Renal replacement therapy with high-cutoff hemofilters: Impact of convection and diffusion on cytokine clearances and protein status

[Extracorporeal procedures in sepsis]

Sepsis and septic shock are frequent and severe clinical pictures in intensive care medicine that result from a dysregulated immune response to an infection and cause a high mortality rate. This article provides an overview of the various extracorporeal procedures used to treat sepsis. Various procedures are used to treat sepsis and septic shock. These include high-volume hemofiltration (HVHF), very high-volume hemofiltration (VHVHF), high cut-off filter (HCO), polymyxin B hemoperfusion and cytokine adsorption filters. The HVHF and VHVHF remove inflammatory mediators but show no significant benefit in terms of stabilization and survival in sepsis patients. The HCO filters effectively eliminate cytokines but so far there is no evidence of a survival benefit. Polymyxin B hemoperfusion shows promising results in initial studies in certain patient groups, while evidence for cytokine adsorption filters is limited. Combined plasma filtration and adsorption (CPFA) and therapeutic plasma exchange (TPE) have so far shown promising results in small studies. Although CPFA shows no survival benefit, TPE may have protective effects on the vascular glycocalyx. Extracorporeal procedures carry risks such as thrombosis and loss of proteins and clotting factors. The therapeutic benefit of these procedures in the treatment of sepsis remains unclear and further prospective randomized multicenter studies are needed to evaluate their efficacy and safety. There are currently no guideline recommendations for the routine use of these procedures in sepsis.

A hypothesis on treatment strategy of severe multicentric Castleman disease with continuous renal replacement therapy

Castleman disease (CD) is a rare lymphoproliferative disorder, with non-specific clinical manifestations, often delayed diagnosis and treatment, which pose a significant challenge in the present times. Patients diagnosed with this disease have poor prognosis due to the limited treatment options. Multicentric CD occurs at multiple lymph node stations and is associated with a proinflammatory response that leads to the development of the so-called 'B symptoms'. IL-6 seems to be a key cytokine involved in various manifestations such as lymphadenopathies, hepatosplenomegaly, and polyclonal hypergammaglobulinemia. Its levels correlate with the activity of the disease. Other consequences of MCD include increased fibrinogen levels leading to deep vein thrombosis and thromboembolic disorders, high hepcidin levels causing anaemia, elevated VEGF levels promoting angiogenesis and vascular permeability, which, along with hypoalbuminemia, induce oedema, ascites, pleural and pericardial effusions, and in severe cases, generalized anasarca. In extreme cases multiple organ failure can occur, often resulting in death. We propose the use of continuous renal replacement therapy (CRRT) in managing severe multicentric CD. Our arguments are based on the principles that CRRT is able to remove IL-6 from circulation thus attenuating the cytokine storm, can influence hepcidin levels, and reduction in oedema, and is often used in multiple organ failure to regain homeostasis control. Therefore, it could be used as a therapy or bridge therapy in severe cases. To sustain our hypothesis with evidence, we have gathered several studies from the literature confirming the successful removal of cytokines, especially IL-6 from circulation, which can be used as a starting point.

Use of Therapeutic Apheresis methods in ICU

Apheresis is a modern medical approach in which plasma or cellular components are separated from the whole blood. Apheresis can be either diagnostic or therapeutic. Diagnostic apheresis is typically applied in hematology and cancer research. Therapeutic Apheresis (TA) includes a broad spectrum of extracorporeal treatments applied in various medical specialties, including Intensive Care Unit (ICU). Considering the complexity of the pathophysiologic characteristics of various clinical entities and in particular sepsis, apheresis methods are becoming increasingly applicable. Therapeutic Plasma Exchange (TPE) is the most common used method in ICU. It is considered as first line therapy for Thrombotic Thrombocytopenic Purpura (TTP) and Guillain Barre Syndrome, while the current data for sepsis are scarce. Over the last decades, technologic evolution has led to increasing application of new and more selective methods based on adsorptive techniques. In this review we will describe the current data of characteristics of different techniques, safety and clinical impact of apheresis methods used in ICUs.

Medium cut-off dialyzer for middle molecular uremic toxins in AKI and chronic dialysis

Uremic toxins accumulate in patients affected by renal failure and can deposit in different organs, including the kidneys and heart. Given their physicochemical characteristics, uremic toxins can contribute to organ dysfunction due to several pathobiological actions at cellular and molecular levels. Several uremic compounds have been described in serum and plasma from patients with acute kidney injury (AKI) and kidney failure; they are usually classified based on their molecular size and protein-binding properties. In this scenario, new dialytic approaches have been proposed in the last few years with the aim of improving uremic toxin removal. Recent studies which focused on the use of medium cut-off membranes in patients on chronic hemodialysis have shown a discrete ability to remove β2-microglobulin and other middle molecules, such as kappa and lambda free light chains, complement factor D and α1-microglobulin. However, current evidence is mainly based on the impact on short-term outcomes and, consequently, longer observational studies are necessary to confirm the efficacy and safety of the medium cut-off dialyzer. Here we present the state-of-the-art on the clinical application of medium cut-off membranes in AKI and chronic dialysis patients.

High cut-off membranes in patients requiring renal replacement therapy: a systematic review and meta-analysis

BACKGROUND

Whether high cut-off (HCO) membranes are more effective than high-flux (HF) membranes in patients requiring renal replacement therapy (RRT) remains controversial. The aim of this systematic review was to investigate the efficacy of HCO membranes regarding the clearance of inflammation-related mediators, β2-microglobulin and urea; albumin loss; and all-cause mortality in patients requiring RRT.

METHODS

We searched all relevant studies on PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Infrastructure, with no language or publication year restrictions. Two reviewers independently selected studies and extracted data using a prespecified extraction instrument. Only randomized controlled trials (RCTs) were included. Summary estimates of standardized mean differences (SMDs) or weighted mean differences (WMDs) and risk ratios (RRs) were obtained by fixed-effects or random-effects models. Sensitivity analyses and subgroup analyses were performed to determine the source of heterogeneity.

RESULTS

Nineteen RCTs involving 710 participants were included in this systematic review. Compared with HF membranes, HCO membranes were more effective in reducing the plasma level of interleukin-6 (IL-6) (SMD -0.25, 95% confidence interval (CI) -0.48 to -0.01, P   =  0.04, I2  = 63.8%); however, no difference was observed in the clearance of tumor necrosis factor-α (TNF-α) (SMD 0.03, 95% CI -0.27 to 0.33, P  = 0.84, I2  = 4.3%), IL-10 (SMD 0.22, 95% CI -0.12 to 0.55, P  = 0.21, I2  = 0.0%), or urea (WMD -0.27, 95% CI -2.77 to 2.23, P  = 0.83, I2  = 19.6%). In addition, a more significant reduction ratio of β 2 -microglobulin (WMD 14.8, 95% CI 3.78 to 25.82, P  = 0.01, I2  = 88.3%) and a more obvious loss of albumin (WMD -0.25, 95% CI -0.35 to -0.16, P  < 0.01, I2  = 40.8%) could be observed with the treatment of HCO membranes. For all-cause mortality, there was no difference between the two groups (risk ratio [RR] 1.10, 95% CI 0.87 to 1.40, P  = 0.43, I2  = 0.0%).

CONCLUSIONS

Compared with HF membranes, HCO membranes might have additional benefits on the clearance of IL-6 and β 2-microglobulin but not on TNF-α, IL-10, and urea. Albumin loss is more serious with the treatment of HCO membranes. There was no difference in all-cause mortality between HCO and HF membranes. Further larger high-quality RCTs are needed to strengthen the effects of HCO membranes.

Continuous renal replacement therapy and extracorporeal membrane oxygenation: implications in the COVID-19 era

The novel severe acute respiratory syndrome coronavirus 2, SARS-CoV-2 (coronavirus Disease 19 (COVID-19)) was identified as the causative agent of viral pneumonias in Wuhan, China in December 2019, and has emerged as a pandemic causing acute respiratory distress syndrome (ARDS) and multiple organ dysfunction. Interim guidance by the World Health Organization states that extracorporeal membrane oxygenation (ECMO) should be considered as a rescue therapy in COVID-19-related ARDS. International registries tracking ECMO in COVID-19 patients reveal a 21%-70% incidence of acute renal injury requiring renal replacement therapy (RRT) during ECMO support. The indications for initiating RRT in patients on ECMO are similar to those for patients not requiring ECMO. RRT can be administered during ECMO via a temporary dialysis catheter, placement of a circuit in-line hemofilter, or direct connection of continuous RRT in-line with the ECMO circuit. Here we review methods for RRT during ECMO, RRT initiation and timing during ECMO, anticoagulation strategies, and novel cytokine filtration approaches to minimize COVID-19's pathophysiological impact.

Timing of kidney replacement therapy initiation for acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common condition among patients in intensive care units (ICUs) and is associated with high numbers of deaths. Kidney replacement therapy (KRT) is a blood purification technique used to treat the most severe forms of AKI. The optimal time to initiate KRT so as to improve clinical outcomes remains uncertain. This is an update of a review first published in 2018. This review complements another Cochrane review by the same authors: Intensity of continuous renal replacement therapy for acute kidney injury.

OBJECTIVES

To assess the effects of different timing (early and standard) of KRT initiation on death and recovery of kidney function in critically ill patients with AKI.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant's Specialised Register to 4 August 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register, ClinicalTrials and LILACS to 1 August 2022.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs). We included all patients with AKI in the ICU regardless of age, comparing early versus standard KRT initiation. For safety and cost outcomes, we planned to include cohort studies and non-RCTs.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors. The random-effects model was used, and results were reported as risk ratios(RR) for dichotomous outcomes and mean difference(MD) for continuous outcomes, with 95% confidence intervals (CI).

MAIN RESULTS

We included 12 studies enrolling 4880 participants. Overall, most domains were assessed as being at low or unclear risk of bias. Compared to standard treatment, early KRT initiation may have little to no difference on the risk of death at day 30 (12 studies, 4826 participants: RR 0.97,95% CI 0.87 to 1.09; I²= 29%; low certainty evidence), and death after 30 days (7 studies, 4534 participants: RR 0.99, 95% CI 0.92 to 1.07; I² = 6%; moderate certainty evidence). Early KRT initiation may make little or no difference to the risk of death or non-recovery of kidney function at 90 days (6 studies, 4011 participants: RR 0.91, 95% CI 0.74 to 1.11; I² = 66%; low certainty evidence); CIs included both benefits and harms. Low certainty evidence showed early KRT initiation may make little or no difference to the number of patients who were free from KRT (10 studies, 4717 participants: RR 1.07, 95% CI 0.94 to1.22; I² = 55%) and recovery of kidney function among survivors who were free from KRT after day 30 (10 studies, 2510 participants: RR 1.02, 95% CI 0.97 to 1.07; I² = 69%) compared to standard treatment. High certainty evidence showed early KRT initiation increased the risk of hypophosphataemia (1 study, 2927 participants: RR 1.80, 95% CI 1.33 to 2.44), hypotension (5 studies, 3864 participants: RR 1.54, 95% CI 1.29 to 1.85; I² = 0%), cardiac-rhythm disorder (6 studies, 4483 participants: RR 1.35, 95% CI 1.04 to 1.75; I² = 16%), and infection (5 studies, 4252 participants: RR 1.33, 95% CI 1.00 to 1.77; I² = 0%); however, it is uncertain whether early KRT initiation increases or reduces the number of patients who experienced any adverse events (5 studies, 3983 participants: RR 1.23, 95% CI 0.90 to 1.68; I² = 91%; very low certainty evidence). Moderate certainty evidence showed early KRT initiation probably reduces the number of days in hospital (7 studies, 4589 participants: MD-2.45 days, 95% CI -4.75 to -0.14; I² = 10%) and length of stay in ICU (5 studies, 4240 participants: MD -1.01 days, 95% CI -1.60 to -0.42; I² = 0%).

AUTHORS' CONCLUSIONS

Based on mainly low to moderate certainty of the evidence, early KRT has no beneficial effect on death and may increase the recovery of kidney function. Earlier KRT probably reduces the length of ICU and hospital stay but increases the risk of adverse events. Further adequate-powered RCTs using robust and validated tools that complement clinical judgement are needed to define the optimal time of KRT in critical patients with AKI in order to improve their outcomes. The surgical AKI population should be considered in future research.

The Supporting Role of Combined and Sequential Extracorporeal Blood Purification Therapies in COVID-19 Patients in Intensive Care Unit

Critical clinical forms of COVID-19 infection often include Acute Kidney Injury (AKI), requiring kidney replacement therapy (KRT) in up to 20% of patients, further worsening the outcome of the disease. No specific medical therapies are available for the treatment of COVID-19, while supportive care remains the standard treatment with the control of systemic inflammation playing a pivotal role, avoiding the disease progression and improving organ function. Extracorporeal blood purification (EBP) has been proposed for cytokines removal in sepsis and could be beneficial in COVID-19, preventing the cytokines release syndrome (CRS) and providing Extra-corporeal organ support (ECOS) in critical patients. Different EBP procedures for COVID-19 patients have been proposed including hemoperfusion (HP) on sorbent, continuous kidney replacement therapy (CRRT) with adsorbing capacity, or the use of high cut-off (HCO) membranes. Depending on the local experience, the multidisciplinary capabilities, the hardware, and the available devices, EBP can be combined sequentially or in parallel. The purpose of this paper is to illustrate how to perform EBPs, providing practical support to extracorporeal therapies in COVID-19 patients with AKI.

Systemic Profile of Cytokines in Arteriovenous Fistula Patients and Their Associations with Maturation Failure

Background

Systemic cytokines are elevated in patients with chronic kidney disease (CKD) and on hemodialysis compared with the general population. However, whether cytokine levels interfere with vascular remodeling, increasing the risk of arteriovenous fistula (AVF) failure, remains unknown.

Methods

This is a case-control study of 64 patients who underwent surgery for AVF creation (32 with AVF maturation failure and 32 matching controls with successful maturation). A total of 74 cytokines, including chemokines, interferons, interleukins, and growth factors, were measured in preoperative plasma samples using multiplex assays. Sixty-two patients were included in the statistical analyses. Associations with AVF failure were assessed using paired comparisons and conditional logistic regressions accounting for paired strata.

Results

Seven cytokines were significantly higher in patients with AVF maturation failure than in matching controls (G-CSF, IL-6, MDC, RANTES, SDF-1α/β, TGFα, and TPO). Of these, G-CSF (odds ratio [OR]=1.71; 95% confidence interval [95% CI], 1.05 to 2.79 per 10 pg/ml), MDC (OR=1.60, 95% CI, 1.08 to 2.38 per 100 pg/ml), RANTES (OR=1.55, 95% CI, 1.10 to 2.17 per 100 pg/ml), SDF-1α/β (OR=1.18, 95% CI, 1.04 to 1.33 per 1000 pg/ml), and TGFα (OR=1.39, 95% CI 1.003, 1.92 per 1 pg/ml) showed an incremental association by logistic regression.

Conclusions

This study identified a profile of plasma cytokines associated with adverse maturation outcomes in AVFs. These findings may open the doors for future therapeutics and markers for risk stratification.

Lesión renal aguda en COVID-19: puesta al día y revisión de la literatura

Los coronavirus humanos son virus que se asocian a varias patologías respiratorias como el síndrome respiratorio agudo severo y el síndrome respiratorio del Medio Oriente. Esto ha puesto a esta familia de virus en el centro de atención de la comunidad científica debido a la alta patogenicidad en humanos, especialmente ahora con la nueva pandemia por la enfermedad por coronavirus del 2019 (COVID-19). La COVID-19 se manifiesta principalmente como enfermedad respiratoria aguda con compromiso respiratorio bajo, pero puede afectar múltiples órganos como lo es el riñón, lo cual a conlleva a peores desenlaces. En este manuscrito revisaremos el compromiso renal por los diferentes coronavirus, en especial en la COVID-19, al igual que las terapias que juegan algún papel en el tratamiento de esta.

Feasibility study and direct extraction of endogenous free metallic cations combining hemodialysis and chelating polymer

In this article, we report the conception and the use of dialysis-based medical device for the extraction of metals. The medical device is obtained by addition in the dialysate of a functionalized chitosan that can chelate endogenous metals like iron or copper. This water-soluble functionalized chitosan is obtained after controlled reacetylation and grafting of DOTAGA. Due to the high mass of chitosan, the polymer cannot cross through the membrane and the metals are trapped in the dialysate during hemodialysis. Copper extraction has been evaluated in vitro using an hemodialysis protocol. Feasibility study has been performed on healthy sheep showing no acute toxicity througout the entire dialysis procedure and first insights of metallic extraction even on healthy animals.

Renal Replacement Techniques in Septic Shock

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to an infection; it carries a risk for mortality, considerably exceeding that of a mere infection. Sepsis is the leading cause for acute kidney injury (AKI) and the requirement for renal replacement therapy (RRT) in intensive care unit (ICU) patients. Almost every second critically ill patient with sepsis will develop AKI. In septic shock, the dysregulated host response to infectious pathogens leads to a cytokine storm with uncontrolled production and release of humoral proinflammatory mediators that evoke cellular toxicity and promote the development of organ dysfunction and increased mortality. In addition to treating AKI, RRT techniques can be employed for extracorporeal adsorption of inflammatory mediators using specifically developed adsorption membranes, hemoperfusion sorbent cartridges or columns; these techniques are intended to decrease the level and early deleterious effects of circulating proinflammatory cytokines and endotoxins during the first hours and days of septic shock treatment, in order to improve patient outcomes. Several methods and devices, such as high cut-off membranes, the Oxiris®-AN69 membrane, CytoSorb® and HA380 cytokine hemoadsorption, polymyxin B endotoxin adsorption, and plasmapheresis have been examined in small study series or are under evaluation as ways of improving patient outcomes in septic shock. However, to date, the data on actual outcome benefits have remained controversial, as discussed in this review.

Immune Modulation in Critically Ill Septic Patients

Sepsis is triggered by infection-induced immune alteration and may be theoretically improved by pharmacological and extracorporeal immune modulating therapies. Pharmacological immune modulation may have long lasting clinical effects, that may even worsen patient-related outcomes. On the other hand, extracorporeal immune modulation allows short-term removal of inflammatory mediators from the bloodstream. Although such therapies have been widely used in clinical practice, the role of immune modulation in critically ill septic patients remains unclear and little evidence supports the role of immune modulation in this clinical context. Accordingly, further research should be carried out by an evidence-based and personalized approach in order to improve the management of critically ill septic patients.

Sepsis-Pathophysiology and Therapeutic Concepts

Sepsis is a life-threatening condition and a global disease burden. Today, the heterogeneous syndrome is defined as severe organ dysfunction caused by a dysregulated host response to infection, with renewed emphasis on immune pathophysiology. Despite all efforts of experimental and clinical research during the last three decades, the ability to positively influence course and outcome of the syndrome remains limited. Evidence-based therapy still consists of basic causal and supportive measures, while adjuvant interventions such as blood purification or targeted immunotherapy largely remain without proof of effectiveness so far. With this review, we aim to provide an overview of sepsis immune pathophysiology, to update the choice of therapeutic approaches targeting different immunological mechanisms in the course of sepsis and septic shock, and to call for a paradigm shift from the pathogen to the host response as a potentially more promising angle.

Efficacy and safety of plasma hemodiafiltration (PHDF) in pediatric patients with multiple organ dysfunction syndrome with shock and DIC: a preliminary study

Background

Multiple organ dysfunction syndrome is the leading cause of death in pediatric intensive care units and can be very critical when combined with shock and disseminated intravascular coagulation (DIC). Currently, there is no effective treatment. We developed a new hemodiafiltration (HDF) method called plasma HDF (PHDF) that uses fresh frozen plasma as replacement fluid and investigated the safety and efficacy of this treatment.

Methods

We enrolled critically ill children with (1) a Pediatric Logistic Organ Dysfunction 2 (PELOD-2) score ≥ 14, (2) a Japanese Ministry of Health and Welfare (JMHW) DIC score ≥ 7, (3) a vasoactive inotropic score (VIS) ≥ 10, and (4) a serum total protein concentration ≤ 5.0 g/dL. PHDF was performed for 5 h and then switched to continuous HDF. The primary endpoint was the 28-day mortality rate. Secondary endpoints included assessment of vital signs, blood test data, and fluid balance from PHDF start to day 7.

Results

Nine patients (four males and five females) between 3 days and 40 months of age, weighing 2.1–13 kg, met the inclusion criteria. Although the median PMR was 0.94 (0.71–0.96), the 28-day mortality rate was 22.2% (2/9). One hour after the start of PHDF, there was an increase in mean arterial pressure and central venous pressure and a decrease in heart rate; by day 7, there was a significant decrease in the PELOD-2 score, the JMHW DIC score, and the VIS. Hypoproteinemia also improved the day after PHDF. Water balance was able to remain negative after day 2.

Conclusions

PHDF was found to be effective in the treatment of DIC and circulatory failure by supplementing coagulation and antithrombotic factors as well as by raising colloid osmotic pressure to increase circulating blood volume. PHDF has been shown to be a safe and useful treatment for critically ill children and has the potential to improve 28-day survival.

Clearance of inflammatory cytokines in patients with septic acute kidney injury during renal replacement therapy using the EMiC2 filter (Clic-AKI study)

BACKGROUND

The EMiC2 membrane is a medium cut-off haemofilter (45 kiloDalton). Little is known regarding its efficacy in eliminating medium-sized cytokines in sepsis. This study aimed to explore the effects of continuous veno-venous haemodialysis (CVVHD) using the EMiC2 filter on cytokine clearance.

METHODS

This was a prospective observational study conducted in critically ill patients with sepsis and acute kidney injury requiring kidney replacement therapy. We measured concentrations of 12 cytokines [Interleukin (IL) IL-1β, IL-1α, IL-2, IL-4, IL-6, IL-8, IL-10, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, vascular endothelial growth factor, monocyte chemoattractant protein (MCP)-1, epidermal growth factor (EGF)] in plasma at baseline (T0) and pre- and post-dialyzer at 1, 6, 24, and 48 h after CVVHD initiation and in the effluent fluid at corresponding time points. Outcomes were the effluent and adsorptive clearance rates, mass balances, and changes in serial serum concentrations.

RESULTS

Twelve patients were included in the final analysis. All cytokines except EGF concentrations declined over 48 h (p < 0.001). The effluent clearance rates were variable and ranged from negligible values for IL-2, IFN-γ, IL-1α, IL-1β, and EGF, to 19.0 ml/min for TNF-α. Negative or minimal adsorption was observed. The effluent and adsorptive clearance rates remained steady over time. The percentage of cytokine removal was low for most cytokines throughout the 48-h period.

CONCLUSION

EMiC2-CVVHD achieved modest removal of most cytokines and demonstrated small to no adsorptive capacity despite a decline in plasma cytokine concentrations. This suggests that changes in plasma cytokine concentrations may not be solely influenced by extracorporeal removal.

TRIAL REGISTRATION

NCT03231748, registered on 27th July 2017.

Acute Kidney Injury in Sepsis: Evidence From Asia

Acute kidney injury (AKI) is one of the most frequent complications of sepsis. Because sepsis and AKI synergistically worsen the outcomes of critically ill patients, better therapeutics against septic AKI urgently are required. In addition to the complexity of disease mechanisms of both sepsis and AKI, there is substantial regional variation in clinical practice, which further hampers the development of new treatments for septic AKI. To overcome this problem, evidence accumulation is necessary for building the foundation for developing novel septic AKI treatments. This review provides a summary of updated evidence regarding septic AKI from Asian regions.

Myoglobin clearance with continuous veno-venous hemodialysis using high cutoff dialyzer versus continuous veno-venous hemodiafiltration using high-flux dialyzer: a prospective randomized controlled trial

Background

Myoglobin clearance in acute kidney injury requiring renal replacement therapy is important because myoglobin has direct renal toxic effects. Clinical data comparing different modalities of renal replacement therapy addressing myoglobin clearance are limited. This study aimed to compare two renal replacement modalities regarding myoglobin clearance.

Methods

In this prospective, randomized, single-blinded, single-center trial, 70 critically ill patients requiring renal replacement therapy were randomized 1:1 into an intervention arm using continuous veno-venous hemodialysis with high cutoff dialyzer and a control arm using continuous veno-venous hemodiafiltration postdilution with high-flux dialyzer. Regional citrate anticoagulation was used in both groups to maintain the extracorporeal circuit. The concentrations of myoglobin, urea, creatinine, β2-microglobulin, interleukin-6 and albumin were measured before and after the dialyzer at 1 h, 6 h, 12 h, 24 h and 48 h after initiating continuous renal replacement therapy.

Results

Thirty-three patients were allocated to the control arm (CVVHDF with high-flux dialyzer) and 35 patients to the intervention arm (CVVHD with high cutoff dialyzer). Myoglobin clearance, as a primary endpoint, was significantly better in the intervention arm than in the control arm throughout the whole study period. The clearance values for urea and creatinine were higher in the control arm. There was no measurable albumin clearance in both arms. The clearance data for β₂-microglobulin and interleukin-6 were non-inferior in the intervention arm compared to those for the control arm. Dialyzer lifespan was 57.0 [38.0, 72.0] hours in the control arm and 70.0 [56.75, 72.0] hours in the intervention arm (p = 0.029).

Conclusions

Myoglobin clearance using continuous veno-venous hemodialysis with high cutoff dialyzer and regional citrate anticoagulation is better than that with continuous veno-venous hemodiafiltration with regional citrate anticoagulation.

Trial registration

German Clinical Trials Registry (DRKS00012407); date of registration 23/05/2017. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00012407.

Effect of high-volume hemofiltration on children with sepsis

BACKGROUND

Sepsis has always been a challenge in pediatric intensive care unit (PICU) with poor prognosis. In order to evaluate the effect between routine continuous renal replacement therapy (CRRT) and high-volume hemofiltration (HVHF) in children with sepsis, we performed out this prospective, randomized, controlled, open-label trial.

METHODS

Forty-seven children with sepsis were enrolled from January 2015 to December 2016. Twenty-two patients in Control group received routine CRRT and 25 patients in HVHF group received HVHF within 6 hours after the diagnosis of sepsis. The oxygenation index, serum creatinine, urea, lactate, inflammatory cytokines (IL-6, IL-10, and TNF-α), pediatric risk of mortality III (PRISM III) and 28-day mortality rate were collected and compared.

RESULTS

The oxygenation index in HVHF group and Control group was significantly increased at 48 hours (P<0.01) and 72 hours after treatment (P<0.05). The same result of arterial lactate was observed. Serum creatinine, urea, IL-6, IL-10, TNF-α and PRISM III score were significantly ameliorated after 72 hours treatment in HVHF group (P<0.01), while there was no significant difference in Control group. After 72 hours of treatment, the oxygenation index, lactate, serum creatinine, urea, TNF-α, IL-6, IL-10 and PRISM III score in HVHF group were significantly improved compared with Control group (P<0.01). There is no significant difference on 28-day mortality between the two groups (P>0.05).

CONCLUSIONS

HVHF might be an effective treatment for children with sepsis.

The impact of CRRT modality in patients with AKI receiving ECMO: A nationwide registry study in Taiwan

PURPOSE

Patients receiving extracorporeal membrane oxygenation (ECMO) commonly develop acute kidney injury (AKI) and frequently require continuous renal replacement therapy (CRRT). The impact of different CRRT modalities on survival in patients receiving ECMO remains unclear.

MATERIALS AND METHODS

Using claims data from Taiwan's National Health Insurance Research Database, a total of 1077 patients who received ECMO and either continuous venovenous hemofiltration (CVVH) or continuous venovenous hemodialysis (CVVHD) for AKI were identified. Inverse probability of treatment weighting was applied using propensity scores to balance the baseline covariates of the two groups. The primary outcome was in-hospital morality.

RESULTS

We identified 1077 patients (mean age 57.9; 71.8% men). Postcardiotomy shock (49.2%) was the most frequently reported indication for ECMO. The CVVH group had a lower risk of in-hospital mortality (68.4% vs. 76.9%; odds ratio 0.65; 95% confidence interval [CI] 0.50-0.85) compared with the CVVHD group. The CVVH group also had a shorter mean ICU stay compared with the CVVHD group (mean difference -4.59 days, 95% CI -9.15 to -0.03 days).

CONCLUSION

Our results suggest that compared with CVVHD, CVVH may be associated with a lower risk of in-hospital mortality in patients with AKI who receive ECMO.

A Double-Blind Randomized Controlled Trial of High Cutoff Versus Standard Hemofiltration in Critically Ill Patients With Acute Kidney Injury

OBJECTIVES

In critically ill patients with acute kidney injury receiving vasopressors, high cytokine levels may sustain the shock state. High cutoff hemofiltration achieves greater cytokine removal in ex vivo and in animal models and may reduce the duration of shock but may also increase albumin losses.

DESIGN

This was a single-center double-blind randomized controlled trial comparing continuous venovenous hemofiltration-high cutoff to continuous venovenous hemofiltration-standard.

SETTING

Tertiary care hospital in Australia.

PATIENTS

Vasopressor-dependent patients in acute kidney injury who were admitted to the ICU.

INTERVENTIONS

Norepinephrine-free time were calculated in critically ill vasopressor-dependent patients in acute kidney injury, randomized to either continuous venovenous hemofiltration-high cutoff or continuous venovenous hemofiltration-standard.

MEASUREMENT AND MAIN RESULTS

A total of 76 patients were randomized with the following characteristics (continuous venovenous hemofiltration-high cutoff vs continuous venovenous hemofiltration-standard); median age of 65 versus 70 year, percentage of males 47% versus 68%, and median Acute Physiology and Chronic Health Evaluation scores of 25 versus 23.5. The median hours of norepinephrine-free time at day 7 were 32 (0-110.8) for continuous venovenous hemofiltration-high cutoff and 56 hours (0-109.3 hr) (p = 0.520) for continuous venovenous hemofiltration-standard. Inhospital mortality was 55.6% with continuous venovenous hemofiltration-high cutoff versus 34.2% with continuous venovenous hemofiltration-standard (adjusted odds ratio, 2.49; 95% CI, 0.81-7.66; p = 0.191). There was no significant difference in time to cessation of norepinephrine (p = 0.358), time to cessation of hemofiltration (p = 0.563), and filter life (p = 0.21). Serum albumin levels (p = 0.192) were similar and the median dose of IV albumin given was 90 grams (20-212 g) for continuous venovenous hemofiltration-high cutoff and 80 grams (15-132 g) for continuous venovenous hemofiltration-standard (p = 0.252).

CONCLUSIONS

In critically ill patients with acute kidney injury, continuous venovenous hemofiltration-high cutoff did not reduce the duration of vasopressor support or mortality or change albumin levels compared with continuous venovenous hemofiltration-standard.

Acute kidney injury from sepsis: current concepts, epidemiology, pathophysiology, prevention and treatment

Sepsis-associated acute kidney injury (S-AKI) is a frequent complication of the critically ill patient and is associated with unacceptable morbidity and mortality. Prevention of S-AKI is difficult because by the time patients seek medical attention, most have already developed acute kidney injury. Thus, early recognition is crucial to provide supportive treatment and limit further insults. Current diagnostic criteria for acute kidney injury has limited early detection; however, novel biomarkers of kidney stress and damage have been recently validated for risk prediction and early diagnosis of acute kidney injury in the setting of sepsis. Recent evidence shows that microvascular dysfunction, inflammation, and metabolic reprogramming are 3 fundamental mechanisms that may play a role in the development of S-AKI. However, more mechanistic studies are needed to better understand the convoluted pathophysiology of S-AKI and to translate these findings into potential treatment strategies and add to the promising pharmacologic approaches being developed and tested in clinical trials.

Hemodynamic efficiency of hemodialysis treatment with high cut-off membrane during the early period of post-resuscitation shock: The HYPERDIA trial

BACKGROUND

After resuscitation of cardiac arrest (CA), an acute circulatory failure occurs in about 50% of cases, which shares many characteristics with septic shock. Most frequently, supportive treatments are poorly efficient to prevent multiple organ failure and death. We evaluated whether an early plasma removal of inflammatory mediators using high cut-off continuous veno-venous hemodialysis (HCO-CVVHD) could improve hemodynamic status and outcome of these patients.

PATIENTS AND METHODS

We performed a randomized open-label trial. Patients with post-cardiac arrest shock (defined as requirement of norepinephrine or epinephrine infusion > 1 mg/h) were included. The experimental group received 2 distinct sessions of HCO-CVVHD during the first 48 h following ICU admission. The control group received continuous veno-venous hemofiltration (CVVH) with standard membranes if needed. The primary endpoint was the delay to shock resolution asssessed by the length of catecholamine infusion. Number of vasopressors-free days at day 28, arterial blood pressure measures every 6-hours, daily fluid balance and mortality (ICU and day-28) were evaluated as secondary endpoints.

RESULTS

35 patients were included: 17 (median age 68.4, 59% male) in the HCO-CVVHD group and 18 (median age 66.3, 83% male) in the control group. Baseline characteristics did not differ between the two groups. Day-28 mortality rate was 64.7% and 72.2% in the HCO-CVVHD and control group, respectively (p = 0.72). Probability of vasopressors discontinuation over time was similar in the two groups (p for logrank test = 0.67). Number of day-28 catecholamine-free days was 25.1 [0, 26.5] and 24.5 [0, 26.2] in the HCO-CVVHD and control group, respectively (p = 0.65). No difference was observed regarding the daily-dose of vasopressors, arterial pressure profile and fluid balance.

CONCLUSION

In cardiac arrest patients, HCO-CVVHD did not decrease the lenght of post-resuscitation shock and had no significant effect on hemodynamic profile.

REGISTRATION

NCT00780299.

Timing of renal replacement therapy initiation for acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common condition among patients in intensive care units (ICUs), and is associated with high death. Renal replacement therapy (RRT) is a blood purification technique used to treat the most severe forms of AKI. The optimal time to initiate RRT so as to improve clinical outcomes remains uncertain.This review complements another Cochrane review by the same authors: Intensity of continuous renal replacement therapy for acute kidney injury.

OBJECTIVES

To assess the effects of different timing (early and standard) of RRT initiation on death and recovery of kidney function in critically ill patients with AKI.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant's Specialised Register to 23 August 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. We also searched LILACS to 11 September 2017.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs). We included all patients with AKI in ICU regardless of age, comparing early versus standard RRT initiation. For safety and cost outcomes we planned to include cohort studies and non-RCTs.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors. The random-effects model was used and results were reported as risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CI).

MAIN RESULTS

We included five studies enrolling 1084 participants. Overall, most domains were assessed as being at low or unclear risk of bias. Compared to standard treatment, early initiation may reduce the risk of death at day 30, although the 95% CI does not rule out an increased risk (5 studies, 1084 participants: RR 0.83, 95% CI 0.61 to 1.13; I2 = 52%; low certainty evidence); and probably reduces the death after 30 days post randomisation (4 studies, 1056 participants: RR 0.92, 95% CI 0.76 to 1.10; I2= 29%; moderate certainty evidence); however in both results the CIs included a reduction and an increase of death. Earlier start may reduce the risk of death or non-recovery kidney function (5 studies, 1076 participants: RR 0.83, 95% CI 0.66 to 1.05; I2= 54%; low certainty evidence). Early strategy may increase the number of patients who were free of RRT after RRT discontinuation (5 studies, 1084 participants: RR 1.13, 95% CI 0.91 to 1.40; I2= 58%; low certainty evidence) and probably slightly increases the recovery of kidney function among survivors who discontinued RRT after day 30 (5 studies, 572 participants: RR 1.03, 95% CI 1.00 to 1.06; I2= 0%; moderate certainty evidence) compared to standard; however the lower limit of CI includes the null effect. Early RRT initiation increased the number of patients who experienced adverse events (4 studies, 899 participants: RR 1.10, 95% CI 1.03 to 1.16; I2 = 0%; high certainty evidence). Compared to standard, earlier RRT start may reduce the number of days in ICU (4 studies, 1056 participants: MD -1.78 days, 95% CI -3.70 to 0.13; I2 = 90%; low certainty evidence), but the CI included benefit and harm.

AUTHORS' CONCLUSIONS

Based mainly on low quality of evidence identified, early RRT may reduce the risk of death and may improve the recovery of kidney function in critically patients with AKI, however the 95% CI indicates that early RRT might worsen these outcomes. There was an increased risk of adverse events with early RRT. Further adequate-powered RCTs using appropriate criteria to define the optimal time of RRT are needed to reduce the imprecision of the results.

Modulation of leucocytic angiotensin-converting enzymes expression in patients maintained on high-permeable haemodialysis

Background

High mortality of haemodialysis patients is associated with systemic chronic inflammation and overactivation of the renin-angiotensin system (RAS). Insufficient elimination of pro-inflammatory immune mediators, especially in the molecular weight range of 15-45 kDa, may be one of the reasons for this. Employment of haemodialysis membranes with increased permeability was shown to ameliorate the inflammatory response and might modulate the effects of local RAS. In this study, we tested the impact of high cut-off (HCO), medium cut-off (MCO) and high-flux (HF) dialysis on leucocytic transcripts of angiotensin-converting enzymes (ACE and ACE2). Additionally, the impact of HCO, MCO and HF sera and dialysates on local ACEs and inflammation markers was tested in THP-1 monocytes.

Methods

Patients' leucocytes were obtained from our recent clinical studies comparing HCO and MCO dialysers with HF. The cells were subjected to quantitaive polymerase chain reaction (qPCR) analyses with TaqMan probes specific for ACE, ACE2 and angiotensin II (AngII) and Ang1-7 receptors. Sera and dialysates from the clinical trials as well as samples from in vitro dialysis were tested on THP-1 monocytic cells. The cells were subjected to qPCR analyses with TaqMan probes specific for ACE, ACE2, interleukin-6 and tumour necrosis factor α and immunocytochemistry with ACE and ACE2 antibodies.

Results

Leucocytes obtained from patients treated with HCO or MCO demonstrated decreased transcript expression of ACE, while ACE2 was significantly upregulated as compared with HF. Receptors for AngII and Ang1-7 remained unchanged. THP-1 monocytes preconditioned with HCO and MCO patients' or in vitro dialysis sera reflected the same expressional regulation of ACE and ACE2 as those observed in HCO and MCO leucocytes. As a complementary finding, treatment with HCO and MCO in vitro dialysates induced a pro-inflammatory response of the cells as demonstrated by elevated messenger RNA expression of tumour necrosis factor α and interleukin-6, as well as upregulation of ACE and decreased levels of ACE2.

Conclusions

Taken together, these data demonstrate that employment of membranes with high permeability eliminates a spectrum of mediators from circulation that affect the RAS components in leucocytes, especially ACE/ACE2.

Clinical characteristics of sepsis-induced acute kidney injury in patients undergoing continuous renal replacement therapy

Objective: The aim of this study was to investigate the clinical characteristics of sepsis-induced acute kidney injury (AKI) in patients undergoing continuous renal replacement therapy (CRRT).

Methods: From 2011 to 2015, we enrolled 340 patients who were treated with CRRT for sepsis at the Presbyterian Medical Center. In all patients, CRRT was performed using the PRISMA platform. We divided these patients into two groups (survivors and non-survivors) according to the 28-day all-cause mortality. We compared clinical characteristics and analyzed the predictors of mortality.

Results: The 28-day all-cause mortality was 62%. Survivors were younger than non-survivors and had higher platelet counts (178 ± 101 × 10³/mL vs. 134 ± 84 × 10³/mL, p < .01) and serum creatinine levels (4.2 ± 2.8 vs. 3.3 ± 2.7, p < .01). However, survivors had lower red blood cell distribution width (RDW) scores (14.9 ± 2.1 vs. 16.1 ± 3.3, p < .01) and APACHE II scores (24.5 ± 5.8 vs. 26.9 ± 5.7, p < .01) than non-survivors. Furthermore, survivors were more likely than non-survivors to have a urine output of >0.05 mL/kg/h (66% vs. 86%, p = .001) in the first day. In a multivariate logistic regression analysis, age, platelet count, RDW score, APACHE II score, serum creatinine level, and a urine output of <0.05 mL/kg/h the first day were prognostic factors for the 28-day all-cause mortality.

Conclusion: Age, platelet count, APACHE II score, RDW score, serum creatinine level, and urine output the first day are useful predictors for the 28-day all-cause mortality in sepsis patients requiring CRRT.

Extracorporeal techniques for the treatment of critically ill patients with sepsis beyond conventional blood purification therapy: the promises and the pitfalls

Sepsis is one of the leading causes of morbidity and mortality worldwide. It is characterized by a dysregulated immune response to infections that results in life-threatening organ dysfunction and even death. Bacterial cell wall components (endotoxin or lipopolysaccharide), known as pathogen-associated molecular patterns (PAMPs), as well as damage-associated molecular patterns (DAMPs) released by host injured cells, are well-recognized triggers resulting in the elevation of both pro-inflammatory and anti-inflammatory cytokines. Understanding this complex pathophysiology has led to the development of therapeutic strategies aimed at restoring a balanced immune response by eliminating/deactivating these inflammatory mediators. Different extracorporeal techniques have been studied in recent years in the hope of maximizing the effect of renal replacement therapy in modulating the exaggerated host inflammatory response, including the use of high volume hemofiltration (HVHF), high cut-off (HCO) membranes, adsorption alone, and coupled plasma filtration adsorption (CPFA). These strategies are not widely utilized in practice, depending on resources and local expertise. The literature examining their use in septic patients is growing, but the evidence to support their use at this stage is considered of low level. Our aim is to provide a comprehensive overview of the technical aspects, clinical applications, and associated side effects of these techniques.

Super High-Flux Continuous Venovenous Hemodialysis Using Regional Citrate Anticoagulation: Long-Term Stability of Middle Molecule Clearance

Continuous renal replacement therapy is a standard treatment in critically ill patients with acute kidney injury. All CRRT techniques provide a high low-molecular weight clearance but even with hemofiltration, clearance of middle molecules is low. We investigated whether a new super high-flux hemofilter provides effective and sustained middle molecule clearance during citrate-anticoagulated continuous venovenous hemodialysis for up to 72 h. We included 14 critically ill patients with AKI-KDIGO-III in a prospective observational trial. We measured/calculated blood and urine concentrations, clearances and sieving coefficients of eight molecules with molecular weights from 60 to 66 kDa, hemodynamic parameters and SAPS-II scores. All filters were patent at 72 h. Clearance and sieving coefficients of small solutes were high and sustained over time, those for larger solutes decreased over 72 h but remained high enough to decrease blood concentrations of solutes up to 25 kDa. Albumin serum levels remained unaffected. Catecholamine doses and SAPS-II scores decreased significantly. This new hemofilter may improve blood purification in critically ill patients with AKI.

Confirmation of High Cytokine Clearance by Hemofiltration with a Cellulose Triacetate Membrane with Large Pores: An in vivo Study

Objective

To confirm in vivo the hypothesis that hemofiltration with a large pore membrane can achieve significant cytokine clearance.

Method

We used a well-known animal model of endotoxinic shock (0.5 mg/kg of lipopolysaccharide from Escherichia Coli over a period of 30 mins). Six pigs were hemofiltrated for 3 hours with a large pore membrane (78 Å pore, 80 kDa cut off) (Sureflux FH 70, Nipro, Osaka, Japan). The ultrafiltration rate was 45 ml/kg/min. Samples were taken from arterial, venous line and in the ultrafiltrate at T120 and T240. We measured concentrations of interleukin 6, interleukin 10 and albumin.

Results

At T120 and T240, the IL-6 clearances were 22 ± 7 and 15 ± 3 ml/min, respectively. The IL-6 sieving coefficients were 0.97 and 0.7 at T120 and T240, respectively. At T120 and T240, the IL-10 clearances were 14 ± 4 and 10 ± 7 ml/min, respectively. The sieving coefficients were 0.63 and 0.45 at T120 and T240, respectively. The concentrations of IL-6 and IL-10 were the same at T0 and T240. At T60 and T240, the plasmatic albumin concentrations were 24 ± 4 g/L and 23 ± 4 g/L, respectively (p = 0.13).

Conclusions

In this animal model of endotoxinic shock, we confirm the high cytokine clearance observed when hemofiltration is applied to a large pore membrane. The loss of albumin seems negligible. The impact of such clearances on hemodynamic stability and survival remains to be proved.

High Cut-off Point Membranes in Septic Acute Renal Failure: A Systematic Review

Objectives

To review the literature on the experimental, physiological and clinical effects of blood purification with high cut-off (HCO) point membranes in septic acute renal failure (ARF).

Study Design

MEDLINE and PubMed database search combining relevant terms and integrating data from studies on the use of HCO membranes.

Setting and Population

Ex vivo studies of endotoxemia, animal studies of bacteremia and clinical studies using HCO membranes in patients with septic ARF. Selection Criteria for Studies: Original data from primary publications. Interventions: HCO membrane-based hemodialysis, hemodiafiltration or hemofiltration. Outcomes: Plasma cytokine clearance, immunological and physiological effects and safety parameters of HCO membranes.

Results

HCO membranes effectively remove cytokines from blood. Treatment using HCO membranes has beneficial effects on immune cell function and increases survival in animal models of sepsis. Preliminary clinical studies show that HCO membranes decrease plasma cytokine levels and the need for vasopressor therapy. HCO membrane-based blood purification has now been applied in four pilot randomized controlled studies of 70 patients with septic ARF with no reports of serious adverse effects.

Limitations

Because of substantial heterogeneity, no formal quantitative analysis could be performed.

Conclusions

The available evidence on HCO blood purification justifies larger randomized controlled trials in patients with septic ARF.

Treatment of Acute Kidney Injury Complicating Septic Shock with EMiC2 High-cutoff Hemofilter: Case Series

Introduction:

Extracorporeal blood purification therapies have been proposed to improve outcomes of patients with severe sepsis, with or without accompanying acute kidney injury (AKI), by removal of excessive inflammatory mediators.

Materials and Methods:

We report our experience with EMiC2 high-cutoff continuous venovenous hemofiltration/hemodialysis (HCO-CVVH/HD) in seven patients with AKI complicating septic shock.

Results:

The median treatment duration was 71 h, and the procedure was well tolerated. Trough serum albumin level of 20 g/L was observed after 2 h of treatment and none of the patients required albumin supplement. The hospital mortality rate was 29%, which appeared more favorable than the predicted mortality of 60%–78% based on disease severity scores. Circulating levels of interleukin-6 (IL-6), IL-10, and tumor necrosis factor-alpha improved over time.

Conclusion:

This case series shows that HCO-CVVH/CVVHD using EMiC2 hemofilter may provide good cytokine modulation, when used along with good quality standard sepsis therapy. A further large-scale prospective randomized controlled trial is recommended.

Clinical Benefits of High-Volume Hemofiltration in Critically Ill Pediatric Patients with Severe Sepsis: A Retrospective Cohort Study

AIMS

The study aimed to assess the clinical benefits of high-volume hemofiltration (HVHF) in pediatric patients with severe sepsis compared with standard-volume continuous veno-venous hemofiltration (CVVH).

METHODS

We retrospectively analyzed the medical records of 155 pediatric patients with severe sepsis admitted to the pediatric intensive care unit of Shanghai Children's Hospital from January 2010 to June 2016. A total of 93 patients were treated with HVHF and 62 patients were treated with CVVH.

RESULTS

HVHF treatment did not significantly reduce 28-day mortality. Moreover, there was no significant difference in reducing the plasma level of inflammatory mediators and improving hemodynamic variables between HVHF and CVVH group. However, the incidence of hyperglycemia was significantly higher in HVHF group than in CVVH group.

CONCLUSIONS

There is no evidence to indicate that HVHF is superior to CVVH in reducing 28-day mortality as an adjunct to the treatment of severe sepsis in pediatric patients.

High Cut-off Membranes in Acute Kidney Injury and Continuous Renal Replacement Therapy

Innovation in continuous renal replacement therapies (CRRT) utilized to treat acute kidney injury (AKI) and sepsis, has brought new machines and techniques. Part of these new advances are due to the availability of innovative biomaterials and the construction of membranes with larger pores and wide distribution of pore sizes. This includes the creation of a new generation of high cut-off membranes whose utilization in clinical practice is promising for the wide spectrum of solutes that are removed during extracorporeal therapies.

However, the enlargement of pore diameters brings some loss of albumin during treatment and this effect is still under evaluation, since there is a possibility that this is detrimental for the patient. A thorough review of the available clinical literature is reported in this paper with a reappraisal of the potential application of these new technologies.

Acute kidney injury in the ICU: from injury to recovery: reports from the 5th Paris International Conference

The French Intensive Care Society organized its yearly Paris International Conference in intensive care on June 18-19, 2015. The main purpose of this meeting is to gather the best experts in the field in order to provide the highest quality update on a chosen topic. In 2015, the selected theme was: "Acute Renal Failure in the ICU: from injury to recovery." The conference program covered multiple aspects of renal failure, including epidemiology, diagnosis, treatment and kidney support system, prognosis and recovery together with acute renal failure in specific settings. The present report provides a summary of every presentation including the key message and references and is structured in eight sections: (a) diagnosis and evaluation, (b) old and new diagnosis tools,

Acute kidney injury in the ICU: from injury to recovery: reports from the 5th Paris International Conference

The French Intensive Care Society organized its yearly Paris International Conference in intensive care on June 18-19, 2015. The main purpose of this meeting is to gather the best experts in the field in order to provide the highest quality update on a chosen topic. In 2015, the selected theme was: "Acute Renal Failure in the ICU: from injury to recovery." The conference program covered multiple aspects of renal failure, including epidemiology, diagnosis, treatment and kidney support system, prognosis and recovery together with acute renal failure in specific settings. The present report provides a summary of every presentation including the key message and references and is structured in eight sections: (a) diagnosis and evaluation, (b) old and new diagnosis tools,

Nutritional management in the critically ill child with acute kidney injury: a review

Acute kidney injury (AKI) in critically ill children is frequently a component of the multiple organ failure syndrome. It occurs within the framework of the severe catabolic phase determined by critical illness and is intensified by metabolic derangements. Nutritional support is a must for these children to improve outcomes. Meeting the special nutritional needs of these children often requires nutritional supplementation by either the enteral or the parenteral route. Since critically ill children with AKI comprise a heterogeneous group of subjects with varying nutrient needs, nutritional requirements should be frequently reassessed, individualized and carefully integrated with renal replacement therapy. This article is a state-of-the-art review of nutrition in critically ill children with AKI.

Inflammatory Cytokines as Uremic Toxins: "Ni Son Todos Los Que Estan, Ni Estan Todos Los Que Son"

Chronic kidney disease is among the fastest growing causes of death worldwide. An increased risk of all-cause and cardiovascular death is thought to depend on the accumulation of uremic toxins when glomerular filtration rate falls. In addition, the circulating levels of several markers of inflammation predict mortality in patients with chronic kidney disease. Indeed, a number of cytokines are listed in databases of uremic toxins and uremic retention solutes. They include inflammatory cytokines (IL-1β, IL-18, IL-6, TNFα), chemokines (IL-8), and adipokines (adiponectin, leptin and resistin), as well as anti-inflammatory cytokines (IL-10). We now critically review the cytokines that may be considered uremic toxins. We discuss the rationale to consider them uremic toxins (mechanisms underlying the increased serum levels and evidence supporting their contribution to CKD manifestations), identify gaps in knowledge, discuss potential therapeutic implications to be tested in clinical trials in order to make this knowledge useful for the practicing physician, and identify additional cytokines, cytokine receptors and chemokines that may fulfill the criteria to be considered uremic toxins, such as sIL-6R, sTNFR1, sTNFR2, IL-2, CXCL12, CX3CL1 and others. In addition, we suggest that IL-10, leptin, adiponectin and resistin should not be considered uremic toxins toxins based on insufficient or contradictory evidence of an association with adverse outcomes in humans or preclinical data not consistent with a causal association.

Organ dysfunction during continuous veno-venous high cut-off hemodialysis in patients with septic acute kidney injury: A prospective observational study

Background

Continuous veno-venous hemodialysis with high cut-off membranes (HCO-CVVHD) removes inflammatory mediators involved in organ dysfunction during sepsis. The aim of the present study was to assess the variations in SOFA score and identify early predictors of short-term mortality in a cohort of patients with septic shock, treated with HCO-CVVHD for acute kidney injury (AKI).

Methods

An observational prospective multicenter cohort study was conducted in four mixed medical-surgical ICUs. Thirty-eight patients with septic shock and AKI (KDIGO stage≥1) treated with HCO-CVVHD have been included in this study. Patients were divided into Survivors and non-Survivors according to mortality observed at 72^nd hr of treatment. The variation of SOFA scores and clinical/biochemical parameters were described over time for the entire population and specifically for Survivors and non-Survivors. Similarly, circulating inflammatory mediators (as IL-6, TNF-a and IL-10) were described over time. A logistic regression analysis was used to identify the baseline clinical and biochemical parameters associated with 72 hrs-ICU mortality.

Results

Overall, the mean SOFA score was 12±3 at baseline, 10.9±3 at 6hrs, 9.8±3 at 12hrs, 8.9±3.3 at 24 hrs, and 8±3.5 at 48 hrs after HCO-CVVHD initiation; and 6.5±2.7 at 24 hrs and 6.6±3 at 48 hrs after HCO-CVVHD discontinuation. In the multivariate regression analysis, baseline serum lactate levels and AKI stage independently correlated with short-term mortality during HCO-CVVHD. A significant reduction was observed in circulating levels of TNFα and IL-6 among Survivors.

Conclusions

SOFA score significantly decreased early after initiation of HCO-CVVHD in patients with septic AKI. Baseline lactate levels and the AKI stage resulted to be associated to 72 hrs-ICU-mortality.

Effectiveness of High Cut-Off Hemofilters in the Removal of Selected Cytokines in Patients During Septic Shock Accompanied by Acute Kidney Injury-Preliminary Study

Background

In recent years there have been attempts to treat sepsis using various methods of extracorporeal blood purification in order to eliminate selected mediators of inflammation.

Material/Methods

This retrospective study assessed 28 patients (17 males, 11 females, age 60.3 ± 14.5 years) in septic shock, treated with continuous venovenous hemodialysis (CVVHD). Oligoanuric patients with acute kidney injury were qualified for 24-hour CVVHD using high cut-off (HCO) hemofilter. Before the start of dialysis and after 24 hours of treatment, the concentration levels of selected cytokines (IFN-α, IFN-γ, TNF-α, IL-1β, IL-2, IL-6, IL-10, IL-12) in serum were assessed. After 12 hours and 24 hours of treatment, the concentration of the same cytokines in the dialysis fluid was assessed. The aim of our study was to evaluate the effectiveness of HCO-CVVHD in the removal of selected cytokines.

Results

After 24-hour HCO-CVVHD treatment, IL-10 and IL-12 levels in serum were significantly lower. Concentrations of INF-α, IL-1β and IL-2 in dialysis fluid significantly increased during HCO-CVVHD, which corresponded with the parallel rise of related clearances. Clearance of IL-6 was approximately four times higher than IL-10. The rise of IL-6 during HCO-CVVHD significantly correlated with mortality due to sepsis.

Conclusions

Continuous venovenous hemodialysis using high cut-off hemofilter proved to be effective in the removal of IFN-α, IL-1β, IL-2 and IL-6, IL-10 and IL-12 from serum in patients during septic shock. The rise of IL-6 during HCO-CVVHD seems to be a marker of bad prognosis in septic shock patients.

High cut-off hemofiltration versus standard hemofiltration: effect on plasma cytokines

PURPOSE

To study the effects of continuous veno-venous hemofiltration (CVVH) with high cut-off filters (CVVH-HCO) on plasma cytokine levels, sieving coefficient and clearance compared to CVVH using standard filters (CVVH-Std) in a nested cohort within a double-blind randomized controlled trial in severe acute kidney injury (AKI) patients.

METHODS

We measured plasma and post-filter levels of IL-6, TNF-alpha, IL-8, IL-1 beta, RANTES, IL-10, IFN-gamma and IFN-alpha in both study groups. We also measured cytokine levels in the ultrafiltrate and calculated sieving coefficients and clearances.

RESULTS

By 72 hours of treatment, IL-6 had decreased during both treatments (p = 0.009 and 0.005 respectively). In contrast, IL-10 had decreased with CVVH-Std (p = 0.03) but not CVVH-HCO (p = 0.135). None of the other cytokines showed changes over time. There were also no significant between group differences in plasma levels for each cytokine over the 72-hour treatment period. For all cytokines combined, however, the median sieving coefficient was higher for CVVH-HCO (0.31 vs. 0.16; p = 0.042) as was the mass removal rate by ultrafiltration (p = 0.027). While overall combined cytokine levels had fallen to 62.2% of baseline at 72 hours for CVVH-HCO (p&lt;0.0001) and to 75.9% of baseline with CVVH-Std (p = 0.008) there were no between group differences.

CONCLUSIONS

CVVH-HCO achieved greater combined sieving coefficient and mass removal rate by ultrafiltration for a group of key cytokines than CVVH-Std. However, this effect did not differentially lower their plasma level over the first 72 hours. Our study does not support the use of CVVH-HCO to lower cytokines in critically ill patients with AKI.

Estimating Catabolism: A Possible Tool for Nutritional Monitoring of Patients With Acute Kidney Injury

Hypercatabolism has been described as the main nutritional change in acute kidney injury. Catabolism may be defined as the excessive release of amino acids from skeletal muscle. Conditions such as fasting, inadequate nutritional support, renal replacement therapy, metabolic acidosis, and secretion of catabolic hormones are the main factors that affect protein catabolism. Given the imprecision of the methods conventionally used to assess and monitor the nutritional status of hospitalized patients, the parameters of protein catabolism, such as nitrogen balance, urea nitrogen appearance, and protein catabolic rate appear to be the main measures in this population. Considering the high prevalence of malnutrition in this population and important limitations in this clinical condition, such as the inflammatory state and altered fluid, catabolism parameters are accurate and reliable methods that could contribute to minimize adverse prognosis in this population.

High cut-off dialysis in chronic haemodialysis patients reduces serum procalcific activity

BACKGROUND

Vascular calcification is enhanced in chronic dialysis patients, possibly due to the insufficient removal of various intermediate molecular weight uraemic toxins such as interleukins with conventional membranes. In this study, we assessed the modulation of in vitro vascular calcification with the use of high cut-off (HCO) membranes in chronic dialysis patients.

METHODS

In a PERCI trial, 43 chronic dialysis patients were treated with conventional high-flux and HCO filters for 3 weeks in a randomized order following a 2-period crossover design. After each phase, serum predialysis samples were drawn. Calcifying human coronary vascular smooth muscle cells (VSMCs) were incubated with the patient's serum samples. Calcification was assessed with alkaline phosphatase (ALP) and alizarin red staining. In the clinical trial, HCO dialysis reduced the serum levels of the soluble tumour necrosis factor receptor (sTNFR) 1 and 2, vascular cell adhesion molecule 1 (VCAM-1) and soluble interleukin-2 receptor (sIL2R). We therefore investigated the in vitro effects of these mediators on vascular calcification.

RESULTS

VSMCs incubated with HCO dialysis serum showed a 26% reduction of ALP with HCO serum compared with high-flux serum. Alizarin was 43% lower after incubation with the HCO serum compared with the high-flux serum. While sIL2R and sTNFR 1 and 2 showed no effects on VSMC calcification, VCAM-1 caused a dose-dependent enhancement of calcification.

CONCLUSIONS

The use of HCO dialysis membranes in chronic dialysis patients reduces the procalcific effects of serum on VSMC in vitro. The mechanisms of the strong effect of HCO on in vitro calcification are not completely understood. One factor may be lower levels of VCAM-1 in HCO serum samples, since VCAM-1 was able to induce vascular calcification in our experiments. Neither sTNFR 1, sTNFR 2 nor sIL2R enhance vascular calcification in vitro. Regardless of the mechanisms, our results encourage further studies of highly permeable filters in chronic dialysis patients.

High-Dose Versus Conventional-Dose Continuous Venovenous Hemodiafiltration and Patient and Kidney Survival and Cytokine Removal in Sepsis-Associated Acute Kidney Injury: A Randomized Controlled Trial

BACKGROUND

Soluble inflammatory mediators are known to exacerbate sepsis-induced acute kidney injury (AKI). Continuous renal replacement therapy (CRRT) has been suggested to play a part in immunomodulation by cytokine removal. However, the effect of continuous venovenous hemodiafiltration (CVVHDF) dose on inflammatory cytokine removal and its influence on patient outcomes are not yet clear.

STUDY DESIGN

Prospective, randomized, controlled, open-label trial.

SETTING & PARTICIPANTS

Septic patients with AKI receiving CVVHDF for AKI.

INTERVENTION

Conventional (40mL/kg/h) and high (80mL/kg/h) doses of CVVHDF for the duration of CRRT.

OUTCOMES

Patient and kidney survival at 28 and 90 days, circulating cytokine levels.

RESULTS

212 patients were randomly assigned into 2 groups. Mean age was 62.1 years, and 138 (65.1%) were men. Mean intervention durations were 5.4 and 6.2 days for the conventional- and high-dose groups, respectively. There were no differences in 28-day mortality (HR, 1.02; 95% CI, 0.73-1.43; P=0.9) or 28-day kidney survival (HR, 0.96; 95% CI, 0.48-1.93; P=0.9) between groups. High-dose CVVHDF, but not the conventional dose, significantly reduced interleukin 6 (IL-6), IL-8, IL-1b, and IL-10 levels. There were no differences in the development of electrolyte disturbances between the conventional- and high-dose groups.

LIMITATIONS

Small sample size. Only the predilution CVVHDF method was used and initiation criteria were not controlled.

CONCLUSIONS

High CVVHDF dose did not improve patient outcomes despite its significant influence on inflammatory cytokine removal. CRRT-induced immunomodulation may not be sufficient to influence clinical end points.

High cut-off dialysis in chronic haemodialysis patients

BACKGROUND

Haemodialysis patients suffer from chronic systemic inflammation and high incidence of cardiovascular disease. One cause for this may be the failure of diseased kidneys to eliminate immune mediators. Current haemodialysis treatment achieves insufficient elimination of proteins in the molecular weight range 15-45 kD. Thus, high cut-off dialysis might improve the inflammatory state.

DESIGN

In this randomized crossover trial, 43 haemodialysis patients were treated for 3 weeks with high cut-off or high-flux dialysis. Inflammatory plasma mediators, monocyte subpopulation distribution and leucocyte gene expression were quantified.

RESULTS

High cut-off dialysis supplemented by a low-flux filter did not influence the primary end-point, expression density of CD162 on monocytes. Nevertheless, treatment reduced multiple immune mediators in plasma. Such reduction proved - at least for some markers - to be a sustained effect over the interdialytic interval. Thus, for example, soluble TNF-receptor 1 concentration predialysis was reduced from median 13·3 (IQR 8·9-17·2) to 9·7 (IQR 7·5-13·2) ng/mL with high cut-off while remaining constant with high-flux treatment. The expression profile of multiple proinflammatory genes in leucocytes was significantly dampened. Treatment was well tolerated although albumin losses in high cut-off dialysis would be prohibitive against long-term use.

CONCLUSIONS

The study shows for the first time that a dampening effect of high cut-off dialysis on systemic inflammation is achievable. Earlier studies had failed due to short study duration or insufficient dialysis efficacy. Removal of soluble mediators from the circulation influences cellular activation levels in leucocytes. Continued development of less albumin leaky membranes with similar cytokine elimination is justified.

Intermittent high-volume hemofiltration promotes remission in steroid-resistant idiopathic nephrotic syndrome

Inflammation is a key part in the etiology and progression of idiopathic nephrotic syndrome (INS), we hypothesize that removing pro-inflammatory cytokines with intermittent high-volume hemofiltration (IHVHF) could improve the outcome in INS patients. The purpose of the current study is to examine whether IHVHF promotes remission in steroid-resistant INS. Fifty-one steroid-resistant INS patients were followed up on an open-label basis with prospective evaluations. Thirty-five patients received mycophenolate mofetil (SRD group) and 16 patients received drugs and IHVHF due to volume overload despite of diuretics (SRDF group). The rate of complete remission (CR) was analyzed. We also recruited 30 healthy individuals and 36 steroid-sensitive (SS) INS patients as controls to investigate the correlation of interleukin (IL)-8, IL-10, IL-6 and IL-17 with INS activity. Compared with the patients in the SRD group, the 6-month CR rate was higher (44% vs. 9%, p < 0.001) and time to first CR was significantly shorter (7.3 ± 3.6 vs. 11.1 ± 5.3 months, p = 0.02) in the SRDF group. Serum IL-8 was highest in the SRDF group and reduced by IHVHF clearance. Serum IL-8 was lower during remission than at onset or recurrence of INS, whereas no significant difference was seen in the other cytokines. Receiver operating characteristic curve analysis demonstrated that serum IL-8 predicted steroid sensitivity with moderate accuracy (area under the curve = 0.79, 95% CI: 0.69-0.87). IHVHF promotes remission in patients with steroid-resistant INS and it may be partly due to serum IL-8 clearance.