Endotoxin in pooled pericardial blood contributes to the systemic inflammatory response during cardiac surgery

Abstract

Although endotoxin has been implicated as an important contributor to the systemic inflammatory response (SIR) during cardiopulmonary bypass (CPB), its source remains unclear. While gut translocation has traditionally been perceived as the primary source of endotoxemia, accumulation of endotoxin in pooled pericardial blood may represent an additional source of endotoxin that is continually reinfused into the CPB circuit. Eighteen patients undergoing primary coronary revascularization procedures were prospectively evaluated. Shed blood pooled in the pericardial space was returned to the CPB circuit through cardiotomy suction catheters at 45 min after placement of the aortic cross-clamp. Simultaneous samples of pooled pericardial and peripheral arterial blood were obtained and analyzed by a limulus amebocyte lysate assay for the determination of endotoxin concentration, and an enzyme-linked immunosorbent assay for tumor necrosis factor (TNF-alpha) levels. Significant elevations in endotoxin were demonstrated in pooled pericardial blood samples compared with arterial blood (3.5 +/- 0.5 vs 0.8 +/- 0.2 pg/ml; p < 0.05). TNF-alpha levels were below the limits of detection in both samples. These data implicate pooled pericardial blood as an important primary source of endotoxin that, when continually reinfused throughout CPB, may contribute to the overall SIR. Because endotoxemia has been identified as an important predictor of adverse outcomes following cardiac surgery, removal of endotoxin antigen in shed pericardial blood, prior to its reinfusion into the CPB circuit, may provide a directed means to improve perioperative outcome without compromising established blood conservation techniques.

Bacterial translocation during liver transplantation: A randomized trial comparing conventional with venovenous bypass vs. piggyback methods

“…However, endotoxemia occurred in the same intensity in the conventionally transplanted group patients. The venovenous bypass, used in the conventional group, has been described as an inductor of endotoxin translocation 34–36. The mechanisms involved are not clearly understood 34, 37.…”

Endotoxin release in cardiac surgery with cardiopulmonary bypass: pathophysiology and possible therapeutic strategies. An update

“…In 18 patients undergoing elective CABG, Spanier et al [17] investigated the levels of endotoxin in pericardial shed blood, which was pooled in the pericardial space for 45 min after placing of the aortic cross-clamp and then returned to the cardiotomy reservoir. Blood samples were taken from the pericardial shed blood and the arterial line at the same time, and before and after reinfusion of the pericardial shed blood in the CPB circuit.…”

Pericardial suction blood separation attenuates inflammatory response and hemolysis after cardiopulmonary bypass

“…DeSomer et al detected that the pericardial blood contaminated by tissue contact is an important activator of the coagulation system and a principle cause of hemolysis (3). Spanier et al found significant higher concentration of endotoxins in the blood pooled in the pericardium compared to arterial samples (4). The dispensed fat particles may also be responsible for lipid emboli in the brain (5,6).…”