Patients receiving transfusions should be monitored for signs of potential complications of transfusion and any suspected problems dealt with swiftly and efficiently. When any unexpected or untoward sign or symptom occurs during or shortly after the transfusion of blood or one of its components, it is important to consider that it might have been caused by the blood component until proven otherwise.
Factors Contributing to Transfusion-Related Adverse Events
Certain circumstances increase the likelihood of a transfusion adverse effect occurring. These include:
Patient Characteristics
Patients who have previously been transfused, multiparous women and patients receiving emergency uncross-matched transfusion are at increased risk of immediate and delayed haemolytic transfusion reactions.
For example, febrile, allergic and anaphylactic reactions occur more commonly in multi-parous 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 (TA-GVHD) occurs more frequently in certain immunocompromised patient groups. Volume overload is a particular risk in the very young, the elderly and in patients with cardiovascular disease.
Blood Component
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.
For example rates of febrile non-haemolytic transfusion reactions to platelets prepared by the PRP (platelet-rich plasma) method are reported at 19-31%, but much lower rates are seen with platelets prepared by the buffy coat method and with pre-storage leucodepletion or leucodepleted apheresis platelets.
Platelets, which require storage at 20-24oC, are associated with higher rates of bacterial contamination than Red Cells. which are routinely refrigerated.
Transfusion of Fresh Frozen Plasma (FFP) 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.
Equipment
All blood components are administered through specifically designed intravenous giving sets, and sometimes specialised leucocyte reduction filters are used. Blood warmers and infusion pumps are often used. All equipment must be specifically designed, and assessed as safe for blood administration. All equipment must be used in accordance with the manufacturer’s operational procedures including regular maintenance and calibration.
Some examples of potential adverse effects due to inappropriate equipment include:
- Failure to deliver platelets to a patient due to selection of an inappropriate filter
- Failure to deliver a leucoreduced component to a patient because of inappropriate
'flushing' of a filter - Heat damage to red cells due to an un-calibrated or poorly maintained blood warmer
- 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).
ABO-compatible plasma or 4% Albumin or other suitable plasma expanders may be used with approval of the patient’s physician.
Crystalloid and colloid solutions containing calcium (such as Haemaccel or Gelofusine) must never be added to or administered through the same intravenous line as blood or component collected in an anticoagulant containing citrate as they reverse the anticoagulant effect, resulting in clotting.
Procedures
Clear written procedures and adequate staff training are essential for all aspects of the clinical transfusion process from initial collection of samples for pre-transfusion 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. Recent reports from the analysis of Serious Hazards of Transfusion (SHOT 2005) in the UK indicate that nearly 60% of adverse events associated with transfusion are a result of 'wrong blood to wrong patient'.
The majority of these errors are the result of failure to follow procedures, or inadequate or unclear procedures.