The Great pretender: the first case of septic shock due to Capnocytophaga canimorsus in Sardinia. A Case report and review of the literature

Capnocytophaga canimorsus (C. canimorsus) is an emerging pathogen in critical care. C. canimorsus is a Gram-negative bacillus, commonly isolated as a commensal microorganism of the oral flora of healthy dogs and cats. A 63-year-old woman came to the emergency department with fever, chills, and malaise 2 days after a minor dog bite. After admission to the medicine ward, she developed respiratory failure and livedo reticularis. In the intensive care unit (ICU), she presented full-blown septic shock with thrombocytopenia, coagulopathy, severe acute kidney injury, and liver injury. We describe the first case of septic shock with Multiple Organ Dysfunction Syndrome related to Capnocytophaga canimorsus infection in Sardinia and its treatment in a tertiary hospital ICU. We also review recent literature on the relevance of C. canimorsus in human disease and critical illness.

Effects of Expanded Hemodialysis with Medium Cut-Off Membranes on Maintenance Hemodialysis Patients: A Review

Kidney failure is associated with high morbidity and mortality. Hemodialysis, the most prevalent modality of renal replacement therapy, uses the principle of semipermeable membranes to remove solutes and water in the plasma of patients with kidney failure. With the evolution of hemodialysis technology over the last half century, the clearance of small water-soluble molecules in such patients is adequate. However, middle molecules uremic toxins are still retained in the plasma and cause cardiovascular events, anemia, and malnutrition, which significantly contribute to poor quality of life and high mortality in maintenance hemodialysis patients. A new class of membrane, defined as a medium cut-off (MCO) membrane, has emerged in recent years. Expanded hemodialysis with MCO membranes is now recognized as the artificial kidney model closest to natural kidney physiology. This review summarizes the unique morphological characteristics and internal filtration–backfiltration mechanism of MCO membranes, and describes their effects on removing uremic toxins, alleviating inflammation and cardiovascular risk, and improving quality of life in maintenance hemodialysis patients.

Continuous Renal Replacement Therapy in the Critically Ill Patient: From Garage Technology to Artificial Intelligence

The history of continuous renal replacement therapy (CRRT) is marked by technological advances linked to improvements in the knowledge of the mechanisms and kinetics of extracorporeal removal of solutes, and the pathophysiology of acute kidney injury (AKI) and other critical illnesses. In the present article, we review the main steps in the history of CRRT, from the discovery of continuous arteriovenous hemofiltration to its evolution into the current treatments and its early use in the treatment of AKI, to the novel sequential extracorporeal therapy. Beyond the technological advances, we describe the development of new medical specialties and a shared nomenclature to support clinicians and researchers in the broad and still evolving field of CRRT.

Comparison of myoglobin clearance in three types of blood purification modalities

Myoglobin, which can cause acute kidney injury, has a relatively high molecular weight and is poorly cleared by diffusion. We compared and examined myoglobin clearance by changing the blood purification membrane and modality in patients with a myoglobin blood concentration ≥ 1000 ng/ml. We retrospectively analyzed three patient groups based on the following three types of continuous hemofiltration (CHF): AN69ST membrane, polymethylmethacrylate (PMMA) membrane, and high-flow hemodiafiltration (HDF) with increased dialysate flow rate using the PMMA membrane. There was no significant difference in clearance in CHF between AN69ST and PMMA membranes. However, the high-flow HDF group showed the highest myoglobin clearance (p = 0.003). In the PMMA membrane, changing the treatment modality to high-flow HDF increased clearance above the theoretical value, possibly due to internal filtration. To remove myoglobin by kidney replacement therapy from patients with hypermyoglobinemia, a modality such as high-flow HDF would be desirable.

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.

Choosing a dialyzer: What clinicians need to know

The objectives of hemodialysis have moved from the diffusive clearance of small molecular weight uremic toxins and achieving dialyzer urea adequacy targets to emphasis on improving clinical outcomes in end stage renal failure patients by increasing larger sized uremic toxin clearance. Clinical emphasis in the last few decades has focused on increasing middle molecule weight toxin clearance by hemodiafiltration. Although long-term data is still lacking, short-term outcomes appear promising. Advancements in nanotechnology have now introduction a new generation of medium cut-off membrane dialyzers which allow diffusive clearance of similar middle molecular weight uremia toxin clearance as hemodiafiltration, without increased albumin losses. As these dialyzers have only recently been introduced into clinical practice, no long-term outcomes are available to determine the relative benefits or advantages of this approach. As dialyzers are now designed to maximize diffusive or convective clearance, or provide a combination, then clinicians can now choose dialyzers tailored to the individual patient needs depending on clinical circumstances. We review the key important features in choosing a dialyzer for patients with end stage renal failure and acute kidney injury.

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.

In Vitro Benchmark of Cytokine Removal by Dialyzers with Various Permeability Profiles

Purpose

Removal of cytokines is relevant for dialysis patients as they are suspected to promote cardiovascular complications. The objective of this study was to benchmark membranes with different permeability profiles under standardized in vitro test conditions using miniaturized devices with respect to their ability to remove cytokines from human serum and to lower cell activating potential.

Methods

In vitro dialysis was used to dialyze cytokine enriched serum in 3 independent experiments per tested membrane. IL-6 in the serum and dialysate was measured at defined times by enzyme-linked immunosorbent assay. IL-8, IL-1β, IL-6 and TNF-α in dialysate were measured by immunoassay. Dialysate samples were subjected to cultured tubular epithelial cells or human fibroblasts to study cell activation via IL-6 generation. Dialysate samples were added to human whole blood with subsequent analysis of granulocyte and monocyte activation by detection of CD11b.

Results

IL-6 decreased in serum and increased in dialysate during in vitro dialysis. IL-8, IL-1β, and TNF-α were identified in dialysate. Dialysate added to cell cultures increased IL-6 concentration in culture medium or increased expression of CD11b. High cut-off membranes showed the strongest transfer of cytokines, albumin and total proteins from serum to dialysate and led to strongest cell activation. This effect was lower for medium cutoff membranes and lowest for conventional high-flux membranes.

Conclusions

This study demonstrated an in vitro test by which membranes were benchmarked with respect to cytokine and cell activation removal capacity. Cell activation levels could be influenced by the choice of membrane by altering cytokine concentration levels.

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.

Hemodiafiltration Decreases Serum Levels of Inflammatory Mediators in Severe Leptospirosis: A Prospective Study

BACKGROUND

Leptospirosis is a health problem worldwide. Its most severe form is a classic model of sepsis, provoking acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI), with associated mortality that remains unacceptably high. We previously demonstrated that early initiation of sustained low-efficiency dialysis (SLED) followed by daily SLED significantly decreases mortality. However, the mode of clearance can also affect dialysis patient outcomes. Therefore, the objective of this study was to compare the effects of SLED with traditional (diffusive) clearance, via hemodialysis, and SLED with convective clearance, via hemodiafiltration (SLEDf), in patients with severe leptospirosis.

METHODS

In this prospective study, conducted in the intensive care unit (ICU) from 2009 through 2012, we compared two groups-SLED (n = 19) and SLEDf (n = 20)-evaluating demographic, clinical, and biochemical parameters, as well as serum levels of interleukins, up to the third day after admission. All patients received dialysis early and daily thereafter.

RESULTS

During the study period, 138 patients were admitted to our ICU with a diagnosis of leptospirosis; 39 (36 males/3 females) met the criteria for ARDS and AKI. All patients were on mechanical ventilation and were comparable in terms of respiratory parameters. Mortality did not differ between the SLEDf and SLED groups. However, post-admission decreases in the serum levels of interleukin (IL)-17, IL-7, and monocyte chemoattractant protein-1 were significantly greater in the SLEDf group. Direct bilirubin and the arterial oxygen tension/fraction of inspired oxygen ratio were significantly higher in the SLED group. We identified the following risk factors (sensitivities/specificities) for mortality in severe leptospirosis: age ≥ 55 years (67%/91%); serum urea ≥ 204 mg/dl (100%/70%); creatinine ≥ 5.2 mg/dl (100%/58%); Acute Physiology and Chronic Health Evaluation II score ≥ 39.5 (67%/88%); Sequential Organ Failure Assessment score ≥ 20.5 (67%/85%); and inspiratory pressure ≥ 31 mmHg (84%/85%).

CONCLUSIONS

The mode of dialysis clearance might not affect outcomes in severe leptospirosis.

Long-term remote organ consequences following acute kidney injury

Acute kidney injury (AKI) has been a global health epidemic problem with soaring incidence, increased long-term risks for multiple comorbidities and mortality, as well as elevated medical costs. Despite the improvement of patient outcomes following the advancements in preventive and therapeutic strategies, the mortality rates among critically ill patients with AKI remain as high as 40–60 %. The distant organ injury, a direct consequence of deleterious systemic effects, following AKI is an important explanation for this phenomenon. To date, most evidence of remote organ injury in AKI is obtained from animal models. Whereas the observations in humans are from a limited number of participants in a relatively short follow-up period, or just focusing on the cytokine levels rather than clinical solid outcomes. The remote organ injury is caused with four underlying mechanisms: (1) “classical” pattern of acute uremic state; (2) inflammatory nature of the injured kidneys; (3) modulating effect of AKI of the underlying disease process; and (4) healthcare dilemma. While cytokines/chemokines, leukocyte extravasation, oxidative stress, and certain channel dysregulation are the pathways involving in the remote organ damage. In the current review, we summarized the data from experimental studies to clinical outcome studies in the field of organ crosstalk following AKI. Further, the long-term consequences of distant organ-system, including liver, heart, brain, lung, gut, bone, immune system, and malignancy following AKI with temporary dialysis were reviewed and discussed.

Future Avenues to Decrease Uremic Toxin Concentration

In this article, we review approaches for decreasing uremic solute concentrations in chronic kidney disease and in particular, in end-stage renal disease (ESRD). The rationale to do so is the straightforward relation between concentration and biological (toxic) effect for most toxins. The first section is devoted to extracorporeal strategies (kidney replacement therapy). In the context of high-flux hemodialysis and hemodiafiltration, we discuss increasing dialyzer blood and dialysate flows, frequent and/or extended dialysis, adsorption, bioartificial kidney, and changing physical conditions within the dialyzer (especially for protein-bound toxins). The next section focuses on the intestinal generation of uremic toxins, which in return is stimulated by uremic conditions. Therapeutic options are probiotics, prebiotics, synbiotics, and intestinal sorbents. Current data are conflicting, and these issues need further study before useful therapeutic concepts are developed. The following section is devoted to preservation of (residual) kidney function. Although many therapeutic options may overlap with therapies provided before ESRD, we focus on specific aspects of ESRD treatment, such as the risks of too-strict blood pressure and glycemic regulation and hemodynamic changes during dialysis. Finally, some recommendations are given on how research might be organized with regard to uremic toxins and their effects, removal, and impact on outcomes of uremic patients.

Renal replacement therapy in acute kidney injury: controversy and consensus

Renal replacement therapies (RRTs) represent a cornerstone in the management of severe acute kidney injury. This area of intensive care and nephrology has undergone significant improvement and evolution in recent years. Continuous RRTs have been a major focus of new technological and treatment strategies. RRT is being used increasingly in the intensive care unit, not only for renal indications but also for other organ-supportive strategies. Several aspects related to RRT are now well established, but others remain controversial. In this review, we review the available RRT modalities, covering technical and clinical aspects. We discuss several controversial issues, provide some practical recommendations, and where possible suggest a research agenda for the future.

Extended characterization of a new class of membranes for blood purification: the high cut-off membranes

High cut-off membranes are a new class of blood purification membranes whose particular characteristics present challenges for commonly-used characterization methods. Dextran sieving curves for representative blood purification membranes of the high-flux and high cut-off types were measured and compared to curves for the glomerular filtration barrier (GFB). The performance was also determined after blood exposure for the most permeable synthetic membranes. High cut-off membranes were observed to be more open than the GFB before blood exposure, but become tighter and more selective after the exposure, keeping the permeation for low and middle molecules while restraining the filtration of large species. Based on dextran sieving experiments for a variety of commercially available blood purification membranes, we present a novel method for classifying blood purification membranes. By using a well-established technique and introducing a new characteristic parameter for the sieving curve--the molecular weight retention onset (MWRO)--a graph of molecular weight cut-off versus molecular weight retention onset provides the landscape of dialysis membrane types. This meaningful representation is based on only one in vitro method, and allows the membrane classification by indirectly considering two structural parameters: pore size and pore size distribution. In this way, the families of low-flux, high-flux, protein leaking, and high cut-off membranes are clearly differentiated. The differentiation allows for the definition of MWCO/MWRO regions for the different types, so that further classification of newly developed membranes can be easily achieved.

Techniques of extracorporeal cytokine removal: a systematic review of the literature on animal experimental studies

BACKGROUND AND AIMS

Extracorporeal cytokine removal may be desirable. We sought to assess extracorporeal blood purification (EBP) techniques for cytokine removal in experimental animal studies.


METHODS

We conducted a targeted, systematic search and identified 17 articles. We analyzed cytokine clearance, sieving coefficient (SC), ultrafiltrate (UF) concentration, and percentage removal. As this review concerns technical appraisal of EBP techniques, we made no attempts to appraise the methodology of the studies included. Results are in descriptive terms only.


RESULTS

Applying predicted clearance for 80 kg human, high volume hemofiltration (HVHF) techniques and plasmafiltration (PF) showed the highest rates of cytokine removal. High cutoff (HCO)/HF and PF techniques showed modest ability to clear cytokines using low to medium flows. Standard hemofiltration had little efficacy. At higher flows, HCO/HF achieved clearances between 30 and 70 ml/min for IL-6 and IL-10. There was essentially no removal of tumor necrosis factor (TNF)-alpha outside of PF.


CONCLUSIONS

Experimental animal studies indicate that HVHF (especially with HCO filters) and plasmafiltration have the potential to achieve appreciable IL-6 and IL-10 clearances. However, only PF can remove TNF-alpha reliably.

High cut-off renal replacement therapy for removal of myoglobin in severe rhabdomyolysis and acute kidney injury: a case series

BACKGROUND/AIM

Rhabdomyolysis is associated with the release of myoglobin into the circulation, promoting acute kidney injury (AKI). In severe rhabdomyolysis, dialysis-dependent AKI doubles mortality. Standard blood purification techniques have limited efficacy in removing myoglobin. We describe high cut-off (HCO) renal replacement therapy (RRT) as a novel approach for extracorporeal elimination of myoglobin in rhabdomyolysis-associated AKI.

METHODS

With an in vivo molecular cut-off at 45 kDa, HCO filters are effective in removing myoglobin (17.8 kDa). Clearances across standard and HCO filters using continuous or intermittent RRT are reviewed in a case series of 11 patients with severe rhabdomyolysis and dialysis-dependent AKI.

RESULTS

Median myoglobin clearance across standard high-flux filters was 3.3 (interquartile range 2.3-3.9) ml/min for sustained low-efficiency daily dialysis (SLEDD) batch hemodialysis (HD) and 3.7 (2.9-6.7) ml/min for conventional HD. Respective clearances using HCO filters (membrane surface area: 1.1 m(2)) were 21.7 (20.3-26.1) ml/min (SLEDD) and 44.2 (41.3-47.0) ml/min (HD). Corrected for filter size, up to 20-fold higher clearances were obtained using HCO filters, resulting in profound and sustained reduction of plasma myoglobin concentration.

CONCLUSIONS

As a novel approach, HCO RRT allows for rapid and effective removal of myoglobin from the circulation. In light of the pathogenic role in AKI, reducing exposure of the kidney to myoglobin may improve renal recovery and patient outcome. Our data pave the way for prospective trials, addressing this issue.

Techniques of extracorporeal cytokine removal: a systematic review of the literature

BACKGROUND AND AIMS

Attempts at achieving cytokine homeostasis include blood purification to deliver cytokine removal. Assessment of ex vivo studies for optimal operating conditions is a vital step.

METHODS

We conducted a systematic search for ex vivo studies on cytokine removal using known modalities of extracorporeal circulation. We selected 29 articles and analyzed data according to clearance, sieving coefficient, ultrafiltrate concentration and percentage removal.

RESULTS

We identified four main techniques for cytokine removal: standard techniques, high cut-off (HCO) techniques, adsorption techniques and combined plasma filtration adsorption. HCO hemofiltration (HCO/HF) showed greatest consistency in cytokine removal among all approaches. Mean albumin clearance with HCO filters was 3.74 ml/min.

CONCLUSION

Ex vivo data support the view that HCO/HF is the most consistently effective approach in terms of sieving and clearance. Further investigation of HCO/HF in randomized controlled trials in animal models and humans seems desirable.

Extracorporeal therapies in sepsis

The treatment of sepsis is an ongoing challenge for clinicians; despite the wide choice of effective antibiotics to treat infection, sepsis remains the leading cause of morbidity and mortality for patients admitted to an intensive care unit. Dysregulation of the immune response is now recognized to be a key factor in multiple organ dysfunction, yet our therapy for inflammation remains ineffective. It has been advocated for more than a decade that cytokine reduction in blood compartment could lead to a reduction in mortality in sepsis. Over the years, multiple extracorporeal techniques have evolved, with the intent of influencing the circulating levels of inflammatory mediators like cytokines and chemokines, the complement system, as well as factors of the coagulation system. These include high-volume hemofiltration, use of high cutoff membranes, and systems based on adsorption, such as coupled plasma filtration adsorption and the polymyxin-B column. In addition, new experimental systems that utilize human phagocytic cells and immobilized antibodies for targeted immunomodulation have emerged. In the context of limited resources and growing expansion in the availability of technologies, a better understanding of these therapies is required before they can be properly integrated into standard clinical practice in the hope of influencing major clinical outcomes. In this article, we will provide a concise overview of selected extracorporeal modalities currently in clinical use and briefly introduce some new promising techniques for sepsis.

Evaluation of a new polysulfone hemofilter for continuous renal replacement therapy

New strategies using continuous renal replacement therapy as a tool to achieve immunomodulation in septic acute kidney injury have been proposed. The hypothesis is based on the possibility to remove inflammatory mediators and oxidants in a wide spectrum of molecular weights, thanks to new, highly permeable synthetic membranes. A new polysulfone hemofilter with high permeability and a sharp high cut-off membrane (CUREFLO™; Asahi Kasei Kuraray Medical Co., Ltd., Tokyo, Japan) has been evaluated in this study to assess IL-6 and advanced oxidation protein product removal in critically ill patients undergoing continuous renal replacement therapy. Unit performance, sieving coefficients and clearances were evaluated in fourteen patients undergoing continuous veno-venous hemofiltration and continuous veno-venous hemodialysis.

High cut-off dialysis membranes: current uses and future potential

The removal of larger uremic toxins by conventional dialysis membranes is restricted by their molecular weight cut-offs. The recent availability of a new generation of hemodialysis membranes with molecular weight cut-offs closer to that of the native kidney (65 kDa) has led to work assessing their potential utility across several different clinical scenarios. Initially designed to remove proinflammatory cytokines in patients with severe sepsis syndrome, clinicians are now using these membranes for the treatment of myeloma kidney and rhabdomyolysis. Further early pilot studies have demonstrated a potential utility for the removal of larger middle molecules in the population with end-stage renal failure. The purpose of this review was to summarize the current evidence base for the use of high cut-off hemodialysis membranes and discuss their future clinical relevance.

Clinical review: blood purification for sepsis

Sepsis is the primary cause of death in the intensive care unit. Extracorporeal blood purification therapies have been proposed for patients with sepsis in order to improve outcomes since these therapies can alter the host inflammatory response by non-selective removal of inflammatory mediators or bacterial products or both. Recent technological progress has increased the number of techniques available for blood purification and their performance. In this overview, we report on the latest advances in blood purification for sepsis and how they relate to current concepts of disease, and we review the current evidence for high-volume hemofiltration, cascade hemofiltration, hemoadsorption, coupled plasma filtration adsorption, high-adsorption hemofiltration, and high-cutoff hemofiltration/hemodialysis. Promising results have been reported with all of these blood purification therapies, showing that they are well tolerated, effective in clearing inflammatory mediators or bacterial toxins (or both) from the plasma, and efficacious for improvement of various physiologic outcomes (for example, hemodynamics and oxygenation). However, numerous questions, including the timing, duration, and frequency of these therapies in the clinical setting, remain unanswered. Large multicenter trials evaluating the ability of these therapies to improve clinical outcomes (that is, mortality or organ failure), rather than surrogate markers such as plasma mediator clearance or transient improvement in physiologic variables, are required to define the precise role of blood purification in the management of sepsis.

Intensive care unit-acquired weakness (ICUAW) and muscle wasting in critically ill patients with severe sepsis and septic shock

Sepsis presents a major health care problem and remains one of the leading causes of death within the intensive care unit (ICU). Therapeutic approaches against severe sepsis and septic shock focus on early identification. Adequate source control, administration of antibiotics, preload optimization by fluid resuscitation and further hemodynamic stabilisation using vasopressors whenever appropriate are considered pivotal within the early-golden-hours of sepsis. However, organ dysfunction develops frequently in and represents a significant comorbidity of sepsis. A considerable amount of patients with sepsis will show signs of severe muscle wasting and/or ICU-acquired weakness (ICUAW), which describes a frequently observed complication in critically ill patients and refers to clinically weak ICU patients in whom there is no plausible aetiology other than critical illness. Some authors consider ICUAW as neuromuscular organ failure, caused by dysfunction of the motor unit, which consists of peripheral nerve, neuromuscular junction and skeletal muscle fibre. Electrophysiologic and/or biopsy studies facilitate further subclassification of ICUAW as critical illness myopathy, critical illness polyneuropathy or critical illness myoneuropathy, their combination. ICUAW may protract weaning from mechanical ventilation and impede rehabilitation measures, resulting in increased morbidity and mortality. This review provides an insight on the available literature on sepsis-mediated muscle wasting, ICUAW and their potential pathomechanisms.

Review article: Renal support in critical illness

PURPOSE

This review provides a focused and comprehensive update on established and emerging evidence in acute renal replacement therapy (RRT) for critically ill patients with acute kidney injury (AKI).

PRINCIPAL FINDINGS

There have been considerable technological innovations in the methods and techniques for provision of extracorporeal RRT in critical illness. These have greatly expanded our capability to provide both renal and non-renal life-sustaining organ support for critically ill patients. Recent data suggest earlier initiation of RRT in AKI may confer an advantage for survival and renal recovery. Two large trials have recently shown no added benefit to augmented RRT dose delivery in AKI. Observational data have also suggested that fluid accumulation in critically ill patients with AKI is associated with worse clinical outcome. However, several fundamental clinical questions remain to be answered, including issues regarding the time to ideally initiate/discontinue RRT, the role of high-volume hemofiltration or other blood purification techniques in sepsis, and extracorporeal support for combined liver-kidney failure. Extracorporeal support with RRT in sepsis, rhabdomyolysis, and liver failure are discussed, along with strategies for drug dosing and management of RRT in sodium disorders.

CONCLUSIONS

We anticipate that this field will continue to expand to promote research and innovation, hopefully for the benefit of sick critically ill patients.

Use of preconditioned human phagocytes for extracorporeal adsorption of viruses

Conventional treatment of severe viral disease is limited by the narrow choice as well as the often-significant side effects or lack of clear efficacy of antiviral chemotherapy. At the same time, however, it is known that a reduction in viral load leads to significant clinical improvement in a number of important viral diseases. In this paper we discuss the possibility of using preconditioned human phagocytes in an extracorporeal biohybrid system for adsorption of viral pathogens. We present data from in vitro experiments testing adsorption of an enterovirus and of hepatitis B virus (HBV) by a preconditioned human promyelocytic cell line. While no clearance of HBV could be detected, the results revealed a near elimination of enterovirus with the cell line displaying robust viability. Enterovirus titers of 1000 (reciprocal) were reduced to a mean titer of 10(0.6) CCID(50) with no virus detectable after adsorption in two out of five samples. Titers of 10000 (reciprocal) were in turn reduced to a mean of 10(1.4) CCID(50). The kinetics of the process was remarkable with this near elimination of the pathogen occurring within only 15min. Extracorporeal viral adsorption by a cellular biohybrid system appears feasible. Pairing target pathogens with suitable cell lines may offer a versatile antiviral technology.

Differences in cytokine levels due to gender in colorectal cancer patients

INTRODUCTION

Female gender is associated with longer survival after treatment for colorectal cancer (CRC). Reasons behind this phenomenon are not entirely clear. In addition, higher interleukin-6 (IL-6) and interleukin-1 (IL-1) levels have been found to be associated with poorer prognosis in CRC patients. The aim of this study was to investigate if cytokine levels were different in male and female CRC patients.

METHODS

Pre- and post-operative levels of IL-1, interleukin-1 receptor antagonist (IL-1ra), IL-6 and tumour necrosis factor-alpha (TNF-alpha) were measured using standard solid phase sandwich ELISA in 104 consecutive eligible patients undergoing elective resection for CRC.

RESULTS

Seventy (67.3%) participants were male and the mean age of the group was 67.6years (standard deviation 10.4years, range 39-86years). Pre-operative IL-1beta and post-operative IL-6 levels were significantly higher in males compared with females (U=486.5, p=0.03, U=424, p=0.04), values approaching statistical significance were obtained for pre-operative IL-6 (U=508.5, p=0.06) and post-operative IL-1beta (U=448, p=0.07). Differences in the levels of TNF-alpha and IL-1ra were not statistically significant. Multiple regression analysis using TNM stage as a covariate, showed that gender was an independent predictor of post-operative IL-6 levels (p=0.04).

CONCLUSION

IL-1beta and IL-6 levels were significantly higher in men than in women. This provides evidence of a possible link between gender and cytokine levels in patients with colorectal cancer.

Combination of hemofiltration and peritoneal dialysis in the treatment of severe acute pancreatitis

OBJECTIVE

Our aim was to study the therapeutic effects and the mechanism of combination of hemofiltration (HF) and peritoneal dialysis (PD) in the treatment of severe acute pancreatitis (SAP).

METHODS

Fifty-one cases of SAP were randomly divided into the HF+PD group (treated group, 36 patients) and the non-HF+PD group (control group, 15 patients). Both groups were treated by the same traditional methods. The relief time of abdominal pain and abdominal distension, computed tomographic scores, acute physiology and chronic health enquiry II scores, length of stay, cost of hospitalization, operability, and recovery rate of the 2 groups were compared. The concentration of tumor necrosis factor-alpha, IL-6, and IL-8 in serum and ascites volumes was determined before and after treatment.

RESULTS

: The mean time of abdominal pain relief, amelioration of abdominal distension, decrease of computed tomographic scores, acute physiology and chronic health enquiry II scores, the mean length of stay, and cost of hospitalization of the treated group were significantly shorter or less than those of the control group. The aforementioned inflammatory cytokines, detected at the end of 1 day and 2 days after HF+PD treatment, were decreased significantly compared with those observed in pretherapy and the control group.

CONCLUSIONS

Inflammatory cytokines, which overproduced in SAP, can be eliminated effectively from the blood and the ascites by HF+PD treatment.

The role of hypercytokinemia in the pathophysiology of tumor lysis syndrome (TLS) and the treatment with continuous hemodiafiltration using a polymethylmethacrylate membrane hemofilter (PMMA-CHDF)

OBJECTIVE

To examine the role of hypercytokinemia in the pathophysiology of tumor lysis syndrome (TLS) and the efficacy of continuous hemodiafiltration in the treatment of TLS.

DESIGN AND SETTING

Retrospective observational study in a general intensive care unit of a university hospital.

PATIENTS

Four patients with hematological disorder developing TLS after the treatment of anti-tumor chemotherapy.

INTERVENTIONS

Continuous hemodiafiltration using a polymethylmethacrylate membrane hemofilter (PMMA-CHDF) was performed at the onset of TLS. Blood samples were collected daily after ICU admission, and clinical parameters and blood levels of cytokines were evaluated.

MEASUREMENTS AND RESULTS

All four patients underwent induction anti-tumor chemotherapy, during which they developed hyperuricemia, hyperkalemia, and acute renal failure. Two of them also developed multiple organ failure. Serum levels of tumor necrosis factor (TNF) -alpha, interleukin-6 (IL-6), and IL-10 prior to the initiation of PMMA-CHDF were 102+/-85 pg/mL, 1097+/-546 pg/mL, and 98+/-83 pg/mL, respectively (mean +/- SD). After three days of PMMA-CHDF treatment, corresponding blood levels were 37+/-55 pg/mL, 326+/-511pg/mL, and 9+/-8 pg/mL, respectively. Thus, all cytokine levels were significantly decreased by three days of PMMA-CHDF treatment (p<0.05, paired t-test). Following three days of PMMA-CHDF treatment, blood urea nitrogen (BUN) and serum creatinine (Cre.) were significantly decreased (pre/post BUN 42.3+/-15.4/16.5+/-8.4 mg/dL, p<0.05, pre/post Cre. 2.7+/-1.2/1.2+/-0.6 mg/dL, mean +/- SD, p<0.05). Furthermore, the clinical condition of each patient was improved after the treatment of PMMA-CHDF, and all of four patients were survived.

CONCLUSION

Hypercytokinemia plays a pivotal role in the pathophysiology of TLS and PMMA-CHDF may be an effective therapeutic modality for TLS patients not only as renal replacement therapy but also as a cytokine modulator.