Clinical blood transfusion remains an essential and irreplaceable part of modern medicine, either as an independent therapeutic modality or an additional support to other clinical therapies. Anaemia, a serious disease with a worldwide burden on both hospitalised patients and society,1 2 3 is often managed with blood transfusion as part of the treatment. Without a reliable substitute, sourcing of the blood used in transfusion relies solely on donations from voluntary, non-remunerated blood donors. Because blood is a biological substance, it is impossible to completely eliminate adverse outcomes during and after transfusion. Worldwide, particularly in developed countries, the ageing of the population and emerging infectious diseases are the two most important and ongoing threats to the sustainability of the safe blood supply. Ageing populations tend to have increased numbers of complex surgeries and cancer treatments requiring increased blood transfusions.4 In 2016, the mean per capital blood use in high-income countries was 32 units of red cell components per 1000 population. Moreover, the most frequently transfused patient group is aged >60 years, accounting for up to 79% among these transfusions.5 Infectious pathogens continue to emerge rapidly, which could adversely affect transfusion safety both directly (if the pathogen is transmitted through blood transfusion) and indirectly (if outbreaks reduce the pool of available donors).6 Recent examples include the Zika virus outbreak in South America and the dengue, hepatitis E, and chikungunya virus outbreaks in Southeast Asia.7 Therefore, maintenance of a sustainable and safe blood supply continues to be a challenging task that requires a substantial amount of effort and resources.

There is evidence associating blood transfusion with less favourable clinical outcomes.8 9 This evidence includes a higher incidence of recurrence in cancer surgeries, higher operative mortality, failure to rescue from sepsis, and other serious complications like renal, neurological, cardiac, and pulmonary dysfunction.10 Patient blood management (PBM) is a patient-centred and multidisciplinary framework that has been rapidly developing throughout the last decade in Western countries to improve the treatment outcomes of patients who may need blood transfusions during their treatment. It refers to evidence-based medical

and surgical concepts designed to improve patient outcomes. Commonly, PBM employs a three-pillar approach: (1) optimise red blood cell mass; (2) minimise blood loss; and (3) manage anaemia (Table 111 12 13 14). Indeed, PBM optimises the patient’s condition before, during, and after the procedure and only recommends transfusion when indicated. It directly addresses the triad of independent risk factors that can affect patient outcomes: anaemia, blood loss, and transfusion. Anaemia is appropriately and timely managed according to its aetiology instead of being bluntly corrected by blood transfusion. Thereby, blood loss is minimised, and the harm associated with inappropriate transfusions is avoided.15 Therefore, countries that have implemented PBM have shown improvement of patients’ outcomes, such as overall survival, disease recurrence, infection rate, length of stay in intensive care unit and hospital, cost, and blood utilisation.16 17 18 19 20 21 22 During the Sixty-third World Health Assembly in 2010, member states were urged to establish or strengthen systems for the safe and rational use of blood products and to provide training for all staff involved in clinical transfusion, to implement potential solutions to minimise transfusion errors and promote patient safety, and to promote the availability of transfusion alternatives including, where appropriate, autologous transfusion and PBM.23

Although Hong Kong has a long history of self-sufficiency in terms of blood supply, population ageing has brought a significant increase in demand for blood over the last decade.24 Since 2015, the Hong Kong Blood Transfusion Service has experienced excessive difficulties at mobilising citizens to maintain a stable, safe blood supply. As a result, the Blood Transfusion Service faces a number of blood safety and donor issues that affect the blood supply. Emerging infectious diseases like Zika virus and low pre-donation haemoglobin due to iron deficiency are typical examples that may prevent apparently healthy persons from donating blood.

As blood is irreplaceable and has a limited shelf life, securing a sustainable and safe blood supply is of paramount importance in the modern healthcare system to ensure that patients’ transfusion needs are met promptly and appropriately. Strategies to enhance new donor recruitment and existing donor retention should be undertaken by the Blood Transfusion Service to increase the blood supply. However, demand control measures should be simultaneously implemented to reduce the pressure on the supply side. In Hong Kong, there has been increasing awareness of the concept of PBM beginning in the past 2 years, and small-scale projects have been initiated. One local project was able to increase the preoperative haemoglobin concentration and reduce the transfusion rate after implementation of PBM.25 In the UK, the National Institute for Health and Care Excellence recommended consideration of single-unit transfusions for adults without active bleeding in November 2015.26 On the basis of this recommendation, some medical departments in Hong Kong have implemented single-unit blood transfusions over the past 2 years, and unpublished audit results demonstrate an overall reduction of red blood cell transfusions in general medical in-patients over that period.

With the objective of improving patients’ outcomes and better managing transfusion demand, a group of experienced clinicians from different specialties and hospitals in Hong Kong has established the Hong Kong Society of Clinical Blood Management to continuously promote PBM in Hong Kong. The Society aims to discuss and make recommendations regarding the implementation of PBM in Hong Kong. Below are three areas of focus that the Society intends to address.

Anaemia is a serious disease burden in both hospitalised patients and society.1 2 3 Haematopoiesis and anaemia management are important modifiable risk factors for adverse outcomes.9 27 28 Beneficial outcomes in this important pillar of PBM are seen in not only surgical patients but also other patient groups, such as those with underlying medical, obstetric, or gynaecological problems. Therefore, clinical guidelines have recommended that anaemia be promptly recognised and the underlying causes identified and managed appropriately.29 Because some surgical patients have an increased risk of bleeding, haemoglobin measurement well before operation in all patients could provide adequate time to manage any anaemia before surgery and improve outcomes.29

Red blood cell transfusion should be restricted to the minimal amount necessary to achieve clinical stability and to patients presenting with severe iron deficiency anaemia and alarming symptoms (eg, haemodynamic instability) and/or risk criteria (eg, coronary heart disease).30 31 As iron deficiency (whether absolute or functional) is commonly found in anaemic patients, its correction should be promptly instituted. Oral iron supplements, provided as ferrous or ferric salts, are usually the first line of treatment for uncomplicated iron deficiency anaemia because of their availability, ease of administration, and relatively low cost. However, because of these supplements’ notorious gastrointestinal adverse effects, intravenous iron should be considered in patients with intolerance to oral iron and when more rapid restoration of the iron store is expected. ‘Newer’ intravenous iron formulations with safer profiles, such as ferric carboxymaltose or iron isomaltoside, which allow for a short-time (15-60 min) infusion of high iron doses (≥1000 mg), are now available for use in both in-patients and out-patients. Such intravenous iron formulations can rapidly correct iron deficiency and anaemia within a few weeks (vs the few months needed for correction via oral iron). At the University Hospitals Plymouth, UK, intravenous iron is given to successfully treat iron deficiency anaemia when surgery with anticipated blood loss of >500 mL is anticipated within 6 weeks.32 As a result, intravenous iron has become an important component of PBM management strategies.

In Hong Kong, the Blood Transfusion Service and the Hong Kong Medical Association have recently issued a simple algorithm to aid general practitioners with early and prompt recognition of anaemia and its management.33 Further work is required to enhance the general population’s awareness of anaemia and iron deficiency issues, their diagnosis, and improving their management.

Reducing or minimising blood loss in hospitalised patients is another approach to reduce the need for blood transfusion and improve patients’ outcomes. Some might consider that this type of planning should only occur in surgical or operative settings, but reducing iatrogenic blood loss in non-operative settings has also been shown to improve patients’ outcomes. Table 234 35 36 37 38 39 40 41 42 43 highlights the measures that have been shown to be effective at minimising blood loss. These measures are safe and have not affected organ function or caused other complications. Instead, they reduce iatrogenic blood loss and avoid blood transfusions.

Temporary cessation of antiplatelet and anticoagulant medications in the perioperative period may lead to reduced blood loss and transfusion requirements if the risks of perioperative thromboembolic events and bleeding are balanced. Meticulous surgical techniques such as performing minimally invasive surgery, judicious use of electrocautery, tourniquets, topical haemostatic agents, and intra-operative blood salvage can minimise surgery-related blood loss.44 45 46 47 48 49

A number of anaesthetic techniques can also help to reduce blood loss. Permissive hypotension refers to the lowering of mean arterial pressure to values between 50 and 65 mm Hg with the goal of reducing blood flow to the surgical field, thereby reducing blood loss and improving visibility in the surgical field.50 Studies have shown that permissive hypotension during anaesthesia reduced blood loss in spinal surgery, radical prostatectomy, functional endoscopic sinus surgery, and orthopaedic surgery.51 52 53 It can also reduce blood loss and blood product utilisation in adult trauma patients with haemorrhagic shock.54 Organ hypoperfusion is the major drawback, and therefore, this strategy may not be suitable for patients with coronary artery disease, cerebrovascular disease, traumatic brain injury, or spinal injury.

Prevention of perioperative hypothermia is another strategy that can help to reduce blood loss. Hypothermia is defined as a core temperature <36°C and is a common consequence of anaesthesia.55 Even mild hypothermia, defined as a core temperature

between 35°C and 36°C, significantly increases perioperative blood loss and augments the transfusion requirement.56 Therefore, measures should be taken to prevent inadvertent hypothermia, including identification of high-risk patients, pre-warming before surgery, intra-operative monitoring of body temperature, using warm intravenous/irrigation fluid and forced-air warming devices, and avoidance of unnecessary body exposure.57

Another method to minimise blood loss is acute normovolaemic haemodilution. Acute normovolaemic haemodilution involves withdrawal of whole blood with concurrent infusion of fluids to maintain normovolaemia.58 The autologous blood is re-infused at the conclusion of the surgery. This method has been shown to significantly reduce the incidence and volume of allogeneic blood transfusion, and its use should be considered in adult patients who undergo surgery in which substantial blood loss is anticipated.44 However, relatively profound anaemia is expected during the surgery, which may induce tissue ischaemia, particularly in the myocardium.45 Furthermore, the effects of normovolaemic haemodilution on morbidity and mortality are uncertain.

Appropriate patient positioning during the intra-operative period may also help to reduce surgery-related blood loss. Elevation of the surgical site above the right atrium facilitates venous return and reduces venous engorgement. For example, the reverse Trendelenburg position has been shown to reduce intra-operative blood loss in endoscopic sinus surgery.46

Using the wide pad support widths of the Wilson frame, when compared with narrow pad support widths, significantly decreased intra-abdominal pressure and intra-operative blood loss in patients undergoing spine surgery in the prone position.47 Pharmacological agents can also be used to facilitate haemostasis. Tranexamic acid has been studied extensively in a wide range of surgeries and has been shown to reduce blood loss effectively without increasing the risk of thromboembolic events.48 49 In case of significant haemorrhage that is refractory to standard treatment, the use of recombinant factor VIIa should also be considered.59

Diagnostic phlebotomy for laboratory testing can also be a significant source of blood loss, especially in critically ill patients.60 Such blood loss has been associated with the development of anaemia and the need for transfusion.61 Therefore, blood tests should be ordered only when necessary, and the volume of blood collected should be the minimum required. Paediatric bottles can be used to minimise the blood volume collected for testing, which in turn reduces iatrogenic blood loss and transfusion requirements.60 Point-of-care testing devices require smaller blood volumes for analysis and serve as an alternative to traditional laboratory testing. Blood sampling from arterial and central venous lines traditionally involves discarding the initial blood sample. The method of returning the initial blood sample back to the patients has been used to significantly reduce iatrogenic blood loss,62 and this measure should be considered.

As blood transfusion is not without risks, consideration should be given to the balance of benefits against risks. Most would advocate the adoption of a quality clinical transfusion process, ie, “transfusion of the right number of units of blood to the right patient at the right time, in the right conditions, and according to appropriate guidelines”.63 Thus, clinicians should proceed through a chain of related events by making appropriate decisions (Fig).

On the basis of the above three areas for consideration, as well as advice from the Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee64 and the World Health Organization,65 the Hong Kong Society of Clinical Blood Management makes the following recommendations:
1. A PBM framework, covering primary, hospital, research, audit, and public health measures, should be developed for use in Hong Kong after engagement of different stakeholders;
2. Healthcare professionals, patients, and the public should be educated on the appropriateness of blood transfusion, and PBM programmes; and
3. A PBM framework should be developed for application in Hong Kong, including early recognition and better management of anaemia and iron deficiency in patients and the general population; optimisation of patients’ haematopoiesis and correction of coagulation before surgical procedures; and application of various blood-saving technologies/techniques and point-of-care testing to optimise patients’ outcomes with less transfusion.

The proposed PBM framework is a multi-pronged approach that encompasses a wide range of sectors, disciplines, specialties, and departments. Its implementation will include hospitals, clinics, healthcare facilities, and public health measures to provide care to in-patients, out-patients, and the public of Hong Kong. However, a number of barriers exist that may hamper PBM implementation in Hong Kong.66 67 These include misconceptions related to blood transfusion and difficulties accessing contemporary evidence and data about PBM. There are also existing cultural pressures to retain the status quo, with inadequate incentive for change, as blood is currently delivered freely and efficiently to receivers in Hong Kong. Resources may be inadequate or unequally allocated, such as ferritin assays and intravenous iron preparations for early diagnosis and effective treatment of anaemia, or cell savers and active patient warming equipment for minimising blood loss and conserving blood during surgery. Logistical complexities such as timely investigation and treatment of preoperative anaemia before elective surgery and establishment of point-of-care testing coagulation management programmes may also present obstacles. Finally, PBM lacks specific established quality mechanisms, such as associated policies, standards, guidelines, documentation, performance indicators, coordination, monitoring, evaluation, and feedback.

To overcome these barriers, strong leadership with central steering and empowerment of PBM advocates is required to reinforce and coordinate the current piecemeal and uncoordinated efforts of PBM promotion. The goal of PBM is not simply to reduce the amount of blood transfusion. It is a continuing programme of quality improvement that has the goal of improving patient outcomes via its different measures. With reference to other countries’ experiences and the barriers and challenges that could limit the implementation of PBM in clinical practice, an appropriate framework with local interest should be developed to implement PBM practices at the hospital and territory level.11 68 69

On the basis of the scientific evidence on the successful implementation of PBM and its improvement of patient outcomes, the Hong Kong Society of Clinical Blood Management strongly recommends that Hong Kong implement PBM as soon as possible. The Society will continue to work with relevant professional bodies, patients, and stakeholders to facilitate the local implementation of PBM.

All authors contributed to the concept or design of the study, acquisition and analysis or interpretation of data, drafting of the manuscript, and critical revision of the manuscript for important intellectual content. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

All authors have disclosed no conflicts of interest.

This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

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