8. If possible, remove the donor to another room for

privacy and to prevent other donors from seeing what

is happening.

9. If there is no other room available, put screens around

the donor.

10. Ensure that someone remains with the donor.

11. Reassure and talk to the donor throughout all these

stages. It may be necessary to advise the donor not to

donate in future.

12. Record the reaction on the donor’s record form.

13. Ensure that the donor rests for some time and is fully

recovered before leaving.

14. Advise the donor that if symptoms persist, they should

contact their doctor of the nearest hospital.

15. Ensure that the donor is discharged by a senior

member of staff.

16. Where feasible, arrange transport home for the donor.

Severe Donor Reactions

A faint may be accompanied by convulsions. Convulsions

may be preceded by all the signs and symptoms of a

vasovagal attack or they may occur without warning.

Convulsions vary in severity from loss of consciousness

accompanied by a slight twitching of extremities to a

grand mal: type seizure with incontinence of urine or

feces. A medical officer or trained nurse must be called

immediately.

Faints are common but convulsions are very uncommon.

If the correct procedure for donor screening has been

Blood Banking (Immunohematology) 367

carried out through the medical history and health check

convulsions should not occur. Most convulsions stop

within a few minutes, but they are often very upsetting for

other donors so staff not actively involved in looking after

a convulsing donor should distract and reassure other

donors.

When Generalized convulsions occur:

1. Turn the donor to a lateral position to maintain a clear

airway.

2. Gently restrain the donor to prevent and injury.

3. Put screens around the donor to maintain privacy.

4. Check the pulse rate frequently.

5. Ensure that the donor is examined by a medical officer.

6. Loosen tight clothing.

7. Keep the donor cool by opening windows or switching

on a fan.

8. If a convulsion lasts longer than 5 minutes, this is a

medical emergency and a medical officer must be

in attendance. Valium may be given intravenously

under the direction of the medical officer. IM Valium

is ineffective in these circumstances.

9. Reassure the donor and explain what has happened.

10. Tactfully advise the donor not to donate blood again.

11. Record the incident:

• On the donor’s record form.

• In the blood bank incident book.

12. Recheck the donor’s medical history and record of the

predonation health check to identify whether there

were any indications that a convulsion might occur.

13. Advise the donor that they should contact their doctor

or the nearest hospital.

14. Ensure that the donor rests for some time and is fully

recovered before leaving the session.

15. Ensure that the donor is discharged by a medical

officer or a very senior member of staff.

16. Inform the donor’s own doctor about the incident.

17. Arrange transport home for the donor when fully

recovered and ensure that they are escorted or arrange

for their transfer to hospital.

Hyperventilation

Hyperventilation is a rapid overbreathing which lowers

the carbon dioxide content of blood. In turn, this leads to

muscle spasms. Talking to the donor to reassure him and

relieve anxiety should prevent hyperventilation.

If hyperventilation occurs:

1. Instruct the donor to breathe quietly and slowly, but

not deeply.

2. If this fails to relieve muscle spasms, instruct the donor

to rebreathe expired air into a paper bag.

3. Explain what is happening and reassure the

donor.

Accidents

There may be a risk of injury to the head or body if a donor

faints and falls

When head injuries or other injuries requiring medical

attention occur:

1. Always ensure that the donor is examined by a medical

officer or senior nurse.

2. If there is any doubt about the donor’s condition,

arrange for his transfer to hospital with a doctor or

qualified nurse as escort.

3. Record the incident:

• On the donor’s record form.

• On an accident form (this should also be filled in if

a member of staff is involved in an accident)

• In the blood bank incident book.

If the Injury is of a minor nature:

1. Ensure that the donor rests for some time and is fully

recovered before leaving, unless transfer to hospital

has been arranged.

2. Ensure that the donor is discharged by a senior

member of staff who should decide whether the

donor’s own doctor should be informed.

3. Advise the donor that if he feels unwell, he should

contact his doctor or the nearest hospital.

Compatibility Testing

The Cross-match

The final green signal for allowing blood transfusion is

compatibility between the donor’s and recipient’s blood.

This is done in vitro in the laboratory/blood bank. A

compatibility test is mandatory before all transfusions.

Cross-matching is done in two parts: (i) the major crossmatch and (ii) the minor cross-match. In the former, the

donor’s cells are mixed with the patient’s serum and in

latter the patient’s cells are mixed with the donor’s serum

(Fig. 11.6).

FIG. 11.6: Cross-matching

368 Concise Book of Medical Laboratory Technology: Methods and Interpretations Saline Cross-match

Saline suspension of the cells is mixed with serum. This

is done at room temperature and only complete, saline

active, ‘cold’ antibodies will be detected.

The Open Slide Method

1. Label one tube with patient’s name or number

(number is preferable as there may be many patients

with the same name).

2. Label another tube with the donor’s name or number__

one for each bottle of blood to be cross-matched.

3. Half-fill each tube with saline.

4. Label one slide for each cross-match. Draw a line in

the middle to separate the two sides. Put the patient’s

number on the left side and mark it ‘P’ on that side. This

is the major side which uses the patient’s (P) serum. Put

the donor’s number on the right side and identify it

further by marking it ‘D’. This is the minor side, which

uses the donor’s (D) serum. Draw two circles one on

each side with a glass marking pencil (Fig. 11.7).

5. Make 5% red cell suspension in each of the labeled

tubes—patient’s and the donor’s bloods. (Get the

donor cells and serum from one of the ‘pilot’ tubes

filled at the end of the donation of blood). Do not

enter the bottle of ACD blood for this purpose unless

absolutely necessary. If you do enter the bottle, you

have almost inevitably introduced bacteria—even if

you have been careful__and that blood should be used

immediately or not at all.

6. To the patient’s (P), major side of the slide, add one

drop of patient’s serum and one drop of the donor’s

cell suspension

7. To the donor’s (D), minor side of the slide, add one

drop of donor’s serum and one drop of the patient’s

cell suspension.

8. Mix by gently rotating the slide and incubate at room

temperature for 10–15 minutes. (Drying will make the

results difficult to interpret. Drying can be retarded if

the slides are kept in a petri dish).

9. Examine both macroscopically and microscopically

for agglutination (by gently rotating and tipping the

slide).