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Clinical school: Haematology > Blood products > Flashcards

Flashcards in Blood products Deck (18)
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1

What types of blood products are available?

  • Whole blood: Rarely used today
  • Packed red cells: Packed to make haematocrit ~70% and is used to treat blood loss or anaemia.
  • Platelet transfusion
  • Fresh frozen plasma: Used to correct clotting defects such as DIC, liver disease, warfarin reversal (if vitamin K too slow), TTP... Most suitable for 'clinically significant' bleeding without 'major haemorrhage'
  • Human albumin solution: Used to replace protein in hypoproteinaemic patients (e.g. liver disease, nephrotic syndrome) who are fluid overloaded. Also used to cover after large volume paracentesis for ascites in order to reduce the risk of paracentesis-induced circulatory dysfunction.
  • Cryoprecipitate: Contains factor VIII, vWD, fibrinogen, factor XIII and fibronectin. Clinically, it is most useful for replacing fibrinogen.
  • Prothrombin complex concentrate: Contains factor II, IX and X. Used for the emergency reversal of anticoagulation in patients with either severe bleeding or a head injury with suspected intracerebral haemorrhage

2

What are the thresholds and targets for packed red cell transfusion?

Patients without ACS:

Threshold - 70 g/L

Target - 70-90 g/L

Patient with ACS:

Threshold - 80 g/L

Target - 80-100 g/L

3

How is the dose of packed red cells needed determined?

  • 1U of packed red cells raises Hb by 10-15 gL
  • Consider giving only single units of packed red cells at a time unless there is active bleeding
  • Repeat FBC inbetween each dose tov determine whether further doses are needed

4

What are the acute (within 24hrs) complications associated with blood transfusions?

  1. Acute haemolytic reaction
  2. Anaphylaxis
  3. Bacterial contamination
  4. Non-haemolytic febrile transfusion reactions
  5. Allergic reactions
  6. Fluid overload
  7. Transfusion-related acute lung injury 

5

What are the chronic (>24hrs) complications associated with transfusions?

  1. Infections (e.g. viruses [Hepatitis B/C, HIV], bacteria, protozoa, prions)
  2. Iron overload
  3. Graft vs. host disease (GVHD)
  4. Post-transfusion purpura (potentially fatal drop in platelet count 5-7 days post transfusion)

6

What is a "massive" blood transfusion and what are the associated complications?

  • Massive blood transfusion is defined as replacement of an individuals blood volume with >10U of blood within 24hrs
  • Associated complications include:
  1. Thrombocythaemia
  2. Hypocalcaemia
  3. Coagulopathy due to reduced numbers of clotting factor
  4. Hypothermia

7

What is the threshold and target for packed red cell transfusion in patients with congestive heart failure?

Threshold - 50 g/L

Target - 60-80 g/L

8

What extra precautions need to be taken account when transfusing patients with CHF?

  • Give each unit over 4hrs
  • Give furosemide with every other unit
  • Check for signs of fluid overload (raised JVP, bibasal crackles...)

9

What are the thresholds for platelet transfusion in patients with active bleeding?

  • Offer platelet transfusions to patients with thrombocytopenia who have clinically significant bleeding (World Health Organization [WHO] grade 2+) and a platelet count below 30×109 per litre.
  • Use higher platelet thresholds (up to a maximum of 100×109 per litre) for patients with thrombocytopenia and either of the following:

  1. Severe bleeding (WHO grades 3 and 4)
  2. Bleeding in critical sites, such as the central nervous system (including eyes)

10

What are the thresholds for prophylactic platelet transfusions?

  • Patients not bleeding or undergoing any invasive procedures - 10 x 109 per litre (unless they are contraindicated)
  • Patients undergoing invasive procedures or surgery - 50 x 109 per litre (threshold and target)
  • Patients undergoing invasive procedures or surgery and are at high risk of bleeding - 50-75 x 109 per litre (threshold and target)
  • Patients undergoing invasive procedures or surgery at critical sites sich as the CNS (including posterior segment of the eyes) - 100 x 109 per litre (threshold and target)

 

11

What are the contraindications to prophylactic platelet transfusions?

  1. Chronic bone marrow failure
  2. Autoimmune thrombocytopenia
  3. Heparin‑induced thrombocytopenia
  4. Thrombotic thrombocytopenic purpura
  5. Patients undergoing procedures with low risk of bleeding such as central venous cannulation, bone marrow aspiration/biopsy

12

What is the dose of platelet transfusions used?

  • Do not routinely transfuse more than a single dose of platelets unless the patients have severe thrombocytopenia and active bleeding in critical sites such as the CNS

 

13

When is fresh frozen plasma used?

  • Patients with clinically significant bleeding but without major haemorrhage if they have abnormal coagulation test results (for example, prothrombin time ratio or activated partial thromboplastin time ratio above 1.5)
  • Consider prophylactic fresh frozen plasma transfusions for patients with abnormal coagulation who are having invasive procedures or surgery with a risk of clinically significant bleeding.

14

When is FFP contraindicated

  1. Are not bleeding (unless they are having invasive procedures or surgery with a risk of clinically significant bleeding)
  2. Need reversal of a vitamin K antagonist

15

When is cryoprecipitate used?

  • Consider cryoprecipitate transfusions for patients without major haemorrhage who have:

  1. Clinically significant bleeding and
  2. A fibrinogen level below 1.5 g/litre
  • Consider prophylactic cryoprecipitate transfusions for patients with a fibrinogen level below 1.0 g/litre who are having invasive procedures or surgery with a risk of clinically significant bleeding.

16

When is cryoprecipitate contraindicated?

  1. Are not bleeding and
  2. Are not having invasive procedures or surgery with a risk of clinically significant bleeding

17

When is the dose of cryoprecipitate used?

Adult dose of 2 pools when giving cryoprecipitate transfusions (for children, use 5–10 ml/kg up to a maximum of 2 pools)

18

When is prothrombin complex used?

  • Offer immediate prothrombin complex concentrate transfusions for the emergency reversal of warfarin anticoagulation in patients with either:
  1. Severe bleeding or
  2. Head injury with suspected intracerebral haemorrhage
  • Consider immediate prothrombin complex concentrate transfusions to reverse warfarin anticoagulation in patients having emergency surgery, depending on the level of anticoagulation and the bleeding risk.