11- Blood transfusion

Question 1

blood transfusion background

Answer 1

Blood products
Any part of the blood that is collected from a donor for use in a blood transfusion.

• Transfusion reactions are relatively common, even in those with appropriately cross-matched blood.
• Blood products are scarce and should therefore only be used when necessary.
• Blood group incompatibility is a rare but life-threatening complication. Blood products therefore need to be appropriately cross-matched and checked to avoid severe consequences.

Question 2

Haemoglobin recommendations
x

Answer 2

Current NICE guidelines recommend a restrictive haemoglobin concentration threshold of 70 g/L for those who need red blood cell transfusions (without any major haemorrhage or acute coronary syndrome) and a haemoglobin concentration target of 70-90 g/L after transfusion.

Question 3

Blood grouping

Answer 3

To minimise transfusion reactions. Two important blood groups:
- Rhesus D (RhD) group
- ABO blood system

Question 4

rhesus D grouping

Answer 4

• RhD+ (85%)
• RhD-

Question 5

RhD-

Answer 5

• If given RhD+ blood patient will make RhD antibody
• This is okay since their blood cells do not have RhD therefore will not attack
  Problem during pregnancy
• As anti-D antibodies can cross the placenta
• Haemolytic disease of the newborn
• Therefore give RhD specific blood to women
• Not a problem for men

Question 6

ABO group

Answer 6

Refers to presence of A and/or B antigens on the surface of RBC

Universal donor: O-ve – this blood can be given to anybody, irrespective of the recipient’s blood group, because there are no AB or Rhesus antigens on the donor RBC surface membrane. The recipient can have both A, B and Rhesus antibodies in their circulation, but they will likely not reject this donor blood, as there are no ABO or Rh antigens to attack.

Universal Acceptor: AB+ve– you can give this recipient any donor blood, irrespective of the ABO or Rhesus status. The recipient does not have any A, B, or Rhesus antibodies in their circulation and therefore cannot mount an immune response to the donor blood.

Question 7

Haemolytic disease of the newborn

Answer 7

• A woman is born with RhD- blood. Her partner is RhD+ and she becomes pregnant with a fetus that is also RhD+. During childbirth/pregnancy, she comes into contact with the foetal (Rh+ve) blood and develops antibodies to it.
• She later becomes pregnant with a second child that is also Rh +ve.
• The woman’s anti-D antibodies cross the placenta during this pregnancy and enter the foetal circulation, which contains RhD+ blood, and bind to the foetus’ RhD antigens on its RBC surface membranes.
• This causes the foetal immune system to attack and destroy its own RBCs, leading to foetal anaemia. This is termed haemolytic disease of the newborn (HDN).

Question 8

tests required for blood transfusion

Answer 8

Group and save (G&S)

Crossmatch (X-match)

Question 9

Group and Save (G&S)

Answer 9

determines the patient’s blood group (ABO and RhD) and screens the blood for any atypical antibodies.
- The process takes around 40 minutes and no blood is issued.
- A G&S is recommended if blood loss is not anticipated, but blood may be required should there be greater blood loss than expected.

Question 10

Crossmatch (X-match) –

Answer 10

Coombes involves physically mixing the patient’s blood with the donor’s blood, in order to see if any immune reaction takes places. If it does not, the donor blood is issued and can be transfused in to the patient.
- This process also takes ~40 minutes, in addition to the 40 minutes required to G&S the blood (which must be done first).
- A X-match is done if blood loss is anticipated, but the surgeon will usually inform you of this.

Question 11

coombes tests

Answer 11

A Coombs test is performed to detect the presence of antibody against red blood cells - indirect test used in a crossmatch

direct- mix patient blood with donor blood
indirect- where they only mix antibodies from the donor blood with the patient blood

Question 12

Requesting a blood product

Answer 12

• Using 3 points of identification to check you are with the correct patient (name, Date of Birth (DOB), and patient number).
• Consent the patient appropriately – many transfusion request forms will now have a script on them, which you should read to the patient. A consent form (as you would use for consent for any procedure) is completed.
• Labelling the bottle at the bedside (pre-printed stickers for blood transfusion are usually not allowed in many countries, including the UK)
• Completing the transfusion request form at the bedside. Before you put the blood bottle into the request bag, check with the patient that they are happy you have labelled things correctly.

Question 13

Storing blood

Answer 13

• Red cells are stored between 2-6 degrees and can be kept for up to 35 days
• Platelets are kept at 22 degrees and are only kept for 5 days
  o Moving shelves which stop them sticking together
• Plasma and cryo are frozen and stored in freezers for up to one year

Question 14

Preparing blood

Answer 14

• Blood must be warmed to prevent hypothermia
• Also prevents haemolysis

Question 15

Administering Blood Products

Answer 15

If a patient requires more than one unit of blood, each unit must be prescribed individually. Whilst the patient is receiving the transfusion, there are specific observations timings that should be carried out:
* Before the transfusion starts.
* 15-20 minutes after it has started.
* At 1 hour.
* At completion.

Question 16

cannulas used for blood transfusion

Answer 16

Blood products should only be administered through a green (18G) or grey (16G) cannula, otherwise the cells haemolyse due to sheering forces in the narrow tube.
NICE guidelines suggest single unit red blood cell transfusions for the surgical patient who does not have active bleeding, reassessing the patient after each transfusion

Question 17

Screening donors

Answer 17

Syphilis, Hepatitis B virus, HIV, HCV, HepE, Human T-lymphotropic virus (HTLV), malaria, T-cruzi, West nile virus, CMV

Question 18

Irradiated Blood Products

Answer 18

Irradiated products are required to reduce the risk of transfusion associated graft-versus-host-disease in at risk populations.
- This occurs when the donor WBCs attack the patients tissues

Question 19

how is blood irradiated

Answer 19

• Blood that is treated with low dose radiation.
• The radiation stops a type of white blood cell (lymphocyte) in donated blood from harming you if you have a low immune system.

Question 20

Who should receive irradiated blood:

Answer 20

• Those receiving blood from first or second-degree family members
• Patients with Hodgkin’s Lymphoma
• Recent haematpoietic stem cell(HSC) transplants
• After Anti-Thymocyte Globulin (ATG) or Alemtuzumab therapy
• Those receiving purine analogues (e.g. fludarabine) as chemotherapy
• Intra-uterine transfusions

Question 21

Types of blood products

Answer 21

When blood is harvested, it is separated into constituent parts
- Red cell transfusion
- Platelet transfusion
- Cryoprecipitate
- Fresh frozen plasma
- Prothrombin complex concentrate

Question 22

packed red cells major constituent

Answer 22

red blood cells

Question 23

indication for packed red cell

Answer 23

• Acute blood loss
• Chronic anaemia, where the Hb ≤70g/L (or ≤100g/L in those with cardiovascular disease) or symptomatic anaemia

Question 24

packed red cells : duration over which to be administered

Answer 24

o 2-4 hours
o It must be completed within 4 hours of coming out of the store

Question 25

How much difference will 1 unit of blood make?

Answer 25

• 1 unit of blood should increase a patient’s haemoglobin by around 10g/L.

Question 26

Why would a patient who has already had a G&S require another?

Answer 26

• Patients given red blood cells may produce autoantibodies to donor surface antigens (of which there are many, other than ABO and RhD).
• Because of this, before any future transfusions, a new G&S will need to be sent (unless the last G&S was sent and processed within around 3 days of the most recent transfusion).

Question 27

platelets indication

Answer 27

o Haemorrhagic shock in a trauma patient;
o Profound thrombocytopenia (<20 x 109/L; normal range 150 – 400);
o Bleeding with thrombocytopenia;
o Pre-operative platelet level <50 x 109/L

Question 28

Platelets: Duration over which it is administered

Answer 28

30 mins

Question 29

fresh frozen plasma (FFP) major constituents

Answer 29

Clotting factors

Question 30

indication for FFP

Answer 30

• Disseminated Intravascular Coagulation (DIC);
• Any haemorrhage secondary to liver disease;
• All massive haemorrhages (commonly given after the 2nd unit of packed red cells)

Question 31

FFP duration over which it is administered

Answer 31

o 30 minutes

Question 32

Cryoprecipitate major constituents

Answer 32

o Fibrinogen
o von Willebrands Factor (vWF)
o Factor VIII
o Fibronectin

Question 33

indication cryoprecipitate

Answer 33

o DIC with fibrinogen <1g/L;
o von Willebrands Disease;
o Massive haemorrhage

Question 34

cryoprecipitate duration over which it is administered

Answer 34

Stat

Question 35

Prothrombin complex concentrate (PPC) major constituents

Answer 35

Vitamin K dependent coagulation factors

Question 36

prothrombin complex concentrate indication

Answer 36

• Indications
  o Rapid warfarin reversal in major or life-threatening bleeding (inc intracranial bleeding)
  o Reversal of anticoagulation prior to urgent surgery
  o Patients who refuse blood products and are bleeding

Question 37

prothrombin complex concentrate duration over which it is administered

Answer 37

STAT

Question 38

Alternate to donor blood

Answer 38

e.g. Jehovas witness
currently no alternative to transfusion of red blood cells that can improve oxygenation in blood. Number of drugs and methods which can be used to help minimise effects.
- medications
- transfusion alternatives

Question 39

medications which can be used as alternative to blood transfusion

Answer 39

1) Tranexamic acid – helps prevent and treat bleeding
- Nausea, vomiting and diarrhoea
2) Iron treatments
3) Erythropoietin
- High BP
- Skin reactions
- Headaches
- Bone pain
- Flu like symptoms
4) rFVIIa (Novoseven)
- blood clotting factor that helps blood toc lot when the body’s own clothing factors are not working
-heart attack and stroke
- has mouse, cow and hamster protein

Question 40

transfusion alternative

Answer 40

intraoperative cell salvage

• A way of collecting blood that is lost during an operation and giving it back to the patient
• ‘autologous blood transfusion’
  Method: blood lost is collected using a cell salvage machine. Blood collected using suction and anticoagulant added to prevent blood clotting
• Red cells are then washed and filtered and returned to you via drip during or just after operation

Question 41

Management of massive blood loss

Answer 41

Answer 42

Complications become more likely with increasing volume
* Clotting abnormalities
* Electrolyte abnormalities
* Hypothermia
* Acute haemolytic reactions
* Transfusion associated circulatory overload
* Transfusion related acute lung injury
Other complications
* Mild allergic reaction
* Anaphylaxis
* Infective/bacterial shock
Delayed transfusion complications
* Infection
* Graft vs host disease
* Iron overload
*

Question 43

Acute haemolytic reaction (ABO incompatibility)

Answer 43

Presentation
- Urticaria
- Hypotension
- Fever
- Haemoglobinuria from rapid haemolysis
- Blood test
o Reduced Hb
o Low serum haptoglobin
o High LDH and bilirubin in
- Positive DAT

Management
Stop transfusion, begin supportive measures
- Fluid resus
- O2

Question 44

Clotting abnormalities

Answer 44

• Due to dilution effect
• Due to packed red cells transfused not having any platelets or clotting factors
• To reduce risk: fresh frozen plasma and platelets should be administered concurrently (if pt receiving more than 4 units of RBC)

Question 45

Electrolyte abnormalities

Answer 45

• Hypocalcaemia – Chelation of calcium by the calcium binding agent in the preservative results in a reduced serum calcium level
• Hyperkalaemia – Due to the (inevitable) partial haemolysis of the red blood cells and the resultant release of intracellular potassium

Question 46

Hypothermia

Answer 46

As blood products are thawed from frozen and then kept at cool temperatures, they may not be up to body temperature by time of transfusion, especially in a major haemorrhage protocol scenario.
Rapid transfusion of these products can lead to a drop in the patient’s core temperature, hence regular monitoring of core body temperature is always required during a blood product transfusion.

Question 47

Transfusion Associated Circulatory Overload

Answer 47

Pathophysiology: excessive rate of transfusion, often pre-existing heart failure

Presentation:
- Pulmonary oedema
- hypertension

Management
- Slow or STOP transfusion
- Obtain an urgent chest radiograph, and for those whose diagnosis is confirmed
- Give oxygen
- Loop diuretic e.g. furosemide (20mg)

Question 48

Transfusion Related Acute Lung Injury (TRALI)

Answer 48

Pathophysiology
This is a form of Acute Respiratory Distress Syndrome (ARDS), a non-cardiogenic cause of pulmonary oedema.
- Secondary increased vascular permeability caused by host neutrophilia that become activated by substances in donor blood
- Due to donor plasma containing antibodies against patients leukocytes.
- Implicated donors are usually multiparous women

Presentation
- Patients are dyspnoeic (hypoxic)
- Pulmonary infiltrates on CXR
- fever
- hypotension

Management
- STOP transfusion
- High flow oxygen (15l non-rebreathe)
- Obtain an urgent chest radiograph (Fig. 3), getting specialist and intensive care input urgently.
- Supportive care

Question 49

Anaphylaxis

Answer 49

When patients have antibodies that react with proteins in transfused blood components. Occurs when individual has previously been sensitised to an allergen present in the donor blood, and on re-exposure releases IgE.
Causes bronchospasm and other problems -> life threatening

Management
* Adrenaline (epinephrine) 0.5-1 mg intramuscularly (IM) and repeat every 10 minutes until improvement occurs.
* High-flow oxygen.
* IV fluids.
* Nebulised salbutamol by face mask if required.
* Steroids are second-line and antihistamines are third-line treatments.

Question 50

compare TRALI vs TACO

Answer 50

basically:
- TACO: hypertension
- TRALI: hypotension and fever

Question 51

What are BNP and NT-proBNP? What is the difference between them?
- N-terminal pro B-type natriuretic peptide (NT-proBNP) is an inactive peptide released along with the active peptide hormone BNP when the walls of the heart are stretched or there is pressure overload on the heart e.g. by fluid overload. BNP then acts on the kidneys causing fluid and sodium loss in the urine and mild vasodilation so releasing the pressure.
- In heart failure the heart cannot pump strongly enough for the body’s requirements, the heart walls are stretched and fluid starts to accumulate causing back pressure and hence more BNP to be released.
- NT-proBNP is released into the circulation in equal amounts to the active hormone but is significantly more stable and hence forms a good marker of BNP output.
- There are many factors which can affect BNP levels (see below) but a low level has been found useful in ruling out heart failure as an explanation of a patient’s symptoms (negative predictive value 97%) so that only patients with a significantly raised level need to be further investigated for this condition.

Question 52

In what other conditions can NT-proBNP be raised?

Answer 52

Left ventricular hypertrophy, right ventricular overload, ischaemia, tachycardia, hypoxaemia, PE, sepsis, COPD, diabetes, liver cirrhosis, age >70 and eGFR <60 ml/min can all increase NT-proBNP.

Question 53

bedside transfusion checklist

Answer 53

Question 54

Venous Access Devices:

Answer 54

Choice of peripheral IV cannula size should be guided by patient anatomy (i.e. size and integrity of veins) and the speed the transfusion is required at. Central lines are generally suitable for transfusing blood components. When using a multi-lumen venous catheter, the lumen specified for blood components should be used. Remember when using a central line for rapid transfusion the blood should be warmed through a blood warming device certified for this use - no other device should be used for warming blood.

Question 55

Co-administration:

Answer 55

Co-administration of other IV fluids or drugs through an infusion line or single lumen being used for a blood component is not advised and should be avoided if possible, as there is a risk of incompatibility (e.g. dextrose and calcium containing solutions can cause haemolysis or lead to clotting of the component).

Drugs must NEVER be directly added to a blood component.

Question 56

Blood warmers

Answer 56

are required when giving large volume rapid transfusion and for patients with clinically significant cold agglutinins.

Question 57

TACO case study

Answer 57

A female patient in her 70s weighing 54kg developed anaemia following orthopaedic revision surgery (Hb 67g/L). She had a number of risks for TACO: positive fluid balance (1215mL), and the pre-transfusion chest X-ray report was suggestive of possible infection and heart failure, however a TACO checklist was not performed before the transfusion. She was transfused two units of red cells. Following the second unit she developed shortness of breath, crackles on chest auscultation, hypoxia, tachycardia and an increase in blood pressure.

The post-transfusion chest X-ray report confirmed findings were consistent with heart failure, fluid overload and possible infection.

She was transferred to the critical care unit for continuous positive airway pressure (CPAP) ventilation. Her respiratory status improved following treatment with diuretics, nitrates and fluid restriction. Her post-transfusion Hb was 108g/L.

This SHOT case study highlights the following:
Patients are at risk of Transfusion-Associated Circulatory Overload (TACO)
The importance of checking patients past medical history and considerations for appropriate fluid and transfusion management
The importance of accurate monitoring and documentation for patients with an increased risk factor for associated potential complications.

Question 58

TALI case study

Answer 58

A young patient in his 30s diagnosed with acute myeloid leukaemia (AML) on induction chemotherapy developed rigors within 2 hours of platelet transfusion, with a rise in temperature of 2.4°C, tachycardia, desaturation, and wheeze. The chest X-ray showed acute respiratory distress syndrome (ARDS) with progression from the previous one. This was assessed as ‘probably’ related to the transfusion.

This SHOT case study highlights the following:
The importance that the patient should be monitored before, during and on completion of a blood transfusion.
Appropriate investigations should be conducted during and after suspected transfusion reaction.
Transfusion reactions should be documented in the patient’s clinical record.

Question 59

Transfusion reactions that patients should be told to watch out for

Answer 59

Acute transfusion reactions can present in a number of ways with any of the following signs or symptoms:
* Fever, chills, rigors, myalgia, nausea
* Urticaria, rash, pruritus, flushing
* Angioedema
* Respiratory symptoms including dyspnoea, stridor, wheeze, hypoxia
* Hypo- or hyper-tension, tachycardia
* Pain
* Severe anxiety or feeling of ‘impending doom’
* Bleeding with acute onset

Question 60

what to do if patient exhibits any signs or symptoms of mild/moderate transfusion reaction

Answer 60

• STOP the transfusion
• Seek medical advice immediately
• Check it is the correct component for the patient: check blood component laboratory produced label against the patient’s identification band, and with the patient themselves (if possible).
• Assess the patient

Treat the signs and symptoms of the mild reaction appropriately. An antipyretic or antihistamine may be required.

Do not use an antihistamine to treat a simple fever. In the event of a mild reaction, the transfusion can usually be restarted after 30 minutes if the patient has responded to symptomatic treatment.

The transfusion should not be restarted if the patient does not respond to treatment or if signs or symptoms worsen

Question 61

what to do if patient exhibits any signs or symptoms of severe transfusion reaction

Answer 61

• STOP the transfusion
• Call the doctor to see the patient urgently
• Check compatibility of unit: check the details on the component against the patient’s identification band, and with the patient themselves (if possible).
• Assess the patient

Management (under medical direction)
- Replace the administration set and preserve IV access with a suitable crystalloid to maintain systolic BP
- Assess the patient
- Check urine for signs of haemoglobinuria
- Commence appropriate treatment; maintain airway and give high flow oxygen.
- If appropriate administer **adrenaline or diuretic and resuscitate **if/as required.
- Reassess patient and treat appropriately - seek expert advice if patient’s condition continues to deteriorate.

The UK BSQRs (2005 as amended) introduced a legal requirement for the reporting of all serious adverse events and reactions to the identified competent authority, check local protocols for method of reporting.

Question 62

DELAYED HAEMOLYTIC TRANSFUSION REACTION (HTR)

Answer 62

This is a rare type of transfusion reaction usually seen in patients who have developed red cell antibodies in the past from transfusion or pregnancy. A combination of the features occurs days after the transfusion, suggesting that the red cells are being destroyed abnormally quickly.

Signs and symptoms include:

Fever
Falling haemoglobin or a rise in Hb less than expected
Jaundice
Haemoglobinuria.

Question 63

Transfusion reactions can be

Answer 63

mild, moderate or severe/life-threatening

Question 64

what is vital to reduce morbidity and mortality associtated with transfusion reactions

Answer 64

early recognition and management
- regular observations
- Early check (after 15 mins) is the most important obs, since the majority of major adverse reactions occur in first 15