title: Quality of Clotting Factor Activity in Fresh Frozen Plasma at Thaw with a Microwave System and after Storage at 4 degrees C for 48 Hours.
abstract: BACKGROUND
  Uncontrolled hemorrhage in polytrauma patients usually results in rapid need of blood products. Despite the shorter thawing times of microwave devices for heating fresh frozen plasma (FFP), their use has remained controversial, and just a few laboratory analyses have been published on this topic. The aim of this study was to analyse the quality of clotting factors immediately after thawing FFP with a microwave device and after 48-hour post thaw storage at 4 degrees C.
  
  
  METHODS
  24 FFP units of all four ABO blood groups (six of each blood group) were thawed with a Transfusio-therm 2000 and later stored at 4 degrees C for 48 hours. Samples were drawn aseptically and investigated on various clotting factors and protein proteases (fibrinogen, antithrombin, FII, FV, FVII, FVIII, FIX, FX, FXI, FXIII, vWF antigen and activity, protein S, and protein C) using standard coagulation and chromogenic assays immediately after thawing and again after a 48-hour storage period at 4 degrees C. All units were tested for both anaerobic and aerobic microbial contamination using standard operating procedures immediately after thawing.
  
  
  RESULTS
  After thawing, all coagulation factors and protein protease activities were within normal ranges. Blood group O individuals had approximately 25% lower plasma levels of vWF antigen and activity. After a 48-hour storage period at 4 degrees C, FVIII and FIX activities declined significantly in all blood groups, whereas the remaining clotting factors remained comparably stable.
  
  
  CONCLUSIONS
  Immediately after rapid thawing using a microwave system, all FFP units contained adequate coagulation factor activities to maintain hemostatic activity at the time of product thaw. The post thaw refrigerated storage caused an anticipated decrease in factor VIII and IX activities, but retained normal coagulation factor levels of many plasma proteins. Therefore we conclude that the Transfusio-therm 2000 has no clinically significant influence on the activity of clotting factors and plasma proteases in FFP units.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kuta
authors.forename: Barbara
authors.initials: B
authors.lastname: Hauck-Dlimi
authors.forename: Julian
authors.initials: J
authors.lastname: Strobel
authors.forename: Robert
authors.initials: R
authors.lastname: Zimmermann
authors.forename: Reinhold
authors.initials: R
authors.lastname: Eckstein
mesh_terms: D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000378:metabolism*; D001780:Blood Coagulation Tests; D001793:Blood Preservation / Q000379:methods*; D003080:Cold Temperature; D015925:Cryopreservation; D004795:Enzyme Stability; D005615:Freezing; D006801:Humans; D008872:Microwaves; D010949:Plasma / Q000378:metabolism* / Q000382:microbiology; D011489:Protein Denaturation; D055550:Protein Stability; D013997:Time Factors
chemical_list: D001779:Blood Coagulation Factors