Patient factors
Patients who have previously been transfused, multiparous women and patients receiving emergency uncrossmatched transfusion are at increased risk of immediate and delayed haemolytic transfusion reactions due to the presence of antibodies.
Febrile, allergic and anaphylactic reactions occur more commonly in multiparous women and in patients with IgA deficiency and anti-IgA antibodies.
Febrile reactions occur more commonly in multi-transfused patients.
Transfusion-associated graft-versus-host disease (TAGVHD) occurs more frequently in certain immunocompromised patient groups.
Transfusion-associated circulatory overload (TACO) is a particular risk in the very young, the elderly and in patients with cardiovascular disease.
Blood component factors
Platelet and granulocyte transfusions are associated with the highest rates of febrile non-haemolytic transfusion reactions. The incidence of such reactions can be modified by changes to the blood component in the way it’s processed and by leucodepletion. All red cell and platelet components produced by Lifeblood are leucodepleted.
Platelets are stored at 20–24 ºC and are associated with higher rates of bacterial contamination than red cells. All platelets are subject to routine bacterial culture and screening, which allows detection of a bacterial contaminated product.
Transfusion of fresh frozen plasma is associated with a higher risk of allergic reactions. Some reactions are mild, but severe life-threatening reactions such as anaphylaxis and Transfusion-related acute lung injury (TRALI) may occur.
Procedural factors
Clear written procedures and adequate staff training are essential for all aspects of the clinical transfusion process—from initial collection of samples for pretransfusion testing through to final documentation of the transfusion process and outcome.
There are numerous opportunities for error during this process if procedures are not strictly followed. Annual reports from the UK Serious Hazards of Transfusion (SHOT) program indicate that the vast majority of adverse events associated with transfusion are a result of 'wrong blood to wrong patient', with patient identification errors being the most common cause of preventable harm. The majority of these errors are the result of failure to follow procedures, or inadequate or unclear procedures.
Equipment
Approved blood administration sets must be used for all blood components. Blood administration sets must incorporate a 170–200 micron filter to remove clots and debris. Examples of potential adverse effects due to inappropriate equipment include: heat damage to red cells due to an un-calibrated or poorly maintained blood warmer (i.e. red cells should not be taken above 40 ºC); and mechanical damage to red cells through use of an inappropriate infusion pump.
Concomitant medications and intravenous fluids
No medication or solutions should be added to or infused through the same tubing with blood or components except 0.9% Sodium chloride, Injection (BP); or 4% Albumin or ABO-compatible plasma with red cells only.
Crystalloid and colloid solutions containing calcium (e.g. Haemaccel) must never be added to or administered through the same intravenous line as blood or component collected in an anticoagulant containing citrate because they interfere with the anticoagulant effect, resulting in clotting.
