A Review of Extracorporeal Blood Purification Techniques for the Treatment of Critically Ill Coronavirus Disease 2019 Patients

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.

Proceedings of the 2022 UAB CRRT Academy: Non-Invasive Hemodynamic Monitoring to Guide Fluid Removal with CRRT and Proliferation of Extracorporeal Blood Purification Devices

In 2022, we celebrated the 15th anniversary of the University of Alabama at Birmingham (UAB) Continuous Renal Replacement Therapy (CRRT) Academy, a 2-day conference attended yearly by an international audience of over 100 nephrology, critical care, and multidisciplinary trainees and practitioners. This year, we introduce the proceedings of the UAB CRRT Academy, a yearly review of select emerging topics in the field of critical care nephrology that feature prominently in the conference. First, we review the rapidly evolving field of non-invasive hemodynamic monitoring and its potential to guide fluid removal by renal replacement therapy (RRT). We begin by summarizing the accumulating data associating fluid overload with harm in critical illness and the potential for harm from end-organ hypoperfusion caused by excessive fluid removal with RRT, underscoring the importance of accurate, dynamic assessment of volume status. We describe four applications of point-of-care ultrasound used to identify patients in need of urgent fluid removal or likely to tolerate fluid removal: lung ultrasound, inferior vena cava ultrasound, venous excess ultrasonography, and Doppler of the left ventricular outflow track to estimate stroke volume. We briefly introduce other minimally invasive hemodynamic monitoring technologies before concluding that additional prospective data are urgently needed to adapt these technologies to the specific task of fluid removal by RRT and to learn how best to integrate them into practical fluid-management strategies. Second, we focus on the growth of novel extracorporeal blood purification devices, starting with brief reviews of the inflammatory underpinnings of multiorgan dysfunction and the specific applications of pathogen, endotoxin, and/or cytokine removal and immunomodulation. Finally, we review a series of specific adsorptive technologies, several of which have seen substantial clinical use during the COVID-19 pandemic, describing their mechanisms of target removal, the limited existing data supporting their efficacy, ongoing and future studies, and the need for additional prospective trials.

Single-Center Experience With the Seraph-100® Microbind® Affinity Blood Filter in Patients With SARS-CoV-2 Infection and Septic Shock at a Military Treatment Facility

INTRODUCTION

Coronavirus disease 2019 (COVID-19) infection is characterized by a dysregulated inflammatory response, which may result in severe hemodynamic instability and septic shock. The Seraph-100® Microbind® Affinity Blood Filter is a commercially available extracorporeal pathogen absorbent device with the ability to bind pathogens and cytokines present within the blood. Our study aimed to evaluate the efficacy of the Seraph-100® for patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and septic shock.

MATERIALS AND METHODS

A retrospective review was performed to evaluate the use of the Seraph-100® blood filter at a Single Center tertiary-care facility at Brooke Army Medical Center from 2020 to 2021. Nine patients (11 treatments) were completed with the Seraph-100® blood filter in patients with SARS-CoV-2 infection and septic shock. The Seraph-100® blood filter was used in combination with continuous renal replacement therapy and slow low-efficiency dialysis or directly in parallel with the extracorporeal membrane oxygenation circuit.

RESULTS

Within this cohort, there was a statistically significant improvement in the following clinical parameters comparing values to before and after treatment with the Seraph-100® blood filter: Mean arterial pressure (mmHg) (64.2 ± 2.36 vs. 76.2 ± 2.68; P < .001), heart rate (beats per minute) (128 ± 6.6 vs. 100.3 ± 6.07; P < .001), administered fraction of oxygen (%) (74.4 ± 10.58 vs. 60.3 ± 10.35; P < .001), serum lactate (mmol/L) (6.14 ± 1.25 vs. 2.8 ± 1.14; P = .0095), and pH (7.29 ± 0.03 vs. 7.39 ± 0.04; P = .0203). There were statistically significant improvements in vasopressor requirements: norepinephrine (mcg/min) (36.3 ± 4.74 vs. 8.3 ± 3.92; P < .001), vasopressin (units/min) (0.04 ± 0.004 vs. 0.02 ± 0.003; P < .001), dobutamine (mcg/kg/min) (2.3 ± 1.00 vs. 0.2 ± 0.75; P = .006) and angiotensin II (ng/kg/min) (34.5 ± 6.4 vs. 3.3 ± 5.26; P < .001).

CONCLUSIONS

The use of the Seraph-100® blood filter was associated with statistically and clinically significant improvements in hemodynamic parameters and decreased vasopressor requirements in patients with septic shock and SARS-CoV-2 infection.

Effects of cytokine hemadsorption as salvage therapy on common laboratory parameters in patients with life-threatening COVID-19

BACKGROUND

The COVID-19 pandemic has led to emergency approval of treatment modalities unusual for viruses, such as therapeutic cytokine Hemadsorption(HA). This study aims to investigate the experience of salvage HA therapy and the effect of HA on routine laboratory tests.

METHODS

Life-threatening COVID-19 patients followed up between April 2020 and October 2022 who underwent HA salvage therapy were retrospectively enrolled. Data derived from the medical records were evaluated to meet the assumptions of statistical tests, and those that met the relevant statistical rules were selected for further analysis. Tests of Wilcoxon, Paired-T, and repeated measures-ANOVA were used to analyse the laboratory tests performed before and after HA among the surviving and nonsurviving patients. P < 0.05 was selected for the statistical significance of the alpha.

RESULTS

A total of 55 patients were enrolled in the study. Fibrinogen (p = 0.007), lactate dehydrogenase (LDH) (p = 0.021), C-reactive protein (CRP) (p < 0.0001), and platelet (PLT) (p = 0.046) levels showed a significant decrease with the HA effect. WBC (p = 0.209), lymphocyte (p = 0.135), procalcitonin (PCT) (p = 0.424), ferritin (p = 0.298), and D-dimer (p = 0.391) levels were not affected by HA. Ferritin level was significantly affected by survival status (p = 0.010). All patients tolerated HA well, and 16.4 % (n = 9) of the patients with life-threatening COVID-19 survived.

CONCLUSION

HA is well tolerated even when used as a last option. However, HA may not affect WBC, lymphocyte, and D-dimer levels. In contrast, the effect of HA could limit the benefits of LDH, CRP, and fibrinogen in various clinical assessments. This study suggests that HA treatment could be beneficial even if selected as a salvage therapy.

Blood filtering system for COVID-19 management: novel modality of the cytokine storm therapeutics

The newly emerged coronavirus (SARS-CoV-2) is virulent, contagious, and has rapidly gained many mutations, which makes it highly infectious and swiftly transmissible around the world. SARS-CoV-2 infects people of all ages and targets all body organs and their cellular compartments, starting from the respiratory system, where it shows many deleterious effects, to other tissues and organs. Systemic infection can lead to severe cases that require intensive intervention. Multiple approaches were elaborated, approved, and successfully used in the intervention of the SARS-CoV-2 infection. These approaches range from the utilization of single and/or mixed medications to specialized supportive devices. For critically ill COVID-19 patients with acute respiratory distress syndrome, both extracorporeal membrane oxygenation (ECMO) and hemadsorption are utilized in combination or individually to support and release the etiological factors responsible for the "cytokine storm" underlying this condition. The current report discusses hemadsorption devices that can be used as part of supportive treatment for the COVID-19-associated cytokine storm.

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.

Effect of Continuous Renal Replacement Therapy with the oXiris Hemofilter on Critically Ill Patients: A Narrative Review

Critically ill patients with sepsis and severe COVID-19 are commonly characterized by a dysregulated immune response and an acute kidney injury. Continuous renal replacement therapy (CRRT) is now proposed as a promising adjuvant therapy to treat these critically ill patients by removing cytokines, pathogen-associated molecular patterns, and damage-associated molecular patterns from the blood. Although multiple hemofilters, including high-cutoff membranes, the oXiris hemofilter, the CytoSorb hemoadsorption device, and the Toraymyxin hemoperfusion cartridge, have been used in current clinical practice, the use of the oXiris hemofilter in critically ill patients is of particular interest because it is the only kind of hemofilter that can provide renal replacement therapy, remove endotoxins, and adsorb cytokines simultaneously. During the past five years, a growing body of literature has shown that CRRT with the oXiris hemofilter can improve hemodynamics and organ function and can decrease cytokines and endotoxins in both septic and COVID-19 patients. Here, we performed a narrative review to describe the development history of the oXiris hemofilter and to discuss the therapeutic effect of oXiris-CRRT on critically ill patients by searching the PubMed, Web of Science, and clinicaltrials.gov databases for articles published from inception to 8 September 2022 (updated on 1 November) with an English language restriction. We also summarized the current knowledge on anticoagulation techniques and safety concerns when delivering oXiris-CRRT sessions.