The effect of salvaged blood on coagulation function as measured by thromboelastography

Abstract

BACKGROUND There is concern that salvaged blood has the potential to activate the coagulation system, which might place patients at risk of thrombotic complications. The aim of this study was to determine whether transfusion of salvaged blood after total knee arthroplasty (TKA) would lead to procoagulopathic changes as measured by thromboelastography (TEG), and furthermore if washing would reduce this risk. STUDY DESIGN AND METHODS Twenty two patients undergoing TKA were enrolled. Control samples were venous blood samples taken before surgery. Test samples were created by mixing the control samples with postoperatively salvaged blood, either washed or unwashed. TEG profiles were measured, noting the time to initiate clotting (R), the time of clot formation (K), the angle of clot formation (α-angle), and the maximum strength of clot (MA). RESULTS The changes in the coagulation profile from control samples to test samples were consistent for both the washed and unwashed groups: R time decreased, MA decreased, and K and alpha-angle remained the same. However, the changes were more pronounced in the unwashed group than the washed group, with a 61% decrease in R time as compared with 14%, and a 26% drop in MA as compared with 6%. CONCLUSION The addition of salvaged blood to the patient’s preoperative blood resulted in decreased clot strength as well as decreased time to initial clot formation. This suggests that the reinfusion of postoperatively salvaged washed or unwashed blood after TKA favors a change towards a more hypocoagulable state, and washing appears to reduce this effect.

Noncitrated blood transfusions used as adjunctive treatment in a 7‐year‐oldShetlandPony with haemoperitoneum due to a rupturedcorpus haemorrhagicum

“…In human hospitals with state‐of‐the art equipment, this concern has become obsolete, since a method called ‘cell washing’ is routinely used to isolate autologous red blood cells for haemotherapy (Hansen and Hansen ; Hansen and Seyfried ; Konig et al . ). Cell washing, however, is not readily available in equine practice.…”

Penetrating Injuries to the Lung and Heart: Resuscitation, Diagnosis, and Operative Indications

“…The platelet inhibition was attributed to competitive inhibition of platelet aggregation due to the high levels of fibrin degredation products in the salvaged blood. Unsurprisingly, both of these effects were reduced when the salvaged blood was washed first [65].…”

“…Despite this hypercoagulopathy on traditional clotting assays, Konig and associates have shown that, on thromboelastography (TEG), salvaged blood actually induces a mixed state of factor hypercoagulability and platelet hypocoagulability when combined with the patient's own blood [65], with a 61 % decrease in R-time and a 26 % decrease in MA [65]. The platelet inhibition was attributed to competitive inhibition of platelet aggregation due to the high levels of fibrin degredation products in the salvaged blood.…”

Blood management in total knee arthroplasty: state-of-the-art review

“…Concerns over unwashed blood include low Hb concentration, and the presence of anticoagulant and inflammatory mediators in the reinfused blood. Both washed and unwashed blood results in a hypocoagulable state, although less so with washed blood,77 but no difference in clinical outcomes has been identified 75…”