[Plasma endotoxin, procalcitonin, C-reactive protein, and organ functions in patients with major burns]

Sepsis is one of the most frequent causes of death after major burn injury. Usually, sepsis appears as a consequence of a gram-negative bacteriaemia with release of endotoxins. In this study, the plasma endotoxin levels of seven patients (three female, four male; average age 51.3 +/- 23.8 years) with burns between 43.5 and 78 % Total Body Surface Area (Abbreviated Burn Severity Index 8 - 12) were determined for five days after thermal trauma every three hours by ELISA and compared with the concentration of procalcitonin (PCT) and C-reactive protein (CRP). A calculation of the Horrowitz-Index (PaO(2)/FiO(2)) and the Pressure-Adjusted Heart Rate (HR x CVP/MAP) took place to show a possible correlation between the endotoxin concentration and the cardiopulmonary organ function. Additionally, we analysed whether operative treatment can influence the level of plasma endotoxin in the early phase after burn injury. At any time after burn trauma, endotoxins could be detected in the plasma of all patients. Between the second and third day, there was a considerable increase in the endotoxin concentration with a maximum after 57 hours of 0.48 +/- 0.32 EU/ml. Two patients with sepsis and death in the further course had a rather distinctive increase. From the fourth day on, occasional episodes of increases in endotoxin concentration were noted. Postoperatively, there was a short increase in plasma endotoxin on the second and fourth day. The plasma endotoxin level showed no correlation with the PCT and CRP or with the oxygenation in the patients' blood. However, a positive correlation could be observed with the Pressure-Adjusted Heart Rate (p = 0.0061; r(2) = 0.212). An explanation for the endotoxin increase after 57 hours could be the translocation of intestinal bacteria, the beginning of bacterial colonisation or decomposition products of the burn wound with protein-protein complexes. Later on, infectious diseases such as pneumonia with gram-negative bacteria are of importance, too. According to the Two-Hit Model, the increase of plasma endotoxin can serve as a trigger and cause a recurrence of systemic inflammation with the changes observed in cardiac organ function, multiple organ dysfunction, and multiple organ failure.