Serious Hazards of Transfusion (SHOT) haemovigilance and progress is improving transfusion safety

Abstract

The Serious Hazards of Transfusion (SHOT) UK confidential haemovigilance reporting scheme began in 1996. Over the 16 years of reporting, the evidence gathered has prompted changes in transfusion practice from the selection and management of donors to changes in hospital practice, particularly better education and training. However, half or more reports relate to errors in the transfusion process despite the introduction of several measures to improve practice. Transfusion in the UK is very safe: 2·9 million components were issued in 2012, and very few deaths are related to transfusion. The risk of death from transfusion as estimated from SHOT data in 2012 is 1 in 322,580 components issued and for major morbidity, 1 in 21,413 components issued; the risk of transfusion-transmitted infection is much lower. Acute transfusion reactions and transfusion-associated circulatory overload carry the highest risk for morbidity and death. The high rate of participation in SHOT by National Health Service organizations, 99·5%, is encouraging. Despite the very useful information gained about transfusion reactions, the main risks remain human factors. The recommendations on reduction of errors through a 'back to basics' approach from the first annual SHOT report remain absolutely relevant today.

Keywords: Serious Hazards of Transfusion; haemovigilance; transfusion errors; transfusion reactions; transfusion safety.

Figure 1

Cumulative data for SHOT categories 1996/7 to 2012, n 11570. Reported events can be divided into three groups: those caused by error that should be preventable, those caused by unpredictable reactions, and an intermediate group of complications that may be preventable by better pretransfusion assessment and monitoring.

Figure 2

Venn diagram showing interrelationships between different adverse incidents following blood transfusion. HTR, Haemolytic transfusion reaction; TTI, Transfusion-transmitted infection; PTP, Post-transfusion purpura; TACO, Transfusion-associated circulatory overload; TAD, Transfusion-associated dyspnoea; TRALI, Transfusion-related acute lung injury; TAGvHD, Transfusion-associated graft versus host disease; SRNM, Specific requirement not met; WCT, Wrong component transfused. Avoidable: transfusions that are unnecessary or given on the basis of wrong blood results. Examples: A wrong component transfusion, e.g. group A red cells transfused to a group O patient is likely to cause a haemolytic transfusion reaction (HTR). A patient with sickle cell disease may have an HTR if transfused with red cells not matched for an antigen that previously has been associated with an antibody in that patient. A patient inappropriately transfused for a wrong haemoglobin result may develop TACO. Symptoms of TACO may overlap with other pulmonary categories, TRALI or TAD. A patient with immune deficiency who receives red that which are not irradiated (specific requirements not met) may develop TAGvHD.

Figure 3

Timeline for SHOT development showing organizations that SHOT reporting has triggered or supported. SHOT, Serious Hazards of Transfusion; NPSA, national patient safety agency; SPN, Safer practice notice; RRR, Rapid response report; NBTC, National blood transfusion committee; UKTLC, UK transfusion laboratory collaborative.