Blood Transfusion

Question 1

Process by which WBCs are removed from a blood transfusion

Answer 1

Leucodepletion

Question 2

Centrifuged FFP

Answer 2

Cyroprecipitate

Question 3

Factor concentrates, albumin, immunoglobulins

Answer 3

Fractionation

Question 4

Antibodies in one individual reacting to cells of another individual

Answer 4

Alloantibodies

Question 5

A type of haemolysis caused by ABO incompatibility

Answer 5

Intravascular

Question 6

A type of haemolysis caused by Rh incompatibility

Answer 6

Extravascular

Question 7

1 unit RBCs is what volume

Answer 7

275ml

Question 8

How are RBCs stored?

Answer 8

4 degresses for less than 35 days

Question 9

Purpose of RBC transfusion

Answer 9

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.

Question 10

Transfusion threshold trigger

Answer 10

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

Question 11

Target Hb conc. for anaemic patients

Answer 11

80-100g/dL

Question 12

Target Hb conc. for patients with inherited anaemias

Answer 12

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

Question 13

Treatment for anaemia in patients with renal disease

Answer 13

Erythropoietin

Question 14

How are platelets stored?

Answer 14

room temp. 5 day shelf life.

Question 15

Adult therapeutic dose of platelety

Answer 15

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

Question 16

In what 4 causes would you transfuse platelets?

Answer 16

Severe thrombocytopenia
Massive haemorrhage
Bone marrow failure
Prophylaxis for surgery

Question 17

Contraindications for platelet transfusion

Answer 17

Heparin induced thrombocytopenia and thrombosis

Thrombotic thrombocytopenic purpura

Question 18

How is fresh frozen plasma stored?

Answer 18

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

Question 19

In what 3 causes would you transfuse someone with FFP

Answer 19

Coagulopathy with bleeding/surgery
Massive haemorrhage
Thrombotic thrombocytopenic purpura

Question 20

Contraindications for fresh frozen plasma infusion

Answer 20

Warfarin reversal

Replacement of single factor deficiency

Question 21

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

Answer 21

Prothrombin complex concentrate

Question 22

When would you require CMV negative blood transfusions

Answer 22

Children

Question 23

Why would you need to irradiate blood before transfusion

Answer 23

To prevent graft vs. host disease

Question 24

Group and Screen

Answer 24

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

Question 25

Compatibility testing 'crossmatching'

Answer 25

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

Question 26

What time scale classes as an acute complication of transfusion

Question 27

Name 4 acute immunological complications of transfusion

Answer 27

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

Question 28

Describe the effects of an acute haemolytic reaction

Answer 28

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

Question 29

Onset of ABO incompatibility/acute haemolytic reaction

Answer 29

During transfusion

Question 30

Signs of Acute haemolytic reaction

Answer 30

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

Question 31

Prognosis for acute haemolytic reaction

Answer 31

fatal in 20-30%

Question 32

Cause of ABO incompatibility

Answer 32

Always human error

Question 33

When does a delayed haemolytic reaction occur

Answer 33

3-14 days after RBC transfusion

Question 34

Clinical features of delayed haemolytic reaction

Answer 34

Fatigue, jaundice and/or fever

Question 35

Pathological cause of delayed haemolytic reaction

Answer 35

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

Question 36

Lab findings of delayed haemolytic reaction

Answer 36

low Hb High LDH high bilirubin

Question 37

Test used to confirm haemolysis is due to antibodies on RBCs

Answer 37

Anti-human globulin (Coomb's test)

Question 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

Answer 38

Transfusion related acute lung injury

Question 39

Time of onset and prognosis for transfusion related acute lung injury

Answer 39

Occurs within 6 hrs | Majority recover in around 3 days

Question 40

Treatment for transfusion related acute lung injury

Answer 40

Supportive e.g. oxygen, mechinical ventilation

Question 41

Symptoms for transufion associated circulatory overload (TACO)

Answer 41

Sudden dyspnoea, orthopneoa, tachycardia, hypertension, hypoxemia

Question 42

Signs of TACO

Answer 42

increased BP | Increased JVP

Question 43

2 main types of allergic reactions in transfusion

Answer 43

Urticarial rash with or without wheeze | Anaphylaxis

Question 44

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

Answer 44

Febrile non haemolytic transfusion reactions

Question 45

Symptoms of febrile non haemolytic transfusion reactions

Answer 45

Fever, rise in temp, shakes/rigor

Question 46

RBCs broken down in the blood vessels

Answer 46

Intravascular haemolysis

Question 47

RBCs broken down by macrophages in the liver/spllen

Answer 47

Extravascular haemolysis

Question 48

Briefly outline the pathology behind thrombotic thrombocytopenic purpura

Answer 48

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.