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.