Page 426 - Essential Haematology

412 / Chapter 29 Blood transfusion

Specifi c i mmunoglobulin ulocyte response begins on the second or third day

and lasts 8 – 10 days. The haemoglobin begins to rise
This may be obtained from donors with high titres

by about the seventh day but, if iron stores have
of antibody (e.g. anti - RhD, anti - hepatitis B, anti -
become depleted, the haemoglobin may not rise
herpes zoster or anti - rubella).
subsequently to normal. Clinical assessment is
needed to gauge whether blood transfusion is

needed. This is usually unnecessary in adults at
Acute b lood l oss

losses less than 500 mL unless haemorrhage is con-
After a single episode of blood loss, there is initial tinuing and may not be needed with losses of up to

vasoconstriction with a reduction in total blood 1.5 L. Blood transfusion is not without risks and

volume. The plasma volume rapidly expands and should not be undertaken lightly. The problems of
the haemoglobin and packed cell volume fall and massive blood loss and massive transfusion are con-

there is a rise in neutrophils and platelets. Th e retic- sidered on p. 360 .
SUMMARY ■ Blood transfusion involves the safe transfer ■ Antibodies may also develop from

of blood components from a donor to a
exposure to the antigen by a transfusion or
pregnancy. Cross - matching of donor red
recipient. Most commonly this is red cells
and the red cells must be matched
cells with recipient plasma is therefore

between recipient and donor.
carried out to ensure they are

■ Careful donor selection and microbiological
compatible.

testing help to protect both donor and
recipient.

haemolytic reactions, febrile reactions to

■ Red cells contain over 400 antigens. It is ■ Complications of blood transfusion include
white cells or proteins, circulatory overload,

the ABO and Rh systems that are most transmission of infections, especially viral,
important in transfusion. Subjects lacking and, in the longer term, iron overload.
an antigen (e.g. group A or B) may ■ Blood components other than red cells can

develop a naturally occurring antibody to also be transfused. These include platelets
it, usually IgM. These antibodies in a and protein products including fresh frozen
recipient may haemolyse or opsonize plasma, albumin solutions, coagulation
donor red cells if these contain the antigen. factor concentrates and immunoglobulin.
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