Dynamic changes in clot formation determined using thromboelastometry after reinfusion of unwashed anticoagulated cell-salvaged whole blood in total hip arthroplasty.

Abstract

Cell salvage is a key part of patient blood management. Different techniques are available for salvaging blood. A new intra-operative autotransfusion filter system became available for reinfusion of unwashed whole blood. Concern exists regarding whether this technique induces coagulation disturbances, offsetting the benefits of the reinfusion of autologous blood. This study was designed to investigate the content of intra-operatively salvaged filtered blood and its impact after reinfusion on clot formation in patients undergoing primary hip arthroplasty. Twenty-five patients scheduled for primary total hip arthroplasty were enrolled in the study. Cell salvage was performed using a new intra-operative autotransfusion filter system. Before surgery and within 1 hour of reinfusion of 300 mL or more of salvaged whole blood, blood samples were taken to assess clot formation by thromboelastometry and standard laboratory-based coagulation profiling. Cytokine content of the salvaged blood was assessed by enzyme-linked immunosorbent assays. Following reinfusion of 460 mL (median) of salvaged blood, thromboelastometry showed normal clot formation and did not indicate a coagulopathy. Clotting time, clot formation time, maximum firmness and maximum lysis all remained within the normal range. Standard laboratory coagulation tests were also normal in all patients before surgery and after reinfusion. Although monocyte chemoattractant protein-1 levels were higher than normal, all other measured cytokines were either undetectable or within the normal range. No adverse events were seen following cell salvage. Reinfusion of unwashed salvaged whole blood did not alter clot formation in our patients. The results add to the knowledge about this approach and contribute to the growing body of evidence regarding the lack of adverse events when reinfusing unwashed shed blood in major orthopaedic procedures.