title: [Thromboelastometric profile of unwashed shed blood after primary knee arthroplasty].
abstract: BACKGROUND
  Knee arthroplasty causes significant blood loss. Different blood-saving measures exist like retransfusion of unwashed salvaged blood. Some studies question the quality of this blood and in particular its ability to clot. These studies use "static" coagulation tests reflecting only partially the reality, unlike viscoelastic methods. The main objective of this study was to evaluate the salvaged blood thromboelastometric profile using ROTEM® system and to compare these results with patient venous blood.
  
  
  METHODS
  We performed an observational, prospective, single-center study conducted over 3 months in 2013. Agreement of local ethical committee and patient consent were obtained beforehand. All adult patients who underwent a primary total knee arthroplasty were included. A thromboelastometric profile and standard laboratory tests (hemoglobin, platelets count, PT, aPTT, fibrinogen) were performed in the same time on patient venous blood and on unwashed salvaged blood in the PACU.
  
  
  RESULTS
  Twenty patients were included. The median duration of surgery was 93 minutes. Thirteen patients (65%) received tranexamic acid during procedure. The median volume of shed blood was 225 mL. Two patients (10%) received a reinfusion. Analysis of shed blood showed a major deficiency of clotting factor in standard biology (PT<10%) and an absence of clot formation in thromboelastometric test (In-tem®, Ex-tem®, Fib-tem® or Ap-tem®). Compared to venous blood, shed blood had significantly lower hemoglobin levels: 8.8 vs 13.5 g/dL (P<0.0001). Allogenic transfusion concerned 5% of patients.
  
  
  CONCLUSIONS
  In this work, we confirmed that shed blood was naturally uncoagulable probably due to a multifactorial mechanism involving a major clot factor deficiency and an activation of fibrinolysis.
authors.affiliation: Département d'anesthésie réanimation, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France. Electronic address: pierre.esnault@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Esnault
authors.affiliation: Département d'anesthésie réanimation, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France.
authors.forename: B
authors.initials: B
authors.lastname: Prunet
authors.affiliation: Département d'anesthésie réanimation, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France.
authors.forename: P J
authors.initials: PJ
authors.lastname: Cungi
authors.affiliation: Service de chirurgie orthopédique et traumatologique, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France.
authors.forename: A
authors.initials: A
authors.lastname: Caubere
authors.affiliation: Département d'anesthésie réanimation, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France.
authors.forename: G
authors.initials: G
authors.lastname: Lacroix
authors.affiliation: Département d'anesthésie réanimation, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France.
authors.forename: J
authors.initials: J
authors.lastname: Bordes
authors.affiliation: Département d'anesthésie réanimation, hospices civils de Lyon, CHU de Lyon Sud, 69310 Lyon, France.
authors.forename: J-S
authors.initials: JS
authors.lastname: David
authors.affiliation: Service de chirurgie orthopédique et traumatologique, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Gonzalez
authors.affiliation: Département d'anesthésie réanimation, hôpital d'instruction des armées Sainte-Anne, 83000 Toulon, France.
authors.forename: E
authors.initials: E
authors.lastname: Kaiser
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008297:Male; D057725:Operative Blood Salvage; D011446:Prospective Studies; D013916:Thrombelastography; D014680:Veins
keywords: Arthroplastie du genou; Coagulation; Hémostase; Knee arthroplasty; Redon récupérateur; Retransfusion drain; Sang épanché; Shed blood; Thromboelastometry; Thromboélastométrie