Endotoxin activity assay and polymyxin B hemoperfusion use in a cohort of critically ill patients

Introduction

Endotoxin plays a crucial role in the pathogenesis of severe sepsis and septic shock (SS&SSh) [1]. The aim of this study is to analyze the impact of extracorporeal endotoxin removal with polymyxin B hemoperfusion (PMX-DHP) (Toraymyxin^®).

Methods

All patients admitted to our ICU between 1 April 2011 and 30 June 2013 who developed SS&SSh and underwent endotoxin activity assay (EAA) measurement were retrospectively evaluated.

Results

During the study period, EAA was dosed in 100 patients. Eighty- one patients were affected by septic shock. The source of infection was identified in 70.4% of cases (45% abdominal) and the percentage of microbiologically confirmed episodes was 77% (81% Gram-negatives). The mortality rate was 49%. The mean EAA level was 0.66 ± 0.2, and in 66% of patients the value was higher than 0.6. No significant differences were found in terms of SAPS II (P = 0.32) and SOFA score (P = 0.67), according to EAA level (>/≤0.6). Patients with levels >0.6 presented a higher percentage of microbiologically confirmed infections (84% vs. 66%; P = 0.09). Thirty-two of 66 patients with EAA >0.6 were treated with Toraymyxin^®. No complications leading to treatment interruption were recorded and a relevant decrease of cardiovascular SOFA score and lactate levels were observed 72 hours after treatment (P = 0.05 and P = 0.06, respectively). Source control and Toraymyxin^® treatment resulted as the only modifiable factors improving the ICU survival rate (Table 1).

Table 1 Multivariate analysis for ICU mortality risk factors

Conclusion

EAA is a rapid and reliable method to identify patients who may be treated with polymyxin B hemoperfusion. Source control and extracorporeal endotoxin removal have appeared as two effective interventions that should be implemented in the early management of patients with SS&SSh.