Purpose of the handbook
The purpose of this handbook is to help the many staff involved in providing and using blood products to make sure that the right blood product is given to the right patient at the right time. Among those who must cooperate to achieve this are:
- clinical staff who assess the patient and prescribe and order the blood product
- laboratory or pharmacy staff who receive the order and prepare the product
- porters and transport staff who collect and deliver samples to the blood bank and deliver blood to the patient
- nurses and other clinicians who ensure that blood is administered correctly and who observe the patient during and after the transfusion
- phlebotomists and others who obtain and send pre-transfusion samples
- telephone operators who have to make vital contacts in an emergency.
The website www.learnbloodtransfusion.org.uk has sections with the key information for these groups of staff.
Terms for blood products
Any therapeutic substance prepared from human blood
Fresh frozen plasma
Plasma proteins prepared from large pools of human plasma under pharmaceutical manufacturing conditions, e.g. coagulation factors, immunoglobulin, albumin
The local procedures for prescribing, ordering, collecting, storing and administering blood components should be defined by the local hospital transfusion committee (HTC). These procedures and clinical policies should be based on national guidelines and made readily available to all staff involved in the transfusion process.
The UK Blood Safety and Quality Regulations 2005 (BSQR) set legally binding standards for quality and safety in the collection, testing, processing, storage and distribution of human blood components. The regulations affect both the blood services (called 'blood establishments' in the BSQR) and hospital blood banks. For the latter, the provisions include the requirement to show the existence of a comprehensive quality system and the provision of appropriate training for blood bank staff. A record must be maintained of the final fate of each blood component pack, i.e. whether it is transfused to a named recipient, discarded or returned to the supplying blood establishment. Hospitals must submit reports of serious adverse reactions and events to the Medicines and Healthcare products Regulatory Agency (MHRA) and/or the Serious Hazards of Transfusion (SHOT) scheme using the SABRE online reporting system (www.shotuk.org).
Guidance on basic standards for clinical transfusion
Standards for transfusion have been developed by NHS Quality Improvement Scotland as a basis for inspection of hospitals in Scotland. Each standard is supported by criteria that can be objectively assessed. These can be found at www.nhshealthquality.org
Important changes since the third edition
This edition contains many changes and much new information. Some of the more important additions are described below, but it is emphasised that the following is not intended to be an exhaustive list of changes.
New randomised controlled clinical trial findings
Red cell transfusion in premature neonates - liberal or restrictive policy?
The Premature Infants in Need of Transfusion (PINT study) is a recently published randomised controlled clinical trial that has evaluated the outcomes of two different red cell transfusion regimes. Threshold haemoglobin levels for transfusion in both arms of the trial depended on the infants' age. The trial has so far failed to show any evidence that a more liberal transfusion regime was associated with better outcomes.
Fluids for resuscitation − saline or human albumin?
The Saline versus Albumin Fluid Evaluation (SAFE) study was a randomised controlled clinical trial that evaluated the outcomes of resuscitation in critically ill patients using albumin or crystalloid solutions. It found no evidence that albumin was associated with worse outcomes.
Variant Creutzfeldt-Jacob disease (vCJD)
vCJD is believed to be caused by an abnormal variant of normal prion protein that is highly resistant to techniques conventionally used to inactivate micro-organisms. There is evidence to suggest that vCJD can be transmitted by blood and three probable cases of transmission to transfusion recipients have been reported. A wide range of precautions has been introduced to minimise the chance of vCJD transmission by transfusion (see vCJD precautionary measures taken by the UK services). It has been calculated that if the abnormal prion protein of variant CJD is present in blood, a substantial proportion of the infectivity will be in the plasma. For this reason, precautionary measures in the UK include the use of imported plasma (pathogen reduced) for younger patients; work to minimise plasma content of red cell and platelet components; and numerous initiatives to reduce patients' exposure to blood.
Plasma reduced red cells
The use of this component is mentioned for some specific indications. A plasma reduced red cell unit contains about 100 ml of plasma compared to about 20 ml in a unit of red cells in additive solution. Guidance on the use of plasma reduced red cells has been altered because of the above concerns (see Table 21).
Red cell collection by apheresis (red cell component donation)
Automated equipment is being used in some countries to collect a double red cell unit from suitable donors.
Fresh frozen plasma for younger patients
Fresh frozen plasma is now imported to the UK from areas with a low incidence of BSE. This plasma is treated by one of two processes to inactivate or reduce infectivity of any infective agents undetected by testing. The products are described in Pathogen-reduced plasma components and Table 4 and the UK Department of Health's policy is that imported, pathogen-reduced plasma should always be used for patients up to 16 years of age (see Table 21).
Fresh frozen plasma for treatment of thrombotic thrombocytopenic purpura
Because of the high donor exposure, the UK Department of Health policy is that these patients should be treated with non-UK pathogen-reduced plasma and that, because there is a limited experience of the use of Methylene Blue FFP for this indication, commercially available solvent-detergent FFP should be used.
Prion removal from blood components
Processes have been developed and are under assessment for efficacy and safety.
Blood tests for vCJD infectivity
Under development by several companies. Timescale for availability not yet known.(PMID9593238)
Recombinant factor VIII and factor IX
In the UK, most young patients with severe haemophilia now receive recombinant factor VIII or IX to reduce the risk of infection resulting from repeated administration of fractionated plasma derivatives (see Factor VIII and factor IX concentrate).
Recombinant factor VIIa
This product is licensed for management of haemophilia A or B patients with inhibitors (antibodies to coagulation factors VIII or IX). It is being evaluated in the management of major haemorrhage (see Recombinant factor VIIa).
Cytomegalovirus (CMV) negative and leucodepleted blood components
The residual leucocyte count in blood components is extremely low (< 5 x 106 per unit). This reduces the risk of transmission of leucocyte-associated agents such as CMV or HTLV. However, for patients at risk of harm from CMV transmission, some clinicians prefer to request components that are CMV-antibody negative (see Prevention of cytomegalovirus transmission).
West Nile virus
A mosquito-borne infection mostly affecting North America and causing encephalitis. The virus can be transmitted by blood donated during the viraemic phase. Donors may not give blood in the UK for 28 days after returning from an affected area unless a suitable test is negative. No cases have been transmitted by transfusion in the UK and no infected UK donors have been detected to date.
Pre-release testing of platelet concentrates for the presence of bacteria has become a requirement in some countries and has been introduced in some blood services in the UK. This may reduce the small incidence of severe reactions due to bacterial contamination (see Adverse effects of transfusion).
Time limits for infusing red cell units
The recommendations have been altered slightly following a review of the evidence (see Figure 5).
Patient information leaflets
Leaflets with information for patients about the benefits and risks of transfusion are available from the UK blood services. Making these available to patients who may need transfusion can help to meet one of the new legal requirements for patient information.
Management of blood shortages
As part of NHS emergency planning there is a contingency plan to ensure that if available blood stocks fall to very low levels, critical transfusion support remains available to those who most need it.
Reducing blood administration errors
Electronic systems being used in some hospitals can assist safe blood administration by improving identification and checking of patients and blood components.
Perioperative autologous blood donation
This procedure is currently little used in the UK. Centres that wish to undertake it must now register as a blood establishment under the Blood Safety and Quality Regulations 2005.
e-Learning about blood transfusion
To learn more about many of the topics covered in this book, go to www.learnbloodtransfusion.org.uk
Web-based consultation on the handbook
The text includes many of the points raised by the numerous responses to the web-based consultation that took place in August 2006. However, there were many points on which opinions differed quite markedly, and clearly not all views can be fully reflected here.
New BCSH guidelines published in 2006
The new guidelines are available at www.bcshguidelines.com and cover the following topics: alternatives to allogeneic blood transfusion, management of massive blood loss, use of prophylactic anti D immunoglobulin and blood grouping and antibody testing in pregnancy.