An update on membranes and cartridges for extracorporeal blood purification in sepsis and septic shock

Hemadsorption with CytoSorb in Infants with Sepsis: Non-Systematic Review of Cases

Sepsis is a severe and potentially life-threatening condition that occurs when the body's response to an infection damages its own tissues and organs. It can lead to organ failure and death if not treated. Cytosorb is a promising medical device for hemadsorption in pediatric septic patients (under 18 years old). As many studies conclude, Cytosorb results in efficient hemodynamics stabilization. This paper is a nonsystematic review of cases. PubMed-, Google Scholar-, and Scopus-indexed journals were used to collect papers for the research. Overall, 11 pediatric cases (six journal articles) were collected. Reductions in interleukin (IL)-6 and IL-10 levels after hemoperfusion with CytoSorb suggest a potential benefit in modulating the inflammatory response in pediatric patients. Moreover, other septic shock indicators such as C-reactive protein, lactate, procalcitonin, ALT, and AST were also significantly reduced in surviving patients within the first few hours of hemadsorption with CytoSorb. The use of CytoSorb seems to be efficient in managing different sepsis-related conditions, even in neonatal and infant populations, as a valuable supplementary tool. However, overcoming the obstacles associated with the age and weight of pediatric patients might necessitate the creation of CytoSorb devices tailored specifically to their needs.

Adverse outcomes with extracorporeal adsorbent blood treatments in toxic systemic inflammation: a perspective on possible mechanisms

BACKGROUND

Extracorporeal blood purification (EBP) treatments may be used in patients with sepsis and related conditions to mitigate toxic systemic inflammation, prevent or reverse vital organ injury, and improve outcome. These treatments lack demonstrable efficacy, but are generally considered safe. However, since late 2020, four clinical studies of EBP treatment using adsorbent devices in inflammatory disease reported significantly increased patient mortality associated with the adsorbent treatments. Criticisms of study design and execution were published, but revealed no decisive flaws. None of these critiques considered possible toxic effects of the adsorbent treatments per se.

PERSPECTIVE AND CONCLUSION

In adsorbent EBP treatment of systemic inflammatory disease the adsorbent media are deployed in patient blood or plasma flow for the purpose of broad spectrum, non-specific adsorptive removal of inflammatory mediators. Adsorption and sequestration of inflammatory mediators by adsorbent media is intended to reduce mediator concentrations in circulating blood and neutralize their activity. However, in the past two decades developments in both biomedical engineering and the science of cytokine molecular dynamics suggest that immobilization of inflammatory proteins on solid scaffolds or molecular carriers may stabilize protein structure and preserve or amplify protein function. It is unknown if these mechanisms are operative in EBP adsorbent treatments. If these mechanisms are operative, then the adsorbent medium could become reactive, promoting inflammatory activity which could result in negative outcomes. Considering the recent reports of harm with adsorbent treatments in diverse inflammatory conditions, caution urges investigation of these potentially harmful mechanisms in these devices. Candidate mechanisms for possible inquiry are discussed.

Evidence-based updates to the 2021 Surviving Sepsis Campaign guidelines: Part 1: Background, pathophysiology, and emerging treatments

ABSTRACT

Sepsis identification and treatment has changed significantly over the last few decades. Despite this, sepsis is still associated with significant morbidity and mortality. This first of a two-part series reviews the history of modern sepsis and presents new research in pathophysiology, treatment, and postsepsis care.

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

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

Application of Adsorptive Blood Purification Techniques during Cardiopulmonary Bypass in Cardiac Surgery

By reason of surgical demand, the majority of cardiovascular procedures still depend on the use of cardiopulmonary bypass (CPB). Due to the nonphysiological state of CPB, it can cause complex and unpredictable inflammatory response, which may lead to significant morbidity and mortality. Unfortunately, the pharmacological and mechanical strategies that currently exist do not offer significant advantages in controlling inflammatory response and improving patient outcomes. The best strategy to reduce inflammation in CPB is still uncertain. In recent years, adsorptive blood purification techniques (BPTs) have emerged, among which CytoSorb is the latest representative device. Currently, the primary application area of adsorptive BPTs is in the control and treatment of systemic hyperinflammatory states, such as refractory septic shock patients. However, the evidences on efficacy and safety of adsorptive BPTs application during CPB surgery are still inconclusive, so we summarize the relevant evidences here and suggest future potential research areas.

Nanobody-loaded immunosorbent for highly-specific removal of interleukin-17A from blood

Elimination of overproduced cytokines from blood can relieve immune system disorders caused by hypercytokinemia. Due to the central roles of interleukin-17A (IL-17A) plays in regulating the immunity and inflammatory responses in humans, here, a novel immunosorbent containing anti-IL-17A nanobodies (Nbs) was constructed for IL-17A removal from blood. The theoretical maximum adsorption capacity estimated from the Langmuir isotherm is up to 11.55 mg/g gel, which is almost consistent with the saturated adsorption capacity determined in dynamic adsorption. The in vitro plasma perfusion test demonstrated a remarkable adsorptive performance of the Nb-coupled sorbent since more than 75% IL-17A could be eliminated under the plasma/sorbent ratio of 1000:1. These results indicated the Nb-loaded immunosorbent can provide a simple and economic platform technology for immunoaffinity depletion of single or even multiple cytokines from plasma.

Sepsis-Pathophysiology and Therapeutic Concepts

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

Adsorption of vancomycin, gentamycin, ciprofloxacin and tygecycline on the filters in continuous renal replacement therapy circuits: in full blood in vitro study

The aim of this study was to assess the in vitro adsorption of antibiotics: vancomycin, gentamicin, ciprofloxacin and tigecycline on both polyethyleneimine-treated polyacrylonitrile membrane of AN69ST filter and polysulfone membrane of AV1000 filter using porcine blood as a model close to in vivo conditions. The porcine blood with antibiotic dissolved in it was pumped into hemofiltration circuit (with AN69ST or AV1000 filter), ultrafiltration fluid was continuously returned to the reservoir containing blood with antibiotic. Blood samples to determine antibiotic concentrations were taken at minutes 0, 5, 15, 30, 45, 60, 90 and 120 from the pre- blood pump of the hemofiltration circuit. To assess possible spontaneous degradation of the drug in the solution there was an additional reservoir prepared for each antibiotic, containing blood with the drug, which was not connected to the circuit. In the case of vancomycin, ciprofloxacine and tigecycline, a statistically significant decrease in the drug concentration in the hemofiltration circuit in comparison to initial value as well as to the concentrations in the control blood was observed, both for polyacrylonitrile and plolysulfone membrane. In the case of gentamicin, significant adsorption was noted only on polyacrylonitrile membrane. Our studies demonstrated that in full blood adsorption of antibiotics may be big enough to be of clinical significance. In particular in the case of polyacrylonitrile membrane.

Multi-Drug-Resistant Organisms in Burn Infections

Background: Infection is the most frequent complication after severe burns and remains the predominant cause of death. Burn patients may require multiple courses of antibiotics, lengthy hospitalizations, and invasive procedures that place burn patients at especially high risk for infections with multi-drug-resistant organisms (MDROs). Methods: The published literature on MDROs in burn patients was reviewed to develop a strategy for managing these infections. Results: Within a burn unit meticulous infection prevention and control measures and effective antimicrobial stewardship can limit MDRO propagation and decrease the antibiotic pressure driving the selection of MDROs from less resistant strains. Several new antimicrobial agents have been developed offering potential therapeutic options, but familiarity with their benefits and limitations is required for safe utilization. Successful management of MDRO burn infections is supported by a multifactorial approach. Novel non-antibiotic therapeutics may help combat MDRO infections and outbreaks. Conclusions: Multi-drug-resistant organisms are being identified with increasing frequency in burn patients. Effective sensitivity testing is essential to identify MDROs and to direct appropriate antibiotic choices for patient treatment.

Intraoperative Hemoadsorption in Patients With Native Mitral Valve Infective Endocarditis

BACKGROUND

Cardiac surgery in patients with infective endocarditis is associated with high mortality owing to postoperative septic multiorgan failure. Hemoadsorption therapy may improve surgical outcomes by reducing the circulating cytokines. We aimed to evaluate the clinical effects of intraoperative hemoadsorption in patients with mitral valve endocarditis.

METHODS

Eligible candidates were patients with infective endocarditis of the native mitral valve undergoing cardiac surgery between January 2014 and July 2018. Patients with intraoperative hemoadsorption (hemoadsorption) were compared with surgery without hemoadsorption (control). The end points were the incidence of postoperative sepsis, sepsis-associated death, and 30-day mortality. Furthermore, postoperative need for epinephrine and norepinephrine and systemic vascular resistance were evaluated.

RESULTS

A total of 58 consecutive patients were included: 30 in the hemoadsorption group and 28 in the control group. Postoperative sepsis occurred in 5 patients in the hemoadsorption group and in 11 in the control group (P = .05). No sepsis-associated death occurred in the hemoadsorption group, whereas five septic patients in the control group died (P = .02). Thirty-day mortality was 10% in the hemoadsorption group versus 18% in the control group (P = .39). On intensive care unit admission, the cumulative need for epinephrine and norepinephrine was 0.15 versus 0.24 μg/kg body weight/min (P = .01) and the median systemic vascular resistance was 1413 versus 1010 dyn·s·cm^-5 (P = .02) in the hemoadsorption versus control group, respectively.

CONCLUSIONS

Intraoperative hemoadsorption might reduce the incidence of postoperative sepsis and sepsis-related death. In addition, patients with intraoperative hemoadsorption showed greater hemodynamic stability. These data suggest that intraoperative hemoadsorption may improve surgical outcome in patients with mitral valve endocarditis.

Recent advances in heparinization of polymeric membranes for enhanced continuous blood purification

Continuous blood purification technology such as hemodiafiltration has been used worldwide for saving patients suffering from severe diseases or organ function failure, especially in the intensive care unit and emergency setting. The filters as core devices are commonly made of polymer materials as hollow fiber membranes. However, the membrane is often inductively blocked by blood clot formation due to its interactions with blood components. Heparin is the anticoagulant often used in clinical practice for anti-coagulation. Recently, heparin is also employed to modify the hollow fiber membranes either chemically or physically to improve the filtration performance. This review summarizes recent advances in methodology for surface heparinization of such hollow fiber membranes, and their filtration performance improvement. The review also provides expert opinions for further research in this rapidly expanding field.

Bioassay for Endothelial Damage Mediators Retrieved by Hemoadsorption

Hemoadsorption devices are used to treat septic shock by adsorbing inflammatory cytokines and as yet incompletely defined danger and pathogen associated molecular patterns. In an ideal case, hemoadsorption results in immediate recovery of microvascular endothelial cells’ (mEC) function and rapid recovery from catecholamine-dependency and septic shock. We here tested a single device, which consists of polystyrene-divinylbenzene core particles of 450 μm diameter with a high affinity for hydrophobic compounds. The current study aimed at the proof of concept that endothelial-specific damage mediators are adsorbed and can be recovered from hemoadsorption devices. Because of excellent clinical experience, we tested protein fractions released from a hemoadsorber in a novel endothelial bioassay. Video-based, long-term imaging of mEC proliferation and cell death were evaluated and combined with apoptosis and ATP measurements. Out of a total of 39 fractions recovered from column fractionation, we identified 3 fractions that caused i) inhibition of mEC proliferation, ii) increased cell death and iii) induction of apoptosis in mEC. When adding these 3 fractions to mEC, their ATP contents were reduced. These fractions contained proteins of approximately 15 kDa, and high amounts of nucleic acid, which was at least in part oxidized. The efficacy for endothelial cell damage prevention by hemoadsorption can be addressed by a novel endothelial bioassay and long-term video observation procedures. Protein fractionation of the hemoadsorption devices used is feasible to study and define endothelial damage ligands on a molecular level. The results suggest a significant effect by circulating nucleic acids – bound to an as yet undefined protein, which may constitute a major danger-associated molecular pattern (DAMP) in the exacerbation of inflammation when patients experience septic shock. Hemoadsorption devices may thus limit endothelial damage, through the binding of nucleic acid-bearing aggregates and thus contribute to improved endothelial barrier function.