An Evaluation of the Usefulness of Extracorporeal Liver Support Techniques in Patients Hospitalized in the ICU for Severe Liver Dysfunction Secondary to Alcoholic Liver Disease

Impact of anion exchange adsorbents on regional citrate anticoagulation

INTRODUCTION

Heparin and citrate are commonly used anticoagulants in membrane/adsorption based extracorporeal liver support systems. However, anion exchange resins employed for the removal of negatively charged target molecules including bilirubin may also deplete these anticoagulants due to their negative charge. The aim of this study was to evaluate the adsorption of citrate by anion exchange resins and the impact on extracorporeal Ca²⁺ concentrations.

METHODS

Liver support treatments were simulated in vitro. Citrate and Ca²⁺ concentrations were measured pre and post albumin filter as well as pre and post adsorbents. In addition, batch experiments were performed to quantify citrate adsorption.

RESULTS

Pre albumin filter target Ca²⁺ concentrations were reached well with only minor deviations. Citrate was adsorbed by anion exchange resins, resulting in a higher Ca²⁺ concentration downstream of the adsorbent cartridges during the first hour of treatment.

CONCLUSIONS

The anion exchange resin depletes citrate, leading to an increased Ca²⁺ concentration in the extracorporeal circuit, which may cause an increased risk of clotting during the first hour of treatment. An increase of citrate infusion during the first hour of treatment should therefore be considered to compensate for the adsorption of citrate.

Incidence of infectious complications is associated with a high mortality in patients with hepatitis B virus-related acute-on-chronic liver failure

BACKGROUND

In China, hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is the most common liver failure characterized by serious clinical syndromes of liver decompensation with a very high mortality. Bacterial and/or fungal infections are the most common complications that are associated with high short-term mortality. Bacterial translocation from the intestine, impaired hepatic clearance, and immune paralysis of circulating immune cells are thought to contribute to infectious complications in liver failure. The control of bacterial and fungal infections is the key to improving HBV-ACLF outcomes. Active prevention, early diagnosis, and timely treatment of bacterial and fungal infections are essential for treating HBV-ACLF.

AIM

To investigate the frequency and role of bacterial and fungal infections in patients with HBV-ACLF.

METHODS

Patients with HBV-ACLF hospitalized at Taihe Hospital, Hubei University of Medicine from January 2014 to December 2017 were retrospectively enrolled. Patient-related information was retrieved from the hospital case database, including general information, blood biochemistry, complications, etc. According to the occurrence of secondary infection or not, the patients were divided into an infection group and a non-infection group. The sites, types, and incidences of bacterial and fungal infections and the influence of infections on the prognosis of HBV-ACLF were statistically analyzed. The risk factors for infections were assessed by unconditional logistic regression.

RESULTS

There were 174 cases of HBV-ACLF that met the enrollment criteria, of which 114 (65.52%) were diagnosed with infectious complications. Infections occurred in the abdominal cavity (87 cases), respiratory tract (51 cases), urinary tract (18 cases), and biliary tract (10 cases). Patients with infectious complications had a significantly higher 28-d mortality (70.18%, 80/114) than those without (40.00%, 24/60) (70.18% vs 40.00%, P < 0.05). And patients with infectious complications had a much higher incidence of non-infectious complications (54.39%, 62/114) (54.39% vs 15.00%, P < 0.05), leading to an extremely high 28-d mortality of 88.71% (55/62) (P < 0.05). The grade of liver failure, period of hospital stay ≥ 30 d, age ≥ 45 years, and percentage of neutrophils > 70% were identified as risk factors for infectious complications.

CONCLUSION

The high incidence of infectious complications in patients with HBV-ACLF is associated with severity and deterioration of the disease and may contribute to the extremely high mortality of these patients.

Effects of dual plasma molecular adsorption system on liver function, electrolytes, inflammation, and immunity in patients with chronic severe hepatitis

Background

To investigate the effects of dual plasma molecular adsorption system (DPMAS) on the liver function, electrolytes, inflammation, and immunity in patients with chronic severe hepatitis (CSH).

Methods

Total of 162 patients with CSH treated in our hospital from March 2016 to December 2018 were enrolled and equally randomly divided into control group (n = 81) and observation group (n = 81). The patients in control group were treated with plasma exchange, while those in observation group were additionally treated with DPMAS based on the treatment in control group. The liver function, electrolytes, inflammation, and immunity were evaluated and compared between the two groups.

Results

After treatment, the liver function indexes in observation group were significantly favorable compared with those in control group, with the reduction in TBIL, DBIL, ALT, and rise of CHE levels (P < 0.05). The levels of K⁺, Na⁺, Cl⁻, and Ca²⁺ in both groups were significantly improved after treatment (P < 0.05), although there were no significant differences between the two groups (P > 0.05). The levels of C‐reactive protein (CRP), interleukin‐6 (IL‐6), and tumor necrosis factor‐α (TNF‐α) in both groups declined after treatment compared with those before treatment, and those levels in observation group were higher than that in control group (P < 0.05). After treatment, the levels of cluster of differentiation 3⁺ (CD3⁺), CD4⁺, and CD4⁺/CD8⁺ were higher in observation group than those in control group, with decreasing level of CD8⁺ (P < 0.05).

Conclusion

Dual plasma molecular adsorption system can effectively improve the liver function, effectively correct the electrolyte disorders, reduce the inflammatory response, and adjust the immunity in patients with CSH.

An evaluation of the usefulness of extracorporeal liver support techniques in patients with severe liver dysfunction

INTRODUCTION

The mortality rate in patients with severe liver dysfunction with no option of transplantation is unacceptably high. The main aim of this study was to evaluate the usefulness of applying extracorporeal liver support (ECLS) techniques in this group of patients.

MATERIAL AND METHODS

Data from hospital admissions of 101 patients with severe liver dysfunction who were admitted to the department of Anaesthesiology and intensive therapy between 2006 and 2015 were retrospectively analysed. The study group was divided into two subgroups. Standard Medical therapy (SMT) was a subgroup of patients receiving standard Medical therapy, and SMT + ECLS was a subgroup containing patients receiving standard medical therapy complemented by at least one extracorporeal liver support procedure.

RESULTS

Significantly lower intensive care unit (ICU) mortality and 30-day mortality rates were found in the SMT + ECLS subgroup (p = 0.0138 and p = 0.0238 respectively). No difference in 3-month mortality was identified between the two groups. In a multivariate model, independent risk factors for ICU mortality proved to be the SOFA score and prothrombin time. The highest discriminatory power for ICU mortality was demonstrated for the SOFA score, followed by APACHE II, SAPS II, MELD UNOS and GCS scores. For 30-day mortality, however, the best discriminatory power was shown for the SAPS II score, followed by SOFA, APACHE II, MELD UNOS and GCS scores.

CONCLUSIONS

Further studies are needed to assess the contribution of non-biological extracorporeal liver support procedures to a decrease in mortality rates in the population of patients with severe liver dysfunction.

Artificial liver support systems: what is new over the last decade?

The liver is a complex organ that performs vital functions of synthesis, heat production, detoxification and regulation; its failure carries a highly critical risk. At the end of the last century, some artificial liver devices began to develop with the aim of being used as supportive therapy until liver transplantation (bridge-to-transplant) or liver regeneration (bridge-to-recovery). The well-recognized devices are the Molecular Adsorbent Recirculating System™ (MARS™), the Single-Pass Albumin Dialysis system and the Fractionated Plasma Separation and Adsorption system (Prometheus™). In the following years, experimental works and early clinical applications were reported, and to date, many thousands of patients have already been treated with these devices. The ability of artificial liver support systems to replace the liver detoxification function, at least partially, has been proven, and the correction of various biochemical parameters has been demonstrated. However, the complex tasks of regulation and synthesis must be addressed through the use of bioartificial systems, which still face several developmental problems and very high production costs. Moreover, clinical data on improved survival are conflicting. This paper reviews the progress achieved and new data published on artificial liver support systems over the past decade and the prospects for these devices.

Albumin Apheresis for Artificial Liver Support: In Vitro Testing of a Novel Filter

Currently there is no direct therapy for liver failure. We have previously described selective plasma exchange therapy using a hemofilter permeable to substances that have a molecular mass of up to 100 kDa. The proof-of-concept studies and a Phase I study in patients with decompensated cirrhosis demonstrated that hemofiltration using an albumin-leaking membrane is safe and effective in removing target molecules, alleviating severe encephalopathy and improving blood chemistry. In this study a novel large-pore filter for similar clinical application is described. The performance of the filter was studied in vitro; it was found to effectively remove a wide spectrum of pathogenic factors implicated in the pathophysiology of hepatic failure, including protein bound toxins and defective forms of circulating albumin. Data on mass transport characteristics and functionality using various modes of filtration and dialysis provide rationale for clinical evaluation of the filter for artificial liver support using albumin apheresis.

A clinical-scale BioArtificial Liver, developed for GMP, improved clinical parameters of liver function in porcine liver failure

Liver failure, whether arising directly from acute liver failure or from decompensated chronic liver disease is an increasing problem worldwide and results in many deaths. In the UK only 10% of individuals requiring a liver transplant receive one. Thus the need for alternative treatments is paramount. A BioArtificial Liver machine could temporarily replace the functions of the liver, buying time for the patient's liver to repair and regenerate. We have designed, implemented and tested a clinical-scale BioArtificial Liver machine containing a biomass derived from a hepatoblastoma cell-line cultured as three dimensional organoids, using a fluidised bed bioreactor, together with single-use bioprocessing equipment, with complete control of nutrient provision with feedback BioXpert recipe processes, and yielding good phenotypic liver functions. The methodology has been designed to meet specifications for GMP production, required for manufacture of advanced therapy medicinal products (ATMPs). In a porcine model of severe liver failure, damage was assured in all animals by surgical ischaemia in pigs with human sized livers (1.2-1.6 kg liver weights). The BioArtificial liver (UCLBAL) improved important prognostic clinical liver-related parameters, eg, a significant improvement in coagulation, reduction in vasopressor requirements, improvement in blood pH and in parameters of intracranial pressure (ICP) and oxygenation.