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Clinical Pathology > Blood Transfusion > Flashcards

Flashcards in Blood Transfusion Deck (48):
1

Process by which WBCs are removed from a blood transfusion

Leucodepletion

2

Centrifuged FFP

Cyroprecipitate

3

Factor concentrates, albumin, immunoglobulins

Fractionation

4

Antibodies in one individual reacting to cells of another individual

Alloantibodies

5

A type of haemolysis caused by ABO incompatibility

Intravascular

6

A type of haemolysis caused by Rh incompatibility

Extravascular

7

1 unit RBCs is what volume

275ml

8

How are RBCs stored?

4 degresses for less than 35 days

9

Purpose of RBC transfusion

To prevent symptoms of anaemia and improve QofL and to prevent damage of end organs in anaemic patients, NOT to normalise the Hb in anaemic patients.

10

Transfusion threshold trigger

Invest the concentration of Hb that is not associated iwth symptoms of anaemia

11

Target Hb conc. for anaemic patients

80-100g/dL

12

Target Hb conc. for patients with inherited anaemias

Aim to suppress endogenous erythropoiesis. Target 100-120g/L

13

Treatment for anaemia in patients with renal disease

Erythropoietin

14

How are platelets stored?

room temp. 5 day shelf life.

15

Adult therapeutic dose of platelety

Platelets from 4 pooled donations or equivalent number from a sinlge apheresis (plasma separated from blood) donation

16

In what 4 causes would you transfuse platelets?

Severe thrombocytopenia
Massive haemorrhage
Bone marrow failure
Prophylaxis for surgery

17

Contraindications for platelet transfusion

Heparin induced thrombocytopenia and thrombosis
Thrombotic thrombocytopenic purpura

18

How is fresh frozen plasma stored?

-30 degrees, for up to 24 months. Thawing takes 20-30 minutes

19

In what 3 causes would you transfuse someone with FFP

Coagulopathy with bleeding/surgery
Massive haemorrhage
Thrombotic thrombocytopenic purpura

20

Contraindications for fresh frozen plasma infusion

Warfarin reversal
Replacement of single factor deficiency

21

A blood transfusion product that contains all the vit. K dependent factors. Used to reverse warfarin over-anticoagulation

Prothrombin complex concentrate

22

When would you require CMV negative blood transfusions

Children

23

Why would you need to irradiate blood before transfusion

To prevent graft vs. host disease

24

Group and Screen

Determines ABO and RH(D) group- plasma screened for antibodies against other clinically significant blood group antigens.

25

Compatibility testing 'crossmatching'

Patients plasma is mized with samples of donor RBCs to see if reaction (agglutination or haemolysis) occurs to identify risk of acute haemolysis.

26

What time scale classes as an acute complication of transfusion

27

Name 4 acute immunological complications of transfusion

Acute haemolytic transfusion reaction 'ABO incompatibility'
Allergic reaction
Transfusion related acute lung injury (TRALI)
Febrile non-haemolytic transfusion reaction

28

Describe the effects of an acute haemolytic reaction

Release of free Hb, deposits in renal tubule
Stimulation of coagulation results in microvascular thrombosis- stimulation of cytokine storm. Scavengers release NO resulting in generalised vasoconstriction

29

Onset of ABO incompatibility/acute haemolytic reaction

During transfusion

30

Signs of Acute haemolytic reaction

Fevers/chills, back pain, infusion pain, hypotension/shock, haemoglobinuria, increased bleeding (DIC), chest pain or feeling of impending death

31

Prognosis for acute haemolytic reaction

fatal in 20-30%

32

Cause of ABO incompatibility

Always human error

33

When does a delayed haemolytic reaction occur

3-14 days after RBC transfusion

34

Clinical features of delayed haemolytic reaction

Fatigue, jaundice and/or fever

35

Pathological cause of delayed haemolytic reaction

IgG antibodies agains RBC antigens other than ABO. Antibodies are formed after the reaction

36

Lab findings of delayed haemolytic reaction

low Hb
High LDH
high bilirubin

37

Test used to confirm haemolysis is due to antibodies on RBCs

Anti-human globulin (Coomb's test)

38

Donor has antibodies to recipient's leucocytes which results in activated WBCs which lodge in pulmonary capillaries and release substances that cause endothelial damage and capillary lead

Transfusion related acute lung injury

39

Time of onset and prognosis for transfusion related acute lung injury

Occurs within 6 hrs
Majority recover in around 3 days

40

Treatment for transfusion related acute lung injury

Supportive e.g. oxygen, mechinical ventilation

41

Symptoms for transufion associated circulatory overload (TACO)

Sudden dyspnoea, orthopneoa, tachycardia, hypertension, hypoxemia

42

Signs of TACO

increased BP
Increased JVP

43

2 main types of allergic reactions in transfusion

Urticarial rash with or without wheeze
Anaphylaxis

44

Acute complication of transfusions which is due to cytokines or biologically active molecules that accumulate during storage of blood components.

Febrile non haemolytic transfusion reactions

45

Symptoms of febrile non haemolytic transfusion reactions

Fever, rise in temp, shakes/rigor

46

RBCs broken down in the blood vessels

Intravascular haemolysis

47

RBCs broken down by macrophages in the liver/spllen

Extravascular haemolysis

48

Briefly outline the pathology behind thrombotic thrombocytopenic purpura

Don't have enough of the enzyme required to break down von willebrand factor. Increased VWF in the blood results in the platelets adhering to the surface endothelium more easily, causing microthombi in the small vessels around the body.