A substantial body of experimental and clinical evidence suggests that neutralising or removing
lipopolysaccharide endotoxin would be an effective adjunctive approach to the management of Gram-negative
sepsis.
Polymyxins are a group of cyclic cationic
polypeptide antibiotics. Although they have useful antimicrobial activity against Gram-negative bacteria, their clinical use has been limited because of toxicity. However, in addition to their antimicrobial property,
polymyxins can bind to and neutralise
endotoxin. Thus, investigators have explored the possibility of using
polymyxin bound to a solid-phase carrier for specific
haem-adsorption in patients with
sepsis, thereby retaining the
lipopolysaccharide-binding properties but minimising systemic toxic effects. This system has been widely used in Japan for many years, but convincing clinical evidence of efficacy is lacking. A recent Italian study has some promising data. Although
polymyxin has been the principal agent used to explore this approach, other molecules have the ability to bind
endotoxin, and some of these have very recently been proposed as the basis for other
endotoxin-removal devices. The available evidence is reviewed to assess the potential use of such devices in clinical practice.