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Chapter 5

BLOOD COMPONENT INFORMATION

PRACTICE POINTS

Ethrocytes:

  • Must be ABO compatible.
  • Erythrocytes for neonates must be cross-matched against maternal samples.
  • Must be RhD compatible for females of child bearing capacity.
  • Best component for improving oxygen carrying capacity.

Whole Blood:

  • Must be ABO compatible.
  • The plasma will be deficient in FV and FVIII and possibly other coagulation factors.
  • Does not contain viable platelets.
  • Used as a substitute for erythrocytes when erythrocytes are not available.

Plasma:

  • Fresh Frozen Plasma (FFP) contains coagulation proteins and albumin.
  • Needs to be ABO compatible.

Platelets:

  • One dose is 4-6 whole blood derived units.
  • Are indicated for bleeding due to severe thrombocytopenia or platelet dysfunction.
  • May be indicated for prevention of bleeding 
  • in some patients.
  • Patients who develop refractoriness to platelets usually have an HPA or HLA 
  • antibody and may benefit from HPA or 
  • HLA matched platelets.
  • Should be ABO compatible.

5.1    ERYTHROCYTES

Erythrocytes (also known as Red Cell suspension or Red Cells) is the standard product for the treatment of anaemia if transfusion is appropriate.

Erythrocytes can be split into paediatric units called paedi-packs. These units are used for neonates and children who require a transfusion of a volume less than one unit of erythrocytes. 

5.1.2    Indications and contraindications

See chapter 4.

Erythrocyte transfusions are given to increase oxygen carrying capacity by treating anaemia. 

5.1.3    Storage conditions erythrocytes

Storage time and temperature:

Unless labelled differently: 35 days at 2– 6º C

Storage time after spiking/opening the bag:

20–24º C     max 4 hours

5.1.4    Compatibility testing

Selection of ABO and RhD:

Erythrocytes must always be ABO and RhD compatible, though not necessarily identical with the recipient (see Table 5.1). To reduce the risk of sensitisation, all RhD negative females of child bearing potential should receive RhD negative blood. Only women who are known to be RhD positive should receive RhD positive blood.

Patient Compatible ABO donor group Preference when more than one group is compatible*
O A B AB
Unknown O 1      
O O only 1      
A A or O 2 1    
B B or O 2   1  
AB AB or A or B or O 4 2 3 1
*A preference of "1" implies this is the best ABO blood group to choose for that patient, "2" second best and so on. If there is no number, that ABO blood group is not compatible for the patient and should not be used.

 

For children younger than 3 months the selection of ABO, RhD blood groups and typing for allo-antibodies should be compatible with the mother (see Table 5.2) . ABO choice is indicated in the table. If there is any doubt, Group O erythrocytes will always be compatible with any ABO groups of mother and child.

Child Mother Donor erythrocytes for child
O O, A, B or AB O
A A or AB O or A
A O or B O
B B or AB O or B
B O or A O
AB  AB O, AB, A or B

 

On request, paediatric units (paedi-packs) with a volume of 70–100 mL prepared from one single donation may be kept for the same patient. This practice will reduce donor exposure to the neonate.

5.1.5    Recommendation prevention of immunization by c, E and Kell

Determination of blood group types, other than ABO and RhD (phenotyping) on erythrocytes is currently not available in Cambodia.

Provision of Kell negative blood for all females of child bearing potential (girls and women of child bearing age) is recommended. Provision of c and E compatible blood for females of child bearing should be considered.

Provision of c, E and K compatible blood is recommended for patients with an inherited disease who need transfusion during their entire life (e.g. Thalassaemia). If at all possible, full phenotype specific blood, to minimize the risk of immunization, should be provided for patients on chronic transfusion programs.

Phenotyped erythrocytes are important when finding compatible blood for patients with alloimmune antibodies, including haemolytic disease of the newborn.

5.1.6    Citrate side effects

Whole blood and erythrocyte concentrates are stored in solutions containing approximately 1.2g citrate. A healthy adult liver can metabolise 3g citrate every 5 minutes. Transfusion rates higher than 1 unit per 5 minutes or transfusion in patients with severe liver impairment may develop hypocalcaemia due to citrate toxicity. Routine administration of calcium after a transfusion is not required. 

5.1.7    Characteristics of Erythrocytes

From 350 mL whole blood, collected in 51 mL sodium citrate solution (CPD-A), plasma is separated. About 54–60 mL of plasma is left on the erythrocytes.

Cross-match is based on the red cell antigens. The volume of plasma (containing ABO antibodies) is low and not clinically relevant.

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This is the standard erythrocyte product for transfusion (see chapter 4) and should be used preferentially to Whole Blood whenever possible or available.

5.1.8    Characteristics of Whole Blood

Whole blood (350 mL in 49 mL CPDA-1 solution), unprocessed, is used when Erythrocytes are not available. Whole blood is composed of plasma in which the cells (red cells, platelets and white cells) are suspended. The oxygen carrying and release capacity per volume is half of that of a red cell concentrate.

Platelets are non-functional and some plasma proteins are at low concentrations. 

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5.1.8.1    Indications and Contraindications

See chapter 4. Whole blood is given to correct anaemia or improve oxygen carrying capacity when no erythrocytes are available.

The plasma component of whole blood has reduced labile factors e.g. Factor VIII. The platelet component of whole blood is not functional due to storage – platelets are not viable when stored at 2-6ºC.

5.1.8.2    Choice of blood group when using Whole Blood

Whole blood contains red cells which are coated in ABO antigens and plasma containing ABO antibodies. Red cell ABO antigen mis-match may lead to life-threating ABO transfusion reactions. Mis-matched plasma antibodies may lead to haemolysis. Group identical cross-match is ideal for whole blood as the red cell antigen and plasma antibodies are both matched. If group identical is not available, red cell antigen group compatibilty is more important than plasma compatibility.

Some donors have low titre anti-A and anti-B and these donors pose a lower risk of haemolysis.

For example, a group A patient (red cell antigen A present and anti-B in the plasma) should be transfused group A whole blood. Second choice should be group O whole blood with low titre anti-A. If transfusion is essential and neither choice is available, always choose blood compatible with the patient’s red cell antigen as third choice, in this example, group O blood. 

Patient Whole Blood Choices
  1st 2nd 3rd
O O    
A A O low tire anti-A, anti-B O
B B O low titre anti-A, anti-B O
AB AB A  O low titre anti-A, anti-B

5.1.8.3    Storage conditions

Between +2ºC and +6ºC in an approved blood bank refrigerator, fitted with a temperature chart and alarm. During storage at +2ºC and +6ºC, changes in composition occur resulting from red cell metabolism (pH, K+).

Transfusion should be started within 30 minutes of removal from refrigerator and completed within 4 hours.

5.1.8.4    Citrate side effects

See note about citrate and calcium in section 5.1.6

Whole blood may cause volume overload and fast transfusion of larger numbers of units may cause hypothermia.

5.2    PLASMA

Fresh Frozen Plasma (FFP) contains all clotting factors and albumin in approximately the same concentrations as circulating plasma.

Plasma from a unit of whole blood or plasma obtained by apheresis is snap frozen as soon as possible after collection (within 8 hours) and thawed at 37º C shortly before use.

5.2.1    Indications

See chapter 4 for indications and contraindications.

5.2.2    Storage conditions

Storage time / temperature: 12 months at –25º C or lower; 24 months at –30º C or lower.

5.2.3    Compatibility

Fresh Plasma should be transfused ABO compatible. If FFP is screened for antibodies then cross-match is not necessary.

Patient Plasma group (donor)
O O, A, B or AB
A A or AB
B B or AB
AB AB

Note: AB plasma is the “universal” plasma donor – it is compatible for any patient.

5.2.4    Side effects

See chapter 13 on Adverse events.

5.2.5      Characteristics of Plasma products

5.2.5.1    Fresh Plasma, frozen and thawed

A whole blood collection has the plasma separated by centrifugation and frozen rapidly to reach a temperature below -30ºC within 1 hour. The plasma is stored at -25ºC and when needed for transfusion, the unit is thawed in an aseptic water bath at 30-37ºC. Thawing is performed by putting the frozen bag of plasma in an overwrap to avoid contamination from the water bath.

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For children usually smaller amounts can be used (paediatric units: 75-100 mL).

Plasma should be administered within 4 hours after thawing and should not be frozen again.

5.2.5.2    Solvent / Detergent treated plasma

Solvent/detergent treated pooled plasma is not available in Cambodia. SD Plasma is prepared by the addition of Tri-(n-butyl)-phosphate [TNBP and detergent (Triton X-100)] to a pool of fresh plasma. This results in a chemical inactivation of specially enveloped viruses. The plasma pools consist of at least 500 individual donations.

5.3    CRYOPRECIPITATE AND CRYODEPLETE PLASMA

Fresh Frozen Plasma is slow thawed at 4ºC until a precipitate forms. This precipitate is collected and frozen as cryoprecipitate. Cryoprecipitate is a concentrate of fibrinogen, Factor VIII, von Willebrand factor and Factor XIII. Cryoprecipitate is thawed at 37ºC shortly before use. A standard adult dose is 5–10 units of cryoprecipitate.

The residual plasma can be frozen and used for clinical purposes. It is called Cryodepleted plasma and can be used to treat patients with Thrombotic Thrombocytopenic Pupura (TTP).

Neither cryoprecipitate nor cryodepleted plasma are available in Cambodia.

5.3.1    Indications

When fibrinogen concentrate is not available, cryoprecipitate is indicated for fibrinogen replacement in patients who are bleeding, or at risk of bleeding, due to low fibrinogen levels e.g. patients with DIC, massive blood loss and congenital fibrinogen deficiencies.

When specific protein concentrates are not available, cryoprecipitate can be used to treat or prevent bleeding in patients with congenital or acquired deficiencies of Factor VIII (Haemophilia A) or von Willebrand disease (VWD).

Cryoprecipitate can be used for congenital deficiency of Factor XIII. 

5.3.2    Storage conditions

Storage time / temperature: 12 months at –25º C or lower; 24 months at –30º C or lower.

5.3.3    Compatibility

Ideally cryoprecipitate and cryodepleted plasma should be transfused ABO compatible (See table 5.4). If the collected plasma is screened for antibodies then cross-match is not necessary. If the plasma has not been screened, then cross-match against patient red cells is required.

5.3.4    Side effects

See chapter 13 on Adverse events.

5.4    PLATELETS

Platelets are the standard product for the treatment of thrombocytopenia or congenital or acquired platelet function defect (thrombocytopathy) if transfusion is appropriate.

Platelets are derived from whole blood, one unit contains about 50 mL and 50 x 109 platelets. A standard adult dose, to elevate the patient platelet count by 20–40 x 109/L, is 4–5 units.

Platelet transfusion should always be based on the clinical situation supported by information on the platelet count.

5.4.1    Indications

See chapter 4 for indications and contraindications.

5.4.2    Storage conditions

Storage time: 5–7 days, with continuous gentle agitation

Storage temperature: 20–24º C (platelet cabinet)

As soon as the product leaves the climatised cabinet it should be transfused within 4 hours.

5.4.3    Compatibility

ABO blood groups are present on platelets. Provision of ABO compatible platelets is desirable however crossing groups is possible. Choice of ABO group is the same as choice of erythrocytes (table 5.1). If the collected plasma is screened for antibodies then cross-match is not necessary. If the plasma has not been screened, then cross-match against patient red cells is required.

Erythrocytes may be present in a platelets product. Therefore transfusion of platelets from a RhD positive donor to a RhD negative patient may cause antibody formation against RhD antigen. If the prevention of anti-D antibodies is indicated (females of child bearing potential) at least 375 IU anti-D immunoglobulin should be administered intramuscular (or subcutaneous in case of thrombocytopenia).

5.4.4    Evaluation

The most important indicator of effectiveness is control of bleeding. A platelet count within 30min – 4 hours following a platelet transfusion is a good guide to improvement of platelet count.

If there is concern of poor response on clinical grounds, a corrected count increment (CCI) can be calculated and may provide additional information to the post-platelet transfusion count. The CCI gives some guidance around the possible cause of poor platelet transfusion response.

CCI calculation: Determine the platelet count in the peripheral blood before, 1 hour after and/or 16–24 hours after transfusion (1 hour/16–24 hours post counts). 

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An insufficient 1-hour post count (CCI < 8) indicates an allo-immunization or drug depending antibodies, but is also seen in sepsis, severe GvHD, use of amfotericin-B, venous occlusive disease, splenomegaly and overt bleedings. A sufficient 1-hour post count, but a poor 16-hours post count (CCI < 4.5) generally excludes alloimmunisation as the cause of low response. Other causes such as infection, disseminated intravascular coagulation, and GvHD should be considered.

5.4.5    Patients refractory to platelet transfusion

Some patients develop refractoriness to platelet transfusions due to alloimmunisation to HLA or HPA antigens. This is indicated by poor clinical response and rapid clearing of transfused platelets according to post-transfusion platelet count or CCI.

HLA-compatible platelets should be considered if a platelet transfusion of ABO compatible random donors at least twice resulted in an insufficient CCI-value, HLA antibodies have been demonstrated and clinical factors associated with increased platelet consumption are excluded. If not all above mentioned requirements are fulfilled, a test transfusion may be considered.

Timely communication between the clinician, the head of the blood transfusion laboratory in the hospital (hospital blood bank) and the responsible physician (clinical consulting service) of the blood establishment, should take place because of the logistics of HLA compatible platelets, donor selection and mobilization, and the necessary tests for infectious disease markers.

HLA antibody testing and provision of HLA compatible platelets are not yet available in Cambodia.

5.4.6    Side Effects

See chapter on Adverse Events

5.4.7    Characteristics of Platelet product

5.4.7.1    Platelets, single unit

From one unit of whole blood (PRP) the platelets are isolated and re-suspended in plasma or platelet additive solution.

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Indication

Standard product for the treatment of thrombocytopenia and/or thrombocytopathy in children < 10 kg body weight.

5.4.7.2    Platelets, pooled

Currently platelet concentrates are not yet pooled, but are to be developed soon from 4-6 ABO identical whole blood units (PRP) the platelets are isolated and pooled in plasma or platelet additive solution.

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Indication

Standard for adults (5 units) for the treatment of thrombocytopenia / thrombocytopathy.

For transfusion to children less (2–4) donor units are pooled.

5.5    MODIFICATIONS

The following modifications are not yet available in Cambodia.

5.5.1    Washed erythrocytes

Erythrocytes are washed in saline three times and resuspended in a red cell additive solution. This process removes many proteins from the erythrocyte component.

Washed erythrocytes can be given to patients with IgA deficiency who have anti-IgA antibodies and patients with recurrent and severe allergic reactions.

5.5.2    CMV seronegative

Blood donations in Cambodia are not currently screened for CMV. When CMV testing is available, the provision of CMV seronegative components may be an appropriate option in the following clinical indications:

  • Intra-uterine transfusions and neonates.
  • All pregnant women regardless of CMV status having antenatal transfusion with ongoing pregnancy.
  • CMV seronegative recipients of allogeneic or autologous stem cell, bone marrow or solid organ transplants.
  • CMV seronegative recipients of highly immunosuppressive chemotherapy.

There is small risk of new CMV disease in immunosuppressed CMV seropositive patients who receive CMV seropositive blood components.

Leucodepletion within 24 hours of blood collection is regarded by some international blood services to be equivalent to CMV seronegative components.

5.5.3    Irradiation of blood components

Irradiation of blood components removes lymphocytes within the blood component. This reduces the risk of transfusion associated graft-versus-host disease (TA-GVHD).

The following groups of patients should get irradiated components:

  • recipients of intrauterine transfusion,
  • neonates who have previously received intrauterine transfusions,
  • patients with congenital immune deficiencies or Hodgkin lymphoma,
  • patients receiving nucleoside analogues or alemtuzumab,
  • recipients of stem cell or bone marrow transplants,
  • recipients of directed donations from family members, and
  • recipients of HLA-compatible single donor platelets and granulocyte transfusions.
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