Haem - mx

Question 1

Indications for RBC transfusion

Answer 1

• Catastrophic haemorrhage - major trauma, associated hypotension
• No safer alternative available - massive bleeding + plain fluids not sufficient
• Anaemic (iron/folate/B12 not appropriate)
• Hb <70g/L + signs of compromise (tachycardia, low BP, narrow pulse pressure, cold peripheries, syncope,dyspnoea)if no signs of compromise try to address underlying issue
• Hb <80g/L + pt >65 y/o + signs of compromise or Hx of IHD/severe respiratory disease

Question 2

Indications for platelet transfusion

Answer 2

• Active bleeding +
• Plt <50 x 10^9/L (Normal 150-400 x 10^9/L)
• DIC
• Bone marrow failure (plt <10 x 10^9/L)
• If low platelets before surgery
• If cardiac bypass surgery needed + patient is on anti-platelets

Question 3

Indications for FFP transfusion

Answer 3

* Fibrinogen <1g/L
or
* INR >1.5
* Reversal of warfarin if pt is bleeding
* Bleeding from excessive anti-coagulation
* Bleeding + abnormal coagulation test results
   TTP
   Isolated factor deficiencies
   Antithrombin III deficiency
   Immunodeficiencies 

NOT to just replace volume loss
NOT to reverse warfarin if pt is not bleeding

Question 4

What does a cryoprecipitate transfusion include?

Answer 4

Very concentrated form of fibrinogen
Fibronectin F8, F13
VWF

Question 5

Indications for cryoprecipitate transfusion

Answer 5

• Massive bleeding + low fibrinogen
• Hypofibrinogenemia / afibrinogenemia
• DIC
• Reversal of anti-coagulation (FFP preferred)
• Haemophilia - emergency back up when factor concentrate not available

Question 6

What does a prothrombin complex concentrate transfusion include?

Answer 6

Factors 2, 7, 9, 10

Question 7

Indications for prothrombin complex concentrate transfusion

Answer 7

• Reversal of warfarin
• Reversal of other vitamin K antagonist anti-coagulants
• Pt with deficiency of one of the included factors (2, 7, 9, 10) (congenital, liver disease, haemophilia)
• Significant bleeding in people with coagulopathy
• Rapid anti-coagulation reversal before surgery (better than FFP)
• Contra-indicated in pt with DIC

Question 8

Sickle cell anaemia - acute painful crisis mx

Answer 8

Fluids, Oxygen, analgesia

Saturate (Oxygen)
Abx if needed
Pain relief
Cannula (IVF)

Question 9

Sickle cell anaemia - stroke mx

Answer 9

Manage as a stroke

Give an exchange blood transfusion

Question 10

Sickle cell anaemia - sequestration crisis/recurrent episodes of splenic sequestration mx

Answer 10

Splenectomy

Question 11

Sickle cell anaemia - chronic cholecystitis mx

Answer 11

Cholecystectomy

Question 12

Sickle cell anaemia mx

Answer 12

Conservative
Trigger avoidance

Medical
Prophylactic abx
Vaccinations - Haemophilus Influenzae type B, Streptococcus pneumoniae, Meningococcus, Hep B
o Oral penicillin prophylaxis started at dx and continued until 5 years of age
Regular blood transfusions - Common prophylactic treatment to maintain HbS below 30%

Hydroxyurea (increases BM ability to make HbF which doesnt have the problematic β gene)

Surgical
MB stem cell transplant (curative)

Question 13

Risks of blood transfusion

Answer 13

Over-transfusion (hyperviscosity, volume overload)
Transfusion reactions (acute, septic, febrile, and allergic)
Alloimmunisation to red cell antigens
Iron overload
Transfusion-transmitted diseases (hepatitis B and C, HIV, and other agents).

Question 14

Which transfusion is used in DIC?

Answer 14

Cryoprecipitate (rich in fibrinogen)

Question 15

Sickle cell trait management

Answer 15

• Adequate hydration
• Avoidance of excessive fluid loss
• Avoidance of severe heat
• Recurrent splenic sequestration is an indication for splenectomy

Question 16

Vasocclusive/sickle cell crisis management (7)

Answer 16

•	Avoid cold, fever, dehydration, stress
•	Analgesia
o	Paracetamol used to treat mild pain
o	NSAIDs used to treat mild to moderate pain – used with caution in patients with mild hepatic/renal impairment 
o	Codeine to treat moderate pain

• Supportive care + correction of cause
o Oxygen
o IVF
o Deep breathing exercises

• Abx if there is evidence of infection
• Blood transfusion – indicated for life-threatening vaso-occlusive events, symptomatic anaemia, acute organ dysfunction
• Hydroxycarbamide (hydroxyurea)
o Can reduce the frequency of painful crises in sickle cell disease
o Given if there are 6+ episodes of vaso-occlusive crisis per year
• Folic acid – in severe haemolysis or pregnancy

Question 17

Chronic sickle cell disease management

Answer 17

• Supportive care – prevention of complications
o Routine vaccinations - Haemophilus Influenzae type B, Streptococcus pneumoniae, Meningococcus, Hep B
o Oral penicillin prophylaxis started at dx and continued until 5 years of age

• Hydroxycarbamide (hydroxyurea)
o Considered in patients aged >2 years with sickle cell anaemia
o Increase in HbF
o Decreases the frequency of sickle cell crises, reduces transfusion requirements, decreases risk of acute chest syndrome

• Repeated blood transfusions
o Common prophylactic treatment to maintain HbS below 30%
o Required for severe anaemia or to reduce the proportion of HbS if there are lung or CNS complications, severe symptoms refractory to treatment (haemodynamic instability due to hypovolaemic shock)
o Iron overload is a common complication – chelation should be started in all children receiving regular blood transfusions (SC deferoxamine, oral deferasirox, oral deferiprone)

• Bone marrow transplantation
o 2nd line, considered in children with severe complications of sickle cell anaemia (e.g. stroke, recurrent acute chest syndrome) who are unresponsive to first-line therapies

• Stroke
o Transcranial Doppler US performed annually in children aged 2-16 years
o Regular blood transfusions considered in those with abnormal findings on transcranial Doppler US

Question 18

Acute chest syndrome as a result of vasocclusive crisis in sickle cell disease management

Answer 18

• Oxygen, incentive spirometry, continuous positive airways pressure
• Analgesia
• Hydration
• Abx (macrolide + IV cephalosporin)
• Transfusion/exchange blood transfusion
• Hydroxycarbamide

Macrolides = azithromycin, erythromycin, claritromycin 
Cephalosporins = cefuroxime, ceftriaxone, cefaclor

Question 19

Priapism as a result of vasocclusive crisis in sickle cell disease management

Answer 19

• Emergency
• Hydration + analgesia
• Minor episodes – bladder emptying, exercise, warm baths, analgesia
• Prolonged episode – aspiration + irrigation of corpora cavernosa with adrenaline or etilefrine

Question 20

What is an acute transfusion reaction + mx?

Answer 20

• Acute transfusion reaction
o Immune system attacking foreign platelets, white cells, serum proteins
o Febrile patient + urticarial skin rash (erythema, hives, itching)

o Confirm blood transfusion, stop temporarily, give paracetamol + anti-histamines, resume transfusion at a lower rate

Question 21

What is anaphylaxis + mx?

Answer 21

• Anaphylaxis
o Due to IgA deficient patients – they have anti-IgA antibodies attacking the IgA in the transfused blood
o Breathless + hypotensive patient

o Adrenaline (IM), chlorphenamine, corticosteroids, fluids

Question 22

What is a haemolytic transfusion reaction + mx?

Answer 22

• Haemolytic transfusion reaction
o Mismatch of ABO alleles- immune destruction of transfused RBC attacked by the recipient’s antibodies
o Cold, feverish, nauseated, chest/flank pain, dark red urine from haemolysis

o Stop the blood transfusion, anticipate shock + DIC, use IV fluids + IV mannitol to flush out the products of haemolysis

Question 23

What is a transfusion associated lung injury + mx?

Answer 23

• Transfusion associated lung injury (TRALI)
o Antibodies in the transfused blood cause the patient’s WBC to aggregate + clog up the pulmonary capillaries
o Breathlessness

o Respiratory support

Question 24

What is a delayed haemolytic reaction + mx?

Answer 24

• Delayed haemolytic reaction
o Mismatch of alleles of non-ABO blood groups (e.g. Duffy Kell, Kidd, Rhesus factor)
o Malaise, jaundice, fever

o Supportive treatment, symptoms are self-limiting

Question 25

What is alloimmunization?

Answer 25

• Alloimmunization o The more transfusions a patient has, the more likely they are to develop antibodies to rarer blood groups (Duffy, Kell) + the harder it becomes to find blood that is compatible with the patient’s serum antibodies

Question 26

What is a post transfusion purpura + mx? | Who is more likely to get it?

Answer 26

• Post-transfusion purpura o Antibodies against residual platelets in the red cell transfusion - these Ab destroy the patient’s own platelets - purpura o Treatment is by IVIG infusion or plasmapheresis o More likely in women who give birth (+ thus potentially been exposed to platelets with different antigens (from the baby))

Question 27

Give 3 non immune complications of blood transfusions

Answer 27

• Transfusion-associated circulatory overload (TACO) o Due to unnecessary over-transfusion + overly aggressive fluid resuscitation o Typically in elderly patients • Coagulopathy o Massive transfusion of RBC - dilutes clotting factors + platelets - blood unable to clot o Treated by transfusing platelets +/or FFP • Transfusion-transmitted infection o Septicaemia/septic shock o Stop transfusion, IV Abx, IV fluids, Oxygen