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.