Different endotoxin release and IL-6 plasma levels after antibiotic administration in surgical intensive care patients

Despite the use of broad-spectrum antibiotics, aggressive fluid resuscitation, vasopressor support, the mortality associated with Gram-negative sepsis and septic shock has not decreased significantly in the last two decades. The consequences of host exposure to endotoxin and the relationship of antibiotic administration to endotoxin release have become important areas of intense interest. In vitro studies have demonstrated that there was a difference in endotoxin release between PBP-3 specific antibiotics (beta-lactam antibiotics) and PBP-2 specific antibiotics (carbapenems). This is the first clinical report of surgical patients admitted to the surgical and anaesthesiology intensive care unit on the missing endotoxin release after imipenem treatment; however cefotaxime and ceftriaxone showed significantly more positive endotoxin tests in the plasma when compared to imipenem. Ciprofloxacin and vancomycin were intermediate in endotoxin release and tobramycin did not cause endotoxin release. There were also significant differences in endotoxin neutralizing capacity. IL-6 levels were decreased after imipenem faster than after ceftriaxone or cefotaxime; ciprofloxacin seemed to increase IL-6. Endotoxin may be harmful in patients where the immune system has been continuously challenged. Timing, dosage, or combination with other compounds as well as the effect of antibiotics on macrophages need to be tested in larger clinical trials. In this respect a consecutive study was started.