<0.011) while hypercalcemia was more frequent during IHD (36.1% vs. 25.6%; p<0.019). Conclusions: Abnormal serum ionized calcium concentrations are frequent in ARF patients before and during renal replacement. Once dialytic therapy is applied, CVVHDF is more likely to lower serum calcium concentrations, while IHD is more likely to induce hypercalcemia. Appreciation of these different biochemical effects may assist clinicians in adjusting dialytic therapy in selected patients.     

Eighteen years experience in pediatric acute dialysis: analysis of predictors of outcome

This study reviewed the 18-year experience of acute dialysis in the pediatric intensive care unit, in order to identify factors that could predict outcome, and to determine whether newer modalities of acute dialysis have influenced this outcome. Sixty-six children (ages 1 day to 19 years) received acute dialysis from May 1980 to April 1998. Factors predicting outcome were analyzed using univariate and Cox regression analysis. Modality of dialysis in the first 15 years was exclusively peritoneal dialysis, with a mortality of 63.9%. However, in the last 3 years, with increasing patient numbers, continuous hemodiafiltration (CHDF) was the modality of choice (56.7%), with a mortality of 73.3%. Univariate analysis showed that age <1 year, coma, acute tubular necrosis, disseminated intravascular coagulopathy, assisted ventilation, and hypotension were associated significantly with poor outcome (P<0.05). Cox regression analysis revealed that mortality was significantly higher in patients on mechanical ventilation (RR 5.96, 95% CI 1.82–19.50), or with age <1 year (RR 2.00, 95% CI 1.08–3.73). In conclusion, despite the increasing use of CHDF over the last 3 years, there was no significant improvement in mortality, probably related to the fact that more critically ill patients were dialyzed. Received: 21 March 2000 / Revised: 12 October 2000 / Accepted: 19 October 2000     

Clinical features and outcome of chronic dialysis patients admitted to an intensive care unit.

BACKGROUND: Information about chronic dialysis (CD) patients admitted to intensive care units (ICU) is scant. This study sought to determine the epidemiology and outcome of CD patients in an ICU setting and to test the performance of the Simplified Acute Physiology Score (SAPS II) to predict hospital mortality in this population. METHODS: All consecutive CD patients admitted to an adult, 10 bed medical/surgical ICU at a university hospital between January 1996 and December 1999 were included in this prospective observational study. Demographics, characteristics of the underlying renal disease, admission diagnosis, the number of organ system failures (OSFs) excluding renal failure and SAPS II, both calculated 24 h after admission, the duration of mechanical ventilation, ICU survival and survival status at hospital discharge and 6 months after discharge were recorded. RESULTS: A total of 92 CD patients, 16 on peritoneal dialysis and 76 on haemodialysis, were included. The main reason for ICU admission was sepsis and the mean ICU length of stay 6.2+/-9.9 days. ICU mortality was 26/92 (28.3%) and was associated in multivariate analysis with SAPS II (P<0.001), duration of mechanical ventilation (P<0.01) and abnormal values of serum phosphorus (high or low; P<0.05). Hospital mortality was 35/92 (38.0%) and was accurately predicted by SAPS II [receiver operating characteristics curve: 0.86+/-0.04; goodness-of-fit test: C = 6.86, 5 degrees of freedom (df), P = 0.23 and H = 4.78, 5 df, P = 0.44]. The 6 month survival rate was 48/92 (52.2%). CONCLUSIONS: CD patients admitted to the ICU are a subgroup of patients with high mortality and SAPS II can be used to assess their probability of hospital mortality. The severity of the acute illness responsible for ICU admission and an abnormal value of serum phosphorus are determinants for ICU mortality.     

Renal failure in the ICU: comparison of the impact of acute renal failure and end-stage renal disease on ICU outcomes

BACKGROUND: Acute renal failure (ARF) is associated with a persistent high mortality in critically ill patients in intensive care units (ICUs). Most studies to date have focused on patients with established, intrinsic ARF or relatively severe ARF due to multiple factors. None have examined outcomes of dialysis-dependent chronic renal failure [end-stage renal disease (ESRD)] patients in the ICU. We examined the incidence and outcomes of ARF in the ICU using a standard definition and compared these to outcomes of ICU patients with either ESRD or no renal failure. We sought to determine the impact of renal dysfunction and/or loss of organ function on outcome. METHODS: We prospectively scored 1530 admissions to eight ICUs over a 10-month period for illness severity at ICU admission using the Acute Physiological and Chronic Health Evaluation (APACHE III) evaluation tool. Patients were defined as having ARF based on the definition of Hou et al (Am J Med 74:243-248,1983) designed to detect significant measurable declines in renal function based on serum creatinine. ESRD patients were identified as being chronically dialysis-dependent prior to ICU admission and the remainder had no renal failure. Clinical characteristics at ICU admission and ICU and hospital outcomes were compared between the three groups. RESULTS: We identified 254 cases of ARF, 57 cases of ESRD and 1219 cases of no renal failure for an incidence of ARF of 17%. Roughly half the ARF patients had ARF at ICU admission and the remainder developed ARF during their ICU stay. Only 11% of ARF patients required dialysis support. ARF patients had significantly higher acute illness severity scores than those with no renal failure, whereas patients with ESRD had intermediate severity scores. ICU mortality was 23% for patients with ARF, 11% for those with ESRD, and 5% for those with no renal failure. There was no difference in outcome between patients who had ARF at ICU admission and those who developed ARF in the ICU. Patients with ARF severe enough to require dialysis had a mortality of 57%. APACHE III predicted outcome very well in patients with no renal failure and patients with ARF at the time of scoring but underpredicted mortality in those who developed ARF after ICU admission and overestimated mortality in patients with ESRD. CONCLUSIONS: ARF is common in ICU patients and has a persistent negative impact on outcomes, although the majority of ARF is not severe enough to require dialysis support. The mortality of patients with ARF from all causes is almost exactly similar to that noted using the same criteria two decades ago. More profound ARF requiring dialysis continues to have an even greater mortality. Nevertheless, acute declines in renal function are associated with a mortality that is not well explained simply by loss of organ function. The majority of ARF patients who did not require dialysis still had a considerably higher mortality than the ESRD patients, all of whom required dialysis; while ARF patients who did require dialysis had a much higher morality than ESRD patients. APACHE III performs well and captures the mortality of patients with ARF at the time of scoring. Development of ARF after scoring has a profound effect on standardized mortality. We were unable to identify a unique mortality associated with ARF, but the presence of measurable renal insufficiency continues to be a sensitive marker for poor outcome.     

SAPS 3 at dialysis commencement is predictive of hospital mortality in patients supported by extracorporeal membrane oxygenation and acute dialysis

Objective: This study examined the association between hospital mortality and five illness–severity scoring systems evaluated at different time points in the intensive care unit (ICU) as well as clinical variables as predictors in critically ill patients supported by extracorporeal membrane oxygenation (ECMO) and acute dialysis. Methods: This multicenter prospective observational study included 104 patients who received ECMO support and acute dialysis from January 2002 to December 2006. Patients’ demographic, clinical and laboratory variables were analyzed as predictors of survival. The SAPS 2, APACHE II, SOFA, MODS, and SAPS 3 scores upon ICU admission and at acute dialysis commencement were evaluated to predict the patient's hospital mortality. Results: Hospital mortality for the study group was 76% (79/104). Among the five scoring systems, only SAPS 3 score showed a significant difference between survivors and non-survivors either upon ICU admission (p = 0.038) or at dialysis commencement (p = 0.001). SAPS 3 score at dialysis commencement showed the best discrimination ability by using the area under the receiver operating characteristic curve (SOFA, 0.55; SAPS 2, 0.56; MODS, 0.58; APACHE II, 0.59; and SAPS 3, 0.73). Multiple logistic regression analysis indicated that SAPS 3 score at dialysis commencement (OR: 1.070, 95% CI: 1.016–1.216) and IABP usage before ECMO (OR: 4.181, 95% CI: 1.448–12.075) were two independent risk factors for hospital mortality. Conclusions: Among five common ICU scoring systems evaluated at different time points, SAPS 3 at dialysis commencement is the best risk adjustment systems to predict hospital mortality in critically ill patients supported by ECMO and acute dialysis. Furthermore, the SAPS 3 score at dialysis commencement and IABP usage before ECMO are two major independent predictors for hospital mortality in patients supported by ECMO and acute dialysis.     

Validation of SAPS 3 Admission Score and comparison with SAPS II

Background: The objective of this study was to validate the Simplified Acute Physiology Score SAPS 3 Admission Score (SAPS 3) and to compare its fit with that of SAPS II in an independent sample of patients admitted to a single-centre intensive care unit (ICU).
Methods: The data for all adult patients consecutively admitted to an eight-bed ICU of a 700-bed university hospital between 1 January 2006 and 2 September 2007 were collected. SAPS II and SAPS 3 were computed, as well as the predicted hospital mortality. The calibration of SAPS II and SAPS 3, according to the general equation (GE), and equations for Southern Europe and Mediterranean countries (SE&MC), and Central and Western Europe (C&WE), were assessed by the goodness-of-fit Hosmer–Lemeshow Ĥ and Ĉ statistics. Standardized mortality ratios (SMR) with 95% confidence interval (95% CI) were computed for SAPS II and SAPS 3 equations.
Results: Six hundred and eighty-four patients were studied (males 63%). The median age was 73 (quartiles 65–80) years. The fit of SAPS 3 using the C&WE equation (Ĥ 13.49, P =0.095; Ĉ 12.73, P =0.121) as well as that of SAPS II was acceptable (Ĥ 6.02, P =0.644; Ĉ12.08, P =0.147), while SAPS 3 GE (Ĥ 23.36, P =0.002; Ĉ 22.37, P =0.004) and S&MC (Ĥ 25.73, P =0.001; Ĉ 26.19, P =0.001) did not fit well. SAPS 3 GE, SAPS 3 SE&M Countries and the SAPS II significantly over estimated the mortality. Only 95% CI of SMR for SAPS 3 C&WE included 1 (SMR 0.97; 95% CI 0.89–1.05).
Conclusion: Each ICU should identify the SAPS 3 equation most suitable for its case mix. The SAPS II model tended to overestimate the mortality.     

Continuous hemodiafiltration in children after cardiac surgery

Acute renal failure (ARF) after congenital cardiac surgery remains a serious complication and leading cause of morbidity and mortality. Continuous hemodiafiltration (CHDF) is presently accepted for pediatric applications. We retrospectively evaluated the effects of CHDF against ARF after congenital cardiac surgery at our hospital. We analyzed data from seven patients aged 23 days to 9 years and weighing 1.7-22.4 kg requiring dialysis therapy using CHDF after congenital cardiac surgery between April 2002 and January 2009. One patient who died could not be weaned from extracorporeal membrane oxygenation support and another died of multiple organ failure. Renal function recovered to normal in the other five (71%) patients. Treatment by CHDF lasted from 14 to 680 h and net ultrafiltration was 3.5 ± 1.4 mL/kg/h. Serum creatinine and urea concentrations were, respectively, 2.3 ± 1.6 and 43.7 ± 17.0 mg/dL before, and 0.5 ± 0.2 and 13.5 ± 8.1 mg/dL, after CHDF (P < 0.05). Thrombocytopenia developed in all patients, and platelet concentrates (0.76 ± 0.7 mL/kg/h) were infused during CHDF. Hypotension developed after changing the CHDF set in one patient. We suggest that CHDF is an effective alternative strategy for treating renal dysfunction after congenital cardiac surgery.     

A Simple Prognostic Index for Patients with Acute Renal Failure Requiring Dialysis

The probability of death inpatients with acute renal failure (ARF) remains high. A valid prognostic index available on patient admission and during follow-up could be helpful for decision making. In this study, 94 ARF patients requiring dialysis (not responding to a previous single dose of furosemide 15 mg/kg) were included. On admission, patients were classified according to a Simplified Acute Physiology Score (SAPS) of ≤15 or >15. The prognostic value of 11 risk factors was analyzed. Only 6 in 11 risk factors were significant by univariate analysis: age (>55 years) (0.02), mechanical ventilation (0.008), oliguria (<500 mL/day during the first 5 days) (0.02), sepsis (0.001), shock (0.007), and serum bilirubin (>30 μmol) (0.001). Only oliguria and sepsis were significant risk factors by multivariate analysis. Overall mortality rate was 41%. Mortality rate was higher in patients with SAPS >15 (65%) than in those with SAPS ≤15 (22%) (0.001). Patients with >3 risk factors showed a significantly higher mortality rate than patients with <3 risk factors (all patients disregarding SAPS) (0.001). Considering the worst combination of risk factors by univariate analysis, mortality prediction was 56% if oliguria, sepsis, and high serum bilirubin were present, and reached 80% if an older age was added (four risk factors). Ventilation increased probability of death to 92% (five risk factors). If all six risk factors were present, the probability rose to 96%. The corresponding observed mortality rate was 32% for three risk factors, 70% for four, 81% for five and 100% for six risk factors. The results suggest that probability of death in ARF requiring dialysis can be correctly estimated when more than three significant risk factors are present. If confirmed, they could avoid using a more complex severity scoring system in patients with ARF requiring dialysis.     

SAPS 3 is not superior to SAPS 2 in cardiac surgery patients

Objectives. Cardiac surgery patients are excluded from SAPS2 but included in SAPS3. Neither score is evaluated for this exclusive population; however, they are used daily. We hypothesized that SAPS3 may be superior to SAPS2 in outcome prediction in cardiac surgery patients. Design. All consecutive patients undergoing cardiac surgery between January 2007 and December 2010 were included in our prospective study. Both models were tested with calibration and discrimination statistics. We compared the AUC of the ROC curves by DeLong's method and calculated OCC values. Results. A total of 5207 patients with mean age of 67.2 ± 10.9 years were admitted to the ICU. The mean length of ICU stay was 4.6 ± 7.0 days and the ICU mortality was 5.9%. The two tested models had acceptable discriminatory power (AUC: SAPS2: 0.777–0.875; SAPS3: 0.757–893). SAPS3 had a low AUC and poor calibration on admission day. SAPS2 had poor calibration on Days 1–6 and 8. Conclusions. Despite including cardiac surgery patients, SAPS3 was not superior to SAPS2 in our analysis. In this large cohort of ICU cardiac surgery patients, performance of both SAPS models was generally poor. In this subset of patients, neither scoring system is recommended.     

Adding a dialysis dose to continuous hemofiltration increases survival in patients with acute renal failure

Acute renal failure (ARF) in critically ill patients is associated with high mortality. Optimal method and dose of continuous renal replacement therapy could improve survival in these patients. We studied the hypothesis that an increase in dialysis dose obtained by continuous veno-venous hemodiafiltration (CVVHDF) is associated with a better survival than continuous veno-venous hemofiltration (CVVH) among critically ill patients with ARF. In a prospective randomized trial, these two methods were compared in patients undergoing renal replacement therapy in two intensive care units (ICUs). The patients had either CVVH (1-2.5 l/h replacement fluid) or continuous CVVHDF (1-2.5 l/h replacement fluid+1-1.5 l/h dialysate) according to their body weight. 28- and 90-day mortalities, renal recovery, and duration of ICU stay were the main outcome measures. Two hundred and six patients were randomized from October 2000 to December 2003. Twenty-eight-day survivals (%) were, respectively, 39 and 59 (P=0.03) in the CVVH and CVVHDF groups. Three months survivals (%) were, respectively, 34 and 59 (P=0.0005) in the CVVH and CVVHDF groups. Apache II score, age, baseline blood urea nitrogen, and hemodiafiltration (hazard ratio 0.59, 95% confidence interval 0.40-0.87; P=0.008) were independent predictors of survival at 90 days. Renal recovery rate among survivors (71 versus 78% in the CVVH and CVVHDF groups respectively, P=0.62) was not affected by the type of renal replacement therapy. These results suggest that increasing the dialysis dose especially for low molecular weight solutes confers a better survival in severely ill patients with ARF.     

Readmission to the intensive care unit: An indicator that reflects the potential risks of morbidity and mortality of surgical patients in the intensive care unit

Purpose  To investigate the characteristics and outcomes of surgical patients who were readmitted to the intensive care unit (ICU). Methods  The data were collected for all readmissions to the surgical ICUs in a tertiary hospital in the year 2003. Results  Of all the 945 ICU discharges, 110 patients (11.6%) were readmitted. They had a longer initial ICU stay (8.05 ± 7.17 vs 5.22 ± 4.95, P < 0.001) and were older and in a more severe condition than those not readmitted, but with a longer hospital stay and higher mortality rate (40% vs 3.6%, P < 0.001). A total of 26.4% of the readmission patients had an early readmission (<48 h), with a lower mortality rate than those with a late readmission (24.1% vs 45.7%, P = 0.049). A total of 46.4% of the patients were readmitted with the same diagnosis while the rest were readmitted with a new complication. Respiratory disease was the most common diagnosis for patients readmitted with a new complication (66.1%). The nonsurvivors had a significantly higher second Acute Physiology and Chronic Health Evaluation (APACHE II) score (22.1 ± 8.8 vs.14.6 ± 7.4, P < 0.001) and second Therapeutic Intervention Scoring System (TISS) score (30.1 ± 8.7 vs 24.7 ± 7.6, P = 0.001) and a longer stay in the first ICU admission (10.4 ± 9 days vs 6.4 ± 5 days, P = 0.010). A multivariate analysis showed that the first ICU length of stay and the APACHE II score at the time of readmission were the two risk factors for mortality. Conclusion  The mortality of surgical patients with ICU readmission was high with respiratory complications being the most important issue.     

Effect of Fenoldopam Mesylate in Critically Ill Patients at Risk for Acute Renal Failure is Dose Dependent

Background: Acute renal failure (ARF) is common and difficult to prevent, especially in intensive care unit (ICU) patients with cancer. Therapeutic trials with various agents have generally been ineffective in preventing ARF. We describe the effects of two different doses of the dopamine DA-1 receptor agonist fenoldopam mesylate on renal function in a series of critically ill cancer patients at risk of developing ARF. Methods: We performed a retrospective chart review of 100 consecutive patients who received fenoldopam mesylate for at least 72 h in the medical and surgical ICUs of The University of Texas M. D. Anderson Cancer Center who were at risk of developing ARF. Eighteen patients received low-dose fenoldopam mesylate (≤ 0.05 µg/kg/min). The remaining 82 patients received high-dose fenoldopam mesylate (0.07–0.1 µg/kg/min). Data were collected relating to drug dosage, patient demographics, severity of illness, and indices of renal function. Results: Patients were moderately ill, with a mean APACHE II score of 18 ± 6 at initiation of fenoldopam infusion. Eighty-five percent of patients had at least two risk factors for the development of ARF, and 20% had four. For the group overall, the incidence of ARF was 13%, and the hospital mortality rate was 37%. When compared with the low-dose group, patients who received high-dose fenoldopam had a significantly shorter ICU length of stay despite a significantly higher APACHE II score (p = 0.01). The high-dose group also had a highly significant decrease in serum creatinine levels at 72 h (p = 0.005). Conclusions: These data support the hypothesis that fenoldopam mesylate may provide a degree of dose-dependent renal protection in cancer patients with early acute renal failure.     

Spectrum of Acute Renal Failure and Factors Predicting Its Outcome in an Intensive Care Unit in India

Identification of factors causing acute renal failure (ARF) and its associated poor prognosis in critically ill patients can help in planning strategies to prevent ARF and to prioritize the utilization of sparse and expensive therapeutic modalities. Most of the studies in such patients have been done in the developed world, and similar data from the developing world is sparse.

We analyzed 45 consecutive patients who developed ARF in the intensive care unit (ICU) during a 12-month period. Demographic and detailed biochemical profile, previous chronic illness, precipitating factors, number of failed organs, type of ARF (oliguric/nonoliguric), and need for and type of renal replacement therapy (RRT) received were recorded at the time of admission to ICU and during the course of illness. The mean age of these patients was 43.1 years, with 75.6% being males. Hypotension, sepsis, and use of nephrotoxic drugs were common precipitating factors for ARF in these patients. However, multiple precipitating factors were present in the majority (80%): 81.5% had at least one organ failure prior to development of ARF, 71.1% had oliguria, and 71.1% required RRT. Intermittent hemodialysis was the most common form of RRT given. Patient mortality was 64.4%, with 15 of the 16 surviving patients becoming dialysis independent. We observed an increase in mortality from 0% to 100%, depending on the number of failed organs from one to six. On comparing the predictor outcomes between survivors and nonsurvivors by multivariate analysis, only the number of failed organs at the time of ARF (2.6 ± 0.9 vs. 4.5 ± 0.8) and serum albumin <3.0 g/dL were found to be statistically significant.

To conclude, ARF in critically ill patients is multifactorial in origin and carries a high mortality. Mortality in these patients increases with increasing numbers of failed organs and with a serum albumin of <3.0 g/dL.     

Outcome in a post-cardiac surgery population with acute renal failure requiring dialysis: does age make a difference?

BACKGROUND: Acute renal failure (ARF), requiring dialysis (ARF-d), develops in 1-5% of patients undergoing cardiac surgery and is associated with higher in-hospital mortality. Age is one of the known risk factors for the development of ARF. As the ageing population is increasing, the nephrologist will be faced with a large population of elderly patients requiring dialysis following cardiac surgery. The aim of our study was to evaluate the influence of age on and the risk factors for in-hospital mortality. METHODS: Eighty-two patients with ARF following cardiac surgery and requiring dialysis between January 1997 and October 2001 were included. Two groups of patients were studied: the younger population (<70 years, 42 patients, mean age 59+/-10) and an elderly population (>/=70 years, 40 patients, mean age 76+/-4). Severity of disease was evaluated using the SAPS (Simplified Acute Physiology Score), the Liano score and the SHARF (Stuivenberg Hospital Acute Renal Failure) score. RESULTS: Overall mortality in the population with ARF-d was 56.1%. No difference in mortality rate was found between the younger (61.9%) and elderly patient group (50.0%). The two groups were very similar in baseline and procedural characteristics with exception of body weight (P=0.02) and preoperative glomerular filtration rate (P=0.0001). No significant difference was found in the scoring systems between the old and the young (SAPS P=0.52; Liano P=0.96; SHARF T0 P=0.06; SHARF T48 P=0.15). Mortality in the elderly was significantly correlated with hypotension before starting renal replacement therapy (RRT) (P=0.002), mechanical ventilation (P=0.002), presence of multiorgan failure (MOF) (P=0.0001) and higher scores in the severity models (SAPS: P=0.01; Liano: P<0.0001 and SHARF: P<0.0001). CONCLUSION: The outcome in the elderly requiring dialysis due to ARF post-cardiac surgery is comparable with the outcome in a younger population. No significant difference was found in severity of disease between the elderly and the younger. Variables predicting mortality in the elderly are the presence of MOF, mechanical ventilation and hypotension 24 h before starting RRT. These findings indicate that at the time the nephrologist is called for an elderly patient requiring dialysis due to ARF following cardiac surgery, age per se is not a reason to withhold RRT.     

CONTINUOUS RENAL REPLACEMENT THERAPY: OUR EXPERIENCE IN INTENSIVE CARE UNIT

Continuous Renal Replacement Therapy (CRRT) indication is still discussed. We report our experience on 98 patients affected with Multiple Organ System Failure (MOSF) and renal failure (acute or chronic) requiring dialysis and timely treated by CRRT. Mortality after 5 days of ICU permanence was 60.2%; the remaining 39 patients were discharged within 21 days and received CRRT treatment for 6.36 ± 5.59 days. APACHE II score was not able to predict the outcome of patients suffering from acute renal failure (ARF). On the contrary, Systemic Inflammatory Response Syndrome (SIRS) incidence was significantly higher in deceased patients compared to recovered patients.

In conclusion, it is important to start dialytic treatment immediately when patients affected with MOSF show renal function damage, even if at an initial stage, in order to improve patients' survival. Moreover a multidisciplinary approach is preferable in ICU patients treatment for not underestimating the management of metabolic and infective complications, the nursing care, and nutritional support.     

Outcomes and APACHE II predictions for critically ill patients with acute renal failure requiring dialysis

BACKGROUND: Despite the widespread availability of dialytic and intensive care unit technology, the probability of early mortality in critically ill patients with acute renal failure (ARF) is still high, and the evaluation of the patients' prognosis has been difficult. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score is a reliable indicator of severity of illness and likelihood of survival in critically ill patients with ARF. We have attempted to determine whether the APACHE II scoring system can be used to predict prognosis. METHODS: A retrospective cohort study evaluated the medical records of 100 consecutive patients in intensive care units with acute renal failure who required dialysis from January 1997 through December 1998. RESULTS: Of the 100 patients studied, 65 were men and 35 were women. The mean age of survivors and nonsurvivors was 59.4 +/- 20.3 years and 58.3 +/- 20.0 years. The overall mortality rate was 71%. There were no significant differences between survivors and nonsurvivors in age, gender, or indication for dialysis. The cause of death in the majority of patients was related to higher APACHE II score during the 24 hours immediately preceding the initiation of acute hemodialysis, and carry mortality rates exceeding 85% with an APACHE II score of 24 or higher. CONCLUSION: We conclude that mortality rate for acute renal failure in intensive care unit patients continues to be high. The use of the APACHE II score determined at the time of initiation of dialysis for patients with ARF is a statistically significant predictor of patient survival. There is a significant trend with APACHE II score for outcome.     

Predicting patient outcome from acute renal failure comparing three general severity of illness scoring systems

BACKGROUND: A major problem of studies on acute renal failure (ARF) arises from a lack of prognostic tools able to express the medical complexity of the syndrome adequately and to predict patient outcome accurately. Our study was thus aimed at evaluating the predictive ability of three general prognostic models [version II of the Acute Physiology and Chronic Health Evaluation (APACHE II), version II of the Simplified Acute Physiology Score (SAPS II), and version II of the Mortality Probability Model at 24 hours (MPM24 II)] in a prospective, single-center cohort of patients with ARF in an intermediate nephrology care unit. METHODS: Four hundred twenty-five patients consecutively admitted for ARF to the Nephrology and Internal Medicine Department over a five-year period were studied (272 males and 153 females, median age 71 years, interquartile range 61 to 78, median APACHE II score 23, interquartile range 18 to 28). Acute tubular necrosis (ATN) accounted for 68.7% (292 out of 425) of patients. Renal replacement therapies (hemodialysis or continuous hemofiltration) were used in 64% (272 out of 425) of ARF patients. RESULTS: Observed mortality was 39.1% (166 out of 425). The mean predicted mortality was 36.2% with APACHE II (P = 0.571 vs. observed mortality), 39.3% with SAPS II (P = 0.232), and 45.1% with MPM24 II (P < 0.0001). Lemeshow-Hosmer goodness-of-fit C and H statistics were 15.67 (P = 0.047) and 12.05 (P = 0.15) with APACHE II, 32.53 (P = 0.0001), 39.8 (P = 0.0001) with SAPS II, 21.86 (P = 0.005), and 20. 24 (P = 0.009) with MPM24 II, respectively. Areas under the receiver operating characteristic (ROC) curve were 0.75, 0.77, and 0.85, respectively. CONCLUSIONS: The APACHE II model was a slightly better calibrated predictor of group outcome in ARF patients, as compared with the SAPS II and MPM24 II outcome prediction models. The MPM24 II model showed the best discrimination capacity, in comparison with both APACHE II and SAPS II models, but it constantly and significantly overestimated mean predicted mortality in ARF patients. None of the models provided sufficient confidence for the prediction of outcome in individual patients. A high degree of caution must be exerted in the application of existing general prognostic models for outcome prediction in ARF patients.     

Does multi-vessel off-pump coronary artery bypass grafting reduce post operative morbidity compared to on-pump CABG?

Background Cardiopulmonary bypass (CPB) may contribute to the complications and it is assumed that eliminating cardiopulmonary bypass has the potential of reducing post operative morbidity after coronary artery bypass grafting (CABG). The study was carried out to compare mortality and morbidity in the off-pump and on-pump CABG groups. Methods We prospectively analysed 200 patients undergoing CABG. Group A consists of 100 patients underwent multi-vessel off-pump CABG and group B consists of 100 patients underwent CABG with CPB. The incidence of complications (mortality, re-exploration for bleeding, myocardial infarction, atrial fibrillation, neurological events, new onset renal failure (s. creatinine>1.6 mg/dL) pulmonary complications, length of ICU stay and hospital stay were recorded, analysed and compared. Results OPCAB patients received 2.73±0.61 grafts/patient and on-pump CABG patients received 3.39±0.75 grafts/patient (p value<0.00001). There was no significant statistical difference in mortality, incidence of stroke between OPCAB and CABG with CPB patients. Length of ICU stay was 32.84±4.22 vs 44.85±7.18 hrs (p value<0.00001) and hospital stay was 6.52±0.69 vs 7.94±0.92 days (p value<0.00001) between group A and group B respectively. Incidence of atrial fibrillation was less in OPCAB group 7% vs 12% although it was statistically not significant (p value 0.33). It was observed in our study that there was no significant deference in worsening of existing renal failure between on-pump CABG and OPCAB 6% vs 2% (P value 0.28). Blood utilization was significantly less in OPCAB group (p value<0.001). Conclusion There was no statistically significant difference in terms of mortality, incidence of stroke and new onset renal failure in both groups. But there was lesser incidence of post operative atrial fibrillation, worsening of existing renal failure in off-pump group though statistically not significant. There was significant reduction in blood utilization, length of ICU and hospital stay in OPCAB group.     

The effect of lead time bias on severity of illness scoring, mortality prediction and standardised mortality ratio in intensive care--a pilot study

The effect of lead time bias on severity of illness scoring, mortality prediction and standardised mortality ratios was examined in a pilot study of 76 intensive care (ICU) patients using APACHE II, APACHE III and SAPS II scoring systems. The inclusion of data collected in the period prior to ICU admission increased severity of illness scores and estimated risk of hospital mortality significantly for all three scoring systems (p < 0.01) by up to 14 points and 42.7% (APACHE II), 50 points and 26.3% (APACHE III) and 23 points and 33.4% (SAPS II), respectively. Standardised mortality ratios fell from 0.99 to 0.79 (APACHE II), 0.96 to 0.84 (APACHE III) and 0.75 to 0.64 (SAPS II), but these changes failed to reach statistical significance. Lead time bias had most effect in medical patients and on emergency admissions, and least effect in patients admitted from the operating theatre. These trends suggest that mortality ratios may not necessarily reflect intensive care unit performance and indicate that a larger study of the effect of lead time bias, case mix, pre-ICU care or post-ICU management on standardised mortality ratios is indicated.