Peri-op Care: Blood Transfusions

Question 1

In which situations are packed red cells used?

Answer 1

Most common transfusion product:

• substantial haemorrhage
• severe anaemia

Question 2

What is FFP and in which situations is it used?

Answer 2

Fresh frozen plasma = plasma separated from fresh whole blood and frozen, containing near normal amounts of clotting factors and other plasma proteins.

Used to:

• replaced clotting factors exhausted during major haemorrhage
• replace deficiencies of coagulation factors in continued bleeding when necessary factors are unavailable, e.g. liver disease, DIC, thrombotic thrombocytopenia purpura

Question 3

In which situations are platelet concentrates used?

Answer 3

Indicated if platelet count <50 x 10^9/L:

• platelet exhaustion during major haemorrhage
• thrombocytopenia (avoid in ITP exp. if life-threatening haemorrhage)

Question 4

In which situations are cryoprecipitate, fibrinogen and other specific clotting factor concentrates used?

Answer 4

In various coagulation deficiencies, e.g. haemophilia, hypofibrinogenaemia

Question 5

Which blood groups are the universal donors? The universal receivers?

Answer 5

Universal donors = O-

Universal receivers = AB+

Question 6

What would you give a patient with <30% blood volume loss?

Answer 6

Requires only crystalloids/colloids (exc. in pre-existing anaemia)

Question 7

What would you give a patient with 30-40% blood volume loss?

Answer 7

Requires red cell transfusion

Question 8

What would you give a patient with >40% blood volume loss (>2L)?

Answer 8

Requires rapid volume replacement with crystalloids/colloids + urgent provision of blood and blood products

Question 9

Define massive blood loss. What is the clinical manifestation of this?

Answer 9

Haemorrhage of 50% blood volume in 3hrs, >1x blood volume in 24hrs or >150ml/min.

Leads to a systolic pressure <90mmHg or HR >110bpm.

Question 10

Describe the massive blood loss protocol.

Answer 10

1. Immediate resuscitation with 4units RBCs (O- blood if blood group unknown).
2. If bleeding continues, further RBCs should be given with FFP to prevent coagulopathy.
3. Platelet concentrates given to maintain levels >100 x 10^9/L.
4. Repeat coagulation screens after every 4 units to determine need for other blood products.
5. If bleeding persists, recombinant activated factor VII occasionally recommended.

Question 11

A patient who has received a blood transfusion immediately has a temp rise >1 degree and starts shivering. What is the likely diagnosis? How would you manage?

Answer 11

Febrile non-haemolytic transfusion reaction

• usually caused by leukocyte incompatibility
• more common in multi-transfused or parous women
• symptoms usually subside after stopping transfusion for 15-30min and administering anti-pyretics and anti-histamines
• rarely life-threatening and rare since universal leucodepletion of blood products

Question 12

A patient receiving a blood transfusion develops a haemolytic transfusion reaction. Why does it occur?

Answer 12

Occurs due to: blood group incompatibility (mostly due to human error). If major ABO incompatibility, massive haemolysis may be fatal. Incompatibility of minor determinants causes lesser degree of haemolysis.

Question 13

What are the symptoms of a haemolytic transfusion reaction? How would you confirm diagnosis?

Answer 13

Symptoms:

• rapidly developing pyrexia at transfusion onset
• dyspnoea and constrictive feeling in chest
• intense headache
• hypotension
• severe loin pain and acute oliguric renal failure with haemoglobinuria (obstruction of tubules with haemoglobin causing ATN)
• jaundice (hrs-days later)
• DIC with spontaneous bruising and haemorrhage

Diagnosis confirmed by blood test:

• hyperbilirubinaemia
• positive Coomb’s test
• new antibody

Question 14

How should a haemolytic transfusion reaction be managed?

Answer 14

Transfusion must be halted immediately and patient resuscitated.

Oliguria treated by osmotic diuresis, e.g. mannitol +/- loop diuretic.

Question 15

A patient having had a blood transfusion develops an acute and rapid onset SOB and cough. What is the diagnosis? How is this managed?

Answer 15

TRANSFUSION-RELATED ACUTE LUNG INJURY

• caused by donor antibodies reacting with Pt’s leucocytes, especially occurs in transfusion of plasma-containing products (implicated donors usually multifarious women so FFP now sourced almost entirely from male donors)
• usually requires intensive care and mechanical ventilation
• typically a ‘white-out’ on CXR

Question 16

1 week after a blood transfusion, a patient develops thrombocytopenia and bleeding. What is the diagnosis? How is this managed?

Answer 16

POST-TRANSFUSION PURPURA

• caused by platelet-specific alloantibodies, potentially fatal (rare)
• most common in women
• treated with high dose IV immunoglobulins (favourable resp in 85%)