Blood Transfusions, Group Types and Compatibilities

Question 1

Discuss the significance of the following statement:

“The D antigen is the most immunogenic of the Rh antigens.”

Answer 1

Presence of a single D antigen confers upon an individual the designation Rh-positive; its absence means that the person is Rh-negative. The letter d is commonly used to indicate the lack of D in Rh-negative individuals, but neither d antigen nor anti-d has been detected.

Question 2

Why is blood type O Rh-negative referred to as the universal donor?

Answer 2

Type O blood lacks antigens on the outside of the red blood cells. This means that our immune system will not react to the blood because there is no antigen to react against.

Question 3

Why is cross-matching necessary prior to a blood transfusion?

Answer 3

Compatibility testing is important to prevent transfusion of incompatible donor red cells that might result in a haemolytic transfusion reaction. Crossmatching is used to confirm compatibility between the patient’s blood (plasma) and the donor red cells

Question 4

What causes a haemolytic transfusion reaction to occur?

Answer 4

• ABO/ Rh mismatch
• Red blood alloantibodies (non ABO) as a result of patient immunisation from previous pregnancy
• O group donor platelets with high titres of Anti-A or anti-B transfused with O recipient.

Question 5

Describe the clinical manifestations associated with a haemolytic transfusion reaction.

Answer 5

rash
dark urine
chills
fainting or dizziness
fever
flank pain
skin flushing
shortness of breath
itching

Question 6

What interventions are required should a haemolytic transfusion reaction occur?

Answer 6

Stop the transfusion immediately

Check and monitor vital signs

Maintain intravenous (IV) access (Do not flush existing line and use a new IV line if required)

Check the right pack has been given to the right patient

Notify your Medical Officer and Transfusion Service Provide

Question 7

Fresh frozen plasma USE?

Answer 7

• Replacement of single coagulation deficiency
• Immediate reversal of wharfarin effect where prothrombin complex is not available
• Inherited coagulation inhibitor deficiency where specific concentrate is not available
• 10-20mL/Kg/Hour

Question 8

Identify the storage temperature required for the following blood products:

Red Cells: ________________
Platelets: ________________
Fresh frozen plasma, cryodepleted plasma, cryoprecipitate: _____________________

Answer 8

Red Cells: 2–6 ºC
Platelets: 20-24ºC
Fresh frozen plasma, cryodepleted plasma, cryoprecipitate: At or below 25ºC

Question 9

What is the maximum time allowed for red cell components to be at room temperature?

Answer 9

Red cells: 4hrs

Question 10

Why should platelets not be transfused through a blood administration set that has been used for red cells?

Answer 10

Platelets must not be transfused through a blood administration set which has been used for red cells, as red cell debris in the inline filter may trap infused platelets.

Question 11

Red cells Infusion Rate?

Answer 11

1-3 hours

Question 12

Platelets Infusion Rate?

Answer 12

15-30 minutes

Question 13

Fresh frozen plasma Infusion Rate?

Answer 13

30 minutes

Question 14

Cryoprecipitate Infusion Rate?

Answer 14

30-60 minutes per standard adult dose

Question 15

When determining blood groups, which three antigens are the most important?

Answer 15

,

Question 16

Compound Sodium Lactate (Hartmann’s):

Indications
Advantages
Disadvantages

Answer 16

Indications:
Restoration of circulating volume and the
replacement of electrolyte deficits.

Advantages:
Good availabilty, safe to use, low cost and aids in buffering acidosis.

Disadvantages:
Rapid movement from the intravascular to the extravsacular space, leading to 3 or more times requirement replacement.

Question 17

Packed Red Blood Cells (PRBC’s):

Indications
Advantages
Disadvantages

Answer 17

Indications:
Restoration of intravsacular voulme and replacement of oxygen carrying capacity.

Advantages:
One unit of RBCs should increase the haemoglobin of a 70kg adult by approx 1g/l in the absence of volume overload or continuing blood loss.

Disadvantages:
Red cells require compatibility testings, risk of transmitting blood-borne pathogens and it should be warmed to prevent hypothermia.

Question 18

Platelets:

Indications
Advantages
Disadvantages

Answer 18

Indications:
Significant thrombocytopenia and for continued haemorrhage.

Advantages:
Compatibilty testing is not required.

Disadvantages:
Postexposure prophylaxis with ant-Rh immune globin should be considered following Rh+ platelet transfusion to an Rh- woman.

Question 19

Albumin:

Indications
Advantages
Disadvantages

Answer 19

Indications:
Albumin is a protein made by the liver, used to treat shock, burns, and low blood protein

Advantages:
fast
high recovery rate

Disadvantages:
Lots of proteins bonds to albumins

Question 20

Normal saline:

Indications
Advantages
Disadvantages

Answer 20

Indications:
is indicated as a source of water and electrolytes.

Advantages:
can be given to anyone
effective in diabetes

Disadvantages:
too much sodium
too much chloride

Question 21

Platelets used for?

Answer 21

• Prophylaxis for surgery
• Thrombocytopenia → low platelet count
• Prevention of bleeding due to thrombocytopenia as in bone marrow failure
• One adult therapeutic dose (ATD) 30-60 minutes

Question 22

Packed red blood cells used for?

Answer 22

• Used to increase O2 carrying ability of blood in cases such as anaemia, surgery and disorders with slow bleeding
• Exchange transfusion
• Red blood cell replacement due to acute blood loss with hypervolemia
• Must be within 4 hours
• 90-120 minutes per unit specifically to the pack that is specific to patient weight to prevent transfusion associated circulatory overload (TACO)

Question 23

Why should platelets not be transfused through a blood administration set that has been used for red cells?

Answer 23

Platelets must not be transfused through a blood administration set that has been used for red cells as red cell debris may trap infused platelets. Red cells may follow platelets through the same blood administration set, but not precede platelets.