Blood transfusions in adults: ensuring patient safety

A blood transfusion is a clinical procedure involving the transfer of whole blood, or one of its components, from a donor to a recipient. It can be life saving for patients.

Careful donor selection, processing, storage and distribution of blood components by healthcare staff is required to ensure safe and effective blood transfusion practice. However, the British Society for Haematology (BSH) (2017) has identified that errors still occur in the requesting, collection and administration of blood components, which can lead to significant risks for patients. These risks and adverse events are monitored by the Serious Hazards of Transfusion (SHOT), which is the UK's independent, professionally led haemovigilance scheme. In 2019, 84.1% (2857/3397) of all reports (including near miss and right blood right patient reports), were due to errors (Narayan and Poles, 2020).

Although it is often a medical responsibility to prescribe blood components, the completion of pre-transfusion sampling, bedside checks and monitoring of the patient during transfusion is most often the responsibility of the nurse (Vasiliki, 2011). The National Institute for Health and Care Excellence (NICE) (2015) has produced guidelines for the assessment and management of blood transfusions. It includes information on patient safety during the blood transfusion process to further reduce errors, as well as providing alternatives to blood transfusion.

Safe transfusion practice using a bedside checklist

The UK national haemovigilance surveillance programme, SHOT, repeatedly identifies that patients are harmed, and some die, as a result of being given the incorrect type of blood.

The Chief Medical Officer and Chief Nursing Office recognised in a CAS alert (Department of Health, 2017) that in 2014 a patient died because of an ABO-incompatible transfusion in a high-profile case. The nurse collected, then administered a unit intended for another patient with a similar name. This would have been prevented if the final bedside check had been undertaken correctly. There were seven ABO-incompatible transfusions reported to SHOT in 2015, and three in 2016. All of these were preventable. In addition to the risk of non-biocompatible transfusion, patients may have other specific, and sometimes critical, transfusion requirements such as irradiated blood, CMV-negative serology blood and extended phenotype blood. Two critical points occur in preparation for transfusion; the first is to correctly identify the patient and label the sample when taking blood for a pre-transfusion blood sample, and the second is to check the details on the unit of blood and the patient's identity at the point of transfusion. Evidence from SHOT shows that the bedside check performed at the point of transfusion is not always undertaken correctly and that this puts patients at risk of serious complications or death.

Blood sample collections

Blood sample collection procedures are a critical step in ensuring the safety of transfusion. Blood sampling from patients, whether in hospital or in the community, is a regular and important part of health care. Nevertheless, as with all interventions, it is not without risk.

Correctly linking the blood sample to the patient from whom it was taken is fundamental, thus confirmation of the patient's identity and labelling the blood sample at the bedside is essential. If the sample in the tube does not belong to the patient whose name is on the tube, and this is not detected, then many different consequences may follow. Wrong blood in tube (WBIT) errors, where the blood in the tube is not that of the patient identified on the label, may lead to catastrophic outcomes, such as death from ABO-incompatible red cell transfusion (Bolton-Maggs et al, 2015).

Blood groups

In the early 1900s it became apparent that some patients were dying after blood transfusions and scientists discovered that there was incompatibility between some blood groups. There are more than 300 blood groups, but only a minority cause clinically significant transfusion reactions (Joint UK Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee (JPAC), 2014a).

The two most important blood groups in clinical practice are ABO and RhD. The ABO system includes four main blood groups: A, B, AB and O. All of these groups are named because of the antigens on the surface of the red blood cells (RBCs). Antibodies can be formed against the antigens which the recipient lacks and can be naturally occurring or stimulated through pregnancy, transfusion or transplantation. Blood groups and compatibility of RBCs are shown in Table 1.

RBCs sometimes have the RhD antigen. If this is present, then the blood group is RhD positive. If there is no RhD antigen present, the blood group is RhD negative.

A patient's Rh status is particularly important in patients with childbearing potential. If a pregnant woman is RhD negative and the fetus is RhD positive this can stimulate the formation of antibodies in the woman that may cross the placenta and destroy the RBCs in the fetus. This is called sensitisation. This process does not normally affect the first pregnancy but, if a subsequent pregnancy with a RhD positive fetus occurs, the woman's body will produce antibodies immediately, which can cross the placenta and cause haemolytic disease of the fetus and newborn (HDFN). Today, pregnant women are offered anti-D immunoglobulin injections during pregnancy to help remove the RhD fetal blood cells before they cause sensitisation. If a woman has already developed anti-D antibodies in a previous pregnancy (she is already sensitised) the immunoglobulin injections are contraindicated and more monitoring of the pregnancy will occur and the baby will require treatment after delivery. Administration when anti-D antibodies are present exposes the patient unnecessarily to a blood product (Norfolk, 2013; NHS website, 2021).

Compatibility

A donor's blood group must be compatible with the recipient's blood group. If it is not, an acute or delayed haemolytic transfusion reaction may occur. For example, if someone with blood group A (antigen A on the RBCs) is given blood group B RBCs the anti-B antibodies in the plasma will attack the group B cells. Therefore, group A RBCs must never be given to someone who has group B blood. Blood group AB has both antigen A and antigen B on its RBCs and no antibodies in the plasma. Those with type AB blood can receive blood from any of the blood groups (see Table 1). RBCs of blood group O do not have any A or B antigen on their surface, therefore the recipient's body will not react against group O RBCs and therefore group O RBCs can be given to a patient of any blood group. However, the presence of RhD has to be taken into consideration, with blood group O negative (no Rh factor) referred to as the ‘universal donor’ and this is most often given to patients in an emergency when the patient's blood group is not known. Type O negative RBCs have no antigens, it will not trigger an immune response, even if the recipient has a different blood type. Blood group AB positive is referred to as the ‘universal recipient’. It is important to note here that in almost all cases patients are transfused with the same blood group as their own so there is less risk of incompatibility.

Indications for blood transfusions

The Blood Safety and Quality Regulations (BSQR) (legislation.gov.uk, 2005) define blood components as a therapeutic constituent of blood (such as RBCs, platelets, fresh-frozen plasma (FFP), cryoprecipitate or granulocytes). There are also licensed medicinal products derived from whole blood or plasma such as solvent detergent (SD) plasma, albumin and anti-D immunoglobulin (JPAC, 2014b). Whole blood is rarely used for transfusion now and patients are given a blood component only where there is a deficiency, which prevents unnecessary use of blood components (Lister et al, 2020).

Red blood cells

RBCs, also called erythrocytes, are the most abundant cell type in the blood. The primary function of RBCs is to transport oxygen to body cells and deliver carbon dioxide to the lungs. RBCs are transfused to patients to restore oxygen-carrying capacity in patients with anaemia or blood loss where alternative treatments are ineffective or inappropriate (JPAC, 2014a). Although local policies will vary, evidence suggests that most patients can tolerate anaemia with a haemoglobin of 70 g/litre in the absence of active bleeding (Lister et al, 2020). Most people can cope with losing a moderate amount of blood without needing a blood transfusion, as this loss can be replaced with other fluids to improve circulating volume. However, if larger amounts of blood are lost, a blood transfusion may be the best way of replacing blood rapidly. A blood transfusion may be needed to treat severe bleeding during or after an operation, childbirth or after a serious accident, for example. A major haemorrhage can be defined as (NICE, 2015):

• The loss of more than 1 blood volume within 24 hours (around 70 ml/kg, or more than 5 litres in a 70 kg adult)
• The loss of 50% of total blood volume in under 3 hours
• Bleeding in excess of 150 ml/minute in adults.

As a practical clinical definition, major haemorrhage is bleeding that leads to:

• A systolic blood pressure of less than 90 mmHg or
• A heart rate of more than 110 beats per minute in adults.

Additionally, blood component transfusions may be given to those patients who are deemed at risk of severe bleeding, such as patients with bleeding disorders (eg disseminated intravascular coagulation and platelet dysfunction).

Haemoglobin within RBCs transports oxygen around the body, therefore if there are fewer RBCs, there is less oxygen transportation, and consequently an increased chance of organ failure and even death.

Sometimes the bone marrow, which produces blood cells, cannot make enough RBCs. This may be due to disease or a failure of the bone marrow to work properly. It may be temporary or a longer term problem. Some treatments, such as chemotherapy, can also affect the bone marrow in this way. In some cases, the anaemia can be treated with medicines; in other cases, a blood transfusion may be the best treatment (NHS Blood and Transplant, 2018).

Platelets

Platelet transfusions are offered to patients with thrombocytopenia who have clinically significant bleeding. In thrombocytopenia patients have low platelet production or increased destruction, therefore a transfusion can be beneficial to prevent or treat bleeding (Lister et al, 2020).

Fresh frozen plasma (FFP)

Plasma is obtained from whole blood donations or component donation by apheresis and is frozen soon after collection to protect its blood-clotting factors. It may be transfused to patients with significant bleeding but without major haemorrhage if they have abnormal coagulation test results and alternative therapies (eg prothrombin complex concentrate) are not available.

Cryoprecipitate

Cryoprecipitate is made from donated FFP, which is then thawed, centrifuged and the precipitate collected. It is used for patients with or without major haemorrhage who have clinically significant bleeding and low fibrinogen levels below 1.5 g/litre (2g/litre in obstetric bleeding). Additionally, dried fibrinogen is now available for prescription as described in the British National Formulary (BNF). This can be administered by intravenous injection (IV), or by intravenous infusion (Joint Formulary Committee, 2021). It should be noted that the licence for fibrinogen concentrate is very restrictive.

Granulocytes

Transfusion of granulocytes is uncommon (these include neutrophils, which are phagocytic white blood cells) but may be indicated in patients with life-threatening soft tissue or organ infections with bacteria or fungi and low neutrophil counts, usually in the setting of severe, prolonged neutropenia after cytotoxic chemotherapy (JPAC, 2014a).

Procedural safety

All hospitals must have a transfusion policy with clear guidelines on blood transfusion practice. Regular training and competency assessment of all staff involved in the blood transfusion process is vital for transfusion safety (NICE, 2015).

Pre-procedure and sampling

The decision to transfuse must be based on a clinical assessment and consideration given to alternative treatments and issues such as religious belief, where patients may refuse a blood transfusion. Once a decision is made that the patient requires a transfusion, consent will be gained from the patient if possible and recorded in the patient's notes (Safety of Blood, Tissues and Organs (SaBTO), 2020). A request is made by the prescribing doctor or registered practitioner and sent to the transfusion laboratory. This will include a blood sample from the patient for their ABO, Rh status, antibody screening and cross match (Vasiliki, 2011) to ensure compatible blood is ordered for the patient. The patient's identity with surname, forename, date of birth and unique identity number retrieved from the patient computer system should be included on the patient's wristband. More widespread use of electronic management systems using barcodes on ID bands and blood components and hand-held scanners linked to the laboratory system will continue to enhance blood transfusion practice (JPAC, 2014a). Collection of the sample and labelling of the sample tubes must be performed as one uninterrupted process involving one competent staff member.

Blood components are stored under temperature-controlled conditions to prevent damage to the product. RBCs are stored in a designated blood component refrigerator under controlled temperatures in a laboratory and contain anti-coagulant to prevent clotting of the infused blood. These must never be stored in ward or drug fridges at any time. Once the blood component is ready in the transfusion laboratory, nurses will ensure the patient is prepared with intravenous access and that the blood component is prescribed correctly before requesting delivery of the blood. The blood should be collected by a staff member who is trained and competent in this process as errors in removal from storage and transportation have been identified as a source of error (Lister et al, 2020). A request slip or transfusion prescription is used to check against the blood collected before signing the blood out to the clinical area. Today, computerised checking systems use bar codes and can scan staff IDs to reduce handwritten documentation and improve safety. Only one unit of blood should be collected at any one time unless it is an emergency requiring rapid transfusion and all blood components should be administered as soon as possible.

Pre-transfusion observations should be carried out on the patient, including blood pressure, temperature, heart rate and respirations no more than 60 minutes before the transfusion (Hurrell, 2014). Equipment should be prepared in advance and cannula access gained.

Administration of the blood product

The identity check between the patient and the blood component to be transfused is usually considered the last opportunity to identify errors made earlier in the process, as well as being the final point at which errors can occur. It is predominantly the responsibility of the nurse to ensure that the right patient receives the right blood. This must be performed at the bedside (Lister et al, 2020). The key principles of safe bedside administration are outlined in Box 1. If there are interruptions during the checking process it must start again and if there are any discrepancies the blood transfusion should not go ahead and discrepancies must be reported to the laboratory (JPAC, 2014a). All relevant documentation should be signed by the person administering the blood and the component donation number, date, time of starting and stopping the transfusion, dose/volume of component transfused, and name of the administering practitioner should be recorded. Blood components must be given using a designated giving set and an infusion device can be used to control the rate of infusion (Lister et al, 2020). Once the transfusion has started, observations including blood pressure, heart rate, respiratory rate and temperature should be recorded on a transfusion record or an electronic patient record within 15 minutes. Most serious reactions such as ABO incompatibility will occur during this time (JPAC, 2014a). It is also important to observe and monitor the patient throughout the transfusion. Any concerns by the nurse or expressed by the patient would indicate the need to perform additional observations. In the event of a reaction, the transfusion should be stopped immediately, resuscitation measures begun if required and contact made with both medical staff and the transfusion lab. Possible reactions are listed in Box 2. Nursing considerations are listed in Box 3 (JPAC, 2014c).

Box 1.Bedside checkThe use of a formal bedside checklist has been mandated since the 2017 CAS alert (Department of Health, 2017)Positive patient identification

• Confirm patient's full name and date of birth
• Ensure information matches the patient's identity wristband
• Ensure patient's hospital ID number is on the form returned to the lab when the transfusion is started

Patient details on component pack

• Check the details match with the patient's identity wristband and prescription

Correct prescription

• Check that the right component has been prescribed Correct component
• Check it is the correct component
• Check that the component is compatible with the recipient's ABO blood group
• Check expiry date
• Ensure that the donation number and blood group matches the laboratory report label
• Check pack for signs of leakage and inspect for any defects

Any specific requirements

• Does the patient need any irradiated blood or specially selected units?
• Does the patient require a diuretic prescription in the case of fluid overload, heart (pump) failure?

Source: Bellamy, 2018

Box 2.Blood transfusion reactions
Source: Suddock and Crookston, 2019

Source: Suddock and Crookston, 2019

Box 3.Nursing considerations

• No drugs or other intravenous fluid must be added to or administered via the same cannula during the transfusion of any blood component
• Flushing through the remainder of the blood in the line with 0.9% sodium chloride is unnecessary and is not recommended because it may result in particles being flushed through the filter
• If another IV infusion is to take place after the blood transfusion, a new IV fluid administration set must be used to reduce the risk of incompatible fluids or drugs causing haemolysis of any residual red cells that may be left in the administration set
• If multiple units of red blood cells are being transfused, the administration set should be changed at least every 12 hours to prevent bacterial growth. Additionally, in cases of massive haemorrhage, where different components are to be given in rapid succession, it is common clinical practice to use a new set for each component

Source: JPAC, 2014c

Post-procedural care

At the end of each unit transfused, the time and volume infused must be recorded. Transfusion should be completed within 4 hours of leaving controlled temperature storage (JPAC, 2014d). It is important that the patient's heart rate, blood pressure, respiratory rate and temperature are recorded no more than 60 minutes after the end of the transfusion (Lister et al, 2020). Inpatients should be observed for late reactions, which can occur up to 24 hours after a transfusion. Day-care patients should be advised to report symptoms developing after discharge. If there is any suspicion of a reaction during the hospital stay, the blood component pack and all records must be sent back to the transfusion lab. Where there are no issues, all documentation must be filed in the patient record. For patients requiring ongoing transfusions, the blood giving set should be changed every 12 hours (Robinson et al, 2018). Once the transfusion is complete all equipment, including the component pack, should be discarded as clinical waste.

Traceability

The UK Blood Safety and Quality Regulations 2005 (as amended) defines ‘traceability’ as ‘the ability to trace each individual unit of blood or blood component from the donor to its final destination (whether this is a recipient, a manufacturer of medicinal products or disposal) and from its final destination back to the donor’ (legislation.gov.uk, 2005; JPAC, 2014a). The regulations place an obligation on both blood establishments (regulation 8) and hospital blood banks (regulation 9) ‘to ensure full traceability of blood and blood components’.

The expectation is that traceability information will therefore be available for all blood and blood components and retained in a retrievable form for 30 years. However, it is acknowledged that, occasionally, the final fate of a specific blood component cannot be confirmed. In such cases, steps should be taken by the blood establishment or hospital blood bank to monitor and investigate each traceability failure.

In clinical practice, it is usually hospital policy that the blood product paper label or sticker is detached following transfusion. If using paper notes the sticker will be placed in the clinical notes. If using electronic notes, this code will be scanned in or typed into the clinical notes system. The blood product label will also be kept in a designated box and sent to the pathology laboratory for recording and storage purposes.

Patient information

NICE (2015) recommends that clinical staff provide verbal and written information to patients who may have or who have had a transfusion, and their family members or carers (as appropriate). This should include the reason for the transfusion, the risks and benefits, the transfusion process, any alternatives and that they would not be eligible to donate blood in future.

Alternatives to blood transfusions

It is important to acknowledge that blood transfusions are only administered if there are no other alternatives and clinical assessment indicates the need for a blood transfusion. Tranexamic acid may be given to patients who are undergoing surgery where potential blood loss is >500ml (NHSBT, 2021). According to NICE (2015), erythropoietin can be given if the patient has anaemia and meets the criteria for blood transfusion, but declines it because of religious beliefs or other reasons, or the appropriate blood type is not available because of the patient's red cell antibodies. Additionally, intravenous or oral iron can be offered before and after surgery to patients with iron-deficiency anaemia (NICE, 2015).

Summary of SaBTO recommendations on consent

According to the guidelines from the expert advisory committee on the Safety of Blood, Tissues and Organs (SaBTO) (2020) on patient consent for blood transfusion, it is recommended that:

• Informed and valid consent for transfusion is completed for all patients who will likely, or definitely, receive a transfusion. These recommendations apply to transfusion of whole blood, red blood cells, platelets, fresh-frozen plasma (FFP), cryoprecipitate and granulocytes, as well as those who are exposed to blood or blood components. These recommendations also apply to where transfusion might occur during a procedure where the patient is incapacitated, for example, where blood is routinely requested prior to surgery or where a ‘group and save’ or ‘cross-match’ sample is taken pre-procedure. Such shared decision-making discussions should be documented in the patient's clinical record.
• Patients who have been given a blood transfusion and were not able to give informed and valid consent prior to the transfusion are informed of the transfusion prior to discharge and provided with relevant paper or electronic information.
• All patients who have received a transfusion have details of the transfusion (type(s) of component), together with any adverse events associated with the transfusion, included in their hospital discharge summary to ensure both the patient and their family doctor are aware. The patient should also be informed that they are no longer eligible to donate blood (with the exception of individuals who have received convalescent plasma from donating convalescent plasma to treat individuals with SARS-CoV-2 infection/COVID-19).
• The UK Blood Services provide a standardised source of information for patients who may receive a blood transfusion in the UK.
• Training in consent for transfusion is included in all relevant undergraduate healthcare practitioners' training, followed by continuous, regular knowledge updates (minimum 3-yearly) for all healthcare practitioners involved in the consent for transfusion process.
• There is a centralised UK-wide information resource for healthcare practitioners to facilitate consent for transfusion discussions, indicating the key issues to be discussed when obtaining informed and valid consent for a blood transfusion, and providing up-to-date information on the risks of transfusion. This resource should be provided by the UK Blood Services. The feasibility of developing and maintaining this resource should be completed by the UK Blood Services within 6 months of the publication of these recommendations.
• All UK healthcare organisations who provide blood transfusions employ mechanisms (such as audit) to monitor the implementation and compliance with these SaBTO recommendations, with subsequent improvement plans developed and implemented if indicated.

Conclusion

The transfusion of blood components is common in clinical practice but is a complex process that requires nurses and other health staff to be vigilant in all aspects of transfusion practice to ensure patient safety is maintained throughout. Clinical guidelines and appropriate education and training are essential to standardise blood transfusion practice and reduce avoidable errors, which are most often attributed to human error (Booth and Allard, 2017). There is now clinical evidence to support the process of ‘patient blood management’, which is an evidence-based multidisciplinary approach aimed at optimising the individual and holistic needs of patients and reducing avoidable use of blood components when alternatives may be suitable (Gallagher et al, 2015).

The majority of blood transfusion reactions occur because of human error. Some reactions can be severe, but many are benign. Anaphylactic reactions to a blood transfusion are very rare but often result in a fatality (American Society of Anesthesiologists, 2014). Transfusion in the UK is generally safe and SHOT data for the 5 years to 2019 show the risk of death from transfusion as 0.87 per 100 000 components issued (Narayan and Poles, 2020). Patients on any ward can receive a blood transfusion and so all nurses must know the potential complications and how to manage them.

LEARNING OUTCOMES

• Understand the different human blood groups and their compatibility for donation
• Know the indications for blood transfusions
• Understand the administration process and patient safety procedures for blood transfusions
• Know the alternatives to blood transfusions