Presence of circulating endotoxins during cardiac operations

Ten patients having coronary artery bypass grafting were intraoperatively and postoperatively analyzed for endotoxins with the Limulus amoebocyte lysate test. A new highly sensitive rocket immunoelectrophoretic assay for reading the reactions of endotoxins with Limulus amoebocyte lysate was used. Preoperatively, all blood samples from the patients had negative Limulus amoebocyte lysate tests, negative blood cultures, normal total white cell counts, and were clinically without signs of infection. Intraoperatively, a substantial amount of endotoxins were found in samples from the extracorporeal circuit, the pulmonary artery, and the cardiac suction lines, which persisted during the cardiopulmonary bypass. The endotoxin content decreased significantly (p less than 0.05) 6 hours after cardiopulmonary bypass and further decreased within the seventh postoperative day (p less than 0.01). A positive Limulus amoebocyte lysate test was also found in some of the fluids administered during the operation, that is, the cardioplegic fluids, the priming fluids for the extracorporeal circuit, the blood transfusions, and the ice for local cooling. Postoperatively, all patients had rectal temperatures below 38.5 degrees C, but no correlation was found between the magnitude of endotoxin content and the degree of fever. Only one of the patients had positive blood cultures. Despite the measured endotoxin content, no intraoperative or postoperative complications were found.