For blood transfusions in the stable, non bleeding, normovolaemic patient, e.g. post-operative patient.

• Give one unit
• Reassess Hb and symptoms
• Give the next unit
• Reassess Hb and symptoms

One unit of red cells (or 4-5 mL/kg) will typically increase an adult's haemoglobin by 10g/L. Patients who are smaller (<60kg) may show a larger increase in haemoglobin.

Decisions about whether to transfuse further units and how many must be based on all of the following information:

• The current haemoglobin level
• The patient's general condition, especially their cardiovascular system and to a lesser extent their respiratory system
• Any symptoms or signs of anaemia
• Any ongoing blood loss
• The desired post transfusion haemoglobin level. (Refer to NZBS Guidelines)
• The estimated haemoglobin increase after transfusion of one unit.

All this information must be assessed before commencing the next unit.

These principles also apply to plasma and platelets.

See also the pages Before Your Transfuse and Assessing the Need.