Besides the haemoglobin level, patient factors, signs and symptoms of hypoxia, ongoing blood loss, the risk to the patient of anaemia with coexisting conditions, and transfusion risk should be considered when using red cells.
Patient’s 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, anaesthesia and shivering; if increased then the patient’s need for red blood cell transfusion could be higher.
For further details, consult the Clinical Practice Guidelines on the Use of Blood Components(1).
