Prolonged direct hemoperfusion using a polymyxin B immobilized fiber cartridge provides sustained circulatory stabilization in patients with septic shock: a retrospective observational before-after study

Effects of Early Initiation of Polymyxin B Hemoperfusion Therapy in Patients with Cancer with Refractory Septic Shock

Background: We aimed to analyze the correlation between in-hospital mortality and hemodynamic changes, using polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) initiation time in patients with cancer with refractory septic shock. Methods: Forty-six patients with cancer who received PMX-DHP for refractory septic shock were retrospectively analyzed and classified into early (≤3 h between refractory septic shock and PMX-DHP; n = 17) and late (>3 h; n = 29) initiation groups. The vasopressor inotropic score (VIS), sequential organ failure assessment (SOFA) score, and lactate clearance before and 24 h post-PMX-DHP were compared. Results: Overall, 52.17% died from multiple organ dysfunction, with a lower mortality rate in the early initiation group. The VIS and SOFA score decreased in both groups, but the magnitude of decrease was not significant. Lactate clearance improved in both groups, with greater improvement in the early initiation group. Univariable analysis identified associations of in-hospital mortality with early initiation, ΔC-reactive protein, lactate clearance, ΔSOFA score, and ΔVIS. Multivariable analysis demonstrated associations of in-hospital mortality risk with ΔSOFA score and early PMX-DHP initiation. Overall survival was higher in the early initiation group. Early initiation of PMX-DHP in patients with cancer with refractory septic shock reduced in-hospital mortality and improved lactate clearance.

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.

Clinical Efficacy of Polymyxin B in Patients Infected with Carbapenem-Resistant Organisms

Purpose

Carbapenem-resistant organisms (CROs) pose great challenges for clinical treatment. Polymyxin B (PMB) is one of the “last resort” choices of CRO infections. We explored the possible factors affecting PMB efficacy.

Patients and Methods

This retrospective study involved CRO-infected patients treated with PMB for ≥72 h. The endpoint indicator was clinical efficacy. We compared the characteristics (demographics, pathogenic bacteria, PMB treatment) between patients who had “clinical success” (CS) and “clinical failure” (CF).

Results

A total of 191 patients were enrolled: 110 in the CS group and 81 in the CF group. The total cumulative dose for the CS group was higher than the CF group [1100 (700–1443.75) vs 800 (500–1112.5) mg; P = 0.001]. Treatment duration in the CS group was longer than the CF group [11 (8–14) vs 8 (6–11) days; P < 0.000]. Multivariate logistic regression analysis showed mechanical ventilation, vasoactive agents, multiple-site infection, and total cumulative dose to be independently associated with clinical efficacy. Cox survival analysis for 30-day mortality also showed that the use of vasoactive agents and the total cumulative dose of PMB could influence survival time and mortality rate independently.

Conclusion

PMB had good efficacy and a low prevalence of adverse reactions. The total cumulative dose, duration of PMB treatment, mechanical ventilation, vasoactive agents, and multiple-site infection were factors associated with the clinical efficacy of PMB.

Impact of Extended Duration of Polymyxin B-Immobilized Fiber Column Direct Hemoperfusion on Hemodynamics, Vasoactive Substance Requirement, and Pulmonary Oxygenation in Patients with Sepsis: An Observational Study

INTRODUCTION

Polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) is used for patients with septic shock, and the recommended hemoperfusion period is 2 h. However, it remains unclear whether the optimal duration is 2 h or longer. The purpose of this study was to compare the effects of PMX-DHP between conventional and longer duration of PMX-DHP.

METHODS

We retrospectively investigated 103 patients with sepsis who underwent PMX-DHP. The demographic data, routine biochemistry, microbiological data, and primary infection site were reviewed in the medical chart. The acute physiology and chronic health evaluation (APACHE) II score, sequential organ failure assessment (SOFA) score, heart rate, mean arterial pressure (MAP), vasoactive-inotropic score (VIS), and PaO2/FiO2, at baseline and day 3, were compared between the standard group (2 h of PMX-DHP) and the extended group (>2 h of PMX-DHP).

RESULTS

Median MAP was significantly lower and median VIS was significantly higher in the extended group at baseline (p < 0.05, 0.01, respectively) There were no significant differences in APACHE II score, SOFA score, and PaO2/FiO2 at baseline between the 2 groups. The increase of MAP and the decrease in VIS from baseline to day 3 were significantly greater in the extended group (p < 0.01, respectively). In the extended group, increase in PaO2/FiO2 was significantly larger in the patients who underwent ≥8 h duration than that in patients who underwent <8 h duration (p < 0.01). The ventilator-free days, the incidence of continuous renal replacement therapy, and the 28-day mortality were not different between the groups.

DISCUSSION/CONCLUSIONS

Longer duration of PMX-DHP was associated with the improved MAP and decreased volume of vasoactive-inotropic agents compared with the conventional duration. Eight and longer hours duration of PMX-DHP was associated with the improvement in the pulmonary oxygenation. Further studies are needed to confirm the efficacy of longer duration of PMX-DHP in patients with septic shock.

Up-to-date information on polymyxin B-immobilized fiber column direct hemoperfusion for septic shock

Endotoxin adsorption therapy by polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) has been used for the treatment of septic shock patients. Endotoxin, an outer membrane component of Gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin triggers a signaling cascade for leukocytes, macrophage, and endothelial cells to secrete various mediators including cytokines and nitric oxide, leading to septic shock and multiple organ dysfunction syndrome. PMX-DHP directly adsorbed not only endotoxin but also monocytes and anandamide. It reduced blood levels of inflammatory cytokines such as interleukin (IL)-1, IL-6, tumor necrosis factor-alpha and IL-17A, adhesion molecules, plasminogen activator inhibitor 1, and high mobility group box-1. As a result, PMX-DHP increased blood pressure and reduced the dose of vasoactive-inotropic agents. PMX-DHP improved monocyte human leukocyte antigen-DR expression in patients with severe sepsis and septic shock. A post hoc analysis of EUPHRATES (Evaluating the Use of Polymyxin B Hemoperfusion in Randomized Controlled Trial of Adults Treated for Endotoxemia and Septic Shock) trial has shown that PMX-DHP significantly reduced 28-day mortality compared with the control group in septic shock patients with endotoxin activity assay level between 0.60 and 0.89. Longer duration of PMX-DHP may be another strategy to bring out the beneficial effects of PMX-DHP. Further studies are needed to confirm the efficacy of PMX-DHP treatment for septic shock.

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.

Preparation of polymyxin B-loaded gellan-polylysine polyion complex fibers with high affinity to endotoxin

Endotoxemia, a life-threatening disease affecting people worldwide, can be treated by hemoperfusion alone. New hemoperfusion materials with high biocompatibility and endotoxin-combination ability are always in demand. Herein, polymyxin B (PMB), a specific endotoxin binding molecule, was loaded onto gellan-polylysine polyion complex, and the obtained material was used in preparing wet-spun fibers. The tensile strength of the as-spun yarns (100 fibers) ranged from 1.49 N to -1.58 N and that of the dried and rewetted yarns ranged from 1.45 N to 1.56 N. The adsorption ability of the fibers with lipopolysaccharides from E. coli was 2.784 ± 0.036 EU/mg in simulated human body fluid and 2.452 ± 0.107 EU/mg in mouse plasma. The fibers showed no cytotoxicity toward U2OS cells and no hemolysis toward mouse blood. The influence of the fibers on the clotting time of mouse blood was negligible, and the blood cells were not adhesive to the fibers. Thus, the PMB-loaded gellan-polylysine complex fiber and its derivate fabrics can be used in hemoperfusion.

Sphingosine-1-Phosphate (S1P) Is a Feasible Biomarker in Predicting the Efficacy of Polymyxin B-Immobilized Fiber Direct Hemoperfusion (PMX-DHP) in Patients with Septic Shock

PURPOSE

The aim of this study was to identify a useful biomarker to predict the efficacy of polymyxin B-immobilized fiber direct hemoperfusion (PMX-DHP) in patients with septic shock.

METHODS

The 44 patients included in this study were divided into two groups. Group A had an increase in systolic blood pressure (SBP) over 30 mmHg after PMX-DHP treatment. Group B had an increase in SBP less than 30 mmHg after PMX-DHP treatment. We evaluated the clinical characteristics and demographics of both groups. We also assessed whether the cause of sepsis affected the efficacy of PMX-DHP and compared the prognosis of both groups. Finally, we investigated whether there were any significant differences in the levels of sepsis-related biomarkers, including sphingosine-1-phosphate (S1P), between both groups before PMX-DHP in an effort to identify a biomarker that could predict the efficacy of PMX-DHP.

RESULTS

PMX-DHP significantly increased SBP regardless of the cause of sepsis. Although there was some tendency, PMX-DHP did not significantly improve the prognosis of effective cases in comparison with non-effective cases, probably because of the limited number of patients included. Among the sepsis-related biomarkers, only S1P values were significantly different between the two groups before PMX-DHP, and S1P levels were significantly increased after treatment in the effective cases.

CONCLUSION

S1P levels prior to PMX-DHP can be used to predict its efficacy. In addition, continuous monitoring of S1P levels can indicate the effectiveness of PMX-DHP in patients with septic shock.