BLOOD TRANSFUSION – Page 2

PART 2

9. Tie tightly the loose knot in the tubing or fold back the tubing and apply a sealing clip, about 20 cm from the needle.

10. Cut the tubing between the clamp and knot

11. Collect a blood sample from the donor into a plain tube for testing (grouping, HIV screening,
etc). Unclamp the tubing and allow 5–7 ml
blood to run out of the tubing into a tube or
vial. Reclamp the tubing.

12. Remove the pressure cuff. Take the needle out of the vein, applying pressure with cotton wool.
Ask the donor to continue applying pressure to the venepuncture site with his or her other hand. Dispose of the needle safely.

13. Mix the blood in the bag and push (‘strip’) the non-anticoagulated blood from the tubing into the blood bag. Mix and allow the tubing to refill with the anticoagulated blood.

14. Write clearly the identity number of the donor on the blood pack and sample tube(s). When a blood pack has already been given an identity number, e.g. from the blood transfusion service use this number on the sample tube(s). Do not
use the manufacturer’s lot or batch number
because this will be the same on several blood packs.

15. After making sure the bleeding has stopped, cover the venepuncture site with a pad of cotton wool and adhesive tape (advise the donor to remove the dressing the following day). Thank the person for donating.

16. Give the donor a drink (not alcohol) to make up his or her fluid loss.
Provide the donor with a dated certificate of blood donation and information concerning future donation.

17. Check that the blood pack and blood sample(s) have been labelled correctly and the same identity number is written on the blood donation certificate.

18. Refrigerate the blood after allowing time for it to cool and for natural bactericidal activity of white
cells (1–2 h). Do not leave a blood bag in direct sunlight. To avoid raising the temperature of the blood bank, first store the blood for 3–4 hours in another refrigerator (when the blood bank is
an absorption type refrigerator.

View Previous Steps

TECHNIQUE OF COLLECTING BLOOD FROM A DONOR

1. Apply a deflated pressure cuff to the upper arm about 6 cm above the elbow. Raise the pressure to between 60 and 80 mm Hg to enable the veins to be seen and felt. Select a large well situated vein for the venepuncture, usually near the bend of the elbow.

2. Clean very well the required part of the arm with cotton wool and 70% ethanol (alcohol). Wipe dry with a clean swab of cotton wool.

3. Take a blood collecting pack:

Make a loose knot (without kinks) in the tubing. When sealing clips are available, there is no need to make a knot in the tubing.
Suspend the bag on a stand (linked to a Balance) about 30 cm below the level of the donor’s arm.
Clamp the tubing near to the needle guard. Whenever possible use plastic forceps to avoid damaging the tubing.

4. Make a venipuncture with the needle directed upwards in the line of the vein. Unclamp the tubing to allow the blood to flow. If necessary, secure the needle in place with a small strip of adhesive tape.

5. When the blood begins to flow, reduce the pressure of the cuff to 40–60 mm Hg, and ask the donor to squeeze slowly a small object.

6. When the blood enters the pack, gently mix it with the anticoagulant by lifting and tilting the bag. Do not squeeze the bag because this can damage the red cells. Mix the blood a further three times during the donation and when the donation is finished.

7. When the pack weighs 500–600g, the donation is complete, i.e. 450–495 ml blood has been collected.

8. Reduce the pressure in the pressure cuff to zero and remove the object from the donor’s hand. Clamp off the tubing 10–15 cm from the needle.

Continue to next steps……

TYPES OF BLOOD COLLECTION PACK

● Single bag collection pack

For collecting 450 ml blood. When concentrated red cells are required, the plasma can be removed and discarded following sedimentation of the red cells or the transfusion can be stopped when the plasma level is reached.

● Double bag collection pack

Collects 450 ml blood which enables plasma to be saved following its transfer (in a closed system) to the attached sterile bag. A double bag pack costs twice the price of a single bag pack.

● Paediatric quadruple bag collection pack

Consists of a blood collecting bag (usually for 250 ml blood) with three small sterile bags attached.
Following blood collection, the well mixed blood is subdivided in a closed sterile system between the three attached sterile bags, providing individual small volume packs. When concentrated red cells only are required, the transfusion can be stopped when the plasma level is reached (packs need to be stored inverted). A paediatric bag pack costs about three times the price of a single bag collection pack.

SOP REQUIREMENTS IN BLOOD TRANSFUSION (PART 2)

Compatibility testing (cross-matching) of blood SOPs should include:

Details of the request form and patient’s
blood sample.
Procedure for compatibility testing including use of controls, interpretation and recording of test results.
Procedure for emergency compatibility testing.
Labelling compatible blood.
Preparation of concentrated red cells.
Procedure for investigating a transfusion reaction.

Safety issues SOPs should include:

Safe handling of blood and blood products.
Decontamination of work surfaces and laboratory-ware and preparation of sodium hypochlorite solutions
Disposal of ‘sharps’
Disposal of contaminated and expired blood.

Procurement of supplies SOPs should include:

Procedures for ordering essential reagents, HIV and other test kits.
Recording expenditures and keeping financial accounts.
Reliable systems for transporting essential supplies.
Checking expiry date and specifications, and recording supplies upon their receipt.
Storage requirements of antisera reagents.

See also:

SOP REQUIREMENTS PART 1

SOP REQUIREMENTS IN BLOOD TRANSFUSION (PART 1)

Use of blood, blood products and blood substitutes SOPs should contain:

Information which must accompany a request for blood.
How to calculate the volume of blood to use, particularly when the patient is a child.
Identity checks and documentation required when collecting blood from a patient, from the blood bank and before setting up a blood transfusion at the bedside of a patient.
Procedure to follow when a patient is being transfused and what action to take should there be an adverse reaction to the blood.
System for auditing how blood is used.

Donation of blood SOPs should contain:

Criteria for accepting a person as a blood donor and details of medical screen and pretesting procedures.
Questionnaire to be used with potential donors covering personal medical history and life style.
Policy and procedure for counselling donors with regard to HIV screening, testing and maintaining the confidentiality of blood donor information.
Details of how to collect blood from a donor.
Labelling donor blood.
Care of the donor following donation and frequency of donation.
Special requirements of mobile blood donation and transportation of blood.
Blood donation records.

Storage of blood SOPs should contain:

Temperature requirement, checking and recording the temperature of the blood bank refrigerator.
Sectioning of refrigerator and location of prescreened, screened, and crossmatched blood.
Procedure for checking the appearance of blood for signs of contamination before it is issued and documentation checks to be performed.
Blood bank records.
Locally important procedures, pertaining to the use and security of a blood bank refrigerator.

See also:

SOP REQUIREMENTS PART 2

BLOOD SAMPLE FOR ABO CELL & SERUM GROUPING

When grouping a donor, use the blood sample collected at the time of blood donation. Test it within 24–36 hours. When grouping a patient, collect 5–7 ml of venous blood into a dry glass tube and label
clearly. When completely clotted, centrifuge the blood at about 1 000 g for 3–5 minutes to separate the cells from the serum. Also collect an EDTA blood sample. Make a 3–5% washed red cell suspension as follows:

Transfer about 0.5 ml of EDTA blood (or red cells from a donor blood sample) into about 5 ml physiological saline.

Centrifuge at about 1 000 g for 2–3 minutes.

Discard the supernatant fluid, resuspend the sedimented red cells in a further 5–7 ml saline and centrifuge. Discard the supernatant fluid.

Make a 3–5% red cell suspension by mixing 1 drop of sedimented cells in 20–25 drops of saline (hold the Pasteur pipette vertically)

See also:

Antisera for ABO grouping

RHESUS BLOOD GROUP SYSTEM

Rhesus blood group system
The Rhesus (Rh) blood group system is next in importance to the ABO system in blood transfusion practice but it is not of equal significance in every country because the frequency of the most important of the Rhesus antigens, i.e. D antigen, varies in
different populations as follows:

Examples. Rhesus (D) positive
Asian. 90–98%
African 94–95%
Nepalese 99–100%
Oriental. 99–100%
South American people: 91- 97%
Ecuador, Chile, Brazil,
Argentina, Uruguay: 82–94%
Caucasian About 85%

Rhesus antigens

The Rhesus blood group system consists of six genes: Cc, Dd, Ee. A single chromosome can carry C but not c, D but not d, and E but not e. A person inherits from each parent a set of three closely positioned Rhesus genes, e.g. CDe/cde. At least 36 Rhesus genotypes are possible based on the combinations of genes that can be inherited ).

When using the Fisher-Race derived nomenclature, Rhesus antigens bear the same name as their genes, i.e. antigens D, C, c, E and e (d gene is not expressed).

Rhesus antigens are only expressed on
red cells. They are not found in body fluids.

Medically, antigen D is the most important of the Rhesus antigens because it is the most immunogenic, capable of producing immune (IgG) anti-D antibody which can cause haemolytic reactions. A person is grouped as Rhesus (Rh) positive or negative based on the presence or absence of antigen D:

Rh positive: A person inherits gene D and their red cells express antigen D.
Rh negative: A person does not inherit gene D and their red cells do not express antigen D.

ANTIBODIES OF ABO BLOOD GROUP SYSTEM

In the ABO blood group system, naturally occurring IgM anti-A and anti-B are present in the serum in the absence of the corresponding red cell antigen.

Although described as naturally occurring (allo-) antibodies, anti-A and anti-B are not detectable in the blood of newborn infants. The antibodies become detectable at about 3 months of age following exposure to A and B like substances present in the environment e.g. in bacteria and some foods.

As a person gets older the concentration of naturally occurring anti-A and anti-B in the blood becomes less and these antibodies may be difficult to detect in the serum of some elderly patients.

Occasionally IgG hyperimmune anti-A and anti-B can be found in the serum of group O persons in response to stimulation by A and B like antigens in the environment, and following pregnancy, or the injection of some vaccines or toxoids. In tropical
countries it is common to find lytic IgG anti-A, anti-B, or both in the fresh serum of up to 50% group O persons. Lytic anti-A is also found in group B persons and lytic anti-B in group A persons (about
25% of sera).

Serious haemolytic reactions can occur when Group O whole blood containing anti-A and anti-B haemolysins is used to transfuse non-group O persons. Immune IgG lytic anti-A and anti-B can cross the placenta and cause ABO haemolytic
disease of the newborn (HDN).

GENERAL GUIDELINES FOR BLOOD TRANSFUSION

Blood is used only when it is absolutely necessary after a careful clinical assessment and measurement of a patient’s haemoglobin (or PCV).

It is inappropriate to use blood to treat patients with:

Stable anaemia without signs of heart failure or respiratory distress which can be treated by other means.
Acute blood loss when it is possible to use replacement fluids (crystalloids or colloids) to maintain blood pressure and oxygenation.

Recipients may be placed at high risk when using blood that;

Has been collected from a high risk donor.
Has not been collected aseptically using a sterile technique.
Has not been transported or stored correctly.
Has not been screened for important pathogens using sensitive assays.
Has not been typed (grouped) and compatibility tested correctly using standardized controlled procedures.

Measures taken to reduce the need for blood transfusion

Reducing the prevalence and severity of anaemia, particularly among pregnant and young children.
Avoiding obstetric related haemorrhages by improving antenatal care and attendance at clinics. Implementing effective malaria control.
Using health education to improve nutrition and awareness of the causes of anaemia and its prevention.
Reducing blood loss during surgery and ensuring alternatives to blood are available

BACTERIALLY CONTAMINATED BLOOD

Bacterially contaminated blood
Transfusion of bacterially contaminated blood can cause fever, shock, collapse and death.

Blood most commonly becomes bacterially contaminated at the time it is collected when the venepuncture site is not
cleansed sufficiently or when a non-sterile blood collection set or blood collecting bag is used.

Blood must always be examined for signs of contamination at the time of use, i.e. when collected from the blood bank and at the patient’s bedside.

When grossly contaminated, blood appears haemolyzed and dark in colour. Some bacteria also cause clotting.

Bacteria which commonly contaminate blood are able to multiply in refrigerated blood.