Endotoxins and Gram-negative Septicemia

Abstract

In approximately 0.39–1.15% of patients admitted to hospitals, gram-negative bacteremia is diagnosed [1, 2]. The large majority of bacteremic patients has clinical characteristics of bacterial infection, most commonly fever, but only a few bacteremic patients will develop the septic syndrome, which can be complicated by hypotension, coagulation activation, increased vascular permeability, and renal failure, and may culminate in a highly lethal syndrome termed multiple organ failure [3]. Although in the past bacteremia was almost considered a gold standard for septicemia, of unselected bacteremic patients only 15% develop clinical symptoms of septicemia [4]. Moreover, it is well established that clinical symptoms of septicemia can develop in patients who have negative blood cultures. These findings may in part be an effect of widespread treatment with antibiotics. More importantly, it has been shown that lipopolysaccharides present in the outer membrane of gram-negative bacteria (endotoxins) can induce many biological phenomena that are observed in septicemia and that endotoxemia may occur in the absence of bacteremia [4–6]. Unfortunately, the clinical criteria for the septic syndrome are rather unspecific, and it remains difficult to make a diagnosis. In this paper we will briefly review evidence, derived from experimental and clinical studies, that endotoxins are of importance in the pathophysiology of septicemia, and we will discuss the usefulness of endotoxin testing in a clinical setting.

This work was supported in part by a grant from the Nederlandse Organisatie voor Wetenschappelijk onderzoek, s’Gravenhage, The Netherlands.