Search

The World Health Organization estimates that the world's population over 60 years of age will nearly double in the next 30 years. This change imposes increasing demands on health and social services with increased disease burden in older people, hereafter defined as people aged 60 years or more. An older population will have a greater incidence of cardiovascular disease partly due to higher levels of blood fibrinogen, increased levels of some coagulation factors, and increased platelet activity. These factors lead to a hypercoagulable state which can alter haemostasis, causing an imbalance in appropriate coagulation, which plays a crucial role in the development of cardiovascular diseases. These changes in haemostasis are not only affected by age but also by gender and the effects of hormones, or lack thereof in menopause for older females, ethnicity, other comorbidities, medication interactions, and overall health as we age. Another confounding factor is how we measure fibrinogen and coagulation through laboratory and point-of-care testing and how our decision-making on disease and treatment (including anticoagulation) is managed. It is known throughout life that in normal healthy individuals the levels of fibrinogen and coagulation factors change, however, reference intervals to guide diagnosis and management are based on only two life stages, paediatric, and adult ranges. There are no specific diagnostic guidelines based on reference intervals for an older population. How ageing relates to alterations in haemostasis and the impact of the disease will be discussed in this chapter. Along with the effect of anticoagulation, laboratory testing of fibrinogen and coagulation, future directions, and implications will be presented.

Background Bleeding during cardiac surgery is a common complication that often requires the transfusion of blood products. The combination of bleeding and blood product transfusion incrementally increases adverse outcomes including infection and mortality. Following bleeding management guideline recommendations could assist with minimising risk but adherence is not high, and the cause for lack of adherence is not well understood. This study aimed to identify barriers and facilitators to practicing and implementing evidenced-based intra-operative, bleeding management in Australian cardiac surgery units. Methods We used a qualitative descriptive design to conduct semi-structured interviews with Australian cardiac surgeons, anaesthetists and perfusionists. The Theoretical Domains Framework (TDF) was utilised to guide interviews and thematically analyse the data. Categorised data were then linked with the three key domains of the COM-B model (capability, opportunity, motivation - behaviour) to explore and understand behaviour. Results Seventeen interviews were completed. Nine of the 14 TDF domains emerged as significant. Analysis revealed key themes to improving capability included, standardisation, monitoring, auditing and feedback of data and cross discipline training. Opportunity for change was improved with interpersonal and interdepartmental collaboration through shared goals, and more efficient and supportive processes allowing clinicians to navigate unfamiliar business and financial models of health care. Results suggest as individuals, clinicians had the motivation to make change and healthcare organisations have an obligation and a responsibility to partner with clinicians to support change and improve goal directed best practice. Conclusion Using a theory-based approach it was possible to identify factors which may be positively or negatively influence clinicians ability to implement best practice bleeding management in Australian cardiac surgical units.

Background and objectives Sheep are increasingly being used as a large in vivo animal model of blood transfusion because they provide several advantages over small animals. Understanding the effects of storage duration on ovine (ov) red cell concentrates (RCCs) and how these changes compare with stored human (hu) RCCs is necessary to facilitate clinical translation of research findings. Materials and methods OvRCCs (n = 5) collected and processed in standard human blood collection packs, and equivalent huRCCs provided by Australian Red Cross Lifeblood (n = 5), were stored at 2-6°C for 42 days, with samples collected weekly. Haemolysis index was determined by measuring supernatant haemoglobin concentration. Biochemical parameters were evaluated using a blood gas analyser. Energy metabolites and biologically active lipids were measured using commercial assays. Osmotic fragility was determined by lysis in various saline concentrations. Extracellular vesicles were characterized by nanoparticle tracking analysis. Results Ovine red blood cells (RBCs) are double in number, smaller in size and more fragile than human RBCs. Haematological values were unchanged throughout storage. In contrast, biochemical and metabolic values, and haemolysis index in three of the five ovRCCs exceeded huRCCs licensing criteria by day 42. Accumulation of extracellular vesicles and biologically active lipids was comparable between huRCCs and ovRCCs. Conclusion This study documents similarities and differences in the storage lesion of ovRCCs and huRCCs. This new information will guide the design of ovine transfusion models to enhance translation of findings to human transfusion settings.

To investigate the blood supply contribution of older donors in five Asia Pacific regions.Older people are often the largest blood user group. Thus, as the population ages blood supply needs increase. Minimum and maximum donation age criteria potentially constrain the size of the donor pool.Haemoglobin values and demographic frequency analytics (sex, age and blood type) were analysed on blood donors aged 60 years or more, from Hong Kong, Indonesia, Japan, Singapore and South Korea over 12 months.Data on 434357 donations was analysed. ABO Rh(D) frequencies of older donors matched that of national frequencies. Older donors were a disproportionately smaller proportion of the total donor pool for each country. Indonesia was the only region with no maximum age limit. Median haemoglobin for older males ranged from 14.2 to 14.8 g/dl and for females 13.1 to 13.9 g/dl. The frequency of female donors was between 15% and 33% of older donors. Older donors had higher donation frequency and lower deferral rates.Older donors are loyal and regular donors but under-represented in all regions studied. They could help meet future blood supply needs, especially post-menopausal female donors. Studies including ferritin levels are needed to determine if upper age limits can be safely modified.

OBJECTIVE This research aims to elucidate drivers of blood use in an older population, with a focus on unplanned transfusions following ED presentation. METHODS In a retrospective cohort study we examined 2015 data for ED presentations and blood use in two hospitals serving a population containing a high proportion (21%) of adults aged ≥65 years. Unplanned blood use was defined as any transfusion ≤24 h of presentation. Data were analysed by age, sex, Major Diagnostic Category, triage category and time to transfusion. RESULTS A total of 5294 blood components were transfused, comprising red cells (n = 3784), fresh frozen plasma (n = 657), platelets (n = 563) and cryoprecipitate (n = 290). Men aged ≥65 years were the highest users (40%, 2107 components). Unplanned transfusions accounted for 28% (n = 1057) of annual red cell use. Of 85 014 ED presentations, 494 (0.6%) were associated with unplanned red cell transfusion. Four Major Diagnostic Categories accounted for 81% (n = 853) of unplanned red cell use: gastrointestinal (n = 375), haematology (n = 267), trauma (n = 144) and cardiovascular (n = 67). Over one-fifth of unplanned transfusions (21%, n = 222 of 1057) were associated with ICD-10 codes for anaemia as a reason for presentation within the Haematology Major Diagnostic Category. Adults aged ≥65 years accounted for 62% of overall red cell use and 61% of transfusions ≤24 h of presentation. Odds of unplanned red cell transfusion increased with age, peaking at odds ratio 28.5 (95% confidence interval 14.2-57.4) in those aged 85 years and above. CONCLUSIONS Unplanned blood use accounted for 28% of annual hospital blood consumption. Blood component use increased with age and was greatest in older men. A significant burden of anaemia treatment was identified by the ED.

Transfusion-related acute lung injury (TRALI) can occur during or after a transfusion, and remains a leading cause of transfusion-associated morbidity and mortality. TRALI is caused by the transfusion of either anti-leukocyte antibodies or biological response modifiers (BRMs). Experimental evidence suggests at least six different pathways that antibody-mediated TRALI might follow: (i) two hit neutrophil activation; (ii) monocyte and neutrophil dependent; (iii) endothelial cell, neutrophil Fc receptor, platelet and neutrophil extracellular trap dependent; (iv) direct monocyte activation; (v) direct endothelial cell activation; and (vi) endothelial cell, complement and monocyte dependent. Two of these pathways (i and v) also apply to BRM-mediated TRALI. Different antibodies or BRMs might initiate different pathways. Even though six pathways are described, these might not be distinct, and might instead be interlinked or proceed concurrently. The different pathways converge upon reactive oxygen species release which damages pulmonary endothelium, precipitating fluid leakage and the clinical symptoms of TRALI. Additional pathways to the six described are likely to also contribute to TRALI pathogenesis, and this requires further investigation. This review also discusses evidence of protective mechanisms and their implications for clinical TRALI treatment. Finally, it suggests directions for future research to support the translation of these findings into strategies to prevent and treat clinical TRALI.

BackgroundBleeding during cardiac surgery is a common complication that often requires the transfusion of blood products. The combination of bleeding and blood product transfusion incrementally increases adverse outcomes including infection and mortality. Following bleeding management guideline recommendations could assist with minimising risk but adherence is not high, and the cause for lack of adherence is not well understood. This study aimed to identify barriers and facilitators to practicing and implementing evidenced-based intra-operative, bleeding management in Australian cardiac surgery units. MethodsWe used a qualitative descriptive design to conduct semi-structured interviews with Australian cardiac surgeons, anaesthetists and perfusionists. The Theoretical Domains Framework (TDF) was utilised to guide interviews and thematically analyse the data. Categorised data were then linked with the three key domains of the COM-B model (capability, opportunity, and motivation) to explore and understand behaviour.ResultsSeventeen interviews were completed. Nine of the 14 TDF domains emerged as significant. Analysis revealed key themes to improving capability included, standardisation, monitoring, auditing, and feedback of data and cross discipline training. Opportunity for change was improved with interpersonal and interdepartmental collaboration through shared goals, and more efficient and supportive processes allowing clinicians to navigate unfamiliar business and financial models of health care. Results suggest as individuals, clinicians had the motivation to make change and healthcare organisations have an obligation and a responsibility to partner with clinicians to support change and improve goal directed best practice. ConclusionUsing a theory-based approach it was possible to identify factors which may be positively or negatively influencing clinicians ability to implement best practice bleeding management in Australian cardiac surgical units.

Reference intervals are vital for interpreting coagulation results. Current interval ranges have no upper age limit, although there is evidence that coagulation function changes with age. This study compared coagulation results from healthy people aged60 years against adult reference intervals for routine clotting assays and thromboelastography (TEG) to determine if reference intervals are relevant to older adults.Samples from healthy blood donors aged60 years (n=30 male, n=30 female) were tested by TEG® 6s, prothrombin time (PT), activated partial thromboplastin time (aPTT), and derived fibrinogen.All older donor-derived fibrinogen results were within the adult reference intervals, however levels were significantly higher in females. A proportion of TEG® 6s and aPTT results were not within the reference intervals. As populations around the world live longer, these findings question whether older adults require age specific coagulation reference intervals.

AIM: To present findings from a longitudinal study on infection risk, mortality, and patient perspective of intravenous immunoglobulin (IVIg) and subcutaneous immunoglobulin (SCIg) treatment for patients with hypogammaglobulinemia secondary to hematological malignancy or its treatment (abbreviated as SID). METHODS: Observational study period included final year of IVIg (13 patients) and of the first 3 years of SCIg (17 patients) with SID. Data were collected on clinical outcomes from medical records and patient perception via study specific questionnaire. RESULTS: The median age was 63 years (53-76 years), and for 82.4% of patients their hematological malignancy was in complete remission. The annual mean serum IgG trough levels remained stable over the 4 years and were 7.0 g/L (±2.77 g/L) with IVIg, and 8.0 g/L (±1.75 g/L), 8.7 g/L (±2.75 g/L), and 7.6 g/L (±2.89 g/L) (year 1, 2, and 3, respectively) with SCIg. While the annual infection rate was similar, the rate of hospitalization due to infection fluctuated, with 37%, 9%, 15%, and 32% in year 1, 2, 3, and 4 respectively. There were no systemic adverse events with IVIg or SCIg. Patients reported a strong preference for SCIg. One patient died due to progression of underlying disease and infection within the study period. CONCLUSION: SCIg was the preferred treatment mode over IVIg in our cohort, but both were well tolerated without any systemic adverse events in 4-year follow up. The dosage and serum IgG levels were stable throughout. However, the number of infections requiring hospitalization fluctuated. It is anticipated that these findings encourage more hospitals to offer SCIg for SID patients.

Immunoglobulin replacement therapy (IRT) is often used to support patients with primary immunodeficiency disease (PID) and secondary immunodeficiency disease (SID). Home-based subcutaneous immunoglobulin (SCIg) is reported to be a cheaper and more efficient option compared to hospital-based intravenous immunoglobulin (IVIg) for PID. In contrast, there is little information on the cost-effectiveness of IRT in SID. However, patients who develop hypogammaglobulinaemia secondary to other conditions (SID) have different clinical aetiology compared to PID. This study assesses whether SCIg provides a good value-for-money treatment option in patients with secondary immunodeficiency disease (SID). A Markov cohort simulation model with six health states was used to compare cost-effectiveness of IVIg with SCIg from a healthcare system perspective. The costs of treatment, infection and quality-adjusted life years (QALYs) for IVIg and SCIg treatment options were modelled with a time horizon of 10 years and weekly cycles. Deterministic and probabilistic sensitivity analyses were performed around key parameters. The cumulative cost for IVIg was A$151 511 and for SCIg A$144 296. The QALYs with IVIg were 3·07 and with SCIg 3·51. Based on the means, SCIg is the dominant strategy with better outcomes and at lower cost. The probabilistic sensitivity analysis shows that 88·3% of the 50 000 iterations fall below the nominated willingness to pay threshold of A$50 000 per QALY. Therefore, SCIg is a cost-effective treatment option. For SID patients in Queensland (Australia), the home-based SCIg treatment option provides better health outcomes and cost savings.

Restrictive transfusion practice is widely promoted, with many international guidelines recommending haemoglobin thresholds of 70 to 80 g/l for adult patients who are asymptomatic. Randomized controlled trials comparing outcomes associated with liberal and restrictive transfusion strategies underpin this approach. Meta‐analyses including trials of adult patients >18 years of age have concluded that restrictive practice is noninferior to liberal transfusion approaches. A restrictive approach to transfusion reduces resource consumption and cost, as well as the hazards associated with unnecessary exposure to blood products. Although adults aged ≥65 years consume over half of the blood supply, there are few randomized controlled transfusion trials exclusive to this cohort. Our 2017 meta‐analysis of a small number of trials focussed on older adults found that higher transfusion haemoglobin thresholds were associated with lower mortality and fewer cardiac complications in this age group. Other studies have also shown that higher transfusion haemoglobin thresholds are beneficial in older adults. This paper presents recent evidence regarding transfusion outcomes in older adults and discusses aspects of the pathophysiology of ageing that impact on the reduced resilience of older patients to anaemic states. This evidence challenges the use of Hb thresholds that apply across the adult lifespan, regardless of age. It proposes that older age be considered as a risk factor in assessing transfusion requirements, and that transfusion practice in older adults may require higher haemoglobin thresholds than for younger adults.

Transfusion-related acute lung injury (TRALI) is still one of the leading causes of transfusion-associated mortality, despite increased awareness and the implementation of various mitigation strategies. TRALI may be either antibody or non-antibody mediated. Understanding the underlying mechanism through clinical cases has been challenging because of the low and unpredictable incidence. Thus, animal models provide an important tool for investigating the mechanism of TRALI in a controlled and systematic fashion. One of the earliest animal models, an ex vivo rabbit lung model, revealed the role of anti-5b (anti-HNA-3a) and granulocytes. In vivo models with mice, rats and pig models have provided further insights into the mechanisms of antibody-mediated TRALI. There is evidence for contributions from neutrophils, neutrophil extracellular traps, platelets, lymphocytes, monocytes and endothelial cells. Elevated levels of C-reactive proteins and cardiopulmonary bypass may predispose to TRALI, while protective roles have been identified with lymphocytes, T-regulatory cells and dendritic cells. Mouse models have shown that IL-10 infusion protects from TRALI if administered prophylactically and successfully treats TRALI reaction if administered therapeutically. Silliman et al. introduced the non-immune mechanism of TRALI with rat models, and since then, there have been sheep and pig models. Non-immune animal models have demonstrated the importance of a priming event (e.g. endotoxin administration) and a role for the protein and lipid biological response modifiers (BRMs) that accumulate during routine blood product storage. This paper focuses on how the key ex vivo and in vivo animal models have progressed our understanding of the mechanisms leading to TRALI.

Summary Background Guidelines for patient blood management recommend restrictive transfusion practice for most adult patients. These guidelines are supported by evidence from randomised controlled trials (RCTs); however, one of the patient groups not explicitly examined in these studies is the geriatric population. We examined RCTs relevant to transfusion outcomes in older patients. Our aim was to determine whether special guidelines are warranted for geriatric patients, recognising the different pathophysiological characteristics of this group. Methods For this systematic review and meta-analysis, we searched PubMed, Scopus, and the Cochrane Library databases from their inception to May 5, 2017, for evidence relating to transfusion outcomes in adults aged 65 years and older. This criterion was widened to include RCTs where a substantial proportion of the study population was older than 65 years. We also included study populations of all clinical settings, and did not limit the search by date, language, or study type. For articles not in English, only available translations of the abstracts were reviewed. Studies were excluded if they did not specify age. Observational studies and duplicate patient and outcome data from studies that generated multiple publications were also excluded. We screened bibliographies of retrieved articles for additional publications. We analysed data extracted from published RCTs comparing restrictive and liberal transfusion strategies in older adults. We generated fixed effects risk ratios (RR) for pooled study data using the Mantel-Haenszel method. Primary outcomes were 30-day and 90-day mortality events for patients enrolled in restrictive and liberal transfusion study groups. We included intention-to-treat outcome data in the meta-analysis when available, otherwise we used per-protocol outcome data. Findings 686 articles were identified by the search, and a further 37 by the snowball approach. Of these articles, 13 eligible papers described findings from nine RCTs (five trials investigating orthopaedic surgery, three cardiac surgery, and one oncology surgery; including 5780 patients). The risk of 30-day mortality was higher in older patients who followed a restrictive transfusion strategy than in those who followed a liberal transfusion strategy (risk ratio [RR] 1·36, 95% CI 1·05–1·74; p=0·017). The risk of 90-day mortality was also higher in those who followed a restrictive transfusion strategy than in those who followed a liberal transfusion strategy (RR 1·45, 95% CI 1·05–1·98; p=0·022). Interpretation Liberal transfusion strategies might produce better outcomes in geriatric patients than restrictive transfusion strategies. This outcome contradicts current restrictive transfusion approaches. Population ageing will challenge resources globally, and this finding has implications for blood supply and demand, and optimal care of older adults. Further research is needed to formulate evidence-based transfusion practice across clinical specialties specific to the geriatric population, and to examine resource effects. Funding Australia's National Blood Authority.

Background Extracorporeal membrane oxygenation (ECMO) is a life-saving modality used in the management of cardiopulmonary failure that is refractory to conventional medical and surgical therapies. The major problems clinicians face are bleeding and clotting, which can occur simultaneously. To discern the impact of pulmonary injury and ECMO on the host’s haemostatic response, we developed an ovine model of smoke-induced acute lung injury (S-ALI) and ECMO. The aims of this study were to determine if the ECMO circuit itself altered haemostasis and if this was augmented in a host with pulmonary injury. Methods Twenty-seven South African meat merino/Border Leicester Cross ewes underwent instrumentation. Animals received either sham injury (n = 12) or S-ALI (n = 15). Control animal groups consisted of healthy controls (ventilation only for 24 h) (n = 4), ECMO controls (ECMO only for 24 h) (n = 8) and S-ALI controls (S-ALI but no ECMO for 24 h) (n = 7). The test group comprised S-ALI sheep placed on ECMO (S-ALI + ECMO for 24 h) (n = 8). Serial blood samples were taken for rotational thromboelastometry, platelet aggregometry and routine coagulation laboratory tests. Animals were continuously monitored for haemodynamic, fluid and electrolyte balances and temperature. Pressure-controlled intermittent mandatory ventilation was used, and mean arterial pressure was augmented by protocolised use of pressors, inotropes and balanced fluid resuscitation to maintain mean arterial pressure >65 mmHg. Results Rotational thromboelastometry, platelet aggregometry and routine coagulation laboratory tests demonstrated that S-ALI and ECMO independently induced changes to platelet function, delayed clot formation and reduced clot firmness. This effect was augmented with the combination of S-ALI and ECMO, with evidence of increased collagen-induced platelet aggregation as well as changes in factor VIII (FVIII), factor XII and fibrinogen levels. Conclusions The introduction of an ECMO circuit itself increases collagen-induced platelet aggregation, decreases FVIII and von Willebrand factor, and induces a transient decrease in fibrinogen levels and function in the first 24 h. These changes to haemostasis are amplified when a host with a pre-existing pulmonary injury is placed on ECMO. Because patients are often on ECMO for extended periods, longer-duration studies are required to characterise ECMO-induced haemostatic changes over the long term. The utility of point-of-care tests for guiding haemostatic management during ECMO also warrants further exploration.

Introduction Fluid resuscitation is a cornerstone of severe sepsis management, however there are many uncertainties surrounding the type and volume of fluid that is administered. The entire spectrum of coagulopathies can be seen in sepsis, from asymptomatic aberrations to fulminant disseminated intravascular coagulation (DIC). The aim of this study was to determine if fluid resuscitation with saline contributes to the haemostatic derangements in an ovine model of endotoxemic shock. Materials and methods Twenty-one adult female sheep were randomly divided into no endotoxemia (n = 5) or endotoxemia groups (n = 16) with an escalating dose of lipopolysaccharide (LPS) up to 4 μg/kg/h administered to achieve a mean arterial pressure below 60 mmHg. Endotoxemia sheep received either no bolus fluid resuscitation (n = 8) or a 0.9% saline bolus (40 mL/kg over 60 min) (n = 8). No endotoxemia, saline only animals (n = 5) underwent fluid resuscitation with a 0.9% bolus of saline as detailed above. Hemodynamic support with vasopressors was initiated if needed, to maintain a mean arterial pressure (MAP) of 60-65 mm Hg in all the groups. Results Rotational thromboelastometry (ROTEM®) and conventional coagulation biomarker tests demonstrated sepsis induced derangements to secondary haemostasis. This effect was exacerbated by saline fluid resuscitation, with low pH (p = 0.036), delayed clot initiation and formation together with deficiencies in naturally occurring anti-coagulants antithrombin (p = 0.027) and Protein C (p = 0.001). Conclusions Endotoxemia impairs secondary haemostasis and induces changes in the intrinsic, extrinsic and anti-coagulant pathways. These changes to haemostasis are exacerbated following resuscitation with 0.9% saline, a commonly used crystalloid in clinical settings.

Immunoglobulin replacement therapy (IRT) has an important role in minimizing infections and improving the health-related quality of life (HRQoL) in patients with immunodeficiency, who would otherwise experience recurrent infections. These plasma-derived products are available as intravenous immunoglobulin (IVIg) or subcutaneous immunoglobulin (SCIg). The global demand for these products is growing rapidly and has placed pressure on supply. Some malignancies and their treatment (as well as other medical therapies) can lead to secondary hypogammaglobulinemia or secondary immunodeficiency (SID) requiring IRT. Although IVIg use in this cohort has well-established therapeutic benefits, little is known about SCIg use. A literature search in July 2015 found only 7 published articles on SCIg use. These articles found that both IRT modes had equivalent efficacy in regard to reduction of bacterial infections. In addition, SCIg was reported to produce higher serum IgG trough levels compared with IVIg on equivalent dosage with the added benefit of fewer adverse effects. Patient HRQoL reports demonstrate preference for SCIg because of reduced adverse effects and hospital visits. There are no health economic models published on SCIg use in SID, but models on primary immunodeficiency disease and IRT conclude that SCIg provided greater economic benefits than IVIg. The findings of this small number of reports suggest that SCIg therapy for patients with SID is likely to be beneficial for both the patient and health care providers. To substantiate wider use of SCIg in SID, larger and more detailed studies are needed to accurately quantify the effectiveness of SCIg.

Extracorporeal membrane oxygenation (ECMO) is a life-saving treatment for patients with severe refractory cardiorespiratory failure. Exposure to the ECMO circuit is thought to trigger/exacerbate inflammation. Determining whether inflammation is the result of the patients' underlying pathologies or the ECMO circuit is difficult. To discern how different insults contribute to the inflammatory response, we developed an ovine model of lung injury and ECMO to investigate the impact of smoke-induced lung injury and ECMO in isolation and cumulatively on pulmonary and circulating inflammatory cells, cytokines, and tissue remodeling. Sheep receiving either smoke-induced acute lung injury (S-ALI) or sham injury were placed on veno-venous (VV) ECMO lasting either 2 or 24 h, with controls receiving conventional ventilation only. Lung tissue, bronchoalveolar fluid, and plasma were analyzed by RT-PCR, immunohistochemical staining, and zymography to assess inflammatory cells, cytokines, and matrix metalloproteinases. Pulmonary compliance decreased in sheep with S-ALI placed on ECMO with increased numbers of infiltrating neutrophils, monocytes, and alveolar macrophages compared with controls. Infiltration of neutrophils was also observed with S-ALI alone. RT-PCR studies showed higher expression of matrix metalloproteinases 2 and 9 in S-ALI plus ECMO, whereas IL-6 was elevated at 2 h. Zymography revealed higher levels of matrix metalloproteinase 2. Circulating plasma levels of IL-6 were elevated 1–2 h after commencement of ECMO alone. These data show that the inflammatory response is enhanced when a host with preexisting pulmonary injury is placed on ECMO, with increased infiltration of neutrophils and macrophages, the release of inflammatory cytokines, and upregulation of matrix metalloproteinases.

Background Animal models have been a valuable tool for research into blood products and outcomes of blood transfusions. Small animal models have been applied extensively and large animal models less frequently. This review describes the experience and details the findings from a recent series of in vivo sheep transfusion models. Aims & Method To discuss: (i) the benefits of sheep as a large animal transfusion model; and (ii) review conclusions from a series of sheep transfusion models. Results & Discussion Similarities in size, anatomy and physiology of sheep compared to humans have supported the use of sheep to model a wide range of human diseases, enabled continuous physiological monitoring using standard human techniques, and the collection of multiple and serial samples. Conclusion The findings discussed demonstrate that sheep are effective models of the blood donor, donations and of transfusion recipients. Importantly, they also define limitations of ovine models, which need to be considered when designing in vivo sheep models of transfusion.

Evidence-based patient blood management guidelines commonly recommend restrictive hemoglobin thresholds of 70 to 80 g/L for asymptomatic adults. However, most transfusion trials have enrolled adults across a broad age span, with few exclusive to older adults. Our recent meta-analysis of transfusion trials that focused on older adults paradoxically found lower mortality and fewer cardiac complications when these patients were managed using higher hemoglobin thresholds. We postulate that declining cardiac output with age contributes to deteriorating oxygen delivery capacity which impacts anemia-associated outcomes in older adults and propose a model to explain this age-related difference. We reviewed evidence concerning the pathophysiology of aging to explore the disparity in transfusion trial outcomes related to hemoglobin thresholds in different age groups. The literature was searched for normative cardiac output values at different ages in healthy adults. Using normative peak cardiac output data, we modeled oxygen delivery capacity in young, middle-aged, and older adults at a range of hemoglobin levels. Cardiovascular and pulmonary systems are impacted by age-related pathophysiological changes. Diminishing peak cardiac output associated with aging reduces the maximal oxygen delivery achievable under metabolic stress. Hence, at low hemoglobin levels, older adults are more susceptible to tissue hypoxia than younger adults. Our model predicts that an older adult with a hemoglobin of 100 g/L has a similar peak oxygen delivery capacity to a young adult with a hemoglobin of 70 g/L. Age-related pathophysiological changes provide some explanation as to why older adults have a lower tolerance for anemia than younger adults. This indicates the need for patient blood management hemoglobin thresholds specific to older as distinct from younger adults. The primary application of this model is in the consideration of patients rehabilitating to life outside hospital. It is important to note that pathophysiological changes associated with critical illness and major surgery are more complex than can be described in a simple model based on cardiac output and hemoglobin concentration. However, our review of oxygen transport and delivery in health and disease states allows the model to be considered in the context of treatment decisions for anemic adults in a range of hospital and community settings.

Background : Bleeding management in cardiac surgery is challenging. Many guidelines exist to support bleeding management; however, literature demonstrates wide variation in practice. In 2012, a quality initiative was undertaken at The Prince Charles Hospital, Australia to improve bleeding management for cardiac surgery patients. The implementation of the quality initiative resulted in significant reductions in the incidence of blood transfusion, re-exploration for bleeding; superficial leg and chest wound infections; length of hospital stay, and cost. Given the success of the initiative, we sought to answer the question; “How and why was the process of implementing a bleeding management quality initiative in the cardiac surgery unit successful, and sustainable?” Methods : A retrospective explanatory case study design was chosen to explore the quality initiative. Analysis of the evidence was reviewed through phases of the ‘Knowledgeto Action’ planned change model. Data was derived from: (1) document analysis, (2) direct observation of the local environment, (3) clinical narratives from interviews, and analysed with a triangulation approach. The study period extended from 10/2011 to 6/2013. Results : Results demonstrated the complexity of changing practice, as well as the significant amount of dedicated time and effort required to support individual, department and system wide change. Results suggest that while many clinicians were aware of the potential to apply improved practice, numerous barriers and challenges needed to be overcome to implement change across multiple disciplines and departments. Conclusions : The key successful components of the QI were revealed through the case study analysis as: (1) an appropriately skilled project manager to facilitate the implementation process; (2) tools to support changes in workflow and decision making including a bleeding management treatment algorithm with POCCTs; (3) strong clinical leadership from the multidisciplinary team and; (4) the evolution of the project manager position into a perpetual clinical position to support sustainability.

Background The last 20 years have seen substantial international efforts to minimize the incidence and risk of transfusion-related acute lung injury (TRALI). Nevertheless, TRALI remains a real morbidity and mortality risk to transfusion recipients. Discussion This review discusses the current knowledge on antibody- and non-antibody-mediated TRALI, as well as current and potential mitigation strategies.

Background Neutrophils or polymorphonuclear neutrophils (PMNs) make up the largest proportion (45 – 70%) of circulating leukocytes and play a pivotal role in innate immunity. Thus, patients with low PMN counts (neutropenia) or defective PMN function are more likely to be overwhelmed by infection. PMN reactive antibodies can cause either allo- or auto-immune neutropenias. In some transfusion-related acute lung injury (TRALI) events, donor derived neutrophil reactive antibodies can cause inappropriate activation of neutrophils leading to collateral damage of the surrounding pulmonary microvasculature with potentially grave clinical consequences. Discussion & Conclusion Clinical outcomes of TRALI and immune neutropenias demand rapid and precise diagnosis using reliable neutrophil serology. The ISBT Granulocyte Immunobiology Working Party brings together members working in diagnostic laboratories, research and clinical fields to enable strong and productive interactions, innovation and collaboration in granulocyte immunobiology, function and pathology.

In 20% to 28% of transfusion-related acute lung injury (TRALI) cases, no leucocyte antibodies have been detected and such cases are described as non-antibody mediated TRALI. In the other 72% to 80% of TRALI cases, leucocyte antibodies are hypothesized to be the “second hit” that precipitates acute lung injury (ALI) in a sick patient. There is a substantial body of evidence demonstrating an association between TRALI and antibodies to human neutrophil antigens (HNA), human leukocyte antigens (HLA) class I and II. Therefore, one of the most widely used TRALI mitigation strategies has been to reduce/avoid use of blood components that contain or are more likely to contain these antibodies. Despite the success of these risk reduction strategies, hemovigilance data show that TRALI remains a serious and sometimes fatal complication of transfusion. This is possibly because the current TRALI risk-reduction strategies all focus on antibody mediated TRALI but do not address non-antibody mediated TRALI. This review discusses the available evidence on non-antibody mediated TRALI.

There is an increased oxidative stress response in patients having cardiac surgery, haemodialysis or extracorporeal membrane oxygenation that is related to poorer outcomes and increased mortality. Exposure of the patients' blood to the artificial surfaces of these extracorporeal devices, coupled with inflammatory responses, hyperoxia and the pathophysiological aspects of the underlying illness itself, all contribute to this oxidative stress response. Oxidative stress occurs when there is a disruption of redox signalling and loss of control of redox balance. Ongoing oxidative stress occurring during extracorporeal circulation (ECC) results in damage to lipids, proteins and DNA and contributes to morbidity and mortality. This review discusses reactive species generation and the potential clinical consequences of oxidative stress during ECC as well as provides an overview of some current antioxidant compounds that are available to potentially mitigate the oxidative stress response.

This paper discusses findings from a systematic review of literature pertaining to the role performance of psychiatric nurses in advanced practice. A search of 11 electronic databases was conducted to identify research involving interventions by psychiatric (or mental health) nurses in advanced practice. A total of 14 studies were identified. In this review, the role performance of psychiatric nurses in advanced practice was categorized into three themes: (1) the provision of psychosocial interventions; (2) the provision of nurse-directed services in health-care contexts; and (3) the provision of psychiatric nursing consultation services. Our results document that psychiatric nurses in advanced practice perform multifaceted roles and provide mental health-care services in various contexts. This systematic review reveals that the nurses obtain significant results in managing clients with depression and psychological stress, and demonstrates their value when developing partnerships with non-mental health service providers. One study, however, showed that the nurses had insignificant results in performing transitional care for pre-discharged mental health service users.

BackgroundOxidative stress from surgery or critically illness has been shown to adversely contribute to morbidity and mortality. Recent studies record that oxidative stress is heightened following packed red blood cell (PRBC) transfusions and that products of oxidative stress accumulate as the PRBC ages. However, there are no studies that investigate if transfusion of aged PRBC actually increases the recipient's oxidative stress profile more than fresh PRBC.

Background The growing awareness of transfusion-associated morbidity and mortality necessitates investigations into the underlying mechanisms. Small animals have been the dominant transfusion model but have associated limitations. This study aimed to develop a comprehensive large animal (ovine) model of transfusion encompassing: blood collection, processing and storage, compatibility testing right through to post-transfusion outcomes. Materials and methods Two units of blood were collected from each of 12 adult male Merino sheep and processed into 24 ovine-packed red blood cell (PRBC) units. Baseline haematological parameters of ovine blood and PRBC cells were analysed. Biochemical changes in ovine PRBCs were characterized during the 42-day storage period. Immunological compatibility of the blood was confirmed with sera from potential recipient sheep, using a saline and albumin agglutination cross-match. Following confirmation of compatibility, each recipient sheep (n=12) was transfused with two units of ovine PRBC. Results Procedures for collecting, processing, cross-matching and transfusing ovine blood were established. Although ovine red blood cells are smaller and higher in number, their mean cell haemoglobin concentration is similar to human red blood cells. Ovine PRBC showed improved storage properties in saline-adenine-glucose-mannitol (SAG-M) compared with previous human PRBC studies. Seventy-six compatibility tests were performed and 171% were incompatible. Only cross-match compatible ovine PRBC were transfused and no adverse reactions were observed. Conclusion These findings demonstrate the utility of the ovine model for future blood transfusion studies and highlight the importance of compatibility testing in animal models involving homologous transfusions. (Less)

Since 2000, Quality Assurance (QA) exercises for the detection and identification of granulocyte antibodies and DNA typing for human neutrophil antigens (HNA) have been distributed within the International Granulocyte Immunobiology Workshops, which are linked to International Society of Blood Transfusion. The exercises were standardised at the outset to enable laboratory performance to be monitored. Between 2000 and 2012, nine exercises were distributed to 20 laboratories. Overall, 45 examples of 42 unique samples containing defined granulocyte reactive antibodies were distributed for serological analysis together with 20 samples for HNA genotyping. The level of satisfactory serological performance was initially set at 50% and later increased to 70%, while the 'cut-off' for HNA genotyping was set at 100% after 2008. Failure to achieve the minimum score in the QA exercises in consecutive years resulted in temporary exclusion. In 2000, the 15 participating laboratories had a mean score of 56.1% for serological analysis and 13 laboratories attempted HNA-1a and -1b genotyping, while 11 attempted HNA-1c typing. Steady improvements in proficiency for serological testing and HNA typing occurred in subsequent exercises. In 2012, the mean score for serology was 88.5% and 12/13 laboratories scored 100% for HNA-1a, -1b, -1c, -3a, -3b, -4a, -4bw, -5a and -5bw genotyping. These QA exercises have provided an invaluable tool to monitor and improve the standard of granulocyte immunology investigations for participating laboratories, thereby enhancing performance for both clinical investigations and donor screening programmes to reduce the incidence of TRALI.

BACKGROUND AND OBJECTIVES: Transfusion of blood products in particular older products is associated with patient morbidity. Previously, we demonstrated a higher incidence of acute lung injury in lipopolysaccharide-treated sheep transfused with stored blood products. As transfusion following haemorrhage is more common, we aimed to determine whether a 'first hit' of isolated haemorrhage would precipitate similar detrimental effects following transfusion and also disrupt haemostasis. MATERIALS AND METHODS: Anaesthetized sheep had 33% of their total blood volume collected into Leukotrap bags (Pall Medical), which were processed into packed red blood cells and cross-matched for transfusion into other sheep. After 30 mins, the sheep were resuscitated with either: fresh (

Background Extracorporeal circulation (ECC), the diversion of blood flow through a circuit located outside of the body, has been one of the major advances in modern medicine. Cardio-pulmonary bypass (CPB), renal dialysis, apheresis and extracorporeal membrane oxygenation (ECMO) are all different forms of ECC. Despite its major benefits, when blood comes into contact with foreign material, both the coagulation and inflammation cascades are activated simultaneously. Short periods of exposure to ECC e.g. CPB (∼2 h duration), are known to be associated with haemolysis, coagulopathies, bleeding and inflammation which demand blood product support. Therefore, it is not unexpected that these complications would be exaggerated with prolonged periods of ECC such as in ECMO (days to weeks duration). The variability and complexities of the underlying pathologies of patients requiring ECC makes it difficult to study the cause and effect of these complications. To overcome this problem we developed an ovine (sheep) model of ECC. Method Healthy female sheep (1–3 y.o.) weighing 40–50 kg were fasted overnight, anaesthetised, intubated and ventilated [1]. Half the group received smoke induced acute lung injury (S-ALI group) (n = 8) and the other half did not (healthy group) (n = 8). Sheep were subsequently cannulated (Medtronic Inc, Minneapolis, MN, USA) and veno-venous ECMO commenced using PLS ECMO circuit and Quadrox D oxygenator (Maquet Cardiopulmonary AG, Hechinger Strase, Germany). There was continuous physiological monitoring and blood was collected at specified time intervals for full blood counts, platelet function analysis (by Multiplate®), routine coagulation and assessment of clot formation and lysis (by ROTEM®). Preliminary results Full blood counts and routine coagulation results from normal healthy sheep were comparable to those of normal human adults. Within 15 min of initiating of ECMO, PT, PTT and EXTEM clot formation time increased, whilst EXTEM maximum clot firmness decreased in both cohorts. Discussion & Conclusions Preliminary results of sheep from both 2 h ECMO cohorts showed that the anatomy, haematology and coagulation parameters of an adult sheep are comparable to that a human adult. Experiments are currently underway with healthy (n = 8) and S-ALI (n = 8) sheep on ECMO for 24 h. In addition to characterising how ECMO alters haematology and coagulation parameters, we hope that it will also define which blood components will be most effective to correct bleeding or clotting complications during ECMO support.

Background: Extra corporeal membrane oxygenation (ECMO) is a complex rescue therapy used to provide cardiac and/or respiratory support for critically ill patients who have failed maximal conventional medical management. ECMO is based on a modified cardiopulmonary bypass (CPB) circuit, and can provide cardiopulmonary support for up-to several months. It can be used in a veno venous configuration for isolated respiratory failure, (VV-ECMO), or in a veno arterial configuration (VA-ECMO) where support is necessary for cardiac +/- respiratory failure. The ECMO circuit consists of five main components: large bore cannulae (access cannulae) for drainage of the venous system, and return cannulae to either the venous (in VV-ECMO) or arterial (in VA ECMO) system. An oxygenator, with a vast surface area of hollow filaments, allows addition of oxygen and removal of carbon dioxide; a centrifugal blood pump allows propulsion of blood through the circuit at upto 10 L/minute; a control module and a thermoregulatory unit, which allows for exact temperature control of the extra corporeal blood. Methods: The first successful use of ECMO for ARDS in adults occurred in 1972, and its use has become more commonplace over the last 30 years, supported by the improvement in design and biocompatibility of the equipment, which has reduced the morbidity associated with this modality. Whilst the use of ECMO in neonatal population has been supported by numerous studies, the evidence upon which ECMO was integrated into adult practice was substantially less robust. Results: Recent data, including the CESAR study (Conventional Ventilatory Support versus Extra corporeal membrane oxygenation for Severe Respiratory failure) has added a degree of evidence to the role of ECMO in such a patient population. The CESAR study analysed 180 patients, and confirmed that ECMO was associated with an improved rate of survival. More recently, ECMO has been utilized in numerous situations within the critical care area, including support in high-risk percutaneous interventions in cardiac catheter lab; the operating room, emergency department, as well in specialized inter-hospital retrieval services. The increased understanding of the risk:benefit profile of ECMO, along with a reduction in morbidity associated with its use will doubtless lead to a substantial rise in the utilisation of this modality. As with all extra-corporeal circuits, ECMO opposes the basic premises of the mammalian inflammation and coagulation cascade where blood comes into foreign circulation, both these cascades are activated. Anti-coagulation is readily dealt with through use of agents such as heparin, but the inflammatory excess, whilst less macroscopically obvious, continues un-abated. Platelet consumption and neutrophil activation occur rapidly, and the clinician is faced with balancing the need of anticoagulation for the circuit, against haemostasis in an acutely bleeding patient. Alterations in pharmacokinetics may result in inadequate levels of disease modifying therapeutics, such as antibiotics, hence paradoxically delaying recovery from conditions such as pneumonia. Key elements of nutrition and the innate immune system maysimilarly be affected. Summary: This presentation will discuss the basic features of ECMO to the nonspecialist, and review the clinical conundrum faced by the team treating these most complex cases.

Background The neutrophil population makes up the largest proportion (40–70%) of white blood cells and is crucial to our innate immune response. An unexpectedly significant proportion of neutrophils (∼28%) is located in the pulmonary circulation. This is an immune system front line wherein neutrophils guard an important interface between the external environment and the body. Neutrophils migrate to sites of infection and/or inflammation, where they phagocytose and destroy foreign microorganisms and mediate inflammation and eventual healing. Therefore, a decrease in neutrophil numbers often results in increased susceptibility to infection. Sustained or transient immune neutropenia occurs when neutrophil-reactive alloantibodies or autoantibodies destroy neutrophils, or significantly compromise their function. Neutrophil-reactive antibodies are capable of activating the neutrophil’s microbicidal arsenal with resultant damage to the surrounding tissue. Antigens and Antibodies There are currently eight well characterized human neutrophil antigens (HNA): HNA-1a, HNA-1b, HNA-1c, HNA-2a, HNA-3a, HNA-3b, HNA-4a and HNA-5a. Only HNA-1a, HNA-1b and HNA-1c are specific to neutrophils, whilst the others are also expressed on other cell types. It is important to remember that neutrophils also express HLA Class I antigens, and that there is some evidence that adequately activated neutrophils may express HLA Class II antigens. This provides an interface between the innate and adaptive immune response. Therefore, both HNA and HLA Class I and II antibodies are capable of reacting with neutrophils in vivo and in vitro. Routine Antigen and Antibody Investigation Antigen genotyping protocols are now available for HNA-1a, HNA-1b, HNA-1c, HNA-3a, HNA-3b, HNA-4a and HNA-5a. The serological examination of neutrophils is reliant on harvesting a representative, pure population of neutrophils, which is difficult because neutrophils are short lived (6–8 h) and fragile. The International Granulocyte Immunobiology Workshop recommends the use of both the granulocyte immunofluorescence test (GIFT) and granulocyte agglutination test (GAT), complemented by the monoclonal antibody immobilization of granulocyte antigen (MAIGA) assay. The GIFT uses paraformaldehyde-fixed neutrophils and detects the binding of antibodies to surface HNA and HLA antigens. Serological reaction in the GAT is reliant on viable neutrophils. It demonstrates the ability of antibodies to sensitize neutrophils and stimulate them to undergo chemotaxis towards other sensitized neutrophils, thus forming microscopic agglutinates. The MAIGA is useful in confirming antibody specificities as it employs monoclonal antibodies to known HNA epitopes. To screen for neutrophil-reactive antibodies, serum or plasma is exposed to a screening panel of neutrophils in the GIFT and GAT. To differentiate between HNA and HLA antibodies, the simple strategy of using platelet pools to absorb out HLA antibodies can be used. Specificity is determined using the GIFT and GAT, and a phenotyped and genotyped neutrophil panel and confirmed with the MAIGA. Application The combination of the GIFT, GAT and MAIGA was originally developed for the reliable investigation of immune neutropenias. However, in the last decade these techniques have become fundamental to the investigation of immune mediated TRALI where neutrophils are a key target and effector cell.

Transfusion-related acute lung injury (TRALI) is a serious transfusion complication that may lead to significant morbidity and mortality. This has driven a significant research effort focused on understanding why and how TRALI develops. The ultimate goal must be prevention or at least mitigation of the clinical consequences of TRALI. The underlying pathophysiology of TRALI is presently best described by two hypotheses which are not mutually exclusive. These are the antibody mediated TRALI mechanism and the two-event or priming TRALI mechanism. One of the key initial findings in TRALI research was the frequent presence of leucocyte antibodies in associated blood products, providing strong evidence for an antibody driven pathogenesis. In contrast, the two-event mechanism proposed that these transfused antibodies activated neutrophils that had first been primed by the patient’s clinical condition. Together, data from haemovigilance programs, clinical reports and experimental findings have led several countries to introduce TRALI risk-reduction strategies. These include either limiting the transfusion of plasma from female donors or, screening female donors for the presence of leucocyte antibodies. Both approaches are justified by adoption of the immune mechanism as the prime driver of the pathogenesis of TRALI. TRALI incidence has gratifyingly been reduced by these measures. Nevertheless, TRALI cases persist and they remain a major concern because of continuing significant morbidity and mortality. While the majority of earlier TRALI research has focused on the role of antibodies in TRALI, evidence for the role of non-antibody factors in TRALI is now growing, based on an increasing number of in vitro, ex vivo and in vivo models. This review aims to present data from such models, which are the foundation for our current understanding of the pathophysiology behind antibody mediated and non-antibody mediated TRALI.

Background and Objectives Severe transfusion-related acute lung injury (TRALI) events have been linked to donor-derived neutrophil antibodies. The journey to developing mass donor neutrophil antibody screening platforms is challenged by the fragility of neutrophils and their unique-specific antigenic characteristics. Material and Methods This article critically evaluates the capabilities and potential of five emerging antibody screening platforms designed to detect neutrophil reactive antibodies relevant to TRALI. They are compared with established neutrophil serological methods. Results Data from two recombinant antigen platforms and a method using human neutrophil antigens-expressing KY cells indicated high specificity. Two mixed cellular flow cytometric assays have the advantage of presenting native conformation of the human polymorphonuclear neutrophil antigenic epitopes. Conclusions To date, the number and specificity of test sera applied to each platform is small. This needs to be substantially increased and further rigorous serological evaluation is yet needed to compare the sensitivity and specificity limits of each new platform with classical methods. With a limited world supply of TRALI-relevant test sera, a collaborative effort of laboratories with neutrophil and TRALI investigation expertise is required.

There is an international need for a large-scale human neutrophils antigen (HNA) antibody screening platform to minimize the risk of antibody-mediated transfusion-related acute lung injury. However, sourcing a substantial, reliable source of HNA, as well as the scarcity of well-characterized HNA antisera for validating new screening platforms, remain as major obstacles. This short communication presents an improved protocol for the effective use of HNA-expressing KY cells as a screening platform using eight well-characterized HNA antisera of a single defined specificity.

Background From 2005 to 2009 transfusion-related acute lung injury (TRALI) has maintained its ranking as the number one cause of transfusion-related fatalities reported to the FDA. This confirms that TRALI remains a serious and potentially fatal transfusion complication. As over 80% of TRALI events have been attributed to donor derived leucocyte antibodies the detection and management of donors with these antibodies is crucial to reducing the TRALI risk. Objective Because blood is a precious medical commodity in limited supply, it would be more effective to exclude only those donors with a risk of triggering TRALI substantiated by objective laboratory evidence (i.e. implicated). This would allow implicated donors to be confidently excluded and would allow other donors only clinically associated with TRALI to be reassessed for continuing to donate. Therefore, the design of an effective and objective TRALI laboratory investigation strategy has to be based on current knowledge of the mechanism of antibody mediated TRALI. Discussion Leucocyte antibodies in the transfused blood product are thought to activate neutrophils in the pulmonary microvasculature. The by-products of neutrophil activation (e.g. reactive oxygen species and enzymes) consequently cause injury to the pulmonary microvasculature resulting in respiratory distress. There is strong evidence for the role of neutrophil reactive antibodies to human neutrophil antigen (HNA)-3a and human leucocyte antigen (HLA)-A2 in serious TRALI events. HLA Class II antibodies have also been implicated and they are thought to activate monocytes, which subsequently activate neutrophils. Neutrophils, which express human neutrophil antigens (HNA) and HLA Class I, are thus key effector cells in TRALI injury. Because of the pivotal role of neutrophils, effective TRALI investigations must include well validated neutrophil assays such as the granulocyte immunofluorescence test (GIFT) and granulocyte agglutination test (GAT). This article will discuss: – TRALI investigation strategy, – assays for detection of antibodies to HNA and HLA, – how to differentiate associated from implicated donors, – and provide thoughts on the remaining 20% of TRALI events (i.e. non-immune mediated).

Background and Objectives Even with the introduction of specific risk-reduction strategies, transfusion-related acute lung injury (TRALI) continues to be a leading cause of transfusion-related morbidity and mortality. Existing small animal models have not yet investigated TRALI resulting from the infusion of heat-treated supernatant from whole blood platelet concentrates. In this study, our objective was the development of a novel in vivo two-event model of TRALI in sheep. Materials and Methods Lipopolysaccharide (LPS; 15 μg/kg) as a first event, modelled clinical infection. Transfusion (estimated at 10% of total blood volume) of heat-treated pooled supernatant from date-of-expiry human whole blood platelet concentrates (d5-PLT-S/N) was used as a second event. TRALI was defined by both hypoxaemia that developed either during the transfusion or within two hours of its completion and post-mortem histological evidence of pulmonary oedema. Results LPS infusion did not cause lung injury itself, but did result in decreased circulating levels of lymphocytes and neutrophils with evidence of the latter becoming sequestered in the lungs. Sheep that received LPS (first event) followed by d5-PLT-S/N (second event) displayed decreased pulmonary compliance, decreased end tidal CO2 and increased arterial partial pressure of CO2 relative to control sheep, and 80% of these sheep developed TRALI. Conclusions This novel ovine two-event TRALI model presents a new tool for the investigation of TRALI pathogenesis. It represents the first description of an in vivo large animal model of TRALI and the first description of TRALI caused by transfusion with heat-treated pooled supernatant from human whole blood platelet concentrates.

Transfusion-related acute lung injury (TRALI) is a serious complication of transfusion and has been ranked as one of the leading causes of transfusion-related fatalities. Nonetheless, many details of the immunopathogenesis of TRALI, particularly with respect to recipient factors are unknown. We used a murine model of antibody-mediated TRALI in an attempt to understand the role that recipient lymphocytes might play in TRALI reactions. Intravenous injection of an IgG2a antimurine major histocompatibility complex class I antibody (34-1-2s) into BALB/c mice induced moderate hypothermia and pulmonary granulocyte accumulation but no pulmonary edema nor mortality. In contrast, 34-1-2s injections into mice with severe combined immunodeficiency caused severe hypothermia, severe pulmonary edema, and approximately 40% mortality indicating a critical role for T and B lymphocytes in suppressing TRALI reactions. Adoptive transfer of purified CD8+ T lymphocytes or CD4+ T cells but not CD19+ B cells into the severe combined immunodeficiency mice alleviated the antibody-induced hypothermia, lung damage, and mortality, suggesting that T lymphocytes were responsible for the protective effect. Taken together, these results suggest that recipient T lymphocytes play a significant role in suppressing antibody-mediated TRALI reactions. They identify a potentially new recipient mechanism that controls the severity of TRALI reactions.

Background: Demand for both fresh components and plasma for fractionation in Australia continues to increase amidst increasing stringency of donor selection guidelines. In 2008/09, platelet supply increased by 1.5% compared with 2007/08 and clinical fresh frozen plasma (cFFP) supply increased by 4.9%. Total intravenous immunoglobulin supply continues to increase at a rate of 10–12 % annually and with it, the demand for plasma for fractionation. Concurrently, the proportion of apheresis-derived platelet and plasma components required to support clinical need in Australia also continues to increase. Transfusion-Related Acute Lung Injury (TRALI) is a severe complication of transfusion where antibodies to Human Neutrophil Antigen (HNA), Human Leucocyte Antigen (HLA) class I and class II have been implicated. As multiparous female donors are more likely to develop leucocyte antibodies, many blood services, including Australia from mid-2007, have begun supplying predominant male cFFP as a TRALI risk reduction strategy. However, extension of this policy to apheresis platelet collection is problematic as this panel is HLA- and HPA-typed and requests for HLA- or HPA-compatible platelets could not be supported by using male donors alone. Thus the place of HLA and HNA antibody testing in apheresis donor selection is currently being considered as a complementary TRALI risk reduction strategy.Aim: This was a pilot study to determine the frequency of HLA and HNA antibodies in an Australian apheresis donor population. Method: De-identified serum samples from 331 random donors were collected and screened using Luminex LSM kits (One Lambda Inc) for HLA class I and II antibodies, and granulocyte agglutination test and immunofluorescence test for HNA antibodies. Gender was recorded. No information was collected on history of transfusion in either male or female donors, or the number of pregnancies in female donors.Results: 108 females and 223 male donors were tested. HLA antibodies were detected in 80 donors (24.1%) and HNA antibodies in six donors (1.8%). 53 (48.1%) of female donors tested had leucocyte antibodies. 28 (25.9%) had HLA class I antibodies only, three (2.8%) HLA class II antibodies only and 19 (17.6%) had both HLA class I and II antibodies. Only one had HNA antibodies alone and another had both HNA and HLA class II antibodies. Unexpectedly, 35 (15.7%) of male donors tested had leucocyte antibodies. HLA Class I antibodies were detected in 27 (12.1%), HLA class II antibodies in three (1.3%) and HNA antibodies in five (2.2%).Conclusion: These pilot data indicate that the incidence of HLA antibodies in Australian male apheresis donors is higher than expected. A further study is planned to determine the factors associated with the development of leucocyte antibodies by gathering donor demographic data including gender, age, pregnancy history and transfusion history. This will allow further refinement of donor selection policies in relation to antibodymediated TRALI risk reduction in the Australian context as well as assess the predictive value and applicability of leucocyte antibody testing platforms to blood donor screening.

Transfusion-related acute lung injury (TRALI) is the major cause of transfusion related morbidity and mortality, world wide. Efforts to reduce or eliminate this serious complication of blood transfusion are hampered by an incomplete understanding of its pathogenesis. Currently, TRALI is thought to be mediated by donor alloantibodies directed against host leukocytes or the result of 2 distinct clinical events. For both proposed mechanisms, the neutrophil is the key effector cell. This article reviews TRALI pathophysiology, explores the role of the neutrophil, details practical information for appropriate diagnosis and promotes further studies into the pathogenesis of TRALI.

The bone marrow immunofluorescenece test (BMIFT) demonstrates autoantibodies to granulocytes and their precursors on fresh-frozen bone marrow slides. It may be used to differentiate childhood autoimmune neutropenia (AIN) from other causes of childhood neutropenia, even when circulating neutrophil counts are low. We sought to characterize the diagnostic utility of the BMIFT in childhood AIN. All BMIFT requests for investigation of children with neutropenia between January 1998 and May 2007 were reviewed. Patients were classified as AIN or nonautoimmune causes. Baseline demographic data, results of BMIFT, granulocyte immunofluorescence testing and bone marrow findings were collected from clinical records and the institutional laboratory database. Seventy-six children had BMIFT performed for investigation of neutropenia. There were 45 patients diagnosed with AIN, 28 with nonimmune neutropenia and three failed tests. The median age of children with AIN was 1.2 years (range 0.3-15.3), compared with 3.6 years (range 0.1-15.7) in the nonautoimmune group. The median neutrophil count in AIN was 0.3 x 10(9)/l (0.9 x 10(9)/l in nonautoimmune). BMIFT was positive in 24 of 45 patients with AIN and 0 of 28 with nonautoimmune neutropenia (sensitivity 53%, specificity 100%, positive predictive value (PPV) 100%, negative predictive value 57%). Ten patients had other autoimmune diatheses at diagnosis. The BMIFT is a simple, highly specific test with excellent PPV and thus is a clinically useful test to confirm AIN in children.

Purpose: To study the effects of systemic inflammatory response syndrome (SIRS) on polymorhonuclear neutrophil (PMN) function and phenotype by comparing neutrophils from critically ill patients with SIRS against those from healthy blood donors. Material and Methods: Intensive care unit patients (n = 110) who met at least one SIRS criterion were recruited to the study. One hundred healthy blood donors were recruited as normal controls. Results: Polymorphonuclear cells from critically ill patients with SIRS were more resistant to activation than PMNs from healthy donors, but when stimulated had an exaggerated microbicidal response. Buffer-treated PMNs from patients with SIRS had significantly higher CD43 surface expression that may inhibit heterotypic cellular contact or ligand stimulation of membrane receptors, had significantly lower expression of IgG receptor CD16, demonstrated resistance to shedding of L-selectin when primed by platelet-activating factor which could be pro-inflammatory, and had reduced respiratory burst when primed by platelet-activating factor than activated by formyl-Met-Leu-Phe. Conclusion: The phenotypic and functional changes observed in neutrophils in the critically ill indicate that they require a higher level of stimulus to become activated. This may represent an auto-protective mechanism where the neutrophils in the already inflamed host may, by this mechanism, avoid excessive inflammation reducing the risk of further host cell injury and death.

Introduction Ex vivo experiments in extracorporeal membrane oxygenation (ECMO) circuits have identified octanol-water partition coefficient (logP, a marker of lipophilicity) and protein binding (PB) as key drug factors affecting pharmacokinetics (PK) during ECMO. Using ovine models, in this study we investigated whether these drug properties can be used to predict PK alterations of antimicrobial drugs during ECMO. Methods Single-dose PK sampling was performed in healthy sheep (HS, n = 7), healthy sheep on ECMO (E24H, n = 7) and sheep with smoke inhalation acute lung injury on ECMO (SE24H, n = 6). The sheep received eight study antimicrobials (ceftriaxone, gentamicin, meropenem, vancomycin, doripenem, ciprofloxacin, fluconazole, caspofungin) that exhibit varying degrees of logP and PB. Plasma drug concentrations were determined using validated chromatographic techniques. PK data obtained from a non-compartmental analysis were used in a linear regression model to predict PK parameters based on logP and PB. Results We found statistically significant differences in pH, haemodynamics, fluid balance and plasma proteins between the E24H and SE24H groups (p ss) in both the E24H and SE24H groups (p p = 0.9) and no relationship with clearance (CL) in all study groups. Although we observed an increase in CL for highly PB drugs in ECMO sheep, PB exhibited a weaker negative linear relationship with both CL (HS, p = 0.01; E24H, p p ss (HS, p = 0.01; E24H, p = 0.004; SE24H, p =0.05) in the final model. Conclusions Lipophilic antimicrobials are likely to have an increased Vss and decreased CL during ECMO. Protein-bound antimicrobial agents are likely to have reductions both in CL and Vss during ECMO. The strong relationship between lipophilicity and Vss seen in both the E24H and SE24H groups indicates circuit sequestration of lipophilic drugs. These findings highlight the importance of drug factors in predicting antimicrobial drug PK during ECMO and should be a consideration when performing and interpreting population PK studies.