Translocation of endotoxin and acute-phase proteins in malleolar fractures

Translocation of endotoxins was demonstrated for multiple injury but not for minor trauma such as isolated malleolar fractures. Major trauma leads to substantial changes in the plasma concentration of acute-phase proteins. However, isolated malleolar fractures are minor trauma. The objective of this study was to elucidate the kinetics of endotoxemia and the ability of plasma to inactivate endotoxin of patients operated on malleolar fractures and to demonstrate the early time course of the acute-phase proteins C-reactive protein, transferrin, alpha1-acid glycoprotein, haptoglobin, and interleukin-6 and to correlate them with the amount of endotoxemia.

Thirty patients with malleolar fractures were operated on within 6 hours after injury. Blood was collected immediately after admission and regularly up to 96 hours after surgery.

Preoperative endotoxin plasma levels were increased compared with that of healthy individuals (0.05 +/- 0.017 vs. 0.02 EU/mL). Endotoxemia peaked 0.5 hours after the surgical procedure at 0.096 +/- 0.03 (p < 0.05 vs. healthy) and decreased to almost normal values after 24 hours. The ability of the plasma to inactivate endotoxin was significantly reduced after the surgical procedure compared with normal subjects (recovery, 0.17 +/- 0.028 EU/mL vs. 0.04 +/- 0.01 EU/mL; p < 0.05). Plasma interleukin-6 peaked 0.5 hours postoperatively (114 +/- 11 pg/mL, p < 0.05 vs. healthy), decreasing thereafter. C-Reactive protein peaked at 45 +/- 5 mg/mL (p < 0.05) 48 hours after injury. Transferrin decreased significantly postoperatively (2.41 +/- 0.12 mg/mL vs. pre-OP 2.65 +/- 0.1 mg/mL) and remained on this level for 96 hours. Both, alpha1-acid glycoprotein and haptoglobin increased postoperatively until day 4 (0.78 +/- 0.06 mg/mL to 1.15 +/- 0.08 mg/mL and 1.51 +/- 0.12 mg/mL to 3.24 +/- 0.22 mg/mL). There was no correlation between endotoxemia and the concentrations of the acute-phase proteins and interleukin-6.

Surgery for malleolar fractures is associated with temporary endotoxemia and temporary reduced endotoxin inactivation capacity of the plasma. The injury and the surgical procedure leads to substantial changes in the plasma concentrations of acute-phase proteins. The relation between endotoxemia and acute-phase response is not dose dependent.