Rationale of extracorporeal removal of endotoxin in sepsis: theory, timing and technique

Several signs and symptoms in sepsis are due to the presence of endotoxin in the circulation. Both in animal and human models, there is an evident immunological response to the endotoxin insult. Furthermore, altered cardiovascular function, lung dysfunction and acute kidney injury are common in sepsis and endotoxemia. In these circumstances it would be extremely important to identify patients with sepsis in the early phases and to characterize the humoral alterations involved with it, including the identification and quantification of circulating endotoxin. Once this is obtained, it seems logical to try to remove as much of the circulating endotoxin as possible in order to mitigate the clinical effects of this condition. This can be achieved today with a very specific hemoperfusion process utilizing cartridges with immobilized polymixin B in an extracorporeal circuit. This approach seems to provide a significant removal of endotoxin with a significant reduction of its circulating levels. The clinical consequences of this approach can be summarized in a mitigation of the septic cascade in the early phases, with improvement of outcome. Recent clinical results seem to confirm these expectations showing a reduction of mortality in patients with early signs of abdominal sepsis due to recent surgery. This opens a new avenue for intervention in sepsis.