"Impact of timing of polymyxin B-immobilized fiber column direct hemoperfusion on outcome in patients with septic shock: a single-center observational study"

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.

Effectiveness of polymyxin B hemoperfusion for sepsis depends on the baseline SOFA score: a nationwide observational study

BACKGROUND

Polymyxin B hemoperfusion (PMX) aims to treat septic shock by removing endotoxin from the patient's blood. However, the relationship between the severity of the patient's organ damage and the survival benefit of PMX treatment is not clear.

METHODS

We analyzed the efficacy of PMX on adult sepsis patients using the propensity score matching method and the Japanese Diagnosis Procedure Combination (DPC) national inpatient database from April 2018 to March 2020. We stratified the patients into five categories based on their baseline Sequential Organ Failure Assessment (SOFA) score and compared the mortality between PMX-treated and non-treated groups in each category. We also compared continuous hemodiafiltration (CHDF)-, ventilator- and noradrenaline-free days between the groups.

RESULTS

Of 44,177 patients included in the study, 2191 received PMX. After 1:1 propensity score matching, we created matched cohorts of 2033 pairs. PMX significantly improved the survival of the patients in the SOFA score categories of 7-9 and 10-12. On the other hand, there was no significant difference in the survival rate in SOFA score categories of 0-6, 13-15, and 16-24. In analyzing organ support-free days, PMX was also beneficial in the 7-9 and 10-12 SOFA categories compared to other categories.

CONCLUSION

Analysis of a large-scale Japanese inpatient database found a significant association between PMX efficacy and baseline SOFA score. This result indicates higher efficacy in patients with medium SOFA scores in the range of 7-12. The result provides a promising hypothesis for selecting appropriate patients for PMX and should be validated in future RCTs.

Clinical effects of polymyxin B-immobilized fiber column direct hemoperfusion for severe bacterial meningitis: A series of 10 cases

Our results suggest a possible role for Polymyxin B-immobilized fiber column direct hemoperfusion in combination with standard therapy in the rapid improvement of impaired consciousness in patients with severe bacterial meningitis.