Release of inflammatory mediators in association with collection of wound drainage blood during orthopaedic surgery.

Ten patients undergoing hip replacement surgery were studied regarding activation of complement and leukocytes in association with collection of wound drainage blood. The blood was collected postoperatively but not reinfused due to the possible risks with reinfusion of blood containing inflammatory mediators. Blood samples for analysis of complement activation (TCC), leukocyte activation (PMN elastase) and cytokines (Interleukin-6) were drawn preoperatively from the patients. Blood samples were also drawn intraoperatively from the wound. Samples were also drawn from the collected wound drainage blood, before and after blood was passed through a microporous filter. There were elevated concentrations of TCC, PMN elastase and IL-6 in the collected wound drainage blood before and after the filter. The filtration did not significantly reduce the concentrations of these factors. In the wound blood the concentrations were higher compared to those found in the systemic blood preoperatively, but lower compared to concentrations found in the collected drainage blood. The study demonstrates that the collection of wound drainage whole blood is associated with activation of complement, release of PMN elastase and cytokines.