Coagulopathies

Platelet disorders

• Decreased marrow production
• Excess destruction
• Poorly-functioning platelets

Coagulation disorders

Haemophilia A

• • Factor VIII deficiency
  • X-linked recessive
  • Coagulopathy-type bleeding - haemarthrosis, bleed into muscle
  • Prolonged APTT and decreased VIII assay
  • Desmopressin IV raises factor VIII levels and may be sufficient for moderate bleeding
  • Major bleeds require recombinant factor VIII

Haemophilia B (Christmas disease)

• • Factor IX deficiency
  • X-linked recessive
  • Behaves clinically like Haemophilia A
  • Treat with recombinant factor IX

Acquired haemophilia

• • Suddenly-appearing autoantibodies that interfere with factor VIII

Liver disease

• • Decreased synthesis of clotting factors, decreased absorption of vitamin K, abnormalities of platelet function

Malabsorption

• • Less uptake of vitamin K, which is needed for factors 2, 7, 9 and 10
  • Treat with IV vitamin K, or human prothrombin complex/FFP acutely

Trauma-induced coagulopathy

• Diagnosis
  • Trauma patients should ideally have TEG on admission
  • Thromboelastography (TEG)
    • Measures the physical properties of the clot in whole blood via a pin suspended in a cup, as the elasticity and strength of the clot changes
    • Allows for real-time interpretation of clot dynamics as the clot develops and is subsequently broken down
    • R-time (reaction time) is the time to clot initiation, dependent on clotting factors (normally 4-8 minutes)
    • K-time (kinetics) is the time needed to reach 20mm clot strength (normally 1-2 mins with rTEG and 1-3 mins with standard TEG - dependent on fibrinogen
    • Alpha = slope of the angle between R and K - dependent on fibrinogen, how fast does the clot build up
    • TNA = time to maximum amplitude
    • MA = maximum amplitude = the ultimate strength of the clot - dependent on platelets and fibrin

• Rotational Thromboelastometry
  • Similar information to TEG but different mechanism (pin rotates instead of cup rotating)
• Not really clear which is better yet, but there is much more literature for TEG than ROTEM

• Treatment
  • Based on coag profile
    • INR >1.2 or aPTT >30 seconds needs resus with plasma
    • Platelets <100,000 for diffuse bleeding or <50,000 for microvascular bleeding were indications for platelets
    • Hypofibrinogenaemia <229 mg/dL is an indication for cryoprecipitate (each unit of cryo should raise fibrinogen by 10mg/dL)