The Australian National Blood Authority has produced guidelines for specific clinical
situations (e.g. critical bleeding) to assist in deciding when your patient needs blood. The development of these has been assisted by Australian and New Zealand members of the ANZSBT and endorsed by NZBS.
ANZSBT and have been adopted by NZBS and Canterbury DHB.
The AABB (formerly American Association of Blood Banks) has a similar guideline.
Appropriate Use of Red Blood Cells
The patient's haemoglobin level, although important, should not be
the sole deciding factor in deciding whether to transfuse red blood cells.
Patient factors, signs and symptoms of hypoxia, ongoing blood loss, the risk to the patient of anaemia
and the risk associated with transfusion should be considered.
Hb*
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Considerations
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< 70g/L
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Lower thresholds may be acceptable in patients without
symptoms and / or where specific therapy is available.
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70 - 100g/L
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Likely to be appropriate during surgery associated with major
blood loss or if there are signs or symptoms of impaired oxygen
transport.
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> 80g/L
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May be appropriate to control anaemia-related symptoms in a
patient on a chronic transfusion regimen or during marrow
suppressive therapy.
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> 100g/L
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Unlikely to be appropriate
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* The use of red blood cells for indications not listed in
this table is unlikely to be considered appropriate as
prophylaxis or therapy. Consult the NHMRC / ANZSBT / NZBS
guidelines for further details. Clinical and Laboratory
indications should be documented.
Specific factors to consider
- Patients cardiopulmonary reserve - if pulmonary function is
not normal, it may be necessary to consider transfusing at a
higher threshold.
- Volume of blood loss - clinical assessment should attempt to
quantify the volume of blood loss before, during and after
surgery, to ensure maintenance of normal blood volume.
- Oxygen consumption - this may be affected by a number of
factors including fever, shivering and anaesthesia; if increased
then the patient's need for red blood cell transfusion could be
higher.
- Atherosclerotic disease - critical arterial stenosis to major
organs, particularly the heart, may modify indications for the
use of red blood cells.
- Speed of onset of the anaemia - slow onset anaemia, e.g. iron
deficiency, may not need transfusion. Correction of the cause of the
anaemia may be sufficient.
- A transfusion of 4-5mL/kg (1 unit in a 60kg patient) will
increase circulating Hb by about 10g/L
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