• Haematological
    • Blood groups
      • O (47%)
        A (42%)
        B (8%)
        AB (3%)
        • O is Mendelian recessive
    • Minimising need for allogenic blood transfusion
      • Pre-op
        • Elective surgery postponed until anaemia investigated
        • Stop anticoagulants
        • Seek haematological advice for patients with bleeding disorders
        • Pre-op autologous donation
      • Intra-op
        • Senior surgeon
        • Tourniquets
        • Temperature control
        • Regional anaesthesia
        • Local with adrenaline
        • Hypotensive anaesthesia
        • Pharmacological therapy (tranexamic acid, desmopressin in Von Willibrand's)
        • Cell saver
          • If blood loss anticipated > 1L
            Rare blood group
            Low Hb
            Objection to allogenic blood (e.g. JW)
    • TEG measurement
      Link:Thromboelastometry
      • Clotting time (R -15-30 mins)
        • From start of curve to 1mm wide. Coagulation factor activation.
      • Clot formation time (K - 6-12 mins)
        • Time taken for graph to widen from 1mm to 20 mm. Coagulation factor amplification.
      • Clot firmness (MA - 50-60mm)
        • Curve at it's widest point
      • Alpha angle (40-50 ͦ)
        • From midline to 1mm point tangental to the curve. Indicates speed of clot formation
      • Lysis time (<7.5% at 30 mins)
        • Decrease time from MA - decrease of > 15% indicates fibrinolysis. Measured at 30 mins and 60 mins after MA recorded.
      • Lambda angle
        • Angle showing lysis rate
    • TED Risk factors
      Link:../Guidence - VTE (NICE)
      • Patient factors
        • Obesity
          DM
          Carcinoma
          Hyperviscosity
          Acute inflammatory conditions
          Age > 60
          Travel > 3hrs in 4 wks prior to surgery
          CVC in situ
          Pregnancy
          COCP
          Musk proliferating disorder
          Severe sepsis
          Recent MI/CVA
      • Thrombophilias
        • APC resistance e.g. Factor V Leiden deficiency
          Protein C deficiency
          Protein S deficiency
          ATIII deficiency
          APS
    • Risks Of Blood Transfusion
      • Immunological
        • Immediate Haemolytic: due to ABO incompatibility
          Delayed haemolytic: due to red cell antibody due to previous transfusion
          Febrile non-haemolytic reaction: due to recipient anti-leucocyte antibodies
          Anaphylaxis
          Urticaria
          TRALI: due to anti leucocyte antibodies in donor blood
      • Infectious
        • Hep B, C, HIV, Malaria, CMV, Brucellosis, bacterial contamination, prions
      • Physiological
        • Hyperkalaemia
          Hypocalcaemia
          Acidosis
          Dilution coagulopathy
          Thrombocytopenia
          Hypothermia
          Impaired oxygen delivery
          DIC
          TACO
          Immunomodulation
    • Sickle Cell Disease
      Link:../Haemoglobinopathies
      • Due to substitution of glutamic acid by valid in 6th amino acid of beta chains
      • Autosomal recessive (trait confers malaria prevention)
      • Prevalent in African and Asian population (trait 1%, SCD 10%)
      • Sickledex does not differentiate between trait and disease
      • Normochromic normocytic anaemia
      • PREVENT
        Dehydration
        Hypothermia
        Acidosis
        Pain
        Hyperaemia
        Tourniquet