Blood transfusion

What it is

Donated blood components given into a vein: red cells for anaemia and blood loss, platelets for low counts with bleeding, fresh frozen plasma and cryoprecipitate for clotting factor deficiency. Each unit is matched to the recipient's ABO and RhD blood groups and screened for antibodies, and identity is checked at every step.

Why it is done

• Major bleeding from trauma, surgery, the gut or childbirth
• Symptomatic anaemia that cannot wait for iron or other treatment; haemoglobin below about 70 g/L in stable patients (80 in heart disease)
• Bone marrow failure and chemotherapy
• Sickle cell disease and thalassaemia (regular transfusions)
• Reversing clotting problems before surgery or in massive haemorrhage

Before the procedure

• A group-and-save or crossmatch sample, labelled at the bedside from a wristband check
• Consent, explaining benefits, risks and alternatives; baseline temperature, pulse and blood pressure
• A cannula in a forearm vein

Step by step

1. Two staff check the unit against the patient's identity and the compatibility label
2. Red cells run over 1.5-3 hours (faster in emergencies); platelets over 30 minutes; plasma over 30-60 minutes
3. Observations are repeated at 15 minutes and at the end of each unit
4. Any fever, rash, breathlessness or pain stops the transfusion immediately for assessment
5. Haemoglobin is rechecked after; each unit of red cells raises it by about 10 g/L

Afterwards

• Most people feel better within hours if anaemia was symptomatic
• Delayed reactions (jaundice, falling haemoglobin) can occur a week or so later
• Women of childbearing age receive RhD-matched and K-negative blood to protect future pregnancies

Recovery

Usually a day-case or in-patient treatment with no recovery period of its own.