Whole blood and red cell concentrates

Whole blood

• is indicated primarily in actively bleeding patients in whom both the intravascular volume and the oxygen carrying capacity must be restored e.g. -
  • red cell replacement in acute blood loss with hypovolaemia
  • exchange transfusion
  • patients needing red cell transfusion where red cell concentrates or suspensions are not available
• whole blood donations of 405–495 mL (mean 470 mL) are collected into 63 mL of citrate phosphate dextrose (CPD) anticoagulant

Red cell

• useful in treating haemorrhages and to improve oxygen delivery to tissue
• in red cell concentrate (packed red cells or plasma reduced blood) most of the plasma has been removed while in red cell suspension or red cells in additive slolution, plasma is removed and replaced by 100 mL saline, adenine, glucose and mannitol additive solution (SAG-M)
• NICE guideline recommends the following regarding red cell transfusion
  • use restrictive red blood cell transfusion thresholds for patients who need red blood cell transfusions and who do not:
    • have major haemorrhage or
    • have acute coronary syndrome or
    • need regular blood transfusions for chronic anaemia.
  • when using a restrictive red blood cell transfusion threshold, consider a threshold of 70 g/litre and a haemoglobin concentration target of 70–90 g/litre after transfusion
  • consider a red blood cell transfusion threshold of 80 g/litre and a haemoglobin concentration target of 80–100 g/litre after transfusion for patients with acute coronary syndrome
  • consider setting individual thresholds and haemoglobin concentration targets for each patient who needs regular blood transfusions for chronic anaemia.
  • consider single-unit red blood cell transfusions for adults (or equivalent volumes calculated based on body weight for children or adults with low body weight) who do not have active bleeding
  • after each single-unit red blood cell transfusion (or equivalent volumes calculated based on body weight for children or adults with low body weight), clinically reassess and check haemoglobin levels, and give further transfusions if needed.

Note:

Major haemorrhage can be defined as any of the following:

• the loss of more than 1 blood volume within 24 hours (around 70 ml/kg, or more than 5 litres in a 70 kg adult).
• a loss of 50% of total blood volume in under 3 hours.
• bleeding in excess of 150 ml/minute in adults.
• as a practical clinical definition, bleeding which leads to:
  • a systolic blood pressure of less than 90 mm/Hg or
  • a heart rate of more than 110 beats per minute in adults (3).

Reference:

• (1) Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee. Handbook of transfusion medicine (2013).
• (2) World Health Organization (WHO). The clinical use of blood - Handbook
• (3) National Institute for Health and Care Excellence (NICE) 2015. Blood transfusion