Increased interleukin-6 in collected drainage blood after total knee arthroplasty - An association with febrile reactions during retransfusion

We determined interleukin-6 (IL-6) concentrations in collected shed drainag e blood intended for retransfusion in a prospective study in 81 patients af ter total knee replacement. We found large increases in IL-6 levels, averag ing 6.5 (SD 3.9) ng/mL, in shed blood collected in the first 6 postoperativ e hours, 3 patients had febrile reactions after collected blood was retrans fused. The IL-6 levels in the drainage blood of these patients were very hi gh (9.6-13.4 ng/mL), In the blood collected after 6 hours, IL-6 concentrati ons increased to 47 (SD 33) ng/mL (p < 0.001). These results suggest a rela tion between increased interleukin-6 concentrations in shed drainage blood and the occurrence of febrile reactions after retransfusion of such blood.