Renal replacement therapy for acute renal failure

Extracorporeal Membrane Oxygenation Support in COVID-19 Patients: A Propensity Score Analysis

Revised guidelines clarify indications for extracorporeal membrane oxygenation (ECMO) support in Coronavirus disease 2019 (COVID-19) patients with acute respiratory distress syndrome (ARDS). Limited data exist to compare clinical outcomes of COVID-19 ARDS patients to non-COVID-19-related ARDS patients when supported with ECMO. An observational propensity-matched study was performed to compare clinical and ECMO-related complications between COVID-19-related ARDS patients (COVID) and non-COVID-19-related ARDS (Control). COVID- patients cannulated from March 1st, 2020, through June 1st, 2021, were included and matched to patients from the historical cohort at our center from 2012 to 2020 based on age, body mass index (BMI), acute physiology and chronic health evaluation (APACHE) II score, and duration ECMO run. The primary outcome was complications during ECMO therapy. A total of 56 patients were propensity matched 1:1 with a mean age of 40.9 years, BMI 32.1 kg/m2, APACHE II score of 26.6, and duration of ECMO support of 22.6 days. In total 18 COVID-19 patients were observed to have more major bleeding complications (18 vs. 9, p = 0.03). Although not statistically significant, they also had more strokes (6 vs. 3) and required more chest tubes (13 vs. 8). Inpatient mortality was not different. ECMO support in COVID-19 patients is associated with more major bleeding complications, strokes, and chest tube placements. The use of ECMO in patients with COVID-19-related ARDS appears to be associated with an increased risk of complications.

The Role of Peritoneal Dialysis in the Treatment of Acute Kidney Injury in Patients With Acute-on-Chronic Liver Failure: A Prospective Brazilian Study

This study aimed to explore the role of peritoneal dialysis (PD) in acute-on-chronic liver disease (ACLD) in relation to metabolic and fluid control and outcome. Fifty-three patients were treated by PD (prescribed Kt/V = 0.40/session), with a flexible catheter, tidal modality, using a cycler and lactate as a buffer. The mean age was 64.8 ± 13.4 years, model of end stage liver disease (MELD) was 31 ± 6, 58.5% were in the intensive care unit, 58.5% needed intravenous inotropic agents including terlipressin, 69.5% were on mechanical ventilation, alcoholic liver disease was the main cause of cirrhosis and the main dialysis indications were uremia and hypervolemia. Blood urea and creatinine levels stabilized after four sessions at around 50 and 2.5 mg/dL, respectively. Negative fluid balance (FB) and ultrafiltration (UF) increased progressively and stabilized around 3.0 L and -2.7 L/day, respectively. Weekly-delivered Kt/V was 2.7 ± 0.37, and 71.7% of patients died. Five factors met the criteria for inclusion in the multivariable analysis. Logistic regression identified as risk factors associated with Acute Kidney Injury (AKI) in ACLD patients: MELD (OR = 1.14, CI 95% = 1.09-2.16, p = 0.001), nephrotoxic AKI (OR = 0.79, CI 95% = 0.61-0.93, p = 0.02), mechanical ventilation (OR = 1.49, CI 95% = 1.14-2.97, p < 0.001), and positive fluid balance (FB) after two PD sessions (OR = 1.08, CI 95% = 1.03-1.91, p = 0.007). These factors were significantly associated with death. In conclusion, our study suggests that careful prescription may contribute to providing adequate treatment for most Acute-on-Chronic Liver Failure (ACLF) patients without contraindications for PD use, allowing adequate metabolic and fluid control, with no increase in the number of infectious or mechanical complications. MELD, mechanical complications and FB were factors associated with mortality, while nephrotoxic AKI was a protective factor. Further studies are needed to better investigate the role of PD in ACLF patients with AKI.

New Approaches to Respiratory Assist: Bioengineering an Ambulatory, Miniaturized Bioartificial Lung

Although state-of-the-art treatments of respiratory failure clearly have made some progress in terms of survival in patients suffering from severe respiratory system disorders, such as acute respiratory distress syndrome (ARDS), they failed to significantly improve the quality of life in patients with acute or chronic lung failure, including severe acute exacerbations of chronic obstructive pulmonary disease or ARDS as well. Limitations of standard treatment modalities, which largely rely on conventional mechanical ventilation, emphasize the urgent, unmet clinical need for developing novel (bio)artificial respiratory assist devices that provide extracorporeal gas exchange with a focus on direct extracorporeal CO2 removal from the blood. In this review, we discuss some of the novel concepts and critical prerequisites for such respiratory lung assist devices that can be used with an adequate safety profile, in the intensive care setting, as well as for long-term domiciliary therapy in patients with chronic ventilatory failure. Specifically, we describe some of the pivotal steps, such as device miniaturization, passivation of the blood-contacting surfaces by chemical surface modifications, or endothelial cell seeding, all of which are required for converting current lung assist devices into ambulatory lung assist device for long-term use in critically ill patients. Finally, we also discuss some of the risks and challenges for the long-term use of ambulatory miniaturized bioartificial lungs.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

Continuous veno-venous hemofiltration yields better renal outcomes than intermittent hemodialysis among traumatic intracranial hemorrhage patients with acute kidney injury: A nationwide population-based retrospective study in Taiwan

OBJECT

Traumatic intracranial hemorrhage (TICH) patients with acute kidney injury (AKI) were reported to have a high mortality rate. Renal replacement therapy (RRT) is indicated for patients with a severe kidney injury. This study aimed to compare the effects of different RRT modalities regarding chronic dialysis rate among adult TICH patients with AKI.

METHODS

A retrospective search of computerized hospital records from 2000 to 2010 for patients with a discharge diagnosis of TICH was conducted to identify the index cases. We collected the data of TICH patients with increased intracranial pressure combined with severe AKI who received intermittent hemodialysis (IHD) or continuous veno-venous hemofiltration (CVVH) as RRT. The outcome was dialysis dependence between 2000 and 2010.

RESULTS

From a total of 310 patients who were enrolled in the study, 134 (43%) received CVVH and 176 (57%) received IHD. The risk of dialysis dependency was significantly lower in the CVVH group than in the IHD group (adjusted hazard ratio: 0.368, 95% CI, 0.158-0.858, P = 0.034). Diabetes mellitus and coronary artery disease were risk factors for dialysis dependency. CVVH compared with IHD modality was associated with lower dialysis dependency rate in TICH patients combined with AKI and diabetes mellitus and those with an injury severity score (ISS) ≥16.

CONCLUSION

CVVH may yield better renal outcomes than IHD among TICH patients with AKI, especially those with diabetes mellitus and an ISS ≥16. The beneficial impact of CVVH on TICH patients needs to be clarified in a large cohort study in future.

RECOMMENDATIONS OF THE BRAZILIAN SOCIETY OF HEPATOLOGY FOR THE MANAGEMENT OF ACUTE KIDNEY INJURY IN PATIENTS WITH CIRRHOSIS

ABSTRACT Acute kidney injury is a common complication of cirrhosis, occurring in up to 20% of patients hospitalized with cirrhosis. This field is rapidly changing, with significant advances in classification, biomarkers and therapy over the last few years. On the behalf of the Brazilian Society of Hepatology, a panel of experts in Hepatology and Nephrology reviewed published evidence to integrate findings and develop the recommendations presented in this manuscript.

Licochalcone A Attenuates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting NF-κB Activation

Licochalcone A (Lico A), a flavonoid found in licorice root (Glycyrrhiza glabra), has been reported to have anti-inflammatory activity. However, the protective effects of Lico A on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) remains unclear. In this study, using a mouse model of LPS-induced AKI, we investigated the protective effects and mechanism of Lico A on LPS-induced AKI in mice. LPS-induced kidney injury was assessed by detecting kidney histological study, blood urea nitrogen (BUN), and creatinine levels. The production of inflammatory cytokines TNF-α, IL-6, and IL-1β in serum and kidney tissues was detected by ELISA. The activation of NF-κB was measured by western blot analysis. Our results showed that Lico A dose-dependently attenuated LPS-induced kidney histopathologic changes, serum BUN, and creatinine levels. Lico A also suppressed LPS-induced TNF-α, IL-6, and IL-1β production both in serum and kidney tissues. Furthermore, our results showed that Lico A significantly inhibited LPS-induced NF-κB activation. In conclusion, our results suggest that Lico A has protective effects against LPS-induced AKI and Lico A exhibits its anti-inflammatory effects through inhibiting LPS-induced NF-κB activation.

PK/PD analysis of biapenem in patients undergoing continuous hemodiafiltration

BACKGROUND

Continuous hemodiafiltration (CHDF) is used as renal replacement therapy for critically ill patients with renal failure, and to treat hypercytokinemia. Since CHDF also clears therapeutic agents, drug pharmacokinetics (PK) should be dependent upon CHDF conditions. Although the antibiotic biapenem (BIPM) is used in patients undergoing CHDF, the optimal therapeutic regimen in such patients has not been fully clarified. In this study, we investigated the PK of BIPM in patients with various levels of renal function undergoing CHDF with polysulfone (PS) membrane, and used PK models to identify the optimal administration regimen.

METHODS

BIPM (300 mg) was administered by infusion in patients undergoing CHDF (n = 7). Blood and filtrate-dialysate were collected for compartment and non-compartment analysis.

RESULTS

The sieving coefficient of PS membrane was 1.00 ± 0.06 (mean ± S.D., n = 7), and CHDF clearance of BIPM was found to be the sum of the dialysate flow rate (QD) and filtrate flow rate (QF). Non-CHDF clearance showed inter-individual variability (4.82 ± 2.48 L/h), depending on residual renal function and non-renal clearance. Based on the average PK parameters obtained with a compartmental model, maximal kill end point (over 40 % T > MIC4 μg/mL) was achieved with regimens of 300 mg every 6 h, 300 mg every 8 h, and 600 mg every 12 h. Monte Carlo simulation indicated that 300 mg infusion for 1 h every 6 h was optimal, and the probability of target attainment at MIC2 μg/mL was 90.2 %.

CONCLUSIONS

Our results establish the optimal regimen of BIPM in patients with various levels of renal function undergoing CHDF with a PS membrane.

Sustained low-efficiency extended dialysis (SLED) with single-pass batch system in critically-ill patients with acute kidney injury (AKI)

BACKGROUND

Single-pass batch dialysis (SBD) is a well-established system for treatment of end-stage renal disease. However, little evidence is available on sustained low-efficiency extended dialysis (SLED) performed with SBD in patients with acute kidney injury (AKI) in the intensive care unit (ICU).

METHODS

All SLED-SBD sessions conducted on AKI patients in nine ICUs between March and June 2010 were retrospectively analyzed regarding the achieved metabolic and fluid control. Logistic regression was performed to identify the risk factors associated with hypotension and clotting during the sessions.

RESULTS

Data from 106 patients and 421 sessions were analyzed. Patients were 54.2 ± 17.0 years old, 51 % males, and the main AKI cause was sepsis (68 %); 80 % of patients needed mechanical ventilation and 55 % vasoactive drugs. Hospital mortality was 62 %. The median session time was 360 min [interquartile range (IQR) 300-360] and prescribed ultrafiltration was 1500 ml (IQR 800-2000). In 272 sessions (65 %) no complications were recorded. No heparin was used in 269/421 procedures (64 %) and system clotting occurred in 63 sessions (15 %). Risk factors for clotting were sepsis [odds ratio (OR) 2.32 (1.31-4.11), p = 0.004], no anticoagulation [OR 2.94 (1.47-5.91), p = 0.002] and the prescribed time (hours) [OR 1.14 (1.05-1.24), p = 0.001]. Hypotension occurred in 25 % of procedures and no independent risk factors were identified by logistic regression. Adequate metabolic and fluid balance was achieved during SLED sessions. Median blood urea decreased from 107 to 63 mg/dl (p < 0.001), potassium from 4.1 to 3.9 mEq/l (p < 0.001), and increased bicarbonate (from 21.4 to 23.5 mEq/l, p < 0.001). Median fluid balance during session days ranged from +1300 to -20 ml/24 h (p < 0.001).

CONCLUSIONS

SLED-SBD was associated with a low incidence of clotting despite frequent use of saline flush, and achieved a satisfactory hemodynamic stability and reasonable metabolic and fluid control in critically-ill AKI patients.

Hemodialysis for near-fatal sodium phosphate toxicity in a child receiving sodium phosphate enemas

OBJECTIVE

This study aimed to demonstrate the importance of considering hemodialysis as a treatment option in the management of sodium phosphate toxicity.

METHODS

This is a case report of a 4-year-old who presented to the emergency department with shock, decreased mental status, seizures, and tetany due to sodium phosphate toxicity from sodium phosphate enemas.

RESULTS

Traditional management of hyperphosphatemia with aggressive hydration and diuretics was insufficient to reverse the hemodynamic and neurological abnormalities in this child. This is the first report of the use of hemodialysis in a child without preexisting renal failure for the successful management of near-fatal sodium phosphate toxicity.

CONCLUSIONS

Hemodialysis can safely be used as an adjunctive therapy in sodium phosphate toxicity to rapidly reduce serum phosphate levels and increase serum calcium levels in children not responding to conventional management.

Use of peripheral ultrafiltration in the postoperative cardiac surgery patient

BACKGROUND

: After cardiac surgery, most patients have development of third-space fluid retention, commonly treated with diuretics. In some patients diuretics are ineffective. In this subset, a simplified system for ultrafiltration was used for fluid extraction.

METHODS

: After obtaining permission from the institutional review board, the hospital charts of the first 30 patients having ultrafiltration were retrospectively reviewed to abstract data on fluid extraction and patient outcomes. Data are expressed as mean ± standard deviation.

RESULTS

: From April 2004 through January 2006, 30 patients were selected for ultrafiltration. In one patient, adequate intravenous access could not be obtained. There were 11 female and 18 male (age, 69 ± 12 years) postoperative cardiac surgery patients. The mean ultrafiltration run was 10.5 ± 9 hours, resulting in fluid extraction of 3528 ± 2111 mL per run and 5596 ± 3870 mL per patient (11 patients had more than 1 run). Hospital stay was 9.4 ± 4.4 days. Three patients died unrelated to ultrafiltration.

CONCLUSIONS

: Ultrafiltration as an alternative means of fluid extraction in postoperative cardiac surgery patients was effective and well tolerated.

Use of online blood volume and blood temperature monitoring during haemodialysis in critically ill patients with acute kidney injury: a single-centre randomized controlled trial

BACKGROUND

Little is known about the clinical impact on cardiovascular stability during intermittent haemodialysis (IHD) for acute kidney injury (AKI) of online monitoring devices that control blood volume (BV) and blood temperature in the intensive care unit (ICU) setting. We compared different dialysis treatment modalities with or without these new systems among critically ill patients requiring IHD.

METHODS

In a prospective single-centre three-arm randomized controlled trial, 600 dialysis sessions in 74 consecutive AKI critically ill patients were involved to assess intradialytic hypotension. Standard dialysis therapy with constant ultrafiltration (UF) rate, cool dialysate and high sodium conductivity (Treatment A) was compared to regimens with adjunctive interventions including BV control (Treatment B) and the combination of BV and active blood temperature control (Treatment C). Each dialysis session was randomly assigned to one of the three treatment arms and served as statistical unit.

RESULTS

Five hundred and seventy-two dialysis sessions were analysed (188, 190 and 194 in Treatments A, B and C, respectively). Hypotension occurred in 16.6% treatments, with similar rates among the arms. Haemodynamic parameters and dialysis-related complications did not differ between therapies. Based on generalized estimating equation adjusted to dialysate sodium conductivity, higher Sequential Organ Failure Assessment the day of dialysis session, the need for vasopressors and lower systolic blood pressure at the onset of the session were identified as independent predictors of hypotensive episodes, whereas regimens containing the new online monitors were not.

CONCLUSIONS

These results suggest that both actively controlled body temperature and UF profiled by online monitoring systems have no significant impact on the incidence of intradialytic hypotension in the ICU setting. Further research is needed before the use of these new sophisticated automatic methods can be applied routinely to the ICU setting.

Effect of hemopurification rate on doripenem pharmacokinetics in critically ill patients receiving high-flow continuous hemodiafiltration

  Hemopurification is an effective therapy for acute kidney injury, defined as creatinine clearance less than 30 ml/min, which occurs frequently in the intensive care unit. These critically ill patients often have severe infectious complications and are thus often treated with antibiotics. However, the effect of hemopurification on the pharmacokinetics of antibiotics is not well understood. In this study, we investigated the pharmacokinetics of doripenem (DRPM) in critically ill patients with accompanying renal dysfunction undergoing continuous hemodiafiltration by high-volume filtration/high-flow dialysis (high-flow CHDF) and compared it to the pharmacokinetics of DRPM during conventional CHDF. We studied 8 patients (2 in the high-flow group and 6 in the conventional group) in whom DRPM was administered while performing CHDF for acute kidney injury. DRPM (250 mg) was intravenously infused over 1 h. For the conventional group, CHDF was performed at a blood flow rate (Q(B)) of 100 ml/min, dialysate flow rate (Q(D)) of 500 ml/h, and filtration flow rate (Q(F)) of 300 ml/h. For the high-flow group, CHDF was performed at a blood flow rate (Q(B)) of 100 ml/min, dialysate flow rate (Q(D)) of 1500 ml/h, and filtration flow rate (Q(F)) of 900 ml/h. For both groups, a polysulfonehemofilter with a membrane area of 1.0 m(2) was used. Mean half-life, total body clearance, and clearance via hemodiafiltration of DRPM were 2.9 h, 118 ml/min, and 41.9 ml/min, respectively, in the high-flow group, and 7.9 h, 58 ml/min, and 13.5 ml/min in the conventional group. Clearance via hemodiafiltration increased approximately 3-fold by tripling the hemopurification rate. Therefore, CHDF parameters greatly affected DRPM pharmacokinetics in patients receiving CHDF. These results suggest that clearance via hemodiafiltration increases proportionally to the hemopurification rate. Thus, it is reasonable to conclude that DRPM dose must be increased to 1.0-1.5 g/day when performing high-flow CHDF.

Outcome among patients with acute renal failure needing continuous renal replacement therapy: A single center study

Outcome of acute renal failure (ARF) and use of continuous renal replacement therapy (CRRT) have shown a consistently high mortality. (1) Evaluate the short-term patient survival. (2) Evaluate dialysis-free survival. (3) Evaluate risk factors associated with overall survival and the continued need for intermittent dialysis. We identified adults (>/=18 years) needing CRRT, treated in the critical care units of Froedtert Medical and Lutheran Hospital from January 1, 2003 till December 31, 2005. Patients were divided into two major groups needing CRRT, end stage renal disease (ESRD) (chronic dialysis) and non-ESRD with ARF. Continuous renal replacement therapy was performed with an average of 2 L replacement fluid exchanges/h. Sigma stat software was used for analysis. Comparison was done for noncontinuous variables by chi-square and t test for categorical and continuous variables, respectively. A total of 110 (ESRD 24/non-ESRD 86) patients received CRRT during study period. Over all in-hospital mortality among non-ESRD patients was 63% vs. 46% for ESRD. Among non-ESRD patients who survived, 47% needed intermittent hemodialysis on intensive care unit discharge and 28% continued to need hemodialysis at last follow-up. Among non-ESRD patients alive at discharge, those who were dialysis dependent on last follow-up were older (64.5) than those who did not require dialysis on last follow-up (58.4) P=0.347. Non-ESRD patients who died were in the hospital for an average of 17.5 days compared with 29 days for those who were discharged from the hospital. Patients with ARF needing CRRT have high in-hospital mortality. A significant percentage of patients remained dialysis dependant on last follow-up.

[Principles of intensive care in severe acute pancreatitis in 2008]

Acute pancreatitis is a dynamic, often progressive disease; 14-20% require intensive care in its severe form due to multiorgan dysfunction and/or failure. This review was created using systematic literature review of articles published on this subject in the last 5 years. The outcome of severe acute pancreatitis is determined by the inflammatory response and multiorgan dysfunction - the prognostic scores (Acute Physiology and Chronic Health Evaluation, Glasgow Prognostic Index, Sepsis-related Organ Failure Assessment, Multi Organ Dysfunction Syndrome Scale, Ranson Scale) can be used to determine outcome. Clinical signs (age, coexisting diseases, confusion, obesity) and biochemistry values (serum amylase, lipase, C-reactive protein, procalcitonin, creatinine, urea, calcium) have important prognostic roles as well. Early organ failure increases the risk of late abdominal complications and mortality. Intensive care can provide appropriate multi-function patient monitoring which helps in early recognition of complications and appropriate target-controlled treatment. Treatment of severe acute pancreatitis aims at reducing systemic inflammatory response and multiorgan dysfunction and, on the other side, at increasing the anti-inflammatory response. Oral starvation for 24-48 hours is effective in reducing the exocrine activity of the pancreas; the efficacy of protease inhibitors is questionable. Early intravascular volume resuscitation and stable haemodynamics improve microcirculation. Early oxygen therapy and mechanical ventilation provide adequate oxygenation. Electrolyte and acid-base control can be as important as tight glucose control. Adequate pain relief can be achieved by thoracic epidural catheterization. Early enteral nutrition with immunonutrition should be used. There is evidence that affecting the coagulation cascade by activated protein C can play a role in reducing the inflammatory response. The complex therapy of acute pancreatitis includes appropriate antibiotics, thrombo-embolic prophylaxis and in certain cases plasmapheresis and/or haemofiltration. Reducing intraabdominal pressure may be necessary in the acute phase. Intensive care multidisciplinary teamwork can reduce the mortality of severe acute pancreatitis from 30% to 10%.

Dialysis and pediatric acute kidney injury: choice of renal support modality

Dialytic intervention for infants and children with acute kidney injury (AKI) can take many forms. Whether patients are treated by intermittent hemodialysis, peritoneal dialysis or continuous renal replacement therapy depends on specific patient characteristics. Modality choice is also determined by a variety of factors, including provider preference, available institutional resources, dialytic goals and the specific advantages or disadvantages of each modality. Our approach to AKI has benefited from the derivation and generally accepted defining criteria put forth by the Acute Dialysis Quality Initiative (ADQI) group. These are known as the risk, injury, failure, loss, and end-stage renal disease (RIFLE) criteria. A modified pediatrics RIFLE (pRIFLE) criteria has recently been validated. Common defining criteria will allow comparative investigation into therapeutic benefits of different dialytic interventions. While this is an extremely important development in our approach to AKI, several fundamental questions remain. Of these, arguably, the most important are "When and what type of dialytic modality should be used in the treatment of pediatric AKI?" This review will provide an overview of the limited data with the aim of providing objective guidelines regarding modality choice for pediatric AKI. Comparisons in terms of cost, availability, safety and target group will be reviewed.

Angiotensin converting enzyme insertion/deletion genetic polymorphism: its impact on renal function in critically ill patients

OBJECTIVE

Previous clinical studies have suggested an association between the insertion/deletion (I/D) genetic polymorphism of angiotensin converting enzyme and acute or chronic diseases. We aimed to test the prognostic value of the I-allele, which is associated with lower angiotensin converting enzyme activity, on acute kidney injury.

DESIGN

Prospective 6-month noninterventional study.

SETTING

Intensive care unit of a University Hospital.

PATIENTS AND METHODS

One hundred eighty consecutive admitted white patients for an expected intensive care unit stay >48 hr. Angiotensin converting enzyme genetic polymorphism was screened for genotype (I/D polymorphism analysis by polymerase chain reaction amplification) and phenotype (measurement of the circulating rate of angiotensin converting enzyme by spectrophotometry). Acute kidney injury was assessed according to Risk, Injury, Failure, Loss, and End-stage Kidney classification.

INTERVENTION

None.

RESULTS

II, ID, and DD genotype frequencies were 25%, 48%, and 27%, respectively. II and ID genotypes were associated with lower baseline circulating rates of angiotensin converting enzyme (20 +/- 14 and 22 +/- 18 U/L, respectively, vs. 30 +/- 23 U/L for DD genotype; p = 0.04). Repartition of angiotensin converting enzyme genotypes were different in patients with and without acute kidney injury (p < 0.0001), with greater II genotype proportion in acute kidney injury patients (42% vs. 13% for those without acute kidney injury). After adjustment on the identified prognostic factors, II genotype was independently associated with increased risk of acute kidney injury (adjusted odds ratio, 6.5; 95% confidence interval, 2.4-17.7; p = 0.0002), then death among patients with acute kidney injury (adjusted odds ratio, 1.7; 95% confidence ratio, 1.1-2.6; p = 0.02).

CONCLUSION

These data confirm the key role of the renin-angiotensin system to maintain glomerular filtration rate, and highlight an association between a genetic factor and susceptibility to and prognosis of acute kidney disease.

A pilot randomized study comparing high and low volume hemofiltration on vasopressor use in septic shock

OBJECTIVE

High volume hemofiltration (HVHF) has shown potential benefits in septic animals and a few reports suggested a hemodynamic improvement in humans. However, randomized studies are still lacking. Our goal was to evaluate the hemodynamic effects of HVHF in septic shock patients with acute renal failure (ARF).

DESIGN AND SETTING

Prospective randomized study in an intensive care unit (ICU).

PATIENTS

Twenty patients with septic shock and ARF.

INTERVENTIONS

Patients were randomized to either high volume hemofiltration [HVHF 65 ml/(kg h)] or low volume hemofiltration [LVHF 35 ml/(kg h). Vasopressor dose was adjusted to reach a mean arterial pressure (MAP) > 65 mmHg.

MEASUREMENTS AND RESULTS

We performed six hourly measurements of MAP, norepinephrine dose, PaO(2)/FiO(2) and lactate, and four daily urine output and logistic organ dysfunction (LOD) score. Baseline characteristics of the two groups were comparable on randomization. Mean norepinephrine dose decreased more rapidly after 24 h of HVHF treatment compared to LVHF treatment (P = 0.004) whereas lactate and PaO(2)/FiO(2) did not differ between the two treatment groups. During the 4-day follow-up, urine output was slightly increased in the HVHF group (P = 0.059) but the LOD score evolution was not different. Duration of mechanical ventilation, renal replacement therapy and ICU length of stay were also comparable. Survival on day 28 was not affected.

CONCLUSION

HVHF decreased vasopressor requirement and tended to increase urine output in septic shock patients with renal failure. However, a larger trial is required to confirm our results and perhaps to show a benefit in survival.

Intermittent versus continuous renal replacement therapy for acute renal failure in adults

BACKGROUND

Renal replacement therapy (RRT) for acute renal failure (ARF) can be applied intermittently (IRRT) or continuously (CRRT). It has been suggested that CRRT has several advantages over IRRT including better haemodynamic stability, lower mortality and higher renal recovery rates.

OBJECTIVES

To compare CRRT with IRRT to establish if any of these techniques is superior to each other in patients with ARF.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL). Authors of included studies were contacted, reference lists of identified studies and relevant narrative reviews were screened. Search date: October 2006.

SELECTION CRITERIA

RCTs comparing CRRT with IRRT in adult patients with ARF and reporting prespecified outcomes of interest were included. Studies assessing CAPD were excluded.

DATA COLLECTION AND ANALYSIS

Two authors assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes or mean difference (WMD) for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

We identified 15 studies (1550 patients). CRRT did not differ from IRRT with respect to in-hospital mortality (RR 1.01, 95% CI 0.92 to 1.12), ICU mortality (RR 1.06, 95% CI 0.90 to 1.26), number of surviving patients not requiring RRT (RR 0.99, 95% CI 0.92 to 1.07), haemodynamic instability (RR 0.48, 95% CI 0.10 to 2.28) or hypotension (RR 0.92, 95% CI 0.72 to 1.16) and need for escalation of pressor therapy (RR 0.53, 95% CI 0.26 to 1.08). Patients on CRRT were likely to have significantly higher mean arterial pressure (MAP) (WMD 5.35, 95% CI 1.41 to 9.29) and higher risk of clotting dialysis filters (RR, 95% CI 8.50 CI 1.14 to 63.33).

AUTHORS' CONCLUSIONS

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. Future research should focus on factors such as the dose of dialysis and evaluation of newer promising hybrid technologies such as SLED. Triallists should follow the recommendations regarding clinical endpoints assessment in RCTs in ARF made by the Working Group of the Acute Dialysis Quality Initiative Working Group.

Survival to discharge among patients treated with continuous renal replacement therapy

Continuous renal replacement therapy (CRRT) is widely used in critically ill patients with acute renal failure (ARF). The survival of patients who require CRRT and the factors predicting their outcomes are not well defined. We sought to identify clinical features to predict survival in patients treated with CRRT. We reviewed the charts of all patients who received CRRT at the Toronto General Hospital during the year 2002. Our cohort (n=85) represented 97% of patients treated with this modality in 3 critical care units. We identified demographic variables, underlying diagnoses, transplantation status, location (medical-surgical, coronary, or cardiovascular surgery intensive care units), CRRT duration, baseline estimated glomerular filtration rate (eGFR), and presence of oliguria (<400 mL/day) on the day of CRRT initiation. The principal outcome was survival to hospital discharge. Among those alive at discharge, we assessed whether there was an ongoing need for renal replacement therapy. Greater than one-third (38%, 32/85) of patients survived to hospital discharge. Three (9%) survivors remained dialysis-dependent at the time of discharge. Survivors were younger than nonsurvivors (mean age 56 vs. 60 years), were on CRRT for a shorter duration (7 vs. 13 days), and had a higher baseline eGFR (74 vs. 62 mL/min/m(2)). Patient survival varied among different critical care units (medical surgical 33%, coronary 38%, and cardiovascular surgery 45%). Multivariable logistic regression revealed that shorter duration of CRRT, nonoliguria, and baseline eGFR >60 mL/min/m(2) were independently associated with survival to hospital discharge (p<0.05). Critically ill patients with ARF who require CRRT continue to have high in-hospital mortality. A shorter period of CRRT dependence, nonoliguria and higher baseline renal function may predict a more favorable prognosis. The majority of CRRT patients who survive their critical illness are independent of dialysis at the time of hospital discharge.

Impact of anemia on outcome in critically ill patients with severe acute renal failure

OBJECTIVE

To evaluate the prognostic value of hemoglobin levels in critically ill patients with acute renal failure (ARF) requiring dialysis.

DESIGN AND SETTING

A prospective observational cohort study in two adult medical ICUs.

PATIENTS

206 consecutive patients with ARF who required dialysis. Overall 28-day mortality was 48%.

MEASUREMENTS AND RESULTS

At ICU admission mean hemoglobin level was 9.1+/-2.1 g/dl. By ROC curve analysis the threshold value of hemoglobin with the highest sensibility/specificity was 9 g/dl. At baseline 63% of patients had anemia, defined as initial hemoglobin below 9 g/dl. Kaplan-Meier analysis showed that these patients had lower survival rate than those with hemoglobin above 9 g/dl. By multivariable analysis three factors were independently associated with 28-day death: hemoglobin lower than 9 g/dl (adjusted odds ratio 2.4, 95% CI 1.1-5.2), age, and SOFA score. Based on age and SOFA a matched cohort analysis of 67 pairs of ARF patients with or without anemia found similar results regarding the negative impact of anemia on outcome. Finally, a multivariable logistic regression analysis on matched cohort identified hemoglobin level below 9 g/dl (adjusted odds ratio 1.32, 95%CI 1.15-1.46), continuous renal replacement therapy, and vasoactive therapy as independent predictors of 28-day death.

CONCLUSIONS

These results suggest that initial hemoglobin level could be helpful in identifying patients with ARF requiring dialysis at high risk of death.

The change in renal replacement therapy on acute renal failure in a general intensive care unit in a university hospital and its clinical efficacy: a Japanese experience

The aim of our study was to examine renal replacement therapies (RRT) that have been used for acute renal failure (ARF) in our intensive care unit (ICU) patients and to compare their outcomes. Sixteen patients who underwent intermittent hemodialysis (IHD), 14 patients who underwent continuous hemofiltration (CHF) in combination with IHD (CHF + IHD), and 38 patients who underwent continuous hemodiafiltration (CHDF) were evaluated. Regarding the effects of blood purification on hemodynamics and renal function, the percentage increase in blood pressure and percent rapid increase in urinary output were the greatest in the CHDF group. The hourly urinary output after the start of initial blood purification increased only in the CHDF group. The survival rate was significantly higher in the CHDF group. These results suggest that CHDF should be the first-line therapy for patients with ARF and that we are moving in the right direction regarding the application of RRT to treat ARF in ICU patients.

Complicated acute myocardial infarction requiring mechanical ventilation in the intensive care unit: Prognostic factors of clinical outcome in a series of 157 patients*

OBJECTIVE

To determine prognostic factors associated with death in patients with complicated acute myocardial infarction requiring mechanical ventilation.

DESIGN

Retrospective chart-based analysis.

SETTING

A 22-bed medical intensive care unit in a university hospital.

PATIENTS

A total of 157 consecutive patients with acute myocardial infarction requiring endotracheal intubation and mechanical ventilation admitted to an intensive care unit during a 6-yr period.

INTERVENTIONS

Coronary reperfusion strategy within 12 hrs following symptom onset.

MEASUREMENTS AND MAIN RESULTS

Clinical characteristics at admission of survivors (n = 77) and nonsurvivors (n = 80) were similar regarding demographics, medical history, and Glasgow Coma Scale score. Twenty-eight-day intensive care unit mortality rate was 51%. The following criteria were higher for nonsurvivors: Simplified Acute Severity Score II, 79 +/- 18 vs. 64 +/- 17 (p <.0001); Acute Physiology and Chronic Health Evaluation (APACHE) II, 33 +/- 13 vs. 25 +/- 6 (p <.0001); incidence of cardiogenic shock (p =.0085) and failing organs (p <.0001); coronary artery disease extension (p =.045); and delay between symptom onset and coronary reperfusion (p =.0348). Nonsurvivors also had higher serum urea and creatinine and lower urine output, arterial pH, and left ventricular ejection fraction (p <.05). Mortality rate was higher in patients with PaO2/FiO2 ratio <200 than in patients with PaO2/FiO2 ratio >200 at admission (log-rank, 5.016; p =.0251). By multivariate analysis, only three factors were independently associated with death: APACHE II >29 (odds ratio, 1.132; 95% confidence interval, 1.013-1.265, p =.0287), serum creatinine >180 micromol/L (odds ratio, 6.151; 95% confidence interval, 1.446-26.166, p =.0139), and initial left ventricular ejection fraction <0.4 (odds ratio, 1.121; 95% confidence interval, 1.049-1.347, p =.0316). Overall, good discrimination was achieved for the risk score model (c-index, 0.852).

CONCLUSIONS

We confirmed the high mortality rate of patients admitted to an intensive care unit with acute myocardial infarction requiring mechanical ventilation. In these patients, the main risk factors for death found, namely high APACHE II, early development of acute renal failure, and low resting left ventricular function, reflected the severity of the myocardial infarction.

The provision and practice of renal replacement therapy on adult intensive care units in the United Kingdom

This study surveyed the availability and current practice of renal replacement therapy on adult general intensive care units in the United Kingdom. Questionnaires were returned from 236 units (89%). Renal replacement therapy was provided by 212 (90%) of responding units, treating 9442 patients per year. Renal physicians were involved in the initiation and prescription of treatment in 22 (11%) units. Ninety-one units (43%) had no step down facility on-site for those patients still requiring renal replacement therapy but no longer requiring intensive care. Continuous techniques are used by the majority of units, most commonly, continuous veno-venous haemofiltration, with an ultrafiltration rate of 2000 ml.h-1. Fifty-eight units (28%) use haemofiltration as adjuvant treatment in septic shock. The provision and practice of renal replacement therapy is now an integral part of intensive care medicine in the United Kingdom.

The prevention of radiocontrast-agent-induced nephropathy by hemofiltration

BACKGROUND

Nephropathy induced by exposure to radiocontrast agents, a possible complication of percutaneous coronary interventions, is associated with significant in-hospital and long-term morbidity and mortality. Patients with preexisting renal failure are at particularly high risk. We investigated the role of hemofiltration, as compared with isotonic-saline hydration, in preventing contrast-agent-induced nephropathy in patients with renal failure.

METHODS

We studied 114 consecutive patients with chronic renal failure (serum creatinine concentration, >2 mg per deciliter [176.8 micromol per liter]) who were undergoing coronary interventions. We randomly assigned them to either hemofiltration in an intensive care unit (ICU) (58 patients, with a mean [+/-SD] serum creatinine concentration of 3.0+/-1.0 mg per deciliter [265.2+/-88.4 micromol per liter]) or isotonic-saline hydration at a rate of 1 ml per kilogram of body weight per hour given in a step-down unit (56 patients, with a mean serum creatinine concentration of 3.1+/-1.0 mg per deciliter [274.0+/-88.4 micromol per liter]). Hemofiltration (fluid replacement rate, 1000 ml per hour without weight loss) and saline hydration were initiated 4 to 8 hours before the coronary intervention and were continued for 18 to 24 hours after the procedure was completed.

RESULTS

An increase in the serum creatinine concentration of more than 25 percent from the base-line value after the coronary intervention occurred less frequently among the patients in the hemofiltration group than among the control patients (5 percent vs. 50 percent, P<0.001). Temporary renal-replacement therapy (hemodialysis or hemofiltration) was required in 25 percent of the control patients and in 3 percent of the patients in the hemofiltration group. The rate of in-hospital events was 9 percent in the hemofiltration group and 52 percent in the control group (P<0.001). In-hospital mortality was 2 percent in the hemofiltration group and 14 percent in the control group (P=0.02), and the cumulative one-year mortality was 10 percent and 30 percent, respectively (P=0.01).

CONCLUSIONS

In patients with chronic renal failure who are undergoing percutaneous coronary interventions, periprocedural hemofiltration given in an ICU setting appears to be effective in preventing the deterioration of renal function due to contrast-agent-induced nephropathy and is associated with improved in-hospital and long-term outcomes.

Approach to intradialytic hypotension in intensive care unit patients with acute renal failure

The increasing prevalence of acute renal failure (ARF) patients with hemodynamic intolerance of intermittent hemodialysis (HD), generally because of septic vasoparesis or severe cardiac dysfunction, has led to the development of several strategies to improve the delivery of renal replacement therapy (RRT) in ARF patients. Intradialytic hypotension (IDH) is caused by the interaction of dialysis-dependent and dialysis-independent factors. Dialysis-dependent factors include the prescriptions for fluid removal, solute removal, and dialysate components such as sodium, buffer, and calcium. Dialysis-independent factors include hemodynamic compromise caused by hypovolemic, cardiogenic, vasodilatory, and mixed mechanisms. We propose an approach to the prevention and management of IDH in critically ill ARF patients, which minimizes hypovolemic, cardiogenic, and vasodilatory insults by optimizing fluid removal, cardiac function, and vascular contractility.

Clinical potential of insulin therapy in critically ill patients

Stress of critical illness is often accompanied by hyperglycaemia, whether or not the patient has a history of diabetes mellitus. This has been considered to be part of the adaptive metabolic response to stress. The level of hyperglycaemia in patients with acute myocardial infarction (MI) or stroke upon admission to the hospital has been related to the risk of adverse outcome. However, until recently, there was no evidence of a causal relationship and thus stress-induced hyperglycaemia was only treated with exogenous insulin when it exceeded 12 mmol/L (220 mg/dL). In patients with known diabetes, even higher levels were often tolerated. Recently, new data became available in support of another approach. In this review, we focus on the new evidence and the clinical aspects of managing hyperglycaemia with insulin in critically ill patients, drawing a parallel with diabetes management. Particularly, the 'Diabetes and Insulin-Glucose infusion in Acute Myocardial Infarction (DIGAMI) study' and the 'insulin in intensive care study' have provided novel insights. The DIGAMI study showed that in patients with diabetes, controlling blood glucose levels below 12 mmol/L for 3 months after acute MI improves long-term outcome. In the recent study of predominantly surgical intensive care patients, the majority of whom did not previously have diabetes, it was shown that an even tighter control of blood glucose with exogenous insulin, aiming for normoglycaemia, dramatically improved outcome. Indeed, in this large prospective, randomised, controlled study, 1548 intensive care patients had been randomly allocated to either the conventional approach, with insulin infusion started only when blood glucose levels exceeded 12 mmol/L, or intensive insulin therapy, with insulin infused to maintain blood glucose at a level of 4.5-6.1 mmol/L (80-110 mg/dL). Intensive insulin therapy reduced intensive care mortality by more than 40% and also decreased a number of morbidity factors including acute renal failure, polyneuropathy, ventilator-dependency and septicaemia. Future studies will be needed to further unravel the mechanisms that explain the beneficial effects of this simple and cost-saving intervention. Although available evidence supports implementation of intensive insulin therapy in surgical intensive care, the benefit for other patient populations, such as patients on medical intensive care units or hospitalised patients who do not require intensive care but who do present with stress-induced hyperglycaemia, remains to be investigated.

Cost of acute renal failure requiring dialysis in the intensive care unit: clinical and resource implications of renal recovery

OBJECTIVE

Acute renal failure can be treated with continuous renal replacement therapy (CRRT) or intermittent hemodialysis. There is no difference in mortality, although patients treated with CRRT may have a higher rate of renal recovery. Given these considerations, an estimate of the costs by modality may help in choosing the method of dialysis. As such, the objective of this study was to estimate the cost of CRRT and intermittent hemodialysis in the intensive care unit and to explore the impact of renal recovery on subsequent clinical outcomes and costs among survivors.

DESIGN

Retrospective cohort study of all patients who developed acute renal failure and required dialysis between April 1, 1996, and March 31, 1999.

SETTING

Two tertiary care intensive care units in Calgary, Canada.

PATIENTS

A total of 261 critically ill patients.

INTERVENTIONS

None.

MEASUREMENTS

All patients were followed to determine in-hospital and subsequent clinical outcomes (survival and frequency of renal recovery). The immediate and potential long-term costs of CRRT and intermittent hemodialysis were measured.

MAIN RESULTS

The cost of performing CRRT ranged from Can 3,486 dollars to Can 5,117 dollars per week, depending on the modality and the anticoagulant used, and it was significantly more expensive than intermittent hemodialysis (Can 1,342 dollars per week). Survivors with renal recovery spent significantly fewer days in hospital (11.3 vs. 22.5 days, p<.001) and incurred less healthcare costs (11,192 dollars vs. 73,273 dollars, p<.001) over the year after hospital discharge compared with survivors who remained on dialysis.

CONCLUSIONS

Immediate cost savings could be achieved by increasing the use of intermittent hemodialysis rather than CRRT for patients with acute renal failure in the intensive care unit. Because of the high cost of ongoing dialysis, CRRT may still be an economically efficient treatment if it improves renal recovery among survivors; further study in this area is required.

Continuous veno-venous hemofiltration for the treatment of contrast-induced acute renal failure after percutaneous coronary interventions

Acute renal failure (ARF) requiring hemodialysis after percutaneous coronary interventions (PCI) is a serious complication with poor prognosis. Hemodialysis-induced hypotension may have deleterious cardiovascular effects, especially in high-risk patients. Ultrafiltrate removal and simultaneous fluid replacement with a solution similar to plasma for high-volume controlled hydration can be obtained with hemodynamic stability by continuous veno-venous hemofiltration (CVVH). We prospectively assessed the safety and effectiveness of percutaneous CVVH (Y-shaped double-lumen catheter, circuit originating from and terminating in the femoral vein) in 33 consecutive patients (23 men and 10 women; mean age, 69 +/- 9 years) who, after PCI, developed oligo-anuric ARF, associated in 20 of them with congestive heart failure. All patients received a concomitant infusion of furosemide (500-1000 mg/day) and dopamine (2 microg/kg/min). During CVVH, the average fluid volume replacement and body fluid net reduction were 1000 +/- 247 and 75 +/- 48 ml/hr, respectively. Treatment with CVVH continued for 4.7 +/- 2.7 days and corrected fluid overload in all cases. No patient experienced systemic hypotension or hypovolemia. Diuresis recovered in 32 (97%) patients, who showed a parallel improvement of renal function parameters. One patient required chronic dialysis. In-hospital and 1-year mortality was 9.1% and 27.3%, respectively. In conclusion, our data indicate that CVVH is a safe and effective therapy of radiocontrast-induced ARF following PCI. It temporarily replaces renal function without deleterious cardiovascular effects, allowing the kidney to recover from the nephrotoxic injury. However, despite promising early results, large randomized trials are required to define the role of CVVH in ARF after PCI.

Physiologic endpoints (efficacy) for acute renal failure studies

Acute renal failure research has been hampered by the lack of useful physiologic surrogate endpoints. Acute renal failure prevention and therapy studies using variables such as urine output and serum and urine chemistries have not yielded interventions proven to decrease the morbidity and mortality associated with acute renal dysfunction. Of those interventions that have been successful in smaller, phase II-level efficacy studies, none subsequently decreased the incidence of clinical (effectiveness) endpoints such as dialysis requirement or mortality in larger phase III trials. Suitable physiologic endpoints are needed to test the efficacy of new proposed therapies for the prevention and management of acute renal failure. Candidate endpoints for efficacy studies in acute renal failure prevention and management include glomerular filtration rate markers, renal blood flow, urine markers, and urine output. Possible endpoints for efficacy studies of renal replacement therapy in acute renal failure include serum markers of renal function and a variety of nonrenal markers. In this article, we present an approach to the choice of physiologic endpoints to determine the efficacy of interventions in acute renal failure.

Acute renal failure in the intensive care unit: a systematic review of the impact of dialytic modality on mortality and renal recovery

BACKGROUND

There is controversy about which dialytic modality should be used for the treatment of acute renal failure (ARF) in the intensive care unit. We performed a systematic review and meta-analysis to determine the relative risks (RRs) of mortality and renal recovery associated with intermittent hemodialysis (IHD) therapy compared with continuous renal replacement therapy (CRRT) in critically ill adults with ARF.

METHODS

Four databases (MEDLINE, Cochrane Library, Database of Abstracts and Reviews, and Science Citation Index), hand searching of conference proceedings and journals, manual review of bibliographies from identified articles, and contact with experts were used. All randomized trials (published or unpublished in any language) that compared mortality between intermittent and continuous treatments were eligible. Trials for which an RR for mortality could not be calculated or with multiple experimental interventions were excluded. Data were extracted separately by two authors and recorded on a standardized form. Disagreements were resolved by consensus.

RESULTS

Six eligible trials were identified; four of these provided data on renal outcomes. RR (mortality) for IHD was 0.96 (95% confidence interval [CI], 0.85 to 1.08; P = 0.50), RR (renal death) was 1.02 (95% CI, 0.89 to 1.17; P = 0.78), and RR (dialysis dependence) in survivors was 1.19 (95% CI, 0.62 to 2.27; P = 0.60; all compared with continuous therapy). Several sensitivity analyses did not change these results. Of the outcomes studied, the risk for dialysis dependence in survivors would be most sensitive to the addition of new trials.

CONCLUSIONS

In comparison to IHD therapy, CRRT does not improve survival or renal recovery in unselected critically ill patients with ARF. Future studies should focus on well-defined subgroups of such patients using lessons learned from the trials in this meta-analysis. The high cost of chronic dialysis therapy and the relative instability of the RR for dialysis dependence suggest that future trials also should evaluate differences in renal recovery between dialytic modalities.

The dialytic management of acute renal failure in the elderly

In this article the different dialysis strategies in the management of acute renal failure (ARF) in the elderly are discussed. Although peritoneal dialysis (PD) offers some theoretical advantages, there are several medical and technical reasons why it is currently less frequently used. The choice between intermittent hemodialysis (HD) and continuous renal replacement therapy (CRRT) is determined by a number of considerations, the most important ones being hemodynamic stability, the need for hyperalimentation and/or ultrafiltration, and the local experience with one or both techniques. Some recent studies with CRRT in elderly ARF patients describe favorable results. Slow extended daily dialysis (SLEDD) modalities may be particularly indicated in elderly, critically ill ARF patients because these techniques combine the advantages of both CRRT and HD. Finally, the importance of the biocompatibility of dialysis membranes is discussed. Although there are a number of theoretical arguments to use biocompatible membranes, this opinion is not always supported by the results of recent comparative studies. It is the opinion of the authors that all dialysis strategies should be mastered and utilized for appropriate indications in elderly ARF patients.

Neurologic complications in intensive care

Neurologic complications in intensive care occur as the result of critical illness, intensive care therapies and procedures, or medical or surgical conditions; perioperatively; or because of underlying primary neurologic disease. These complications occur at greater frequency and are often unrecognized because critically ill patients are often intubated, sedated, and/or receiving neuromuscular blocking agents. Encephalopathy is the most common neurologic complication in the ICU and is usually multifactorial in origin. Sepsis is associated with the highest incidence of neurologic complications. Neurologic complications are associated with increased disability, longer hospital stay, and increased mortality. This review focuses on neurologic complications that are the result of critical illnesses and intensive care management.

Anticoagulation for continuous renal replacement therapy

Anticoagulation during continuous renal replacement therapy should aim for an optimal filter performance allowing the delivery of an adequate dose of renal replacement therapy. On the other hand, the patient's safety should not be endangered. Although numerous options have been proposed, none of them appears to be ideal. Unfractionated heparin is still the most widely used anticoagulant. Reported experience with low-molecular-weight heparin is limited and does not confirm the anticipated increased safety. Regional citrate anticoagulation has been shown to reduce bleeding complications during continuous haemodialysis. A recent report demonstrates the feasibility and safety of citrate anticoagulation during continuous predilution haemofiltration. However, its use is labour intensive and the prevention of side-effects requires meticulous monitoring. Hirudin, a selective thrombin inhibitor, appears to be a suitable, although not completely safe, alternative in patients with heparin-induced thrombocytopenia. Continuous renal replacement therapy without anticoagulation may result in acceptable filter lives in patients with reduced coagulatory potential or an increased risk of bleeding. Although receiving little attention in the literature, the adequate selection of treatment characteristics may also contribute to an improved filter performance.