A new endotoxin adsorber in septic shock: observational case series

Kinetics of Different Blood Biomarkers during Polymyxin-B Extracorporeal Hemoperfusion in Abdominal Sepsis

INTRODUCTION

Comparison of the marker kinetics procalcitonin, presepsin, and endotoxin during extracorporeal hemoperfusion with polymyxin-B adsorbing cartridge (PMX-HA) has never been described in abdominal sepsis. We aimed to compare the trend of three biomarkers in septic post-surgical abdominal patients in intensive care unit (ICU) treated with PMX-HA and their prognostic value.

METHODS

Ninety abdominal post-surgical patients were enrolled into different groups according to the evidence of postoperative sepsis or not. Non-septic patients admitted in the surgical ward were included in C group (control group). ICU septic shock patients with endotoxin levels <0.6 EAA receiving conventional therapy were addressed in S group and those with endotoxin levels ≥0.6 EAA receiving treatment with PMX-HA, besides conventional therapy, were included in SPB group. Presepsin, procalcitonin, endotoxin and other clinical data were recorded at 24 h (T0), 72 h (T1) and 7 days (T2) after surgery. Clinical follow-up was performed on day 30.

RESULTS

SPB group showed reduced levels of the three biomarkers on T2 versus T0 (p < 0.001); presepsin, procalcitonin and endotoxin levels decreased, respectively, by 25%, 11%, and 2% on T1 versus T0, and 40%, 41%, and 26% on T2 versus T0. All patients in C group, 73% of patients in SPB group versus 37% of patients in S group survived at follow-up. Moreover, procalcitonin had the highest predictive value for mortality at 30 days, followed by presepsin.

CONCLUSION

The present study showed the reliability of presepsin in monitoring PMX-HA treatment in septic shock patients. Procalcitonin showed better predicting power for the mortality riSsk.

Challenges in Septic Shock: From New Hemodynamics to Blood Purification Therapies

Sepsis and septic shock are associated with high mortality, with diagnosis and treatment remaining a challenge for clinicians. Their management classically encompasses hemodynamic resuscitation, antibiotic treatment, life support, and focus control; however, there are aspects that have changed. This narrative review highlights current and avant-garde methods of handling patients experiencing septic shock based on the experience of its authors and the best available evidence in a context of uncertainty. Following the first recommendation of the Surviving Sepsis Campaign guidelines, it is recommended that specific sepsis care performance improvement programs are implemented in hospitals, i.e., "Sepsis Code" programs, designed ad hoc, to achieve this goal. Regarding hemodynamics, the importance of perfusion and hemodynamic coherence stand out, which allow for the recognition of different phenotypes, determination of the ideal time for commencing vasopressor treatment, and the appropriate fluid therapy dosage. At present, this is not only important for the initial timing, but also for de-resuscitation, which involves the early weaning of support therapies, directed elimination of fluids, and fluid tolerance concept. Finally, regarding blood purification therapies, those aimed at eliminating endotoxins and cytokines are attractive in the early management of patients in septic shock.

Extracorporeal blood purification strategies in sepsis and septic shock: An insight into recent advancements

BACKGROUND

Despite various therapies to treat sepsis, it is one of the leading causes of mortality in the intensive care unit patients globally. Knowledge about the pathophysiology of sepsis has sparked interest in extracorporeal therapies (ECT) which are intended to balance the dysregulation of the immune system by removing excessive levels of inflammatory mediators.

AIM

To review recent data on the use of ECT in sepsis and to assess their effects on various inflammatory and clinical outcomes.

METHODS

In this review, an extensive English literature search was conducted from the last two decades to identify the use of ECT in sepsis. A total of 68 articles from peer-reviewed and indexed journals were selected excluding publications with only abstracts.

RESULTS

Results showed that ECT techniques such as high-volume hemofiltration, coupled plasma adsorption/filtration, resin or polymer adsorbers, and CytoSorb^® are emerging as adjunct therapies to improve hemodynamic stability in sepsis. CytoSorb^® has the most published data in regard to the use in the field of septic shock with reports on improved survival rates and lowered sequential organ failure assessment scores, lactate levels, total leucocyte count, platelet count, interleukin- IL-6, IL-10, and TNF levels.

CONCLUSION

Clinical acceptance of ECT in sepsis and septic shock is currently still limited due to a lack of large random clinical trials. In addition to patient-tailored therapies, future research developments with therapies targeting the cellular level of the immune response are expected.

Recent advances in the pharmacological management of sepsis-associated acute kidney injury

INTRODUCTION

Acute kidney injury is a common occurrence in patients with sepsis and portends a high mortality as well as increased morbidity with numerous sequelae including the development of chronic kidney disease. Currently, there are no specific therapies that either prevent AKI or hasten its recovery. Thus, clinicians typically rely on management of the underlying infection, optimization of hemodynamic parameters as well as avoidance of nephrotoxins to maximize outcomes.

AREAS COVERED

Recent advances in understanding the mechanisms of sepsis as well as how these pathways may interact to lead to acute kidney injury have opened the door to the development of new, targeted therapies. This review focuses on the operative pathways in sepsis that have been identified as critical in leading to acute kidney injury and associated therapeutic agents that target these pathways.

EXPERT OPINION

Despite increased understanding of the pathogenesis of sepsis, development of effective therapeutics to decrease the incidence of AKI have lagged. This is likely due to the complex pathophysiology with overlapping pathways and need for multiple therapies guided by specific biomarkers. Biomarkers that detail operative pathways may be able to guide the institution of more specific therapies with the hope for improved outcomes.

Advances in the Development of Biomaterials for Endotoxin Adsorption in Sepsis

Sepsis, a life-threatening and intractable disease without any specific treatment, is activated by endotoxin. Some attempts at removing endotoxin to treat sepsis from the blood circulation using different hemoperfusion cartridges have been proposed recently, but they have failed to reduce the mortality of severe septic patients. This review summarizes the latest advances in the development of endotoxin adsorbents. In particular, we highlight two critical parameters for endotoxin adsorbents when they are applied in blood purification: the dissociation constant and the maximum adsorption capacity. We also discuss potential challenges and research directions for the future development of endotoxin adsorbents.

Endotoxin Removal in Septic Shock with the Alteco LPS Adsorber Was Safe But Showed no Benefit Compared to Placebo in the Double-Blind Randomized Controlled Trial-the Asset Study

PURPOSE

Lipopolysaccharides (LPS) are presumed to contribute to the inflammatory response in sepsis. We investigated if extracorporeal Alteco LPS Adsorber for LPS removal in early gram-negative septic shock was feasible and safe. Also, effects on endotoxin level, inflammatory response, and organ function were assessed.

METHODS

A pilot, double-blinded, randomized, Phase IIa, feasibility clinical investigation was undertaken in six Scandinavian intensive care units aiming to allocate 32 septic shock patients with abdominal or urogenital focus on LPS Adsorber therapy or a Sham Adsorber, therapy without active LPS binding. The study treatment was initiated within 12 h of inclusion and given for 6 h daily on first 2 days. LPS was measured in all patients.

RESULTS

The investigation was terminated after 527 days with eight patients included in the LPS Adsorber group and seven in the Sham group. Twenty-one adverse effects, judged not to be related to the device, were reported in three patients in the LPS Adsorber group and two in the Sham group. Two patients in the Sham group and no patients in the LPS Adsorber group died within 28 days. Plasma LPS levels were low without groups differences during or after adsorber therapy. The changes in inflammatory markers and organ function were similar in the groups.

CONCLUSIONS

In a small cohort of patients with presumed gram-negative septic shock, levels of circulating endotoxin were low and no adverse effects within 28 days after LPS adsorber-treatment were observed. No benefit compared with a sham device was seen when using a LPS adsorber in addition to standard care.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02335723. Registered: November 28, 2014.

Endotoxin and cytokine reducing properties of the oXiris membrane in patients with septic shock: A randomized crossover double-blind study

BACKGROUND

Endotoxin induces an inflammatory response, with secondary release of cytokines, which can progress to shock and multiple organ failure. We explored whether continuous renal replacement therapy (CRRT) using a modified membrane (oXiris) capable of adsorption could reduce endotoxin and cytokine levels in septic patients.

METHODS

Sixteen patients requiring CRRT for septic shock-associated acute renal failure and who had endotoxin levels >0.03 EU/ml were prospectively randomized in a crossover double-blind design to receive CRRT with an oXiris filter or with a standard filter. Endotoxin and cytokine levels were measured at baseline and 1, 3, 8, 16 and 24 hours after the start of CRRT. Norepinephrine infusion rate and blood lactate levels were monitored.

RESULTS

During the first filter treatment period, endotoxin levels decreased in 7 of 9 (77.8%) oXiris filter patients, but in only 1 of 6 (16.7%) standard filter patients (P = 0.02). Levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8 and interferon (IFN)γ decreased more with the oXiris filter than with the standard filter. Lactate concentration decreased with oXiris (-1.3[-2.2 to -1.1] mmol/l, P = 0.02), but not with the standard filter (+0.15[-0.95 to 0.6]). The norepinephrine infusion rate was reduced during oXiris CRRT, but not during standard filter CRRT. In the second filter treatment period, there was no significant reduction in endotoxin or cytokine levels in either group.

CONCLUSIONS

CRRT with the oXiris filter seemed to allow effective removal of endotoxin and TNF-α, IL-6, IL-8 and IFNγ in patients with septic shock-associated acute renal failure. This may be associated with beneficial hemodynamic effects.

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.

Challenges in the management of septic shock: a narrative review

While guidelines provide important information on how to approach a patient in septic shock, "many challenges remain" for the management of these patients. In this narrative review, the panel discusses the challenges in identifying the right hemodynamic target, optimization of fluid therapy, selection of vasopressor agents, identification of patients who may benefit from inotropic agents or on the contrary beta-blockade, and use of steroids. The place for microcirculation-targeted therapy is debated as well as the use of alternative techniques (blood purification) and therapies (vitamin C). The implications of hemodynamic alterations on antibiotic doses is discussed. Finally, the specific challenges in low- and middle-income countries are addressed. Ongoing trials address some of these challenges, but many uncertainties will remain, and individualized therapies based on careful clinical assessment will continue to be essential to optimizing the care of patients with septic shock.

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.

Biocompatibility and Cytotoxic Evaluation of New Sorbent Cartridges for Blood Hemoperfusion

BACKGROUND/AIMS

The use of adsorption cartridges for hemoperfusion (HP) is rapidly evolving. For these devices, the potential induced cytotoxicity is an important issue. The aim of this study was to investigate potential in vitro cytotoxic effects of different sorbent cartridges, HA130, HA230, HA330, HA380 (Jafron, China), on U937 monocytes.

METHODS

Monocytes were exposed to the sorbent material in static and dynamic manners. In static test, cell medium samples were collected after 24 h of incubation in the cartridges. In dynamic test, HP modality has been carried out and samples at 30, 60, 90, and 120 min were collected.

RESULTS

Compared to control samples, there was no evidence of increased necrosis or apoptosis in monocytes exposed to the cartridges both in the static and dynamic tests.

CONCLUSION

Our in vitro testing suggests that HA cartridges carry an optimal level of biocompatibility and their use in HP is not associated with adverse reactions or signs of cytotoxicity.

The Use of Endotoxin Adsorption in Extracorporeal Blood Purification Techniques. A Case Report

Sepsis and septic shock are major healthcare problems, resulting in high morbidity and mortality. The Surviving Sepsis Campaign (SSC), which standardised the approach to sepsis, was recently updated. Strategies to decrease the systemic inflammatory response have been proposed to modulate organ dysfunctions. Endotoxin, derived from the membrane of Gram-negative bacteria, is considered a major factor in the pathogenesis of sepsis. Endotoxin adsorption, if effective, has the potential to reduce the biological cascade of Gram-negative sepsis. We present a case of a 64-year-old man with severe Gram-negative sepsis, following purulent peritonitis secondary to rectosigmoid adenocarcinoma. To reduce the amplitude of the general effects of endotoxins we used a novel device, the Alteco® LPS Adsorber (Alteco Medical AB, Lund, Sweden), for lipopolysaccharide (LPS) adsorption. The efficacy markers were: the overall haemodynamic profile, translated into decreased vasopressor requirements, the normalisation of the cardiac index, the systemic vascular resistance index combined with the lactate level and the reduction in procalcitonin (PCT) levels. A decrease in the sequential organ failure assessment (SOFA) score at twenty-four hours was demonstrated. The clinical course following treatment was favourable for the days immediately following the treatment.This was attributed to the removal of endotoxin from the systemic circulation. The patient died one week after the endotoxin removal session, developing an ischemic bowel perforation with subsequent multiple organ failures.

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.

Abdominal Septic Shock - Endotoxin Adsorption Treatment (ASSET) - endotoxin removal in abdominal and urogenital septic shock with the Alteco® LPS Adsorber: study protocol for a double-blinded, randomized placebo-controlled trial

Background

Severe sepsis and septic shock are common in intensive care and carry high mortality rates. In patients with Gram-negative infections, early and extensive removal of endotoxin may limit the inflammatory response that characterizes septic shock. The Alteco® LPS Adsorber (hereafter referred to cited as the lipopolysaccharide (LPS) Adsorber) can be used for endotoxin removal and attenuate the deleterious inflammatory and clinical responses seen in septic shock.

Methods/design

The Abdominal Septic Shock – Endotoxin Adsorption Treatment (ASSET) trial is a pilot study investigating the feasibility and safety of LPS Adsorber therapy. This pilot, multicenter, stratified, parallel, double-blinded, randomized, phase IIa, feasibility clinical investigation will be performed in five Scandinavian intensive care units. Thirty-two subjects with early septic shock and organ failure, following adequate resuscitation, will be randomized to receive either: extracorporeal veno-venous hemoperfusion therapy with the LPS Adsorber or veno-venous hemoperfusion therapy with a placebo adsorber (without active LPS-binding peptide). Patients will be stratified by infection focus such that 20 subjects with an abdominal focus (stratum A) and 12 subjects with a urogenital focus (stratum B) will be included in a parallel design. Thereafter, an interim analysis will be performed and an additional 12 patients may be included in the study. The study is designed as adaptive a priori: the patients from this study can be included in a later phase IIb study. The aim of the study is to investigate the feasibility of LPS Adsorber therapy commenced early in the time-course of septic shock. The primary endpoint will be a characterization of all reported unanticipated serious adverse device effects and anticipated serious adverse device effects. Secondary outcomes are decrease in endotoxin plasma concentration, impact on clinical outcome measures and impact on inflammatory response by LPS Adsorber therapy, as well as detailed description of the relevant mediators bound to the LPS Adsorber. Recruitment of patients will start in September 2015.

Discussion

The ASSET trial will give insight into the feasibility and safety of this LPS Adsorber therapy and preliminary data on its potential clinical effects in septic shock. Moreover, this pilot trial will provide with necessary data for designing future studies.

Trial registration

ClinicalTrials.gov Identifier NCT02335723. Registered on 28 November 2014.

Endotoxin Elimination in Patients with Septic Shock: An Observation Study

To evaluate the effectiveness of endotoxin elimination with an adsorption column in patients with septic shock and endotoxemia. The elimination therapy was guided by a new bedside method of measuring endotoxin activity (EA). Intensive care unit (ICU) patients with septic shock and suspected Gram-negative infection were consecutively added to the study group within the first 24 h. Endotoxin elimination was performed using hemoperfusion with the Alteco LPS Adsorber. The primary endpoint was improvement in organ function within the first 24 h of treatment. A secondary objective was to assess the usefulness of a new method of measuring EA to help guide endotoxin elimination therapy. Out of 64 patients 18 had a high baseline EA [0.70 EA units (0.66–0.77)]. Those patients had endotoxin elimination treatment in addition to conventional medical therapy. At 24 h after endotoxin elimination, the EA had decreased to 0.56 EA units (0.43–0.77), (p = 0.005); MAP increased from 69 (62–80) to 80 mm Hg (68–88), (p = 0.002), and noradrenaline use decreased from 0.28 (0.15–0.80) to 0.1 μg/kg/min (0.00–0.70) at the same time (p = 0.04). The SOFA score had decreased from 11 (9–15) to 9 (7–14) points 24 h after endotoxin elimination (p = 0.01) with a median delta SOFA –2 points. Endotoxin elimination did not have a significant effect on the ICU length of stay or ICU mortality. Effective endotoxin elimination resulted in a significant improvement in hemodynamic parameters and of organ function. The application of the EA assay was useful for the bedside monitoring of endotoxemia in critically ill ICU patients.

Alteco endotoxin hemoadsorption in Gram-negative septic shock patients

Background and Aims:

Severe sepsis and septic shock are common causes of mortality and morbidity in an intensive care unit setting. Endotoxin, derived from the outer membranes of Gram-negative bacteria, is considered a major factor in the pathogenesis of sepsis. This study investigated the effect of Alteco endotoxin hemoadsorption device on Gram-negative septic shock patients.

Materials and Methods:

An open, controlled, prospective, randomized, single-center trial was conducted between February 2010 and June 2012. Patients with septic shock due to intra-abdominal sepsis were randomized to either conventional therapy (n = 8) or conventional therapy plus two 2-hourly sessions of Alteco endotoxin hemoadsorption (n = 7). Primary endpoint was the Sequential Organ Failure Assessment (SOFA) score changes from 0 to 72 h. Secondary end points included vasopressor requirement, PaO₂/FiO₂ ratio (PFR), length of stay (LOS), and 28-day mortality.

Results:

This study was terminated early as interim analysis showed a low probability of significant findings. No significant difference was noted between the two groups with respect to change in SOFA score, vasopressor score, PFR, LOS, and 28-day mortality. Side-effect was minimal.

Conclusions:

We could not identify any clinical benefit on the addition of Alteco endotoxin hemoadsorption to conventional therapy in patients who suffered from intra-abdominal sepsis with shock. The side effect profile of this novel device was acceptable.

Endotoxin adsorption using polymyxin B immobilized fiber cartridges in severe sepsis patients following cardiac surgery

INTRODUCTION

Sepsis still represents an obstacle in modern medicine. The purpose of this study was to evaluate the safety and effectiveness of selective lipopolysaccharide (LPS)-adsorption therapy using polymyxin B immobilized fiber cartridges in adult patients complicated with severe sepsis after cardiac surgery.

METHODS

65 patients received extracorporeal LPS-adsorption procedures using Toraymyxin columns (PMX; Toray, Tokyo, Japan) in addition to the standard treatment according to the Surviving Sepsis Campaign guidelines. The inclusion criteria were clinical signs of severe sepsis, endotoxin activity assay (EAA)≥0.6, and blood plasma procalcitonin (PCT)>2 ng/ml. For the control group, we selected 40 patients who were comparable with the study group but who received only the standard therapy.

RESULTS

Each patient received 2 standard LPS-adsorption procedures (lasting for 120 min each). After the LPS-adsorption course, we noted any indices of hemodynamic improvements, including an increase in mean arterial pressure from 73 to 89 mmHg (p<0.001), mean oxygenation index (213-265, p<0.001. We observed a decrease in LPS concentrations by the EAA (0.71-0.55, p<0.001) and by the LAL test (1.44-0.36 EU/ml, p<0.001). In the control group, there were no significant changes in any of the studied parameters. Moreover, the 28-day mortality was 42% in the study group and 65% in the control group (p=0.032). The endotoxin adsorption procedures were not associated with any adverse reactions, and specifically, no extracorporeal circuit thrombosis cases were noted.

CONCLUSIONS

Selective LPS-adsorption is a safe and possibly effective adjunctive treatment method for severe sepsis patients.

Endotoxin adsorbents in extracorporeal blood purification: do they fulfill expectations?

INTRODUCTION

Lipopolysaccharides (LPS) are extremely strong stimulators of inflammatory reactions, act at very low concentrations, and are involved in the pathogenesis of sepsis and septic shock. Because of its toxicity, the efficient removal of endotoxin from patients' blood is very important in clinical medicine. The purpose of this study was to determine the endotoxin adsorption capacities of commercial endotoxin adsorbers for endotoxin removal in buffer solution, protein solution, serum and heparinized plasma; some of these were also characterized in whole blood. The tested LPS adsorbers were Toraymyxin® PMX-20R, Alteco® LPS Adsorber, DEAE-Sepharose, Polymyxin B-Agarose, and EndoTrap® red.

METHODS

The adsorber materials were tested in buffer and protein solutions spiked with fluorescently labeled LPS (100 ng/ml). Additionally, batch tests with LPS-spiked serum, heparinized plasma and whole blood were performed with an LPS concentration of 5 ng/ml. Additionally, the washing solutions of the two tested Polymyxin B (PMB)-based adsorbers were analyzed for PMB release to determine if the resulting LPS inactivation was caused by PMB leakage.

RESULTS

The results show that DEAE-Sepharose was most effective in LPS adsorption. Of the other tested endotoxin removal materials, only the PMB-based adsorbers were able to reduce the LPS activity. However, we were able to show that the reduction in LPS activity was caused by desorbed PMB, which inactivates endotoxins.

CONCLUSIONS

None of the adsorbents that were tested in this study showed promising results for potential use in extracorporeal blood purification.

Immunomodulation in sepsis: the role of endotoxin removal by polymyxin B-immobilized cartridge

Severe sepsis results in high morbidity and mortality. Immunomodulation strategies could be an adjunctive therapy to treat sepsis. Endotoxin is a component of gram-negative bacteria and plays an important role in the pathogenesis of septic shock when it is recognized by immune cells. Removal of endotoxin could be an effective adjunctive approach to the management of sepsis. Devices to adsorb endotoxin or inflammatory cytokines have been designed as a strategy to treat severe sepsis, especially sepsis caused by gram-negative bacteria. Polymyxin B-immobilized cartridge has been successfully used to treat patients with sepsis of abdominal origin. Although this cartridge was conceived to adsorb endotoxin, several other immunological mechanisms have been elucidated, and this device has also yielded promising results in patients with nonseptic respiratory failure. In this paper, we summarize the immune modulation actions of Polymyxin B-immobilized cartridge to explore its potential usefulness beyond endotoxin elimination.