1b Acute transfusion reactions

The vast majority of blood transfusions are uneventful and the desired result is achieved safely. Nevertheless, about 10% of transfusion recipients may suffer some form of untoward effect, yet severe morbidity and mortality are relatively rare. Febrile non-haemolytic transfusion reactions due to the presence of white cell antibodies in the recipient are the commonest type of reaction; although these cause great discomfort to the patient, they are not life-threatening. Although a minority of severe transfusions reactions, such as transfusion related lung injury (TRALI) cannot be prevented, the vast majority of serious reactions are preventable. ABO incompatibility is the most common cause of immediate deaths following transfusion reactions and invariably occurs as a result of procedural errors resulting in mis-identification of the recipient. Appropriate monitoring of patients during blood transfusion will enable prompt remedial action. Serious reactions due to bacterial contamination of blood products are becoming increasingly common and meticulous cleansing of the donor's arm, storage of blood and blood components compliant with recommended standards and guidelines and examination of the unit before transfusion will prevent most of these reactions. Other preventable serious hazards are caused by accidental injection of water into the circulation, administering red cells through a small gauge cannula, inappropriate heating of blood prior to administration or accidental freezing.

While every endeavour should be made to eliminate preventable hazards of transfusion, over-transfusion is unfortunately still a problem in many countries. In order to present serious adverse effects, clinicians should be mindful that blood transfusions should only be prescribed when the benefits clearly outweigh the risks.