Pilot study on the effects of high cutoff hemofiltration on the need for norepinephrine in septic patients with acute renal failure

The Efficacy and Safety of Continuous Veno-Venous Hemodiafiltration With High Cutoff Membrane Versus High Flux Membrane in Septic Acute Kidney Injury: A Randomized Controlled Study

BACKGROUND

The application of high cutoff (HCO) membranes for continuous renal replacement therapy remains unclear in septic acute kidney injury (S-AKI) patients.

METHODS

S-AKI patients who received continuous veno-venous hemodiafiltration (CVVHDF) were randomly assigned to the experimental group (HCO membrane) and the control group (high flux membrane, HF membrane). Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in serum and waste fluid were measured at 0, 2, 12, and 24 h after CVVHDF initiation and the 28-day mortality.

RESULTS

Eleven patients were randomized to the HCO group, and 9 patients in the HF group, with a mean age of 54.9 ± 3.2 years and 6 patients (30%) being female. After 24 h of treatment with CVVHDF, there were significant reductions in serum IL-6 and TNF-α concentrations in the HCO group (p = 0.001, 0.015) and HF group (p = 0.004, 0.031). The serum IL-6 reduction rate of the HCO group was significantly higher than that of the HF group (79.21% vs. 42.69%, p = 0.025), while serum TNF-α reduction rates were comparable between the 2 groups. There were no significant changes in serum albumin after 24 h using either HCO membrane (28.7 ± 1.7 g/L vs. 32.7 ± 1.6 g/L, p = 0.138) or HF membrane (29.6 ± 1.1 g/L vs. 32.6 ± 1.3 g/L, p = 0.055). The two groups had similar 24-h filter clotting rates and 28-day mortality.

CONCLUSION

While CVVHDF with the HCO membrane and HF membrane both achieved significant reductions in serum cytokine levels, the HCO membrane was associated with a greater reduction rate in IL-6 but not in TNF-α. No difference was observed in serum albumin, mortality, or filter clotting.

TRIAL REGISTRATION

Registry number: ChiCTR2000039725.

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.

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.

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.

Extrakorporale Behandlungsstrategien der Sepsis

Hintergrund Die Mortalität der Sepsis bleibt auch im 21. Jahrhundert sehr hoch. Verschiedene adjuvante Strategien zur extrakorporalen Zytokinelimination wurden als zusätzliche therapeutische Maßnahmen bei Sepsis und septischem Schock untersucht.

Ziele Zusammenfassung einer Auswahl extrakorporaler Blutreinigungstechniken und der aktuellen Erkenntnisse in der klinischen Anwendung mit besonderem Schwerpunkt auf dem therapeutischen Plasmaaustausch.

Methoden Nicht systematische Literaturrecherche.

Ergebnisse Verschiedene extrakorporale Blutreinigungstechniken mit unterschiedlichen Evidenzniveaus hinsichtlich Zytokinelimination, Verbesserung der Hämodynamik und Verringerung der Mortalität werden derzeit klinisch eingesetzt. Die am ausführlichsten untersuchten Modalitäten umfassen die hochvolumige Hämofiltration/Dialyse mit und ohne High-Cut-off-Filter sowie Hämoadsorptionstechniken (einschließlich CytoSorb- und Polymyxin-B-Filter). Trotz teilweise ermutigender Beobachtungen bezüglich der Entfernung proinflammatorischer Zytokine und verbesserten Hämodynamik zeigten randomisierte Outcome-Studien bislang keinen positiven Einfluss auf das Überleben. Aufgrund der Verwendung von Spenderplasma als Substitutionsflüssigkeit stellt der therapeutische Plasmaaustausch das einzige Verfahren dar, das neben einer reinen Elimination zusätzlich verbrauchte protektive Faktoren ersetzen kann.

Schlussfolgerungen Die Anwendung extrakorporaler Blutreinigungsmethoden kann für Sepsispatienten außerhalb klinischer Studien bisher nicht empfohlen werden, da derzeit keine Beweise für ihre Wirksamkeit vorliegen. Zukünftige Untersuchungen sollten darauf abzielen, das Patientenkollektiv hinsichtlich des klinischen Schweregrads, des Zeitpunkts der Intervention und verschiedener inflammatorischer (Sub-)Phänotypen zu homogenisieren.

Signaling pathways and intervention therapies in sepsis

Sepsis is defined as life-threatening organ dysfunction caused by dysregulated host systemic inflammatory and immune response to infection. Over decades, advanced understanding of host-microorganism interaction has gradually unmasked the genuine nature of sepsis, guiding toward new definition and novel therapeutic approaches. Diverse clinical manifestations and outcomes among infectious patients have suggested the heterogeneity of immunopathology, while systemic inflammatory responses and deteriorating organ function observed in critically ill patients imply the extensively hyperactivated cascades by the host defense system. From focusing on microorganism pathogenicity, research interests have turned toward the molecular basis of host responses. Though progress has been made regarding recognition and management of clinical sepsis, incidence and mortality rate remain high. Furthermore, clinical trials of therapeutics have failed to obtain promising results. As far as we know, there was no systematic review addressing sepsis-related molecular signaling pathways and intervention therapy in literature. Increasing studies have succeeded to confirm novel functions of involved signaling pathways and comment on efficacy of intervention therapies amid sepsis. However, few of these studies attempt to elucidate the underlining mechanism in progression of sepsis, while other failed to integrate preliminary findings and describe in a broader view. This review focuses on the important signaling pathways, potential molecular mechanism, and pathway-associated therapy in sepsis. Host-derived molecules interacting with activated cells possess pivotal role for sepsis pathogenesis by dynamic regulation of signaling pathways. Cross-talk and functions of these molecules are also discussed in detail. Lastly, potential novel therapeutic strategies precisely targeting on signaling pathways and molecules are mentioned.

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.

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.

Rationale of Blood Purification in the Post-Resuscitation Syndrome following Out-of-Hospital Cardiac Arrest: A Narrative Review

Even today, little is known about the pathophysiology of the post-resuscitation syndrome. Our narrative review is one of the first summarizing all the knowledge about this phenomenon. We have focused our review upon the potential role of blood purification in attenuating the consequences of the post-resuscitation syndrome. Blood purification can decrease the cytokine storm particularly when using a CytoSorb absorber. Acrylonitrile 69-based oXiris membranes can remove endotoxin and high-mobility group box 1 protein. Blood purification techniques can quickly induce hypothermia. Blood purification can be used with veno-arterial extracorporeal membrane oxygenation to remove excess water. Further trials are needed to provide more concrete data about the use of blood purification in the post-resuscitation syndrome.

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.

[Extracorporeal techniques for blood purification in sepsis: an update]

BACKGROUND

Despite ongoing development, mortality in sepsis remains considerable. Various techniques for extracorporeal cytokine removal have been described, but evidence remains conflicting.

OBJECTIVES

The aim of this article is to summarize currently used extracorporeal blood purification techniques and their evidence.

METHODS

Non-systematic literature review RESULTS: There are currently various blood purification techniques used with different levels of evidence regarding cytokine removal, vasopressor sparing effects and reduction of mortality, including high-volume dialysis with and without high cut-off filters, special adsorption filters (including CytoSorb®, CytoSorbents Europe, Berlin, Germany, and polymyxin‑B filters). There is development regarding therapeutic plasma exchange. For some blood purification techniques such as combined plasma filtration and adsorption, multicentric randomized studies found a negative effect on survival.

CONCLUSIONS

Despite a theoretical rationale, the use of blood purification methods cannot be recommended for sepsis patients due to the lack of evidence of their efficacy. Heterogeneous inflammatory responses in sepsis render conduction of larger trials difficult. Thus, future studies should cautiously identify appropriate sepsis subtypes to be included. Available techniques should be chosen as individualized complementary treatments and not as competing systems.

Early use of endotoxin absorption by oXiris in abdominal septic shock: A case report

RATIONALE

Septic shock leads to multiple organ failure and increases mortality rate. We reported a critical patient with abdominal septic shock, which was the first case successfully treated with continuous renal replacement therapy (CRRT) and a newly designed endotoxin removal device oXiris in mainland China.

PATIENT CONCERNS

A 51-year-old man developed gastric ulcer perforation after resection of a benign peritoneal tumor and had a second abdominal surgery. His blood pressure decreased to 70/40 mm Hg with oliguria, requiring large doses of noradrenaline and intravenous fluid for resuscitation. The abdominal cavity was not sutured after the second open surgery due to severe abdominal infection and distention. His leukocyte count was over 30109/L, while the blood lactic acid was 12.5 mmol/L and procalcitonin (PCT) was >100 ng/mL.

DIAGNOSIS

Since the bacterial culture of peritoneal exudate showed positive with Enterobacter aerogenes and Pseudomonas aeruginosa after the second surgery, and the patient had severe low blood pressure, hyoxemia and oliguria, combined with the laboratory tests results, he was diagnosed with Gram-negative related septic shock, acute kidney injury, and multiple organ dysfunction.

INTERVENTIONS

CRRT with oXiris membrane was performed for 80hours and followed by AN69 ST membranes during the subsequent 27 days. Antibiotics together with other medical treatment were applied to the patient in the meantime.

OUTCOMES

At the end of 80 hours treatment with oXiris, PCT of the patient had decreased to 14.52 ng/mL and lactic acid decreased to 4.2 mmol/L. The total sequential organ failure assessment (SOFA) score decreased from 15 to 11. Urine output steadily increased to 250 mL/h, and vital signs and blood pressure were stable without noradrenaline. At the end of the 27 days of conventional CRRT, his kidney function had completely recovered with a total sequential organ failure assessment score (SOFA score) of 6.

LESSONS

oXiris, with its enhanced endotoxin adsorption, appeared to accelerate improvement in organ dysfunction and ultimate survival in our patient. In critical patients with abdominal septic shock, oXiris is an important adjunctive consideration to supplement definitive source control and antimicrobial therapy.

Blood Purification Techniques for Sepsis and Septic AKI

Sepsis is the primary cause of acute kidney injury in critically ill patients. During the past decades, several extracorporeal blood purification techniques have been developed for sepsis and sepsis-induced acute kidney injury management. These therapies could act on both the infectious agent itself and the host immune response. In this article, we review the available literature discussing the different extracorporeal blood purification techniques, including high-volume hemofiltration, cascade hemofiltration, hemoperfusion, coupled plasma filtration adsorption, plasma exchange, and specific optimized renal replacement therapy membranes.

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.

High Efficiency Removal of Cytokines and HMGB-1 by Continuous Hemofiltration With a Dual Layered Polyethersulfone Membrane: An Ex Vivo Study

Cytokines and high mobility group box chromosomal protein-1 (HMGB-1) play key roles in inflammatory conditions. While hemofiltration has been shown to remove cytokines, removal of cytokines and HMGB-1 by hemofiltration using a polyethersulfone membrane has not been reported. This study aimed to test the hypothesis that the polyethersulfone membrane will achieve higher removal performance for substances including inflammatory cytokines compared to other hemofilters, while retaining low albumin removal capacity. Subjects were eight healthy volunteers. We collected 400 mL each of blood samples into containers with heparin and added 30 mg of lipopolysaccharide to spike cytokines and HMGB-1. After incubation at 39ºC for 12 h, each blood sample was circulated through a hemofiltration circuit with a polyethersulfone hemofilter (2.1 m² or 1.1 m² ) at a filtration flow rate of 2 L/h. Measurement samples were collected from arterial, venous, and ultrafiltrate sampling points. Concentrations of cytokines (IL-1ß, IL-4, IL-6, IL-8, IL- 10, and tumor necrosis factor [TNF-a]), HMGB-1, and albumin were determined at each time point (1, 4, 8, 12, and 24h). High sieving coefficients (SCs) above 0.8 were obtained for all cytokines except for TNF-a as well as HMGB-1, whereas the SC for albumin was less than 0.04 with both hemofilters. The hemofilter with a larger membrane area achieved significantly higher clearances for TNF-a and HMGB-1, and slower decreases in SCs over time for IL-1ß, IL-6, IL-8, TNF-a, and albumin. Continuous hemofiltration with a polyethersulfone membrane achieved high efficiency removal of cytokines and HMGB-1, without excessive removal of albumin.

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.

High cut-off membrane for in-vivo dialysis of free plasma hemoglobin in a patient with massive hemolysis

Background

The possibility of clearing Cell-free Plasma Hemoglobin (CPH) from human plasma may appear attractive, especially when considering the noxious effects that CPH has on the immune function and the renal damage caused by its filtration. The existence of the so-called High Cut-Off (HCO) filters, possessing pores as big as 60 kDa, could potentially allow the clearance of the αβ dimers (31.3 kDa), the form in which the α2β2 hemoglobin tetramers (62.6 kDa) physiologically dissociate in plasma. We present herein the first reported case in which such an attempt was made.

Case presentation

The patient was a 51-year-old man with hemolytic crisis due to glucose-6-phosphate dehydrogenase deficiency, further complicated by pigment-induced nephropathy. He underwent a 48-h CVVHD session, in which a HCO filter was used. The Sieving Coefficient (SC) for CPH was initially 0.08 and decreased to 0.02 after 24 h. This unexpected low SC was due to the initial high concentration of CPH (4.24 g/L). At such concentrations, the α2β2 tetramer poorly dissociates into the αβ dimer; but increases exponentially at concentrations lower than 1 g/L.

Conclusions

Clearance of CPH through a HCO filter is technically feasible but its performance markedly relies on the initial concentration of CPH. Critically ill patients with smoldering hemolysis, as it happens during septic shock or ECMO treatment, may benefit the most from the use of this membrane in order to clear CPH.

Targeting proinflammatory cytokines ameliorates calcifying phenotype conversion of vascular progenitors under uremic conditions in vitro

Severe vascular calcification develops almost invariably in chronic kidney patients posing a substantial risk to quality of life and survival. This unmet medical need demands identification of novel therapeutic modalities. We aimed to pinpoint components of the uremic microenvironment triggering differentiation of vascular progenitors to calcifying osteoblast-like cells. In an unbiased approach, assessing the individual potency of 63 uremic retention solutes to enhance calcific phenotype conversion of vascular progenitor cells, the pro-inflammatory cytokines IL-1β and TNF-α were identified as the strongest inducers followed by FGF-2, and PTH. Pharmacologic targeting of these molecules alone or in combination additively antagonized pro-calcifying properties of sera from uremic patients. Our findings stress the importance of pro-inflammatory cytokines above other characteristic components of the uremic microenvironment as key mediators of calcifying osteoblastic differentiation in vascular progenitors. Belonging to the group of "middle-sized molecules", they are neither effectively removed by conventional dialysis nor influenced by established supportive therapies. Specific pharmacologic interventions or novel extracorporeal approaches may help preserve regenerative capacity and control vascular calcification due to uremic environment.

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.

Broad adsorption of sepsis-related PAMP and DAMP molecules, mycotoxins, and cytokines from whole blood using CytoSorb® sorbent porous polymer beads

OBJECTIVE

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. In sepsis and septic shock, pathogen-associated molecular pattern molecules (PAMPS), such as bacterial exotoxins, cause direct cellular damage and/or trigger an immune response in the host often leading to excessive cytokine production, a maladaptive systemic inflammatory response syndrome response (SIRS), and tissue damage that releases DAMPs, such as activated complement and HMGB-1, into the bloodstream causing further organ injury. Cytokine reduction using extracorporeal blood filtration has been correlated with improvement in survival and clinical outcomes in experimental studies and clinical reports, but the ability of this technology to reduce a broader range of inflammatory mediators has not been well-described. This study quantifies the size-selective adsorption of a wide range of sepsis-related inflammatory bacterial and fungal PAMPs, DAMPs and cytokines, in a single compartment, in vitro whole blood recirculation system.

MEASUREMENTS AND MAIN RESULTS

Purified proteins were added to whole blood at clinically relevant concentrations and recirculated through a device filled with CytoSorb® hemoadsorbent polymer beads (CytoSorbents Corporation, USA) or control (no bead) device in vitro. Except for the TNF-α trimer, hemoadsorption through porous polymer bead devices reduced the levels of a broad spectrum of cytokines, DAMPS, PAMPS and mycotoxins by more than 50 percent.

CONCLUSIONS

This study demonstrates that CytoSorb® hemoadsorbent polymer beads efficiently remove a broad spectrum of toxic PAMPS and DAMPS from blood providing an additional means of reducing the uncontrolled inflammatory cascade that contributes to a maladaptive SIRS response, organ dysfunction and death in patients with a broad range of life-threatening inflammatory conditions such as sepsis, toxic shock syndrome, necrotizing fasciitis, and other severe inflammatory conditions.

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.

Acute PD: Evidence, Guidelines, and Controversies☆

Peritoneal dialysis (PD) may be a feasible, safe, and complementary alternative to hemodialysis not only in the chronic setting, but also in the acute setting. It previously was widely accepted for acute kidney injury (AKI) treatment, but its practice decreased in favor of other types of extracorporeal therapies. The interest in PD to manage AKI patients has been reignited and PD now frequently is used in developing countries because of its lower cost and minimal infrastructural requirements. Studies from these countries have shown that, with careful thought and planning, critically ill patients can be treated successfully using PD. Some of the classic limitations of PD use in AKI, such as a high chance of infectious and mechanical complications and poor metabolic control, have been overcome with the use of cyclers, flexible catheters, and a high volume of dialysis fluid. However, in developing countries the infrastructure for quality research often is lacking and the result has been limited evidence on standardized treatment regimens such as indications, dosing, and technical failure and mortality. The recent publication of the International Society for Peritoneal Dialysis guidelines for PD in AKI have tried to address these issues and provide an evidence-based standard by which to initiate therapy. In this article, advances in technical aspects and the advantages and limitations of PD are discussed, and recent literature on clinical experience with PD for the treatment of AKI patients is reviewed.

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.

Immune disorders in sepsis and their treatment as a significant problem of modern intensive care

Despite the great advances in the treatment of sepsis over the past 20 years, sepsis remains the main cause of death in intensive care units. In the context of new possibilities of treating sepsis, a comprehensive response of the immune system to the infection, immunosuppression, in particular, has in recent years gained considerable interest. There is vast evidence pointing to the correlation between comorbid immunosuppression and an increased risk of recurrent infections and death. Immune disorders may impact the clinical course of sepsis. This applies in particular to patients with deteriorated clinical response to infections. They usually suffer from comorbidities and conditions accompanied by immunosuppression. Sepsis disrupts innate and adaptive immunity. The key to diagnose the immune disorders in sepsis and undertake targeted immunomodulatory therapy is to define the right biomarkers and laboratory methods, which permit prompt "bedside" diagnosis. Flow cytometry is a laboratory tool that meets these criteria. Two therapeutic methods are currently being suggested to restore the immune homeostasis of sepsis patients. Excessive inflammatory response may be controlled through extracorporeal blood purification techniques, in large part derived from renal replacement therapy. These are such techniques as high-volume haemofiltration, cascade haemofiltration, plasma exchange, coupled plasma filtration and adsorption, high-absorption membranes, high cut-off membranes. The main task of theses techniques is the selective elimination of middle molecular weight molecules, such as cytokines. Pharmacotherapy with the use of such immunostimulants as interleukin 7, granulocyte-macrophage colony-stimulating factor, interferon gamma, PD-1, PD-L1 and CTLA-4 antagonists, intravenous immunoglobulins may help fight immunosuppressive immune disorders.

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.

The effect of a novel extracorporeal cytokine hemoadsorption device on IL-6 elimination in septic patients: A randomized controlled trial

Objective

We report on the effect of hemoadsorption therapy to reduce cytokines in septic patients with respiratory failure.

Methods

This was a randomized, controlled, open-label, multicenter trial. Mechanically ventilated patients with severe sepsis or septic shock and acute lung injury or acute respiratory distress syndrome were eligible for study inclusion. Patients were randomly assigned to either therapy with CytoSorb hemoperfusion for 6 hours per day for up to 7 consecutive days (treatment), or no hemoperfusion (control). Primary outcome was change in normalized IL-6-serum concentrations during study day 1 and 7.

Results

97 of the 100 randomized patients were analyzed. We were not able to detect differences in systemic plasma IL-6 levels between the two groups (n = 75; p = 0.15). Significant IL-6 elimination, averaging between 5 and 18% per blood pass throughout the entire treatment period was recorded. In the unadjusted analysis, 60-day-mortality was significantly higher in the treatment group (44.7%) compared to the control group (26.0%; p = 0.039). The proportion of patients receiving renal replacement therapy at the time of enrollment was higher in the treatment group (31.9%) when compared to the control group (16.3%). After adjustment for patient morbidity and baseline imbalances, no association of hemoperfusion with mortality was found (p = 0.19).

Conclusions

In this patient population with predominantly septic shock and multiple organ failure, hemoadsorption removed IL-6 but this did not lead to lower plasma IL-6-levels. We did not detect statistically significant differences in the secondary outcomes multiple organ dysfunction score, ventilation time and time course of oxygenation.

Clearance of Selected Plasma Cytokines with Continuous Veno-Venous Hemodialysis Using Ultraflux EMiC2 versus Ultraflux AV1000S

BACKGROUND

High cutoff hemofilters might support the restoration of immune homeostasis in systemic inflammation by depleting inflammatory mediators from the circulation.

METHODS

Interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor-alpha depletion was assessed in 30 sepsis patients with acute renal failure using continuous veno-venous hemodialysis with high cutoff versus standard filters (CVVHD-HCO vs. CVVHD-STD) over 48 h.

RESULTS

The transfer of IL-6 and IL-8 was significantly higher for CVVHD-HCO, as shown by increased IL-6 and IL-8 effluent concentrations. The mean plasma cytokine concentrations decreased over time for all cytokines without detectable differences for the treatment modalities. No transfer of albumin was observed for either of the filters. C-reactive protein remained stable over time and did not differ between CVVHD-HCO and CVVHD-STD, while procalcitonin decreased significantly over 48 h for both treatment modalities.

CONCLUSION

CVVHD-HCO achieved enhanced removal of IL-6 and IL-8 as compared to CVVHD-STD, without differentially reducing plasma cytokine levels.

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,

Granulocyte and monocyte adsorptive apheresis ameliorates sepsis in rats

Background

Overwhelming activation of granulocytes and monocytes is central to inflammatory responses during sepsis. Granulocyte and monocyte adsorptive apheresis (GMA) is an extracorporeal leukocyte apheresis device filled with cellulose acetate beads and selectively adsorbs granulocytes and monocytes from the peripheral blood.

Methods

In this study, septic rats received the GMA treatment for 2 h at 18 h after cecal ligation and puncture.

Results

GMA selectively adsorbed activated neutrophils and monocytes from the peripheral blood, reduced serum inflammatory cytokine expression, and seemed to improve organ injuries and animal survival. GMA potentially reduced lung injury by alleviating the infiltration of inflammatory cells and the secretion of cytokines.

Conclusions

This study showed that selective granulocyte and monocyte adsorption with cellulose acetate beads might ameliorate cecal ligation and puncture (CLP)-induced sepsis and improve survival and organ function.

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.

Mechanisms of endothelial activation in sepsis and cell culture models to study the heterogeneous host response

Sepsis is currently viewed as a fundamental disintegration of control functions from intracellular signalling to immunoregulatory and neuroendocrine mechanisms. The immediate threat in sepsis is invasive infection, and the need to activate immune defense mechanisms to clear the pathogen before irreparable damage occurs. In the process of pathogen elimination, however, the systemic host response to infection may cause collateral damage to the endothelium and may lead to the destruction of host tissues.A number of experimental models have been developed to monitor endothelial activation and to study endothelial dysfunction under septic conditions. Here, we review the application of these models to assess the highly variable host response in sepsis and to investigate the efficacy of adsorbent-based extracorporeal therapies. We also highlight the need for efficient diagnostic tools, which are indispensable to select patients who are likely to benefit from distinct adjunctive therapies.

High-volume haemofiltration for sepsis in adults

BACKGROUND

Severe sepsis and septic shock are leading causes of death in the intensive care unit (ICU), despite advances in the treatment of patients with severe sepsis and septic shock, including early recognition, appropriate treatment with antibiotics and support of organs that may have been affected by the illness. High-volume haemofiltration (HVHF) is a blood purification technique that may improve outcomes in severe sepsis or septic shock. The technique of HVHF has evolved from renal replacement therapies used in the ICU to treat critically ill patients with acute kidney injury (AKI). This review was first published in 2013 and was updated in 2016.

OBJECTIVES

To investigate whether HVHF improves outcomes in critically ill adults admitted to the intensive care unit with severe sepsis or septic shock. The primary outcome of this systematic review is patient mortality; secondary outcomes include duration of stay, severity of organ dysfunction and adverse events.

SEARCH METHODS

For this updated version, we extended searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Latin American Caribbean Health Sciences Literature (LILACS), Web of Science and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) to 31 December 2015. The original search was performed in 2011. We also searched trials registers.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-randomized trials comparing HVHF or high-volume haemodiafiltration versus standard or usual dialysis therapy, as well as RCTs and quasi-randomized trials comparing HVHF or high-volume haemodiafiltration versus no similar dialysis therapy. These studies involved adults treated in critical care units.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data and assessed trial quality. We sought additional information from trialists as required.

MAIN RESULTS

We included four randomized trials involving 200 participants. Owing to small numbers of studies and participants, it was not possible to combine data for all outcomes. Two trials reported 28-day mortality, and one trial reported hospital mortality; in the third trial, the number of deaths stated did not match the quoted mortality rates. The pooled risk ratio (95% confidence interval) for 28-day mortality associated with HVHF was 0.89 (0.60 to 1.32, two trials, 146 participants, low-quality evidence). One study (137 participants, low-quality evidence) reported length of stay in the ICU. Two trials (170 participants, low-quality evidence) reported organ dysfunction, but we could not pool results owing to reporting differences. Three studies (189 participants, low-quality evidence) reported on haemodynamic changes, but we could not pool results owing to reporting differences. Investigators reported no adverse events. Overall, the included studies had low risk of bias.

AUTHORS' CONCLUSIONS

Investigators reported no adverse effects of HVHF (low-quality evidence). The results of this meta-analysis show that very few studies have been conducted to investigate the use of HVHF in critically ill patients with severe sepsis or septic shock (four studies, 201 participants, low-quality evidence). Researchers should consider additional randomized controlled trials that are large and multi-centred and have clinically relevant outcome measures. The cost-effectiveness of HVHF should also be studied. .

Plasmapheresis and other extracorporeal filtration techniques in critical patients

Plasmapheresis is an extracorporeal technique that eliminates macromolecules involved in pathological processes from plasma. A review is made of the technical aspects, main indications in critical care and potential complications of plasmapheresis, as well as of other extracorporeal filtration techniques such as endotoxin-removal columns and other devices designed to eliminate cytokines or modulate the inflammatory immune response in critical 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.

Plasmadiafiltration ameliorating gut mucosal barrier dysfunction and improving survival in porcine sepsis models

BACKGROUND

The object of this study is to explore whether the plasmadiafiltration (PDF) is more effective in improving the intestinal mucosal barrier function by removing more key large molecular inflammatory mediators and then prolonging the survival time.

METHODS

Totally, 24 porcine sepsis models induced by cecal ligation and puncture (CLP) operation were randomly divided into three groups: PDF group, high-volume hemofiltration (HVHF) group, and control group, and received 8 h treatment, respectively. The expression of ZO-1 and occludin in intestinal mucosal epithelial cells were detected by immunohistochemistry, and apoptotic protein caspase-3-positive lymphocytes were signed in mesenteric lymph nodes by TUNEL staining. The hemodynamic parameters were measured by invasive cavity detection. The tumor necrosis factor alpha (TNFα) and high-mobility group protein 1 (HMGB1) were tested by ELISA method. And then, the survival curves with all-cause death were compared with three groups.

RESULTS

PDF led to a superior reversal of sepsis-related hemodynamic impairment and serum biochemistry abnormalities and resulted in longer survival time compared with HVHF and control (p < 0.01). Definitive protection from excessive TNF-α and HMGB1 response were only achieved by PDF. A more regular distribution pattern of ZO-1 and occludin along the epithelium was found in PDF animals (p < 0.01). The presence of apoptotic lymphocytes was significantly reduced in the PDF animals (p < 0.01).

CONCLUSIONS

PDF can effectively eliminate more pivotal inflammatory mediators of TNFα and HMGB1 and reduce the inflammation damage of the intestinal mucosal barrier and apoptosis of lymphocyte then improve the circulation function and prolong the survival time.

Renal Replacement Therapy

During the last few years, due to medical and surgical evolution, patients with increasingly severe diseases causing multiorgan dysfunction are frequently admitted to intensive care units. Therapeutic options, when organ failure occurs, are frequently nonspecific and mostly directed towards supporting vital function. In these scenarios, the kidneys are almost always involved and, therefore, renal replacement therapies have become a common routine practice in critically ill patients with acute kidney injury. Recent technological improvement has led to the production of safe, versatile and efficient dialysis machines. In addition, emerging evidence may allow better individualization of treatment with tailored prescription depending on the patients' clinical picture (e.g. sepsis, fluid overload, pediatric). The aim of the present review is to give a general overview of current practice in renal replacement therapies for critically ill patients. The main clinical aspects, including dose prescription, modality of dialysis delivery, anticoagulation strategies and timing will be addressed. In addition, some technical issues on physical principles governing blood purification, filters characteristics, and vascular access, will be covered. Finally, a section on current standard nomenclature of renal replacement therapy is devoted to clarify the "Tower of Babel" of critical care nephrology.

Extracorporeal renal replacement therapies in the treatment of sepsis: where are we?

Acute kidney injury (AKI) is common among the critically ill, affecting approximately 40% of patients. Sepsis is the cause of AKI in almost 50% of cases of intensive care patients, however, any evidence-based treatment for sepsis-associated AKI is lacking. Furthermore, the underlying pathophysiology of septic AKI is inadequately understood given the disparity between severe functional changes and limited tubular injury. What is clear is that within this complex interplay leading to septic AKI, the inflammatory response plays a pivotal role and hence modulation of this response may translate to improved outcomes. We outline the use of extracorporeal therapies in the treatment of sepsis and septic AKI. We consider the classic aspects of extracorporeal renal replacement therapy including indications, timing, and delivered dose. The various techniques that currently are used to try and achieve immune homeostasis also are outlined. As well as discussing the evidence accumulated to date, we also suggest possibilities for the future treatment of our patients.

Renal replacement therapy in adult and pediatric intensive care : Recommendations by an expert panel from the French Intensive Care Society (SRLF) with the French Society of Anesthesia Intensive Care (SFAR) French Group for Pediatric Intensive Care Emergencies (GFRUP) the French Dialysis Society (SFD)

Acute renal failure (ARF) in critically ill patients is currently very frequent and requires renal replacement therapy (RRT) in many patients. During the last 15 years, several studies have considered important issues regarding the use of RRT in ARF, like the time to initiate the therapy, the dialysis dose, the types of catheter, the choice of technique, and anticoagulation. However, despite an abundant literature, conflicting results do not provide evidence on RRT implementation. We present herein recommendations for the use of RRT in adult and pediatric intensive care developed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system by an expert group of French Intensive Care Society (SRLF), with the participation of the French Society of Anesthesia and Intensive Care (SFAR), the French Group for Pediatric Intensive Care and Emergencies (GFRUP), and the French Dialysis Society (SFD). The recommendations cover 4 fields: criteria for RRT initiation, technical aspects (access routes, membranes, anticoagulation, reverse osmosis water), practical aspects (choice of the method, peritoneal dialysis, dialysis dose, adjustments), and safety (procedures and training, dialysis catheter management, extracorporeal circuit set-up). These recommendations have been designed on a practical point of view to provide guidance for intensivists in their daily practice.