Direct hemoperfusion using a polymyxin B-immobilized polystyrene column for COVID-19

Blood perfusion with polymyxin B immobilized columns in patients with COVID-19 requiring oxygen therapy

Extracorporeal blood purification with polymyxin B immobilized fiber column direct hemoperfusion (PMX-DHP), is reported to be effective in treating COVID-19 pneumonitis with oxygen demand. This multicenter prospective study evaluated the efficacy and safety of PMX-DHP in oxygen-requiring patients with COVID-19 admitted between September 28, 2020, and March 31, 2022. The primary endpoint was the percentage of clinical improvement 15 days after treatment. The secondary endpoint was the percentage of worsened disease status. Data from the COVID-19 patient registry were used for the synthetic control group. The improvement rate on Day 15 did not differ between PMX-treated patients and controls; however, the deterioration rate was 0.38 times lower in the PMX-treated group, and the death rates on Day 29 were 0 and 11.1% in the PMX-treated and control groups, respectively. The PMX group showed a 0.73 times higher likelihood for reduced intensive care demand, as 16.7% of PMX-treated patients and 22.8% of controls worsened. After treatment blood oxygenation improved, urinary β2-microglobulin and liver-type fatty acid-binding protein showed significant decreases, and IL-6 decreased once during treatment but did not persist. In this study, PMX treatment effectively prevented the worsening of COVID-19 pathology, accompanied by improved oxygenation. PMX treatment to remove activated cells may effectively improve patient outcomes.

AKI in Adults with COVID-19 Infection: Mechanisms of Development and Role of Blood Filtration Devices in Treatment

During the coronavirus disease 2019 (COVID-19) pandemic, acute kidney injury (AKI) was a common sequela of COVID-19 infection and predicted disease severity and mortality. Extracorporeal blood purification techniques involving blood filtration devices are an emerging treatment for AKI in the setting of severe COVID-19 infections. In this review, we discuss potential mechanisms for the development of AKI in COVID-19 patients as well as the various available blood filtration devices and the role they may play in managing the AKI in COVID-19 patients. A total of seven blood filters currently available were compared based on their potential in treating AKI in COVID-19 patients. Blood filtration devices show potential as an emerging treatment modality for COVID-19-induced AKI, but further clinical trials are necessary before their widespread adoption and usage.

Repurposing clinically available drugs and therapies for pathogenic targets to combat SARS-CoV-2

The coronavirus disease 2019 (COVID-19) pandemic has affected a large portion of the global population, both physically and mentally. Current evidence suggests that the rapidly evolving coronavirus subvariants risk rendering vaccines and antibodies ineffective due to their potential to evade existing immunity, with enhanced transmission activity and higher reinfection rates that could lead to new outbreaks across the globe. The goal of viral management is to disrupt the viral life cycle as well as to relieve severe symptoms such as lung damage, cytokine storm, and organ failure. In the fight against viruses, the combination of viral genome sequencing, elucidation of the structure of viral proteins, and identifying proteins that are highly conserved across multiple coronaviruses has revealed many potential molecular targets. In addition, the time- and cost-effective repurposing of preexisting antiviral drugs or approved/clinical drugs for these targets offers considerable clinical advantages for COVID-19 patients. This review provides a comprehensive overview of various identified pathogenic targets and pathways as well as corresponding repurposed approved/clinical drugs and their potential against COVID-19. These findings provide new insight into the discovery of novel therapeutic strategies that could be applied to the control of disease symptoms emanating from evolving SARS-CoV-2 variants.

Recent updates on the biological efficacy of approved drugs and potent synthetic compounds against SARS-CoV-2

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, has triggered a global pandemic that has prompted severe public health concerns. Researchers worldwide are continuously trying to find options that could be effective against COVID-19. The main focus of research during the initial phase of the pandemic was to use the already approved drugs as supportive care, and efforts were made to find new therapeutic options. Nirmatrelvir (PF-07321332), a Pfizer chemical, recently received approval for usage in conjunction with ritonavir. This mini-review summarises the biological effectiveness of vital synthetic compounds and FDA-approved medications against SARS-CoV-2. Understanding how functional groups are included in the creation of synthetic compounds could help enhance the biological activity profile of those compounds to increase their efficacy against SARS-CoV-2. This opened the way for researchers to explore opportunities to develop better therapeutics by investigating synthetic analogs.

The Impact and Treatment of COVID-19 in Hemodialysis Patients

BACKGROUND

Patients with coronavirus disease 2019 (COVID-19) undergoing maintenance hemodialysis have a poor prognosis and limited treatment options.

METHODS

This paper outlines the impact of COVID-19, its treatment, and the efficacy of vaccines in Japanese patients undergoing hemodialysis with a review of the literature.

RESULTS

Patients undergoing dialysis in dialysis facilities are at greater risk of exposure to severe acute respiratory syndrome coronavirus 2 than the general population due to limited isolation capabilities. Therefore, vaccines are expected to be effective for patients undergoing dialysis. In addition, effective use of available medications is important because treatment options are limited.

CONCLUSIONS

Efforts should be made to prevent the spread of the infection to high-risk patients undergoing dialysis while ensuring the effective use of vaccines.

Outcome and Complications of Hemoperfusion in Patients with COVID-19 in Intensive Care Unit: A Cross-Sectional Study

BACKGROUND & OBJECTIVE

The use of the hemoperfusion method is recommended for treating cytokine storms and reducing complications in patients with COVID-19. The side effects of this treatment are not known; therefore, this study was performed to determine the final outcome and complications of hemoperfusion in patients with COVID-19 hospitalized in ICU.

METHODS

In this retrospective cross-sectional study, all patients with severe COVID-19 without any comorbidities or organ failure underwent hemoperfusion treatment in ICU at Kosar Hospital in Semnan, Iran, from March to November 2021 were included. The clinical data and short-term complications up to 10 days after hemoperfusion and the final outcome were extracted from medical files.

RESULTS

The mean age of 40 patients with severe COVID-19 undergoing hemoperfusion was 57.5±15.9 years. Most (24, 60%) patients were male. The time interval from hospitalization to hemoperfusion and the time interval between hemoperfusion and final outcome was 4.85 days and 8.30 days, respectively. Arrhythmia, bleeding, thrombocytopenia, and coagulation disorders were the most common short-term complications of hemoperfusion in patients with COVID-19, respectively. Most complications occurred on the second and third days after hemoperfusion. Mortality occurred in 20 (50 %) patients with severe COVID-19 undergoing hemoperfusion in ICU.

CONCLUSION

It seems that the short-term complications and deaths due to hemoperfusion are relatively high in patients with COVID-19 admitted to the ICU. Further studies are recommended.

Effect of extracorporeal hemoadsorption in critically ill patients with COVID-19: A narrative review

COVID-19 has been affecting the world unprecedentedly and will remain widely prevalent due to its elusive pathophysiological mechanism and the continuous emergence of new variants. Critically ill patients with COVID-19 are commonly associated with cytokine storm, multiple organ dysfunction, and high mortality. To date, growing evidence has shown that extracorporeal hemoadsorption can exert its adjuvant effect to standard of care by regulating immune homeostasis, reducing viremia, and decreasing endotoxin activity in critically ill COVID-19 cases. However, the selection of various hemofilters, timing of initiation and termination of hemoadsorption therapy, anticoagulation management of extracorporeal circuits, identification of target subgroups, and ultimate survival benefit remain controversial. The purpose of this narrative review is to comprehensively summarize the rationale for the use of hemoadsorption in critically ill patients with COVID-19 and to gather the latest clinical evidence in this field.

Establishment and clinical application of SARS-CoV-2 catch column

BACKGROUND

A certain number of patients with coronavirus disease 2019 (COVID-19), particularly those who test positive for SARS-CoV-2 in the serum, are hospitalized. Further, some even die. We examined the effect of blood adsorption therapy using columns that can eliminate SARS-CoV-2 on the improvement of the prognosis of severe COVID-19 patients.

METHODS

This study enrolled seven patients receiving mechanical ventilation. The patients received viral adsorption therapy using SARS-catch column for 3 days. The SARS-catch column was developed by immobilizing a specific peptide, designed based on the sequence of human angiotensin-converting enzyme 2 (hACE2), to an endotoxin adsorption column (PMX). In total, eight types of SARS-CoV-2-catch (SCC) candidate peptides were developed. Then, a clinical study on the effects of blood adsorption therapy using the SARS-catch column in patients with severe COVID-19 was performed, and the data in the present study were compared with historical data of severe COVID-19 patients.

RESULTS

Among all SCC candidate peptides, SCC-4N had the best adsorption activity against SARS-CoV-2. The SARS-catch column using SCC-4N removed 65% more SARS-CoV-2 than PMX. Compared with historical data, the weaning time from mechanical ventilation was faster in the present study. In addition, the rate of negative blood viral load in the present study was higher than that in the historical data.

CONCLUSION

The timely treatment with virus adsorption therapy may eliminate serum SARS-CoV-2 and improve the prognosis of patients with severe COVID-19. However, large-scale studies must be performed in the future to further assess the finding of this study (jRCTs052200134).

Potential survival benefit and early recovery from organ dysfunction with polymyxin B hemoperfusion: perspectives from a real-world big data analysis and the supporting mechanisms of action

Background

Endotoxin (ET) removal therapy with polymyxin B-immobilized fiber column hemoperfusion (PMX-HP) has been used for the treatment of septic shock. Some observational studies reported clinical benefits, particularly in specific subgroups of patients. However, larger randomized controlled trial results have been disappointing.

Main body

The four studies that revealed the survival benefit of PMX-HP were based on the Japanese Diagnosis Procedure Combination (DPC) national inpatient database (J-DPC study). Nevertheless, one J-DPC study and a randomized controlled trial (RCT) conducted in France evaluated PMX-HP in patients with abdominal septic shock and did not report a significant survival benefit. In both studies, the severity of illness was too low to find substantial significant differences in mortality. The results of the J-DPC studies further suggest that some subpopulations of patients could benefit from PMX-HP. Based on these results, this review revisited prior RCTs and other large-scale studies on PMX-HP. In addition, four J-DPC studies and one large-scale study reported a survival benefit with PMX-HP. A secondary analysis of the EUPHRATES trial, the most recent double-blinded RCT of PMX-HP conducted in North America, suggested a survival benefit in patients with high levels of endotoxemia. In the J-DPC studies and the EUPHRATES trial, ventilator-free days, vasoactive drug-free days, and renal replacement-free days were significantly improved in the PMX-HP groups. These findings suggest that PMX-HP can contribute to early recovery from organ dysfunction. The reduction of supportive care likely provides important health and economic benefits for managing patients with septic shock. Finally, the blood levels of mediators or biomarkers related to respiratory, cardiovascular, and renal dysfunction have been reported to be normalized with PMX-HP.

Conclusions

These results support the biological rationale for the improvement in organ dysfunction observed in the J-DPC studies and other large-scale studies, including the EUPHRATES trial. Real-world evidence from large data sets suggests an appropriate patient population that are likely to benefit from the utility of PMX-HP for septic shock.

Apheresis and COVID-19 in intensive care unit (ICU)

Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease has since spread worldwide, and on March 2020 the World Health Organization (WHO) declared it as pandemic, causing a public health crisis. Symptoms of COVID-19 are variable, ranging from mild symptoms like fever, cough, and fatigue to severe illness. Elderly patients and those with comorbidities like cardiovascular disease, diabetes, chronic respiratory disease, or cancer are more likely to develop severe forms of the disease. Asymptomatic infections have been well documented. Accumulating evidence suggests that the severity of COVID-19 is due to high levels of circulating inflammatory mediators including cytokines and chemokines leading to cytokine storm syndrome (CSS). Patients are admitted in ICU with severe respiratory failure, but can also develop acute renal failure and multi organ failure. Advances in science and technology have permitted the development of more sophisticated therapies such as extracorporeal organ support (ECOS) therapies that includes renal replacement therapies (RRTs), venoarterial (VA) or veno-venous (VV) extracorporeal membrane Oxygenation (ECMO), extracorporeal CO2 removal (ECCO2R), liver support systems, hemoperfusion, and various blood purification devices, for the treatment of ARDS and septic shock.

The Characteristics of Patients with Severe COVID-19 Pneumonia Treated with Direct Hemoperfusion Using Polymyxin B-Immobilized Fiber Column (PMX-DHP)

Purpose

The characteristics of patients with severe COVID-19 pneumonia who underwent direct hemoperfusion using polymyxin B-immobilized fiber column (PMX-DHP), in addition to steroids and immunomodulators, remain unclear.

Patients and Methods

We conducted a retrospective observational study on 31 patients with severe COVID-19 pneumonia treated with PMX-DHP in an intensive care unit (ICU) from December 2020 to September 2021.

Results

Outcomes 28 days after admission to the ICU were 20 in the survival group and 11 in the death group. Parameters significantly different between the survival and death group before PMX-DHP were percentage of invasive mechanical ventilation (25% vs 72.7%, P = 0.0209), PaO₂/F_IO₂ (P/F) ratio (104.5 vs 75, P = 0.0317), and sequential organ failure assessment (SOFA) score (2 vs 3, P = 0.0356). Invasive mechanical ventilation avoidance rate was significantly different between the survival (100%) and death group (0%) (P = 0.0012). P/F ratio, respiratory ratio (RR), and lymphocyte counts improved significantly after PMX-DHP for all patients. The lymphocyte counts changed significantly in the survival (P < 0.0001), but not the death group (P = 0.7927).

Conclusion

PMX-DHP, in addition to steroids and immunomodulators, may improve oxygenation and alleviate tachypnea by modulating the lymphocyte numbers and levels of various mediator against severe COVID-19 pneumonia. It may be better to perform PMX-DHP before multi organ dysfunction and lung injury has progressed. Furthermore, the early increase in lymphocyte counts after PMX-DHP might be an indicate a positive outcome.

Endotoxin removal therapy with Polymyxin B immobilized fiber column as a COVID-19-bedside strategy protocol for endotoxic shock

Endotoxin -induced sepsis is a leading cause of ICU mortality. From 1994 to the present, PMX-HP has been available as an adjuvant therapy for endotoxin removal and immunomodulation. The efficacy and usefulness of this therapy have been demonstrated for more than a quarter of a century and are partially supported by clinical studies. However, it appears that selected subgroups of patients with endotoxic shock and with appropriate timing could benefit. Endotoxemia may be involved in the pathophysiology of COVID-19, based on enterocyte dysfunction and malabsorptive syndrome. Due to the characteristics of the microbiota, Gram-negative bacteria or their fragments (i.e., endotoxin) may translocate into the systemic circulation leading to inflammatory activation, immune dysfunction, and sepsis. In addition, patients with severe forms of COVID-19 are at risk of superimposed infections. Endotoxemia can arise due to the translocation of Gram-negative bacteria or their fragments from the gut barrier. According to the most updated evidence available from large randomized trials, septic shock patients with MODS > 9 and EA levels ranging from 0.6 to 0.9 are those who may benefit the most from PMX-HP treatment in terms of improvement of survival. As shown in a previous publication, we believe that similarly to the source control, microbiological cultures, and antibiotics administration, EA evaluation at regular intervals, and the targeted use of PMX-HP could be lifesaving and adequate within the golden hour for the diagnosis and treatment of endotoxic shock. In our center, we applied a diagnostic-clinical flowchart also for endotoxic shock related to COVID-19.

For safe and adequate blood purification therapy in severe COVID-19 ‒ what we have learned so far

Acute kidney injury (AKI) is defined as an increase in serum creatinine within 48 h or 1 week, or a decrease in urine output within 6-24 h. Continuous renal replacement therapy (CRRT) plays an important role in patients with severe AKI. In addition to direct cytotoxicity caused by the severe acute respiratory syndrome coronavirus 2, patients with coronavirus disease (COVID-19) experience endothelial cell damage, increased thrombogenic inflammation, and impaired immune responses. It has been reported that the more severe the case, the greater overproduction of cytokines and the more advanced the multiorgan failure. The kidney is widely recognized as one of the primary target organs; and COVID-19 positive AKI has been reported to have a greater rate of subsequent decline in renal function than COVID-19 negative AKI. Blood purification therapy has been used to prevent or alleviate organ damage in patients with moderate-to-severe COVID-19. Cytokine regulation is one of the primary therapeutic goals for these patients. Even with the widespread use of vaccines and antibody therapy, a certain percentage of patients develop moderate-to-severe diseases.

Committee report: Questionnaire survey on the treatment of COVID-19 in patients receiving dialysis therapy

Background

Patients with coronavirus disease 2019 (COVID-19) who receive dialysis therapy develop more severe disease and have a poorer prognosis than patients who do not. Although various data on the treatment of patients not receiving dialysis therapy have been reported, clinical practice for patients on dialysis is challenging as data is limited. The Infection Control Committee of the Japanese Society for Dialysis Therapy decided to clarify the status of treatment in COVID-19 patients on dialysis.

Methods

A questionnaire survey of 105 centers that had treated at least five COVID-19 patients on dialysis was conducted in August 2021.

Results

Sixty-six centers (62.9%) responded to the questionnaire. Antivirals were administered in 27.7% of facilities treating mild disease (most patients received favipiravir) and 66.7% of facilities treating moderate disease (most patients with moderate or more severe conditions received remdesivir). Whether and how remdesivir is administered varies between centers. Steroids were initiated most frequently in moderate II disease (50.8%), while 43.1% of the facilities initiated steroids in mild or moderate I disease. The type of steroid, dose, and the duration of administration were generally consistent, with most facilities administering dexamethasone 6 mg orally or 6.6 mg intravenously for 10 days. Steroid pulse therapy was administered in 48.5% of the facilities, and tocilizumab was administered in 25.8% of the facilities, mainly to patients on ventilators or equivalent medications, or to the cases of exacerbations. Furthermore, some facilities used a polymethylmethacrylate membrane during dialysis, nafamostat as an anticoagulant, and continuous hemodiafiltration in severe cases. There was limited experience of polymyxin B-immobilized fiber column-direct hemoperfusion and extracorporeal membrane oxygenation. The discharge criteria for patients receiving dialysis therapy were longer than those set by the Ministry of Health, Labor and Welfare in 22.7% of the facilities.

Conclusions

Our survey revealed a variety of treatment practices in each facility. Further evidence and innovations are required to improve the prognosis of patients with COVID-19 receiving dialysis therapy.

The Rationale and Current Status of Endotoxin Adsorption in the Treatment of Septic Shock

Lipopolysaccharide, the main component of the outer membrane of Gram-negative bacteria is a highly potent endotoxin responsible for organ dysfunction in sepsis. It is present in the blood stream not only in Gram-negative infections, but also in Gram-positive and fungal infections, presumably due to sepsis-related disruption of the intestinal barrier. Various pathways, both extra- and intracellular, are involved in sensing endotoxin and non-canonical activation of caspase-mediated pyroptosis is considered to have a major role in sepsis pathophysiology. Endotoxin induces specific pathological alterations in several organs, which contributes to poor outcomes. The adverse consequences of endotoxin in the circulation support the use of anti-endotoxin therapies, yet more than 30 years of experience with endotoxin adsorption therapies have not provided clear evidence in favor of this treatment modality. The results of small studies support timely endotoxin removal guided by measuring the levels of endotoxin; unfortunately, this has not been proven in large, randomized studies. The presence of endotoxemia can be demonstrated in the majority of patients with COVID-19, yet only case reports and case series describing the effects of endotoxin removal in these patients have been published to date. The place of blood purification therapies in the treatment of septic shock has not yet been determined.

Blood Filters in Children with COVID-19 and AKI: A Review

COVID-19 has challenged the global healthcare system through rapid proliferation and lack of existing treatment resulting in over 180 million cases and 3.8 million deaths since December 2019. Although pediatric patients only comprise 1-2% of diagnosed cases, their incidence of acute kidney injury ranges from 8.2% to 18.2% compared to 49% in adults. Severe infection, initiated by dysregulated host response, can lead to multiorgan failure. In this review, we focus on the use of various blood filters approved for use in pediatric kidney replacement therapy to mitigate adverse effects of severe illness. Therapeutic effects of these blood filters range from cytokine removal (CytoSorb, HA330, HCO/MCO), endotoxin removal (Toraymyxin, CPFA), both cytokine and endotoxin removal (oXiris), and non-specific removal of proteins (PMMA) that have already been established and can be used to mitigate the various effects of the cytokine storm syndrome in COVID-19.

Blood purification could tackle COVID-19?

Coronavirus disease 2019 (COVID-19) threatened human lives worldwide since first reported. The current challenge for global intensivists is to establish an effective treatment for severe COVID-19. Blood purification has been applied to the treatment of various critical illnesses. Theoretically, its technique also has an enormous possibility of treating severe COVID-19 in managing inflammatory cytokines and coagulopathy. Recent clinical studies have revealed the positive clinical effect of therapeutic plasma exchange. Other studies have also indicated the considerable potential of other blood purification techniques, such as Cytosorb, AN69 surface-treated membrane, and polymyxin b hemoperfusion. Further research is needed to elucidate the actual effects of these applications.

Hemoperfusion and blood purification strategies in patients with COVID-19: A systematic review

BACKGROUND

Coronavirus disease-19 (COVID-19) ranges from asymptomatic infection to severe cases requiring admission to the intensive care unit. Together with supportive therapies (ventilation in particular), the suppression of the pro-inflammatory state has been a hypothesized target. Pharmacological therapies with corticosteroids and interleukin-6 (IL-6) receptor antagonists have reduced mortality. The use of extracorporeal cytokine removal, also known as hemoperfusion (HP), could be a promising non-pharmacological approach to decrease the pro-inflammatory state in COVID-19.

METHODS

We conducted a systematic review of PubMed and EMBASE databases in order to summarize the evidence regarding HP therapy in COVID-19. We included original studies and case series enrolling at least five patients.

RESULTS

We included 11 articles and describe the characteristics of the populations studied from both clinical and biological perspectives. The methodological quality of the included studies was generally low. Only two studies had a control group, one of which included 101 patients in total. The remaining studies had a range between 10 and 50 patients included. There was large variability in the HP techniques implemented and in clinical and biological outcomes reported. Most studies described decreasing levels of IL-6 after HP treatment.

CONCLUSION

Our review does not support strong conclusions regarding the role of HP in COVID-19. Considering the very low level of clinical evidence detected, starting HP therapies in COVID-19 patients does not seem supported outside of clinical trials. Prospective randomized data are needed.

Investigation of plasma exchange and hemoperfusion effects and complications for the treatment of patients with severe COVID-19 (SARS-CoV-2) disease: A systematic scoping review

Some previous studies suggested that the plasma exchange (PE) and hemoperfusion (HP) played a cardinal role in the treatment of severe coronavirus disease 2019 (COVID-19) cases by diminishing the cytokine storm. This study aimed to assess the effects of PE and HP on cytokine storms in patients with severe COVID-19 through a systematic scoping review. Four Electronic databases (Medline [accessed from PubMed], Scopus, Science Direct, and Cochrane library) were searched systematically on February 2, 2021, using MESH terms and related keywords in the English language. Considering the titles and abstracts, unrelated studies were excluded. The full texts of the remained studies were evaluated by authors, independently. Then, their findings were assessed and reported. A total of 755 articles were obtained within the first step of searching, and 518 remained after removing the duplications. Through the title and abstract screening, 438 were removed. Of the rest, 59 papers were excluded. Finally, after reading the full text of the remained articles, 21 were included in data extraction. Most of the previously reported evidence were case reports and case series. Findings were summarized in two categories. The first category encompassed nine studies regarding HP and continuous renal replacement therapy, and the second category included twelve studies about PE. The results revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients. Highlights Some studies showed that plasma exchange (PE) and hemoperfusion (HP) played an important role in the treatment of patients with severe COVID-19 disease. The results of this systematic scoping review revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients.

Application of extracorporeal therapies in critically ill COVID-19 patients

The coronavirus disease 2019 (COVID-19) pandemic is a major public health event caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has spread widely all over the world. A high proportion of patients become severely or critically ill, and suffer high mortality due to respiratory failure and multiple organ dysfunction. Therefore, providing timely and effective treatment for critically ill patients is essential to reduce overall mortality. Convalescent plasma therapy and pharmacological treatments, such as aerosol inhalation of interferon-α (IFN-α), corticosteroids, and tocilizumab, have all been applied in clinical practice; however, their effects remain controversial. Recent studies have shown that extracorporeal therapies might have a potential role in treating critically ill COVID-19 patients. In this review, we examine the application of continuous renal replacement therapy (CRRT), therapeutic plasma exchange (TPE), hemoadsorption (HA), extracorporeal membrane oxygenation (ECMO), and extracorporeal carbon dioxide removal (ECCO₂R) in critically ill COVID-19 patients to provide support for the further diagnosis and treatment of COVID-19.

The effect of hemoperfusion on the outcome, clinical and laboratory findings of patients with severe COVID-19: a retrospective study

Hemoperfusion is a method of blood filtering to remove toxins and inflammatory factors. Cytokine storms and high levels of inflammatory factors play a role in the pathogenesis of coronavirus disease 2019 (COVID-19). The present study aims to evaluate the effect of hemoperfusion on the clinical and laboratory findings and outcomes of patients with severe COVID-19. Forty-eight patients with severe COVID-19 and a positive PCR test, who were admitted to the intensive care unit (ICU), participated in the study. All patients were treated by routine treatment protocol for COVID-19. Hemoperfusion was performed for 24 patients in addition to treatment with conventional antiviral therapies. The other 24 patients made up the control group. Demographic data, laboratory findings and patient outcomes before and after treatment were retrospectively collected and analysed. There was no significnt difference in mortality or length of hospital stays between the control group and the hemoperfusion group. The breathing rate (P-vaalue = 0.001) and heart beat rate (P-value = 0.028) of patients decreased after hemoperfusion. The hemoperfusion resulted in a significant increase in the SpO2 levels and a significant decrease in the CRP of patients compared to the conventional treatment (P-value = 0.009). Hemoperfusion can improve respiratory distress. It can reduce the CRP in patients with severe COVID-19 but has no effect on mortality.

Therapeutic Rationale for Endotoxin Removal with Polymyxin B Immobilized Fiber Column (PMX) for Septic Shock

Endotoxin removal therapy with polymyxin B immobilized fiber column (PMX) has been clinically applied for sepsis and septic shock patients since 1994. The effectiveness and usefulness of this therapy have been demonstrated for more than a quarter of a century. However, a documented survival benefit has not yet been demonstrable in a large, multicenter, randomized and controlled trial. Following the findings derived from a large sepsis clinical trial with PMX in North America, a new trial is ongoing to determine if PMX has a long-term survival benefit when administered to septic patients. Another approach to support a survival benefit from intervention with PMX is to utilize a detailed analysis available from a large clinical data base. The endotoxin adsorption capacity of PMX columns in vitro and the effectiveness of PMX columns can be further demonstrable in animal models. The capability of PMX and details of its mechanism of action to intervene in the sepsis cascade and impede organ dysfunction in septic patients is not fully understood. The surface antigen expression in monocytes and neutrophils are improved after PMX therapy. Immunomodulatory effects as a result of endotoxin removal and/or other mechanisms of action have been suggested. These effects and other potential immune effects may explain some of the improved effects upon organ dysfunction of sepsis and septic shock patients. Endotoxemia may be involved in the pathophysiology of other diseases than sepsis. A rapid diagnostic method to detect and target endotoxemia could allow us to practice precision medicine and expand the clinical indications of endotoxin removal therapy.

Direct hemoperfusion using a polymyxin B-immobilized polystyrene column for COVID-19

Objective

To evaluate the efficacy and safety of direct hemoperfusion using a polymyxin B‐immobilized polystyrene column (PMX‐DHP) in severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2)‐positive pneumonia patients.

Methods

This study was a case series conducted at a designated infectious diseases hospital. Twelve SARS‐CoV‐2‐positive patients with partial pressure of arterial oxygen/percentage of inspired oxygen (P/F) ratio < 300 were treated with PMX‐DHP on two consecutive days each during hospitalization. We defined day 1 as the first day when PMX‐DHP was performed. PMX‐DHP efficacy was assessed on days 7 and 14 after the first treatment based on eight categories. Subsequently, improvement in P/F ratio and urinary biomarkers on days 4 and 8, malfunctions, and ventilator and extracorporeal membrane oxygenation avoidance rates were also evaluated.

Results

On day 14 after the first treatment, disease severity decreased in 58.3% of the patients. P/F ratio increased while urine β2‐microglobulin decreased on days 4 and 8. Cytokine measurement pre‐ and post‐PMX‐DHP revealed decreased levels of interleukin‐6 and the factors involved in vascular endothelial injury, including vascular endothelial growth factor. Twenty‐two PMX‐DHPs were performed, of which seven and five PMX‐DHPs led to increased inlet pressure and membrane coagulation, respectively. When the membranes coagulated, the circuitry needed to be reconfigured. Circuit problems were usually observed when D‐dimer and fibrin degradation product levels were high before PMX‐DHP.

Conclusions

Future studies are expected to determine the therapeutic effect of PMX‐DHP on COVID‐19. Because of the relatively high risk of circuit coagulation, coagulation capacity should be assessed beforehand.