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Febrile, Allergic and Hypotensive Reactions (FAHR) Cumulative Data


The reactions assessed are isolated febrile type (not associated with other specific reaction categories), allergic and hypotensive reactions occurring up to 24 hours following a transfusion of blood or components, for which no other obvious cause is evident.

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SHOT has collected data on febrile, allergic and hypotensive reactions (FAHR) since 1996. Originally, this category was called acute transfusion reactions (ATR).

Since 2012 SHOT has excluded ‘mild reactions’, and now only collects data on moderate or severe reactions according to the International Society for Blood Transfusion/International Haemovigilance Network (ISBT/IHN) definitions.


Recent Recommendations

  • Pooled platelets suspended in platelet additive solution (PAS) are associated with a reduction in allergic response (BSH Estcourt et al. 2017). Hospitals should consider preferential use of readily available pooled platelets suspended in PAS in patients with a history of allergic reactions. This should include paediatric patients where apheresis platelets are usually the platelet component of choice. If reactions continue, despite antihistamine cover, then platelets re-suspended in 100% PAS can be supplied
  • Give appropriate targeted treatment and if needed, preventative cover for future transfusion (BSH Tinegate et al. 2012)
  • Transfusion teams should audit appropriateness of treatment given for acute transfusion reactions and take relevant actions
  • Outpatient departments and day care units, including those in the community, should ensure patients have information about what to do if they experience a reaction after leaving the unit
  • The treatment of reactions and management of subsequent transfusions should be directed by recognised guidelines e.g. BSH guidelines on the investigation and management of acute transfusion reactions (BSH Tinegate et al. 2012)
  • Action: Hospital transfusion teams (HTT)
  • Reporters should report cases fully, including clinical data such as temperature and blood pressure prior to, and during, a reaction, especially if fever or hypotension are featured. The International
    Society for Blood Transfusion/International Haemovigilance Network (ISBT/IHN) classification should be used to grade severity (Table 16.2)
  • SHOT has a role in identifying trends in reactions and events, including the monitoring of new components. It is therefore important to identify the implicated component e.g. standard/washed red cells; pooled/apheresis and or washed or human leucocyte antigen (HLA)-matched platelets; standard/virally inactivated (including type) plasma
  • Action: SHOT reporters
  • Patients who have experienced transfusion reactions should only be tested for platelet or granulocyte antibodies within guidelines such as those set out in England by the National Health Service Blood and Transplant (NHSBT) in their Histocompatibility and  Immunogenetics user guide (NHSBT 2015/16). The main indication, other than platelet refractoriness, is persistence of severe reactions despite the use of platelets where the plasma has been removed and replaced by suspension medium
  • Action: HTT, Histocompatibility and Immunogenetics laboratories
  • Transfusions should only be performed where there are facilities to recognise and treat anaphylaxis, according to United Kingdom Resuscitation Council (UKRC) guidelines (Resuscitation Council
    2008). This recommendation is also relevant for other transfusion-related emergencies such as respiratory distress caused by transfusion-associated circulatory overload (TACO) or transfusion-related acute lung injury (TRALI). When supplying to community hospitals or for home transfusions, providers must ensure that staff caring for patients have the competency and facilities to deal with reactions. This is particularly relevant in the light of proposals to increase patient treatment outside of secondary care
  • Action: HTT, Royal College of General Practitioners

FAHR Resources

FAHR Annual Report Chapters