This guideline promotes best practice regarding blood use. Further information on blood transfusion, including details regarding sampling, administration, blood products and management of reactions is available on NHSGGC StaffNet by searching 'Blood Transfusion Information'.
An acute blood loss of greater than 20% of blood volume (about 1000ml blood) will often need a transfusion though it should be guided by measured Haemoglobin (Hb) levels when available. Do not delay ordering blood in situations where blood loss is acute and rapid. If blood loss is very rapid, follow the site specific protocol for dealing with major haemorrhage.
Consider transfusion if:
Hb <80g/L – Transfusion to an Hb of 80 - 100g/L is desirable. Evaluate effect of each unit as it is given. In patients who may have impaired cardiac function, be particularly aware of the risk of Transfusion associated Circulatory Overload (TACO). Investigation of the cause of anaemia is required.
Some anaemias will respond to treatment of a deficiency e.g. iron, B12, folate. Always consider cause before transfusing.
Hb <70g/L – Consider transfusion but evaluate after each unit.
Hb 70– 90g/L and normovolaemic patients – Consider transfusion only if they have symptomatic anaemia or significant comorbidity.
Symptoms and signs of anaemia include:
Transfusion to an Hb above 100g/L is rarely indicated and the reason must be documented. Transfusion when Hb is already >100g/L is seldom indicated.
Further information, including educational links, is available on NHSGGC StaffNet by searching under 'Blood Transfusion'.
Guideline reviewed: October 2022
Page last updated: December 2022