Haem: Blood Tranfusions Pt.3

Question 1

How are acute and delayed transfusion reactions defined?

Answer 1

Acute < 24 hours

Delayed > 24 hours

Question 2

List some causes of acute transfusion reactions.

Answer 2

• Acute haemolytic (ABO incompatibility)
• Allergic/anaphylaxis
• Infection (bacterial)
• Febrile non-haemolytic
• Respiratory (TACO, TRALI)

TACO - Transfusion associated cardiovascular overload
TRALI - Transfusion related acute lung injury

Question 3

List some causes of delayed transfusion reactions.

Answer 3

• Delayed haemolytic transfusion reaction
• Infection (viral, malaria, vCJD)
• TA-GvHD
• Post-transfusion purpura
• Iron overload

Question 4

What are some early clinical signs that might be suggestive of acute transfusion reaction?

Answer 4

• Rise in temperature
• Tachycardia
• Fall in BP

NOTE: these can occur before the patient experiences any symptoms

Question 5

List some symptoms of an acute transfusion reaction.

Answer 5

• Fever
• Rigors
• Flushing
• Vomiting
• Dyspnoea
• Pain at transfusion site
• Chest pain
• Urticaria and itching
• Collapse

Question 6

If the patient is unconscious, how might you detect an early transfusion reaction?

Answer 6

• Baseline temperature, pulse, RR and BP before transfusion
• Repeat every 15 mins (most reactions start within 15 mins)
• Repeat hourly and at the end of the transfusion

Question 7

What are the clinical features of a febrile non-haemolytic transfusion reaction?

Answer 7

• Occurs during/soon after transfusion (of blood or platelets)
• Rise in temperature, chills and rigors

Unpleasant, but not life-threatening

Question 8

What causes febrile non-haemolytic transfusion reactions?

Answer 8

Release of cytokines from white cell during storage

NOTE: this used to be common before blood was leucodepleted

Question 9

How is febrile non-haemolytic transfusion reaction treated?

Answer 9

Slow/stop the transfusion and treated with paracetamol

Question 10

Describe the clinical features of an allergic transfusion reaction.

Answer 10

• Mild urticarial or itchy rash
• Sometimes causes a wheeze

Common especially with plasma transfusions

Question 11

How is an allergic transfusion reaction managed?

Answer 11

• Stop or slow the transfusion
• IV antihistamines

Question 12

What usually causes allergic transfusion reactions?

Answer 12

Allergy to donor plasma proteins

NOTE: it is more common in patients with a history of atopic disease and it may not recur

Question 13

List some symptoms of an acute haemolytic transfusion reaction.

Answer 13

Symptoms

• Chest/loin pain
• Fever
• Vomiting
• Flushing
• Collapse
• Haemoglobinuria (later)

Obs

• Low BP
• High HR
• High Temp

Question 14

In an acute haemolytic transfusion reaction, why is it important to take a blood sample?

Answer 14

Send for FBC, biochemistry, coagulation, repeat X-match and DAT

Question 15

What is the cause of acute haemolytic transfusion reaction?

Answer 15

Tranfusion of wrong ABO blood group leading to IgM-mediated intravascular haemolysis

Question 16

How does bacterial contamination from donated blood products present?

Answer 16

Similarly to sepsis/ABO mismatch

• Fever
• Vomiting
• Flushing
• Collapse

Obs (shock)

• Low BP
• Increased HR
• Increased temperature

Question 17

What happens when bacteria infect donated blood products?

Answer 17

• Bacteria can produce an endotoxin that causes immediate collapse
• The bacteria could have come from the donor or from the processing of blood products

Question 18

List blood products in order of likelihood of getting contaminated?

Answer 18

• Platelets (most likely)
• RBCs
• Plasma (least likely)

Question 19

What measures can be taken to reduce the likelihood of bacterial contamination?

Answer 19

• Donor questioning
• Arm cleaning
• Diversion of first 20 mL into a pouch

Question 20

Describe the storage and shelf-life of RBCs.

Answer 20

• Stored in 4 degree fridge for 35 days
• If kept out for >30 mins -> cannot be re-stored
• Complete transfusion must take place within 4.5 hours of leaving the fridge