Endotoxaemia during left ventricular assist device insertion: relationship between risk factors and outcome

A Phase II, Double-Blind, Placebo-Controlled, Ascending-Dose Study of Eritoran (E5564), a Lipid A Antagonist, in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass

BACKGROUND

Lipid A, the toxic moiety of endotoxin, is linked to multiple complications after cardiac surgery, including fever, vasodilation, and pulmonary and renal dysfunction. The lipid A antagonist eritoran (or E5564) prevents endotoxin-induced systemic inflammation in animals and humans. In this study we assessed the safety of eritoran administration in patients undergoing cardiac surgery and obtained preliminary efficacy data for the prophylaxis of endotoxin-mediated surgical complications.

METHODS

A double-blind, randomized, ascending-dose, placebo-controlled study was conducted at nine hospitals. Patients undergoing coronary artery bypass graft and/or cardiac valvular surgery with cardiopulmonary bypass were enrolled. Patients received a 4-h infusion of placebo (n = 78) vs 2 mg (n = 24), 12 mg (n = 26), or 28 mg (n = 24) of eritoran initiated approximately 1 h before cardiopulmonary bypass.

RESULTS

No significant safety concerns were identified with continuous safety monitoring, and enrollment continued to the highest prespecified dose (28 mg). No statistically significant differences were observed in most variables related to systemic inflammation or organ dysfunction/injury.

CONCLUSIONS

This Phase II safety study suggests that the administration of the novel lipid A antagonist, eritoran, is not associated with overt toxicity in cardiac surgical patients. Blocking lipid A with eritoran does not appear to confer any clear benefit to elective cardiac surgical patients.

Abdominal organ injury after cardiac surgery

Gastrointestinal complications occur in about 2.5% of patients undergoing cardiac surgery, are associated with a high mortality (about 33%), and account for nearly 15% (and perhaps increasing) of all postoperative deaths. The various complications and risk factors are reviewed. Splanchnic ischemia prior to, during, and especially postoperatively appears to be an important cause of these complications. In addition, splanchnic ischemia is hypothesized to be one cause of the systemic inflammatory response syndrome and multiorgan failure that may follow cardiac surgery. The physiology of splanchic perfusion and the effects of cardiac surgery, including cardiopulmonary bypass, on it are reviewed. Finally, possible methods to minimize splanchnic ischemia and reduce the incidence of abdominal complications are discussed.

Recent Advances in Alcoholic Liver Disease I. Role of intestinal permeability and endotoxemia in alcoholic liver disease

A significant body of evidence indicates that endotoxemia and endotoxin-mediated hepatocellular damage play a crucial role in the pathogenesis of alcoholic liver disease. A close correlation between endotoxemia and the severity of alcohol-induced liver injury is supported by a number of clinical and experimental studies. Elevated intestinal permeability appears to be the major factor involved in the mechanism of alcoholic endotoxemia and the pathogenesis of alcoholic liver disease. Ethanol and its metabolic derivatives, acetaldehyde in particular, alter intracellular signal-transduction pathways leading to the disruption of epithelial tight junctions and an increase in paracellular permeability to macromolecules. Studies addressing the mechanisms of such epithelial disruption and the protective factors that prevent ethanol and acetaldehyde-mediated disruption of epithelial tight junctions are critically important in the investigations toward the search of preventive and therapeutic strategies for alcoholic liver disease.