Blood Groups

Question 1

Describe the three responses to blood loss

Answer 1

• Reducing blood loss through haemostasis
• Increasing production of RBC
• Actions of the sympathetic nervous system

Question 2

Describe the process of erythropoiesis

Answer 2

Erythropoiesis is the process which produces red blood cells, which is the development from erythropoietic stem cell for mature red blood cell. It is stimulated by decreased O₂ in circulation, which is detected by the kidneys, which then secrete the hormone erythropoietin.

Question 3

Describe the response of the SNS (sympathetic nervous system) to significant blood loss

Answer 3

INCREASES::

• Heart rate and strength of contraction and cardiac output
• Constriction of veins, venous return and cardiac output
• Peripheral resistance
• Production of adrenaline

Question 4

What are the three types of blood transfusion?

Answer 4

• Whole blood
• Re-suspended red cells
• Autologous

Question 5

Describe Whole blood transfusion

Answer 5

Transfusions are indicated when blood loss is rapid and substantial

Question 6

Describe Re-suspended red cells blood transfusion

Answer 6

Consists of blood with plasma removed and replaced by additive solution

Question 7

Describe Autologous blood transfusion

Answer 7

Giving a patient a transfusion of their own blood

Question 8

Why is re-suspended red blood cell blood transfusion used?

Answer 8

For restoring oxygen-carrying capacity from severe blood loss or severe anaemia

Question 9

Define the term antigen

Answer 9

A substance that is recognised as foreign by the immune system and generates an immune response

Question 10

Using the ABO classification name the four main blood groups and state what antigens each blood group has

Answer 10

Group A
	- A antigens
Group B
	- B antigens
Group AB
	- A and B antigens
Group O
        - Neither A or B antigens

Question 11

For each of the four blood groups state what antibodies would be present in the plasma

Answer 11

Group A
- B antibody

Group B
- A antibody

Group AB
- Neither A or B antibody

Group O
- Both A and B antibody

Question 12

State the blood type for universal recipients & explain why this type can receive blood from all blood groups

Answer 12

People with AB positive blood are called “universal recipients” since they do have A, B and antigens, and thus do not have any A, B or antibodies in their plasma

Question 13

State the blood type that is called the universal donor and explain why this blood type can donate to all blood groups

Answer 13

People with O negative blood are called “universal donors” since they do not have A, B or D antigens, and do have A and B antibodies

Question 14

Define Blood Typing

Answer 14

Identifying the blood group

Question 15

Define Cross-matching

Answer 15

The mixing of donor and recipient blood for compatibility

Question 16

List the six different types of blood transfusion reactions

Answer 16

• Acute haemolytic
• Febrile
• Mild allergic
• Anaphylactic & severe allergic
• Circulatory overload
• Sepsis

Question 17

Describe what causes an acute haemolytic reaction

Answer 17

Transfusion of incompatible blood transfusion (given the wrong blood type)

Question 18

Describe what causes a febrile reaction

Answer 18

Reaction and sensitivity to donor WBC, platelets or plasma proteins

Question 19

Describe what causes a mild allergic reaction

Answer 19

Sensitivity to foreign plasma proteins

Question 20

Describe what causes an anaphylactic & severe allergic reaction

Answer 20

Sensitivity to foreign plasma proteins

Question 21

Describe what causes a circulatory overload reaction

Answer 21

Fluid administered faster than circulation can accommodate

Question 22

Describe what causes a sepsis reaction

Answer 22

Transfusion of bacterially contaminated blood components

Question 23

Describe the clinical signs & symptoms you would observe if a person had a circulatory overload reaction

Answer 23

• Cough
• Dyspnoea
• Pulmonary congestion
• Headache
• Hypertension
• Tachycardia
• Distended neck veins

Question 24

What are the two major physiological events that occur during an acute haemolytic reaction

Answer 24

• Agglutination (clumping) of RBC

- Haemolysis of RBC’s

Question 25

Describe what happens during Agglutination

Answer 25

• Occurs when antibodies attach to a number of RBC’s which are carrying the corresponding antigen
• This causes them to clump together and prevents them to not flow freely
• Obstruction of blood capillaries hindering blood flow to tissues

Question 26

Describe what happens during Haemolysis

Answer 26

Rupture of RBC’s. Haemoglobin in released into plasma and is trapped in the kidney tubules blocking them, causing acute renal failure and may cause death

Question 27

Why is an Acute Haemolytic reaction so severe?

Answer 27

• The recipients antibodies attack the antigens on the donors red blood cells
• The recipient will produce antibodies in huge numbers to attack the donor’s RBC’s

Question 28

Explain what is meant by rhesus positive

Answer 28

People who have the D antigen on RBC surface will be Rhesus positive. They have inherited the Rh factor from either their mother or father

People without the D antigen will be Rhesus negative

Question 29

What are the three homeostatic responses to blood loss IN ORDER?

Answer 29

• Vasoconstriction (Vascular Spasm)
• Platelet plug formation
• Coagulation (blood clotting)

Question 30

Function of Vasoconstriction

Answer 30

Narrowing of the blood vessels which helps to restrict blood flow and prevent blood loss

Question 31

Function of Platelet Plug Formation

Answer 31

Seals the damaged area in the blood vessel temporarily to prevent blood loss

Question 32

Function of Coagulation?

Answer 32

Formation of a stable clot (liquid to gel) to secure the platelet plug and prevent blood loss. It enables time for tissue to repair
- Clotting factors are activated