Although some studies have shown that endotoxin measurements may be of value in predicting outcome and presence of gram-negative bacteremia, other studies have been inconclusive, and the clinical value of endotoxin measurement in patients with sepsis remains unclear. A large number of previous studies have attempted to measure endotoxin in the circulation of patients with sepsis and relate these findings to other clinical, microbiologic, and pathophysiologic findings. Although this detection system is highly sensitive, it is susceptible to a number of interfering substances found in human plasma, which may activate or inhibit the Limulus reaction independent of endotoxin itself. Endotoxin levels are often measured by using a Limulus amebocyte lysate reactivity assay. The measurement of endotoxin in the systemic circulation has been complicated by the fact that humans are exquisitely susceptible to endotoxin, and accurate measurement of endotoxin in plasma is technically difficult. Injection of larger doses of endotoxin (∼1 mg) into humans has been followed by severe hypotension and multiorgan dysfunction within 2 h of intravenous administration. Īdministration of endotoxin to humans in minute quantities (2–4 ng/kg) precipitates typical signs and symptoms of clinical sepsis, activates the complement and coagulation systems, and triggers release of the proinflammatory cytokines. These host-derived mediators function in concert to induce the systemic inflammatory response syndrome. These effector cells appear to be activated through a family of Toll-like receptors and subsequently release a network of proinflammatory mediators, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, IL-12, cyclic endoperoxides, platelet-activating factor, complement tissue factor, and other inflammatory products. This complex macromolecule induces its injurious effects by a noncytotoxic interaction with CD14-bearing inflammatory cells, which include the macrophage-monocyte lineage and circulating neutrophils. ![]() The quantitative level of both endotoxin and LBP may have prognostic significance in patients with severe sepsis.īacterial endotoxin, a component of the outer cell membrane of gram-negative bacteria, is a principal mediator in the pathophysiology of gram-negative bacterial sepsis. No correlation was found between endotoxin and LBP levels. 05) in nonsurvivors than survivors over the 28-day study period. 01), and LBP levels were less highly elevated (28.0 vs. Median endotoxin levels at study entry were more highly elevated (515 vs. Median LBP levels in patients with sepsis were 31.2 µg/mL (interquartile range, 22.5–47.7 µg/mL). LBP levels were elevated in 97% of patients compared with normal control values of 4.1 ± 1.65 µg/mL. Median endotoxin levels in patients with sepsis were 300 pg/mL (25%–75% interquartile range, 110–726 pg/mL). Endotoxin levels were significantly greater than control levels ( n = 33 mean ± SD, 5.1 ± 7.3, pg/mL) in 78.3% of patients. ![]() Plasma endotoxin and lipopolysaccharide-binding protein (LBP) levels were measured in a group of 253 patients at the onset of severe sepsis and/or septic shock.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |