Polymyxin B hemoperfusion in clinical practice: the picture from an unbound collaborative registry

After the publication of the EUPHAS trial, the clinical use of polymyxin B hemoperfusion (Toraymyxin®) increased significantly in Italy. Nevertheless, no structured data collections have been carried out to underline the characteristics of treated patients. Therefore, a collaborative registry of clinical data was promoted among users in order to better define the structure of the prospective data collection named the EUPHAS2 project. Neither inclusion criteria nor therapeutic constraints were imposed, highlighting adherence to clinical evidence provided by previous randomized controlled trials, and also unusual or borderline practice in the selection of patients for polymyxin B-based cartridges (PMX-DHP). This first retrospective phase of data collection included patients with severe sepsis and septic shock treated with Toraymyxin over the last 3 years, up to July 2013. Thirty-one hospitals participated in the EUPHAS2 study, collecting data on 306 patients. Enrolled patients were grouped according to the main source of sepsis: abdominal (41.8%) and nonabdominal (58.2%). The abdominal patients had characteristics well matching those selected for the EUPHAS randomized controlled trial in terms of time-to-enrolment, severity of the illness, 28-day mortality and in-hospital mortality. Their 28-day mortality rate was 35% with a significant reduction of the Sequential Organ Failure Assessment Score (SOFA) score after 72 h of treatment (p < 0.001). Patients with nonabdominal sepsis were heterogeneous and only a few of them had their endotoxin activity tested in a manner not allowing a reliable evaluation of the real efficacy of the treatment and organ dysfunction control. Their 28-day mortality rate was 49% and the SOFA score did not significantly change before and after treatment. In conclusion, clinical experience confirms the results of the original EUPHAS randomized trial in terms of outcome for patients with abdominal severe sepsis. Specific studies focused on a population of patients with Gram-negative infections of nonabdominal origin are needed before recommending treatment with Toraymyxin as an effective therapy.