General Principles of Transfusion Practice
Historically, blood component therapy has played a central role in the advances and practice of modern medicine but allogeneic blood component therapy is now no longer regarded as essential for a wide range of medical and surgical conditions. Most major surgery can now be conducted without allogeneic blood component therapy due to improvements in surgical and anaesthetic techniques and other aspects of supportive care.
Blood transfusion should be viewed in a similar light to other risk/benefit decisions in clinical medicine. As with all modern medical therapy, blood component therapy presupposes an understanding of disease in terms of pathophysiology, definition, classification, diagnosis, indicators of severity and prediction of the natural history of untreated and treated disease.
There should thus be appropriate attention to accurate diagnosis, understanding of the consequences of untreated disease, knowledge of available therapeutic options and the potential hazards of individual therapeutic approaches.
Infusion of blood components is generally a temporising therapy and although appropriate endpoints may be achieved in terms of measurable parameters or clinical response, evidence that these traditional “outcomes” are relevant in relation to the final outcome for the patient may be lacking.
There are multiple appropriate endpoints within any medical process that are central to a successful final outcome, but there are others where dogma rather than evidence has dominated clinical practice.
Allogeneic blood transfusion is supportive therapy and in most circumstances is generally required for haematological deficiencies until the primary disease process can be corrected.
Therapy may be given to control the effects of a deficiency as treatment or prophylaxis to improve patient outcomes.
Allogeneic transfusion in the perioperative setting need not be regarded as the first line of therapy for patients with haemopoietic defects. For most patients it is possible to minimise requirements for allogeneic blood components or to correct or manage the effects of deficiencies in the haematopoietic system without transfusing allogeneic blood components.
Clearly, if allogeneic blood can be avoided the potential hazards of its use need not be considered.