The safe provision of emergency blood

According to latest guidance issued by the National Patient Safety Agency (NPSA), delays in the provision of blood and blood components to patients in emergency situations are still resulting in cases of serious harm and even death to the patients involved. A Rapid Response Report (RRR) has been produced by the NPSA following reports of 11 deaths and 83 incidents between October 2006 and September 2010, where the patient suffered harm as a result of delays in the provision of blood in acute situations ranging between 15 minutes and 2 hours. Of these 94 incidents, 22 related to delay in accessing emergency supplies of O RhD negative blood, while 63 related to timely supply of crossmatched blood. The other nine involved platelets and frozen plasma. The RRR asks NHS organisations to ensure that local protocols are in place to detail the roles and actions of clinical teams, laboratory staff and support services to enable timely access to the blood and blood components. To assist this the NPSA also recommends that blood transfusion laboratory staff are informed of patients with a massive haemorrhage at the earliest opportunity so they can activate the procedures necessary to deal with the provision of blood in the event of an emergency situation. The NPSA also recommends that a ‘trigger phrase’ is used to activate these procedures, whereby clinical teams dealing with patients with a massive haemorrhage, nominate a member of the team to act in a liaison role with the laboratory staff and support services to avoid the potential for miscommunication and repeated calls to the laboratory by different people. In the event of an incident occurring According to latest guidance issued by the National Patient Safety Agency (NPSA), delays in the provision of blood and blood components to patients in emergency situations are still resulting in cases of serious harm and even death to the patients involved. A Rapid Response Report (RRR) has been produced by the NPSA following reports of 11 deaths and 83 incidents between October 2006 and September 2010, where the patient suffered harm as a result of delays in the provision of blood in acute situations ranging between 15 minutes and 2 hours. Of these 94 incidents, 22 related to delay in accessing emergency supplies of O RhD negative blood, while 63 related to timely supply of crossmatched blood. The other nine involved platelets and frozen plasma. The RRR asks NHS organisations to ensure that local protocols are in place to detail the roles and actions of clinical teams, laboratory staff and support services to enable timely access to the blood and blood components. To assist this the NPSA also recommends that blood transfusion laboratory staff are informed of patients with a massive haemorrhage at the earliest opportunity so they can activate the procedures necessary to deal with the provision of blood in the event of an emergency situation. The NPSA also recommends that a ‘trigger phrase’ is used to activate these procedures, whereby clinical teams dealing with patients with a massive haemorrhage, nominate a member of the team to act in a liaison role with the laboratory staff and support services to avoid the potential for miscommunication and repeated calls to the laboratory by different people. In the event of an incident occurring is normally only used as an initial ‘lifesaving’ intervention as most blood banks only carry limited supplies of O RhD negative units. A sample for subsequent testing must therefore be collected prior to administration of any emergency blood so that group compatible uncrossmatched or ‘type specific’ red cells can be issued when a transfusion is still required urgently, but before full compatibility testing can be completed. Then, ideally, an emergency “full crossmatch” can be performed whereby compatible group specific units for the patient can be issued by the blood bank if and when time permits. Serological crossmatching in blood banks was, historically, performed using manual techniques, which were both time consuming and labour intensive and could, typically, result in delays of anything up to two hours to supply compatible units for patients. However, the advent of serological techniques employing powerful monoclonal blood typing antisera; the use of disposable column technology cassettes to replace glassware; and particularly the implementation of automated blood grouping and antibody screening analysers has enabled the time taken to issue emergency crossmatched blood to be reduced to less than 30 minutes. Closely following the introduction of automation into blood banks came the “computer” or “electronic crossmatch” (EXM). Historically, blood banks relied on the traditional serological crossmatch as a pre-transfusion safeguard to ensure that group compatible blood is issued for eventual transfusion to patients, both in routine and in emergency situations. Although many of the elements and technical procedures involved with the crossmatch have changed over the years, essentially it still comprises an indirect antiglobulin test (IAT) combined with a verification of the patient’s own ABO and RhD type. The IAT component of the crossmatch is designed to detect any red cell antibodies in the patient’s serum against donor red cell antigens which may be dangerous to the patient, and an “immediate spin” test can also be employed to guard against ABO incompatibility, which could, potentially, be fatal if a serious mismatch occurs.

An EXM sea change

With the advent of computer technology into blood transfusion, combined with the increasing use of automation, there has been a sea change away from compatibility testing using the traditional serological crossmatch towards the introduction of the EXM. Effectively, the EXM is based on the elimination of any direct serological testing between the patient and the donor, relying instead on the use of automated techniques combined with an interfaced computer laboratory information management system or LIMS to ensure that compatible ABO and RhD type blood is issued. This procedure effectively removes any human intervention, which is a reported potential source of error in transfusion adverse incidents, according to previous SHOT data. Additionally, all computer software and automated equipment used to facilitate the EXM must be fully validated to ensure complete compliance with the recommended requirements for ABO and Rh compatibility testing. In abandoning traditional serological techniques, the EXM essentially employs the use of a robust antibody-screening test to detect any clinically significant patient red cell antibodies. Fundamental to electronic issue is a requirement to establish and verify the blood group of the patient and compare with historical data held within the LIMS. The result of the patient’s antibody status and blood group details are then stored on a computer system to be accessed if blood is required for the patient at a later date. Compatible units can then be quickly selected and assigned to the patient by the computer when required, which utilises software to prevent the issue of any ABO incompatible units and also checks for the presence of atypical antibodies in the patient records. Crucial to any EXM system is the incorporation of a comprehensive high quality panel of antibody screening cells conforming to all existing British Committee for Standards in Haematology guidelines, as well as a fully computerised stock control system employing barcode scanning of all blood components. The main advantage that the EXM has over traditional serological cross matching, however, is in emergency situations, particularly major haemorrhage scenarios requiring massive transfusions. In these instances, the EXM allows suitable blood to be quickly selected from stock and rapidly issued to where it is required with the minimum of delay. Before any laboratory implements the EXM the pros and cons of its use should be carefully examined. As stated, the main advantage of the EXM is speed in providing blood, particularly in urgent situations plus the fact that blood no longer needs to be reserved in advance except in certain circumstances such as rare blood groups or the presence of atypical antibodies. Hospitals that have introduced the EXM have also seen a significant reduction in time-expired units and consequently reported savings in both time and money. The “remote release” of blood in satellite hospitals or geographical remote areas is also possible using an electronic issue system and this has future possibilities for some hospital Trusts. On the downside, before the EXM can be implemented a high degree of automation is desirable for a fully secure system and requires capital investment. Even when electronic issue is in place, there will still be a need to perform standard serological crossmatching and blood issue as it is estimated that around 10% of requests are considered unsuitable for computer issue. Equipment failure is another problem that the EXM is especially susceptible to due to analyser or computer problems and for this reason a fallback system must always be readily available in the event of this happening. So, what next for the safe provision of emergency blood? Perhaps a vendingstyle machine situated in the operating theatre itself, capable of dispensing units of different blood groups on demand? This may sound far-fetched but it is already happening. The “HemoSafe” system, said to be the world’s most advanced blood dispensing system, is currently on trial in several UK hospitals. Running on special remote kiosks, HemoSafe can track blood units within the hospital environment and also allows allocated and unallocated blood units to be stored outside of the blood bank. The blood itself is stored in the HemoSafe unit, which is effectively a fully validated refrigerated vending machine for blood packs utilising a design that incorporates a carousel with 150 individually lockable compartments for allocated and unallocated units. HemoSafe dispenses the appropriate blood unit for the patient by opening one of these compartments, but only after the patient has been correctly and positively identified. However, HemoSafe does not make decisions on the electronic allocation eligibility of patients or the assignment of specific blood units, but communicates directly with the blood bank computer system via a bidirectional interface for this information. HemoSafe’s smaller cousin, the “HemoNine” is a nine drawer locking system with one drawer for each blood group and one for crossmatched units. Blood is automatically dispensed, assigned and labelled at the kiosk in less than 60 seconds following the positive identification of the patient. Both HemoSafe and HemoNine units can be located practically anywhere within the hospital, in areas such as A&E, operating theatres and other key areas, thus allowing remote access to blood when it is required. This can also remove the need to contact the blood bank at all, thereby significantly reducing the time taken to provide blood to patients. Other advantages of the system include the elimination of unnecessary allocating and labelling of blood, reduced blood wastage and improved overall management of blood stocks. One other important advantage is that the system can support the allocation of blood units at remote, off-site satellite locations, 24/7 without the need for any blood transfusion staff being present there.