title: In vitro combinations of red blood cell, plasma and platelet components evaluated by thromboelastography.
abstract: BACKGROUND
  Thromboelastography is increasingly used to evaluate coagulation in massively bleeding patients. The aim of this study was to investigate how different combinations of blood components affect in vitro whole blood clotting measured by thromboelastography.
  
  
  METHODS
  Packed red blood cells, plasma and platelets from fresh and old blood components were mixed in vitro, in proportions of 4:4:1, 5:5:2, 8:4:1 and 2:1:0, and analysed with thromboelastography. For the ratio 4:4:1 the experiment was done at both 37 °C and 32 °C.
  
  
  RESULTS
  Thromboelastography curves were within normal reference values for the blood component proportions of 4:4:1 and 5:5:2. For 8:4:1, the angle and maximal amplitude were reduced below normal values, indicating low levels of fibrinogen and/or platelets. For the 2:1:0 proportion, all parameters were affected resulting in severely impaired in vitro clot formation. The reaction-time, reflecting the coagulation factor-dependent, initial clot formation, was slightly increased at a low temperature. Prolonged storage of the components did not affect the curve.
  
  
  CONCLUSIONS
  With the introduction of guidelines on the management of massive bleeding it is important to have tools for the assessment of the new protocols. In vitro evaluation of mixtures of packed red blood cells, plasma and platelets by thromboelastography may be relevant in the prediction of in vivo clot formation and haemostasis.
authors: Department of Medicine, Division of Haematology, Coagulation Unit, Karolinska University Hospital, Stockholm, Sweden Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden.
authors: Anna
authors: A
authors: Agren
authors: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden Department of Medicine, Division of Haematology, Karolinska University Hospital, Stockholm, Sweden.
authors: Gustaf
authors: G
authors: Edgren
authors: Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Stockholm, Sweden.
authors: Malin
authors: M
authors: Kardell
authors: Department of Anaesthesiology and Intensive Care, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden.
authors: Anders
authors: A
authors: Ostlund
authors: Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Stockholm, Sweden Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.
authors: Agneta Taune
authors: AT
authors: Wikman
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D001792:Blood Platelets / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D001793:Blood Preservation; D004912:Erythrocytes / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D010949:Plasma / Q000737:chemistry* / Q000378:metabolism; D013916:Thrombelastography