title: A mathematical model for fresh frozen plasma transfusion strategies during major trauma resuscitation with ongoing hemorrhage.
abstract: BACKGROUND
  Randomized controlled trials of how best to administer fresh frozen plasma (FFP) in the presence of ongoing severe traumatic hemorrhage are difficult to execute and have not been published. Meanwhile, coagulopathy remains a common occurrence during major trauma resuscitation and hemorrhage remains a major cause of traumatic deaths, suggesting that current coagulation factor replacement practices may be inadequate.
  
  
  METHODS
  We used a pharmacokinetic model to simulate the dilutional component of coagulopathy during hemorrhage and compared different FFP transfusion strategies for the prevention or correction, or both, of dilutional coagulopathy. Assuming the rates of volume replacement and loss are roughly equal, we derived the hematocrit and plasma coagulation factor concentration over time based on the rate of blood loss and replacement, the hematocrit and coagulation factor concentration of the transfusate, and the hematocrit and plasma factor concentration at the time when FFP transfusion begins.
  
  
  RESULTS
  Once excessive deficiency of factors has developed and bleeding is unabated, 1-1.5 units of FFP must be given for every unit of packed red blood cells (PRBC) transfused. If FFP transfusion should start before plasma factor concentration drops below 50% of normal, an FFP:PRBC transfusion ratio of 1:1 would prevent further dilution.
  
  
  CONCLUSIONS
  During resuscitation of a patient who has undergone major trauma, the equivalent of whole-blood transfusion is required to correct or prevent dilutional coagulopathy.
authors.affiliation: Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR, PRC. hoamh@cuhk.edu.hk
authors.forename: Anthony M H
authors.initials: AM
authors.lastname: Ho
authors.forename: Peter W
authors.initials: PW
authors.lastname: Dion
authors.forename: Claudia A Y
authors.initials: CA
authors.lastname: Cheng
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Karmakar
authors.forename: Gregory
authors.initials: G
authors.lastname: Cheng
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Peng
authors.forename: Yu Wai
authors.initials: YW
authors.lastname: Ng
mesh_terms: D001778:Blood Coagulation Disorders / Q000517:prevention & control; D016913:Blood Component Transfusion / Q000379:methods*; D006801:Humans; D015601:Injury Severity Score; D008962:Models, Theoretical; D010949:Plasma; D012151:Resuscitation / Q000379:methods*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012771:Shock, Hemorrhagic / Q000209:etiology / Q000628:therapy*; D014947:Wounds and Injuries / Q000150:complications