How I diagnose and treat neonatal thrombocytopenia.

Neonatal thrombocytopenia, defined as the presence of a circulating platelet count <150 × 109/L, is a common abnormality in babies admitted to neonatal intensive care units. Thrombocytopenia that is typically mild and self-limiting often accompanies neonatal stress in scenarios such as premature delivery or intrauterine growth restriction. However, the differential diagnosis of neonatal thrombocytopenia is wide and includes potentially life-threatening disorders, such as bacterial sepsis, viral infection, and necrotizing enterocolitis. Distinguishing these causes of thrombocytopenia from entities such as genetic thrombocytopenia and fetal and neonatal alloimmune thrombocytopenia is critical for the accurate quantitation of significant adverse events, such as intracranial bleeding, and for the selection of treatments, such as platelet transfusion. In this review, we focus on common differential diagnoses of neonatal thrombocytopenia and highlight how the landscape of diagnosis and management is changing with recent advances in genomic technology and the completion of pivotal clinical trials of platelet transfusion practice. Increasing evidence highlights the need for judicious and restrictive use of platelet transfusions in neonates.

Guidelines for the diagnosis and management of adult aplastic anaemia: A British Society for Haematology Guideline.

Pancytopenia with hypocellular bone marrow is the hallmark of aplastic anaemia (AA) and the diagnosis is confirmed after careful evaluation, following exclusion of alternate diagnosis including hypoplastic myelodysplastic syndromes. Emerging use of molecular cyto-genomics is helpful in delineating immune mediated AA from inherited bone marrow failures (IBMF). Camitta criteria is used to assess disease severity, which along with age and availability of human leucocyte antigen compatible donor are determinants for therapeutic decisions. Supportive care with blood and platelet transfusion support, along with anti-microbial prophylaxis and prompt management of opportunistic infections remain key throughout the disease course. The standard first-line treatment for newly diagnosed acquired severe/very severe AA patients is horse anti-thymocyte globulin and ciclosporin-based immunosuppressive therapy (IST) with eltrombopag or allogeneic haemopoietic stem cell transplant (HSCT) from a matched sibling donor. Unrelated donor HSCT in adults should be considered after lack of response to IST, and up front for young adults with severe infections and a readily available matched unrelated donor. Management of IBMF, AA in pregnancy and in elderly require special attention. In view of the rarity of AA and complexity of management, appropriate discussion in multidisciplinary meetings and involvement of expert centres is strongly recommended to improve patient outcomes.

How I use platelet transfusions.

Platelet transfusions are commonly administered for the prevention or treatment of bleeding in patients with acquired thrombocytopenia across a range of clinical contexts. Recent data, including randomized trials, have highlighted uncertainties in the risk-benefit balance of this therapy, which is the subject of this review. Hemovigilance systems report that platelets are the most frequently implicated component in transfusion reactions. There is considerable variation in platelet count increment after platelet transfusion, and limited evidence of efficacy for clinical outcomes, including prevention of bleeding. Bleeding events commonly occur despite the different policies for platelet transfusion prophylaxis. The underlying mechanisms of harm reported in randomized trials may be related to the role of platelets beyond hemostasis, including mediating inflammation. Research supports the implementation of a restrictive platelet transfusion policy. Research is needed to better understand the impact of platelet donation characteristics on outcomes, and to determine the optimal thresholds for platelet transfusion before invasive procedures or major surgery (eg, laparotomy). Platelet transfusion policies should move toward a risk-adapted approach that does not focus solely on platelet count.

Opportunities to improve feedback to reduce blood component wastage: Results of a national scheme evaluation.

BACKGROUND: Blood components are costly and scarce. The Blood Stocks Management Scheme (BSMS) was established in the United Kingdom (UK) to support hospital transfusion services and national blood services through collection, analysis, and monthly feedback of data on blood component inventory and wastage management. There is a growing evidence base on how best to deliver feedback for quality improvement. We assessed the quality and utility of the monthly BSMS component reports. METHODS: We assessed the content of BSMS reports issued in March 2023 against established criteria for effective feedback. Two researchers independently rated whether criteria spanning the five domains of goal setting, data collection, feedback content, feedback display and feedback delivery were fully, partially or not met. Disagreements were resolved through discussion. We conducted an online questionnaire survey of recipients of BSMS reports during March 2023 to assess their use of reports and seek suggestions for improvement. RESULTS: Five out of 20 criteria for effective feedback were fully met. Areas for improvement included placing more emphasis in the feedback on positive change, linking data and summary messages, and including specific suggestions for action. Respondents highlighted the value of benchmarked comparisons with other hospital transfusion services. CONCLUSION: There is scope for enhancing the effectiveness and utility of BSMS feedback reports and hence reducing wastage of blood components. This methodology for evaluation of feedback could be utilized to improve other areas of transfusion practice.

Rethinking the transfusion pathway in myelodysplastic syndromes: Study protocol for a novel randomized feasibility n-of-1 trial of weekly-interval red cell transfusion in myelodysplastic syndromes.

BACKGROUND: Anemia in myelodysplastic syndromes (MDS) is associated with poorer health-related quality of life (HRQoL) and physical function, and is frequently treated with transfusions. The current common practice of transfusing multiple red blood cells (RBC) units every 2-4 weeks may result in peaks/troughs in hemoglobin (Hb) level, yet maintaining a stable Hb may better improve HRQoL. We describe a study protocol aiming to investigate the feasibility of weekly low-dose RBC transfusion in MDS patients, including assessing HRQoL and physical function outcomes. STUDY DESIGN AND METHODS: In this n-of-1 pilot study, patients receive two treatment arms, with randomly allocated treatment sequence: arm A (patient's usual transfusion schedule) and arm B (weekly transfusion, individualized per patient). To facilitate timely delivery of weekly transfusion, extended-matched RBCs are provided, with transfusion based upon the previous week's Hb/pre-transfusion testing results to eliminate delays of awaiting contemporaneous cross-matching. Primary outcome is the feasibility of delivering weekly transfusion. Secondary outcomes include HRQoL, functional activity measurements, RBC usage, and alloimmunization rates. A qualitative substudy explores patient and staff experiences. RESULTS: The trial is open in Australia, Netherlands, and UK. The first patient was recruited in 2020. Inter-country differences in providing RBCs are observed, including patient genotyping versus serological phenotyping to select compatible units. DISCUSSION: This pilot trial evaluates a novel personalized transfusion approach of weekly matched RBC transfusion and challenges the dogma of current routine pre-transfusion matching practice. Findings on study feasibility, HRQoL, and physical functional outcomes and the qualitative substudy will inform the design of a larger definitive trial powered for clinical outcomes.

A review and analysis of outcomes in randomized clinical trials of plasma transfusion in patients with bleeding or for the prevention of bleeding: The BEST collaborative study.

BACKGROUND: Previous systematic reviews have revealed an inconsistency of outcome definitions as a major barrier in providing evidence-based guidance for the use of plasma transfusion to prevent or treat bleeding. We reviewed and analyzed outcomes in randomized controlled trials (RCTs) to provide a methodology for describing and classifying outcomes. STUDY DESIGN AND METHODS: RCTs involving transfusion of plasma published after 2000 were identified from a prior review (Yang 2012) and combined with an updated systematic literature search of multiple databases (July 1, 2011 to January 17, 2023). Inclusion of publications, data extraction, and risk of bias assessments were performed in duplicate. (PROSPERO registration number is: CRD42020158581). RESULTS: In total, 5579 citations were identified in the new systematic search and 22 were included. Six additional trials were identified from the previous review, resulting in a total of 28 trials: 23 therapeutic and five prophylactic studies. An increasing number of studies in the setting of major bleeding such as in cardiovascular surgery and trauma were identified. Eighty-seven outcomes were reported with a mean of 11 (min-max. 4-32) per study. There was substantial variation in outcomes used with a preponderance of surrogate measures for clinical effect such as laboratory parameters and blood usage. CONCLUSION: There is an expanding literature on plasma transfusion to inform guidelines. However, considerable heterogeneity of reported outcomes constrains comparisons. A core outcome set should be developed for plasma transfusion studies. Standardization of outcomes will motivate better study design, facilitate comparison, and improve clinical relevance for future trials of plasma transfusion.

Red cell transfusion thresholds in outpatients with myelodysplastic syndromes: Results of a pilot randomized trial RBC-ENHANCE.

BACKGROUND: The optimal hemoglobin (Hb) threshold for red blood cell transfusions in adult patients with myelodysplastic syndromes (MDS) has not been defined. STUDY DESIGN AND METHODS: We conducted a pilot randomized multi-center study of two transfusion algorithms (liberal, to maintain Hb 110-120 g/L, transfuse 2 units if Hb < 105 g/L and 1 unit if Hb 105-110 g/L vs. restrictive, 85-105 g/L, transfuse 2 units when Hgb < 85 g/L). Primary objectives were 70% compliance in maintaining the q2 week hemoglobin within the targeted range and the achievement of a 15 g/L difference in pre-transfusion Hb. Secondary outcomes included measures of quality of life (QOL), iron studies and safety. RESULTS: Twenty-eight patients were randomized between February 2015-2020, 13 to the restrictive arm and 15 to the liberal arm in three tertiary care centers. The compliance was 66% and 45% and the mean pre-transfusion Hb thresholds were 86 (standard deviation [SD] 8) and 98 g/L (SD 10) in the restrictive and liberal arms, (mean difference 11.8 g/L, p < .0001), respectively. Patients in the liberal arm experienced a mean of 3.4 (SD 2.6) more transfusion visits and received a mean of 5.3 (SD 5.5) more units of blood during the 12-week study. Ferritin increased by 1043 (SD 1516) IU/L and 148 (SD 1319) IU/L in the liberal and restrictive arms, respectively. Selected QOL scores were superior pre-transfusion and more patients achieved clinically important improvements in the liberal arm compared with the restrictive arm for selected symptoms and function domains. CONCLUSION: The results establish that policies for transfusion support can be delivered in practice at multiple hospitals, but further research is required to understand the full clinical effects and safety of liberal transfusion policies in MDS outpatients.

E-learning in transfusion medicine: An exploratory qualitative assessment.

BACKGROUND AND OBJECTIVES: E-learning programmes are increasingly offered in transfusion medicine (TM) education. The aim of this study was to explore facilitators and barriers to TM e-learning programmes, including assessment of learning outcomes and measures of effectiveness. MATERIALS AND METHODS: Participants selected from a prior survey and representing a diverse number of international e-learning programmes were invited to participate. A mixed methodology was employed, combining a survey and individual semi-structured one-on-one interviews. Interview data were analysed inductively to explore programme development, evaluation, and facilitators and barriers to implementation. RESULTS: Fourteen participants representing 13 institutions participated in the survey and 10 were interviewed. The e-learning programmes have been in use for a variable duration between 5 and 16 years. Funding sources varied, including government and institutional support. Learner assessment methods varied and encompassed multiple-choice-questions (n = 12), direct observation (n = 4) and competency assessment (n = 4). Most regional and national blood collection agencies rely on user feedback and short-term learning assessments to evaluate their programmes. Only one respondent indicated an attempt to correlate e-learning with clinical practices. Factors that facilitated programme implementation included support from management and external audits to ensure compliance with regulatory educational and training requirements. Barriers to programme implementation included the allocation of staff time for in-house development, enforcing compliance, keeping educational content up-to-date and gaining access to outcome data for educational providers. CONCLUSION: There is evidence of considerable diversity in the evaluation of e-learning programmes. Further work is needed to understand the ultimate impact of TM e-learning on transfusion practices and patient outcomes.

Intravenous albumin in cardiac and vascular surgery: a systematic review and meta-analysis.

BACKGROUND: Intravenous albumin is commonly utilised in cardiovascular surgery for priming of the cardiopulmonary bypass circuit, volume replacement, or both, although the evidence to support this practice is uncertain. The aim was to compare i.v. albumin with synthetic colloids and crystalloids for paediatric and adult patients undergoing cardiovascular surgery for all-cause mortality and other perioperative outcomes. METHODS: A systematic review and meta-analysis of randomised controlled trials (RCTs) of i.v. albumin compared with synthetic colloids and crystalloids on the primary outcome of all-cause mortality was conducted. Secondary outcomes included renal failure, blood loss, duration of hospital or intensive care unit stay, cardiac index, and blood component use; subgroups were analysed by age, comparator fluid, and intended use (priming, volume, or both). We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CCRT) from 1946 to November 23, 2022. RESULTS: Of 42 RCTs, mortality was assessed in 15 trials (2711 cardiac surgery patients) and the risk difference was 0.00, 95% confidence interval (CI) -0.01 to 0.01, I2=0%. Among secondary outcomes, i.v. albumin resulted in smaller fluid balance, mean difference -0.55 L, 95% CI -1.06 to -0.4, I2=90% (nine studies, 1975 patients) and higher albumin concentrations, mean difference 7.77 g L-1, 95% CI 3.73-11.8, I2=95% (six studies, 325 patients). CONCLUSIONS: Intravenous albumin use was not associated with a difference in morbidity and mortality in patients undergoing cardiovascular surgery, when compared with comparator fluids. The lack of improvement in important outcomes with albumin and its higher cost suggests it should be used restrictively. SYSTEMATIC REVIEW PROTOCOL: PROSPERO; CRD42020171876.

Management and outcomes of women with low fibrinogen concentration during pregnancy or immediately postpartum: A UK national population-based cohort study.

INTRODUCTION: Pregnant women with a fibrinogen level <2 g/L represent a high-risk group that is associated with severe postpartum hemorrhage and other complications. Women who would qualify for fibrinogen therapy are not yet identified. MATERIAL AND METHODS: A population-based cross-sectional study was conducted using the UK Obstetric Surveillance System between November 2017 and October 2018 in any UK hospital with a consultant-led maternity unit. Any woman pregnant or immediately postpartum with a fibrinogen <2 g/L was included. Our aims were to determine the incidence of fibrinogen <2 g/L in pregnancy, and to describe its causes, management and outcomes. RESULTS: Over the study period 124 women with fibrinogen <2 g/L were identified (1.7 per 10 000 maternities; 95% confidence interval 1.4-2.0 per 10 000 maternities). Less than 5% of cases of low fibrinogen were due to preexisting inherited dysfibrinogenemia or hypofibrinogenemia. Sixty percent of cases were due to postpartum hemorrhage caused by placental abruption, atony, or trauma. Amniotic fluid embolism and placental causes other than abruption (previa, accreta, retention) were associated with the highest estimated blood loss (median 4400 mL) and lowest levels of fibrinogen. Mortality was high with two maternal deaths due to massive postpartum hemorrhage, 27 stillbirths, and two neonatal deaths. CONCLUSIONS: Fibrinogen <2 g/L often, but not exclusively, affected women with postpartum hemorrhage due to placental abruption, atony, or trauma. Other more rare and catastrophic obstetrical events such as amniotic fluid embolism and placenta accreta also led to low levels of fibrinogen. Maternal and perinatal mortality was extremely high in our cohort.

Healthcare provider's perceptions of bleeding in patients with acute leukaemia undergoing induction chemotherapy: A qualitative study.

BACKGROUND: Bleeding is a primary outcome for many transfusion-related trials in acute leukaemia (AL) patients, typically graded using the World Health Organisation (WHO) bleeding scale (clinically significant bleed (CSB) is ≥grade 2). This composite outcome fails to differentiate minor bleeds that may not be significant, poorly represents the total burden of bleeding and lacks input from healthcare providers (HCPs) and patients. As part of a multi-step project to create a better bleeding tool for trials, our objective was to identify HCPs' perspectives on the components of CSB in AL patients. STUDY DESIGN AND METHODS: Using qualitative description, we interviewed 19 physicians and nurses who care for AL patients undergoing induction chemotherapy. Participants were recruited from professional organisations, networks and social media. An inductive approach to conventional content analysis was used. RESULTS: HCPs identified features of CSB as the anatomical site of bleeding, amount of bleeding, need for intervention and changes in vital signs. Using these characteristics, bleeding events were categorised into three groups: clinically significant, could evolve into a CSB and not clinically significant. HCPs considered the patient's condition, bleeding history and clinical intuitions when deciding whether a bleed could escalate into serious bleeding. DISCUSSION: Using data from HCPs, we categorised bleeds as clinically significant, could evolve into a CSB, and not significant. A study of patients' perspectives on the importance of different kinds of bleeding is the next step to creating a bleeding definition that is informed by evidence, clinicians and patients.

Iron Deficiency in Anemic Children Surviving Critical Illness: Post Hoc Analysis of a Single-Center Prospective Cohort in Canada, 2019-2022.

OBJECTIVES: Many children leave the PICU with anemia. The mechanisms of post-PICU anemia are poorly investigated, and treatment of anemia, other than blood, is rarely started during PICU. We aimed to characterize the contributions of iron depletion (ID) and/or inflammation in the development of post-PICU anemia and to explore the utility of hepcidin (a novel iron marker) at detecting ID during inflammation. DESIGN: Post hoc analysis of a single-center prospective study (November 2019 to September 2022). SETTING: PICU, quaternary center, Canada. PATIENTS: Children admitted to PICU with greater than or equal to 48 hours of invasive or greater than or equal to 96 hours of noninvasive ventilation. We excluded patients with preexisting conditions causing anemia or those admitted after cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Hematological and iron profiles were performed at PICU discharge on 56 participants of which 37 (37/56) were diagnosed with anemia. Thirty-three children (33/56; 59%) were younger than 2 years. Median Pediatric Logistic Organ Dysfunction score was 11 (interquartile range, 6-16). Twenty-four of the 37 anemic patients had repeat bloodwork 2 months post-PICU. Of those, four (4/24; 16%) remained anemic. Hematologic profiles were categorized as: anemia of inflammation (AI), iron deficiency anemia (IDA), IDA with inflammation, and ID (low iron stores without anemia). Seven (7/47; 15%) had AI at discharge, and one had persistent AI post-PICU. Three patients (3/47; 6%) had IDA at discharge; of which one was lost to follow-up and the other two were no longer anemic but had ID post-PICU. Eleven additional patients developed ID post-PICU. In the exploratory analysis, we identified a diagnostic cutoff value for ID during inflammation from the receiver operating characteristic curve for hepcidin of 31.9 pg/mL. This cutoff would increase the detection of ID at discharge from 6% to 34%. CONCLUSIONS: The burden of ID in children post-PICU is high and better management strategies are required. Hepcidin may increase the diagnostic yield of ID in patients with inflammation.

Small-volume blood sample collection tubes in adult intensive care units: A rapid practice guideline.

BACKGROUND: This Intensive Care Medicine Rapid Practice Guideline (ICM-RPG) provides an evidence-based recommendation to address the question: in adult patients in intensive care units (ICUs), should we use small-volume or conventional blood collection tubes? METHODS: We included 23 panelists in 8 countries and assessed and managed financial and intellectual conflicts of interest. Methodological support was provided by the Guidelines in Intensive Care, Development, and Evaluation (GUIDE) group. We conducted a systematic review, including evidence from observational and randomized studies. Using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, we evaluated the certainty of evidence and developed recommendations using the Evidence-to-Decision framework. RESULTS: We identified 8 studies (1 cluster and 2 patient-level randomized trials; 5 observational studies) comparing small-volume to conventional tubes. We had high certainty evidence that small-volume tubes reduce daily and cumulative blood sampling volume; and moderate certainty evidence that they reduce the risk of transfusion and mean number of red blood cell units transfused, but these estimates were limited by imprecision. We had high certainty that small-volume tubes have a similar rate of specimens with insufficient quantity. The panel considered that the desirable effects of small-volume tubes outweigh the undesirable effects, are less wasteful of resources, and are feasible, as demonstrated by successful implementation across multiple countries, although there are upfront implementation costs to validate small-volume tubes on laboratory instrumentation. CONCLUSION: This ICM-RPG panel made a strong recommendation for the use of small-volume sample collection tubes in adult ICUs based on overall moderate certainty evidence.

How are granulocytes for transfusion best used? The past, the present and the future.

Granulocyte transfusions continue to be used in clinical practice, predominantly for treatment of refractory infection in the setting of severe neutropenia. There is biological plausibility for effectiveness in these patients with deficiencies of neutrophils, either as a consequence of disease or treatment. However, there is a chequered history of conducting and completing interventional trials to define optimal use, and many uncertainties remain regarding schedule and dose. Practice and clinical studies are severely limited by the short shelf life and viability of current products, which often restricts the timely access to granulocyte transfusions. In the future, methods are needed to optimise donor-derived granulocyte products. Options include use of manufactured neutrophils, expanded and engineered from stem cells. Further possibilities include manipulation of neutrophils to enhance their function and/or longevity. Granulocyte transfusions contain a heterogeneous mix of cells, and there is additional interest in how these transfusions may have immunomodulatory effects, including for potential uses as adjuncts for anti-cancer effects.

Granulocyte transfusion during cord blood transplant for relapsed, refractory AML is associated with massive CD8+ T-cell expansion, significant cytokine release syndrome and induction of disease remission.

In high-risk myeloid malignancy, relapse is reduced using cord blood transplant (CBT) but remains the principal cause of treatment failure. We previously described T-cell expansion in CBT recipients receiving granulocyte transfusions. We now report the safety and tolerability of such transfusions, T-cell expansion data, immunophenotype, cytokine profiles and clinical response in children with post-transplant relapsed acute leukaemia who received T-replete, HLA-mismatched CBT and pooled granulocytes within a phase I/II trial (ClinicalTrials.Gov NCT05425043). All patients received the transfusion schedule without significant clinical toxicity. Nine of ten patients treated had detectable measurable residual disease (MRD) pre-transplant. Nine patients achieved haematological remission, and eight became MRD negative. There were five deaths: transplant complications (n = 2), disease (n = 3), including two late relapses. Five patients are alive and in remission with 12.7 months median follow up. Significant T-cell expansion occurred in nine patients with a greater median lymphocyte count than a historical cohort between days 7-13 (median 1.73 × 109 /L vs. 0.1 × 109 /L; p < 0.0001). Expanded T-cells were predominantly CD8+ and effector memory or TEMRA phenotype. They exhibited markers of activation and cytotoxicity with interferon-gamma production. All patients developed grade 1-3 cytokine release syndrome (CRS) with elevated serum IL-6 and interferon-gamma.

Defective T-cell response to COVID-19 vaccination in acute myeloid leukaemia and myelodysplastic syndromes.

Limited data exist on COVID-19 vaccination efficacy in patients with acute myeloid leukemia and myelodysplasia with excess blasts (AML/MDS-EB2). We report results from a prospective study, PACE (Patients with AML and COVID-19 Epidemiology). 93 patients provided samples post-vaccine 2 or 3 (PV2, PV3). Antibodies against SARS-COV-2 spike antigen were detectable in all samples. Neutralization of the omicron variant was poorer than ancestral variants but improved PV3. In contrast, adequate T-cell reactivity to SARS-COV-2 spike protein was seen in only 16/47 (34%) patients PV2 and 23/52 (44%) PV3. Using regression models, disease response (not in CR/Cri), and increasing age predicted poor T cell response.

An epitope-based approach of HLA-matched platelets for transfusion: a noninferiority crossover randomized trial.

Platelet transfusion refractoriness results in adverse outcomes and increased health care costs. Managing refractoriness resulting from HLA alloimmunization necessitates the use of HLA antigen-matched platelets but requires a large platelet donor pool and does not guarantee full matching. We report the first randomized, double-blind, noninferiority, crossover trial comparing HLA epitope-matched (HEM) platelets with HLA standard antigen-matched (HSM) platelet transfusions. Alloimmunized, platelet-refractory, thrombocytopenic patients with aplastic anemia, myelodysplastic syndrome, or acute myeloid leukemia were eligible. HEM platelets were selected using HLAMatchMaker epitope (specifically eplet) matching. Patients received up to 8 prophylactic HEM and HSM transfusions provided in random order. The primary outcome was 1-hour posttransfusion platelet count increment (PCI). Forty-nine patients were randomized at 14 UK hospitals. For intention to treat, numbers of evaluable transfusions were 107 and 112 for HEM and HSM methods, respectively. Unadjusted mean PCIs for HEM and HSM methods were 23.9 (standard deviation [SD], 15) and 23.5 (SD, 14.1), respectively (adjusted mean difference, -0.1; 95% confidence interval [CI], -2.9 to 2.8). Because the lower limit of the 95% CI was not greater than the predefined noninferiority limit, the HEM approach was declared noninferior to the HSM approach. There were no differences in secondary outcomes of platelet counts, transfusion requirements, and bleeding events. Adequate 1-hour PCI was more frequently observed, with a mean number of 3.2 epitope mismatches, compared with 5.5 epitope mismatches for inadequate 1-hour increments. For every additional epitope mismatch, the likelihood of an adequate PCI decreased by 15%. Epitope-matched platelets should be considered to support HLA alloimmunized patients. This trial was registered at www.isrctn.com as #ISRCTN23996532.

An analysis of quality of life and functional outcomes as reported in randomized trials for red cell transfusions.

BACKGROUND: Meta-analyses of randomized controlled trials (RCTs) evaluating thresholds for red blood cell (RBC) transfusion typically focus on mortality; however, other outcomes are highly relevant. The aim of this study is to summarize the effects of different transfusion thresholds on the outcomes of quality of life (QoL) and function. STUDY DESIGN: We extracted data from RCTs identified in a recently published Cochrane systematic review. Primary analysis was descriptive. RESULTS: A total of 23 RCTs with 13,743 adult participants were included. Fifteen RCTs included patients in the postoperative period, of which 9 RCTs were conducted in hip (n = 3024) and 6 (n = 8672) in cardiac surgeries; 5 RCTs (n = 489) were in patients with hematological malignancies; 2 in the setting of bleeding (gastrointestinal bleed [n = 936] and postpartum [n = 521]); and one RCT (n = 936) included critically ill patients. QoL and function were reported using a variety of questionnaires and tools. The timing of assessments varied between trials. No clear clinical differences in QoL outcomes were identified in comparisons between restrictive and liberal transfusion thresholds. DISCUSSION: There is no evidence that a liberal transfusion strategy improves QoL and functional outcomes. However, the substantial limitations of many included studies indicate the need for further well-designed and adequately powered trials.

Systematic reviews on platelet transfusions: Is there unnecessary duplication of effort? A scoping review.

BACKGROUND AND OBJECTIVES: Platelet transfusions are used across multiple patient populations to prevent and correct bleeding. This scoping review aimed to map the currently available systematic reviews (SRs) and evidence-based guidelines in the field of platelet transfusion. MATERIALS AND METHODS: A systematic literature search was conducted in seven databases for SRs on effectiveness (including dose and timing, transfusion trigger and ratio to other blood products), production modalities and decision support related to platelet transfusion. The following data were charted: methodological features of the SR, population, concept and context features, outcomes reported, study design and number of studies included. Results were synthesized in interactive evidence maps. RESULTS: We identified 110 SRs. The majority focused on clinical effectiveness, including prophylactic or therapeutic transfusions compared to no platelet transfusion (34 SRs), prophylactic compared to therapeutic-only transfusion (8 SRs), dose, timing (11 SRs) and threshold for platelet transfusion (15 SRs) and the ratio of platelet transfusion to other blood products in massive transfusion (14 SRs). Furthermore, we included 34 SRs on decision support, of which 26 evaluated viscoelastic testing. Finally, we identified 22 SRs on platelet production modalities, including derivation (4 SRs), pathogen inactivation (6 SRs), leucodepletion (4 SRs) and ABO/human leucocyte antigen matching (5 SRs). The SRs were mapped according to concept and clinical context. CONCLUSION: An interactive evidence map of SRs and evidence-based guidelines in the field of platelet transfusion has been developed and identified multiple reviews. This work serves as a tool for researchers looking for evidence gaps, thereby both supporting research and avoiding unnecessary duplication.

Definitions of massive transfusion in adults with critical bleeding: a systematic review.

BACKGROUND: Definitions for massive transfusion (MT) vary widely between studies, contributing to challenges in interpretation of research findings and practice evaluation. In this first systematic review, we aimed to identify all MT definitions used in randomised controlled trials (RCTs) to date to inform the development of consensus definitions for MT. METHODS: We systematically searched the following databases for RCTs from inception until 11 August 2022: MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Cumulative Index to Nursing and Allied Health Literature, and Transfusion Evidence Library. Ongoing trials were sought from CENTRAL, ClinicalTrials.gov, and World Health Organisation International Clinical Trials Registry Platform. To be eligible for inclusion, studies had to fulfil all the following three criteria: (1) be an RCT; (2) include an adult patient population with major bleeding who had received, or were anticipated to receive, an MT in any clinical setting; and (3) specify a definition for MT as an inclusion criterion or outcome measure. RESULTS: Of the 8,458 distinct references identified, 30 trials were included for analysis (19 published, 11 ongoing). Trauma was the most common clinical setting in published trials, while for ongoing trials, it was obstetrics. A total of 15 different definitions of MT were identified across published and ongoing trials, varying greatly in cut-offs for volume transfused and time period. Almost all definitions specified the number of red blood cells (RBCs) within a set time period, with none including plasma, platelets or other haemostatic agents that are part of contemporary transfusion resuscitation. For completed trials, the most commonly used definition was transfusion of ≥ 10 RBC units in 24 h (9/19, all in trauma), while for ongoing trials it was 3-5 RBC units (n = 7), with the timing for transfusion being poorly defined, or in some trials not provided at all (n = 5). CONCLUSIONS: Transfusion of ≥ 10 RBC units within 24 h was the most commonly used definition in published RCTs, while lower RBC volumes are being used in ongoing RCTs. Any consensus definitions should reflect the need to incorporate different blood components/products for MT and agree on whether a 'one-size-fits-all' approach should be used across different clinical settings.