1. Coagulopathy and blood component transfusion in trauma

2. life-threatening bleeding
Trauma
1 in 10 death worldwide
uncontrolled bleeding
40% of trauma-related deaths
leading cause of potentially preventable and early in-hospital death
life-threatening bleeding
vascular injury
coagulopathy
consumption and dilution of coagulation factors and platelets, dysfunction of platelets and the coagulation system, increased fibrinolysis, compromise of the coagulation system by the infusion of colloid, hypocalcemia, and disseminated intravascular coagulation-like syndrome

3. Pathophysiology of coagulopathy in trauma 2) Consumption coagulopathy
precise cause is difficult to identify and multifactorial

4. Pathophysiology of coagulopathy in trauma 3) Increased fibrinolysis
trauma pts. demonstrate both hypofibrinolytic and hyperfibrinolytic states
severity of injury, time from injury에 따라 달라 진다
Simmons et al.
trauma 직후 : fibrinolytic activity increase
mild~moderate inj.: 24h 이후 normal
major inj.: remain elevated
hypothermia : fibrinolytic activity 증가

5. Pathophysiology of coagulopathy in trauma 4) Hypothermia-induced coagulopathy
significant risk factors for life-threatening coagulopathy
injury severity score > 25
systolic BP < 70mmHg
acidosis with pH < 7.10
hypothermia with BT < 34℃
lethal triad
hypothermia, metabolic acidosis, progressive coagulopathy

6. Pathophysiology of coagulopathy in trauma 4) Hypothermia-induced coagulopathy
effect of hypothermia on coagulopathy is difficult to identify by routine coagulation screening tests (PT, aPTT)
hypothermia
impairs thrombin generation and the formation of platelet plugs and fibrin clots
increase clot lysis
results in coagulopathy and uncontrollable bleeding

7. Pathophysiology of coagulopathy in trauma 5) Decreased levels of coagulation factors and platelets
large volumes of crystalloid and colloid
thrombocytopenia is seen commonly in pts. received massive blood transfusion
platelets are present in whole blood
현재는 RBC unit 사용
negligible amounts of coagulation factors and platelets
thrombocytopenia and subnormal levels of coagulation factors often occur at early stage during massive RBC transfusion

8. Pathophysiology of coagulopathy in trauma 6) The effect of acute RBC loss on coagulation
unclear
as no data from trauma pts. are available, the effect of acute RBC loss on coagulation is unknown

9. Effect of massive RBC transfusion on coagulation
과거 수혈은 주로 whole blood에 의존, 현재는 specific component therapy
blood component therapy
optimizes the use of resources by allowing components to be used in different pts.
avoids potentially harmful effects caused by transfusion of surplus constituents
whole blood와 비교했을 때 massive RBC transfusion 시 earlier stage에서 coagulopathy 발생 (low levels of platelets and clotting factors)

10. Effect of massive RBC transfusion on coagulation
relationship between volume of blood loss, replacement volume and the reduction in coagulation factor and platelet levels are difficult to establish
increased acid load from RBC units may also contribute to coagulopathy
pH of an RBC unit is low, and decreases progressively during storage from 7.0 to 6.3
plasma의 high-buffering capacity로 acid-base disturbance는 잘 일어나지 않는다
trauma pts. are already acidotic, massive transfusion of RBCs further increase acid load, exacerbate the ongoing coagulopathy

11. Unresolved issues regarding blood transfusion in trauma 1) Optimal replacement therapy for FFP and platelets
massive RBC transfusion 시 FFP, platelets, fibrinogen concentrate or cryoprecipitate를 같이 줘야한다는 건 알 고 있지만 universal guideline은 없다
based on experts’ opinion or personal experience

12. Unresolved issues regarding blood transfusion in trauma 1) Optimal replacement therapy for FFP and platelets
1st approach
transfuse FFP and plts. prophylactically after a certain number of units of RBCs
FFP:RBC → 1:10 ~ 2:3
plt:RBC → 6:10 ~ 12:10
coagulopathy의 발생을 예방하거나 bleeding을 줄인다는 증거는 없다
benefit도 확실하지 않다

13. Unresolved issues regarding blood transfusion in trauma 1) Optimal replacement therapy for FFP and platelets
2nd approach
transfuse FFP, plt, cryoprecipate only when there is clinical or laboratory evidence of coagulopathy
microvascular bleeding
PT or aPTT > 1.5 times normal value
thrombocytopenia < 50000
fibrinogen concentration < 1g/L
occult site의 microvascular bleeding은 발견하기 힘들다
lab. test may take 30~60min

14. Effect of RBC transfusion on longer-term outcome in trauma 1) Multiple organ failure (MOF)
RBC transfusion has been to shown to be an independent risk factor for post-injury MOF
513명의 major trauma, severe bleeding and haemorrhagic shock 환자에 대한 연구에서 injury MOF 발생한 환자는 첫 12h 이내에 RBC 13unit 수혈받음
MOF 발생하지 않은 환자는 3.8unit
decrease in volume of RBC transfused may decrease the risk and severity of MOF

15. Effect of RBC transfusion on longer-term outcome in trauma 2) Post-injury infection
large amounts of foreign antigens may lead to downregulation of the immune system
alternative non-immune-mediated mechanism
stored RBCs are less deformable and more rigid, once transfused they may obstruct capillary blood flow, predisposing tissue to ischemia and infection as well as poor delivery of prophylactic antibiotics

16. The need for haemostatic agents
ideal hemostatic agent should be efficacious in a wide range of hemostatic dysfunctions, simple to store and use, and have a rapid action
activated recombinant factor Ⅶ (rFⅦa) is a potential candidate
effective hemostasis in a wide range of bleeding conditions
significantly dcreased RBC transfusion requirement in pts. with major trauma
optimal preconditions should be achieved before administration

17. The need for haemostatic agents
optimal preconditions
fibrinogen concentration ≥ 0.5g/L
platelet count ≥ 50/L
pH ≥ 7.2

18. Conclusions
non-surgically correctable bleeding remains a major challenge
currently, blood component replacement therapy remains the mainstay of coagulopathy-related bleeding
although RBC transfusion can be life-saving, its negative effects on post-injury outcome have been well documented
hemostatic agents, which can effectively control bleeding and reduce the amount of RBC required, may decrease mortality and morbidity in trauma pts. but are unlikely to replace blood transfusion completely