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.

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.

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.

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.

The SWiFT trial (Study of Whole Blood in Frontline Trauma)-the clinical and cost effectiveness of pre-hospital whole blood versus standard care in patients with life-threatening traumatic haemorrhage: study protocol for a multi-centre randomised controlled trial.

BACKGROUND: Early blood transfusion improves survival in patients with life-threatening bleeding, but the optimal transfusion strategy in the pre-hospital setting has yet to be established. Although there is some evidence of benefit with the use of whole blood, there have been no randomised controlled trials exploring the clinical and cost effectiveness of pre-hospital administration of whole blood versus component therapy for trauma patients with life-threatening bleeding. The aim of this trial is to determine whether pre-hospital leukocyte-depleted whole blood transfusion is better than standard care (blood component transfusion) in reducing the proportion of participants who experience death or massive transfusion at 24 h. METHODS: This is a multi-centre, superiority, open-label, randomised controlled trial with internal pilot and within-trial cost-effectiveness analysis. Patients of any age will be eligible if they have suffered major traumatic haemorrhage and are attended by a participating air ambulance service. The primary outcome is the proportion of participants with traumatic haemorrhage who have died (all-cause mortality) or received massive transfusion in the first 24 h from randomisation. A number of secondary clinical, process, and safety endpoints will be collected and analysed. Cost (provision of whole blood, hospital, health, and wider care resource use) and outcome data will be synthesised to present incremental cost-effectiveness ratios for the trial primary outcome and cost per quality-adjusted life year at 90 days after injury. We plan to recruit 848 participants (a two-sided test with 85% power, 5% type I error, 1-1 allocation, and one interim analysis would require 602 participants-after allowing for 25% of participants in traumatic cardiac arrest and an additional 5% drop out, the sample size is 848). DISCUSSION: The SWiFT trial will recruit 848 participants across at least ten air ambulances services in the UK. It will investigate the clinical and cost-effectiveness of whole blood transfusion versus component therapy in the management of patients with life-threatening bleeding in the pre-hospital setting. TRIAL REGISTRATION: ISRCTN: 23657907; EudraCT: 2021-006876-18; IRAS Number: 300414; REC: 22/SC/0072, 21 Dec 2021.

Prophylactic Platelet Transfusions: Why Less Is More.

Preterm neonates are a highly transfused patient group, with platelet transfusions being the second most transfused cellular blood component. Historically, however, evidence to inform optimal platelet transfusion practice has been limited. In pediatrics, much of the evidence has been inferred from studies in adult patients, although neonatologists have generally applied more cautious and liberal platelet transfusion thresholds to mitigate the complications of intraventricular hemorrhage. A total of three randomized controlled trials have now been published comparing different platelet transfusion strategies in neonates.

Red Blood Cell Transfusion: 2023 AABB International Guidelines.

Importance: Red blood cell transfusion is a common medical intervention with benefits and harms. Objective: To provide recommendations for use of red blood cell transfusion in adults and children. Evidence Review: Standards for trustworthy guidelines were followed, including using Grading of Recommendations Assessment, Development and Evaluation methods, managing conflicts of interest, and making values and preferences explicit. Evidence from systematic reviews of randomized controlled trials was reviewed. Findings: For adults, 45 randomized controlled trials with 20 599 participants compared restrictive hemoglobin-based transfusion thresholds, typically 7 to 8 g/dL, with liberal transfusion thresholds of 9 to 10 g/dL. For pediatric patients, 7 randomized controlled trials with 2730 participants compared a variety of restrictive and liberal transfusion thresholds. For most patient populations, results provided moderate quality evidence that restrictive transfusion thresholds did not adversely affect patient-important outcomes. Recommendation 1: for hospitalized adult patients who are hemodynamically stable, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). In accordance with the restrictive strategy threshold used in most trials, clinicians may choose a threshold of 7.5 g/dL for patients undergoing cardiac surgery and 8 g/dL for those undergoing orthopedic surgery or those with preexisting cardiovascular disease. Recommendation 2: for hospitalized adult patients with hematologic and oncologic disorders, the panel suggests a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (conditional recommendations, low certainty evidence). Recommendation 3: for critically ill children and those at risk of critical illness who are hemodynamically stable and without a hemoglobinopathy, cyanotic cardiac condition, or severe hypoxemia, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). Recommendation 4: for hemodynamically stable children with congenital heart disease, the international panel suggests a transfusion threshold that is based on the cardiac abnormality and stage of surgical repair: 7 g/dL (biventricular repair), 9 g/dL (single-ventricle palliation), or 7 to 9 g/dL (uncorrected congenital heart disease) (conditional recommendation, low certainty evidence). Conclusions and Relevance: It is good practice to consider overall clinical context and alternative therapies to transfusion when making transfusion decisions about an individual patient.

Early and Empirical High-Dose Cryoprecipitate for Hemorrhage After Traumatic Injury: The CRYOSTAT-2 Randomized Clinical Trial.

Importance: Critical bleeding is associated with a high mortality rate in patients with trauma. Hemorrhage is exacerbated by a complex derangement of coagulation, including an acute fibrinogen deficiency. Management is fibrinogen replacement with cryoprecipitate transfusions or fibrinogen concentrate, usually administered relatively late during hemorrhage. Objective: To assess whether survival could be improved by administering an early and empirical high dose of cryoprecipitate to all patients with trauma and bleeding that required activation of a major hemorrhage protocol. Design, Setting, and Participants: CRYOSTAT-2 was an interventional, randomized, open-label, parallel-group controlled, international, multicenter study. Patients were enrolled at 26 UK and US major trauma centers from August 2017 to November 2021. Eligible patients were injured adults requiring activation of the hospital's major hemorrhage protocol with evidence of active hemorrhage, systolic blood pressure less than 90 mm Hg at any time, and receiving at least 1 U of a blood component transfusion. Intervention: Patients were randomly assigned (in a 1:1 ratio) to receive standard care, which was the local major hemorrhage protocol (reviewed for guideline adherence), or cryoprecipitate, in which 3 pools of cryoprecipitate (6-g fibrinogen equivalent) were to be administered in addition to standard care within 90 minutes of randomization and 3 hours of injury. Main Outcomes and Measures: The primary outcome was all-cause mortality at 28 days in the intention-to-treat population. Results: Among 1604 eligible patients, 799 were randomized to the cryoprecipitate group and 805 to the standard care group. Missing primary outcome data occurred in 73 patients (principally due to withdrawal of consent) and 1531 (95%) were included in the primary analysis population. The median (IQR) age of participants was 39 (26-55) years, 1251 (79%) were men, median (IQR) Injury Severity Score was 29 (18-43), 36% had penetrating injury, and 33% had systolic blood pressure less than 90 mm Hg at hospital arrival. All-cause 28-day mortality in the intention-to-treat population was 26.1% in the standard care group vs 25.3% in the cryoprecipitate group (odds ratio, 0.96 [95% CI, 0.75-1.23]; P = .74). There was no difference in safety outcomes or incidence of thrombotic events in the standard care vs cryoprecipitate group (12.9% vs 12.7%). Conclusions and Relevance: Among patients with trauma and bleeding who required activation of a major hemorrhage protocol, the addition of early and empirical high-dose cryoprecipitate to standard care did not improve all cause 28-day mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT04704869; ISRCTN Identifier: ISRCTN14998314.

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.

Prophylactic Platelet Transfusion: Is There Evidence of Benefit, Harm, or No Effect?

The optimal use of prophylactic platelet transfusion remains uncertain in a number of clinical scenarios. Platelet count thresholds have been established in patients with hematologic malignancies, yet thresholds backed by scientific data are limited or do not exist for many patient populations. Clinical scenarios involving transfusion thresholds for thrombocytopenic patients with critical illness, need for surgery or invasive procedures, or those involving specials populations like children and neonates, lack clear evidence for discerning favorable outcomes without undue risk related to platelet transfusion. In addition, while prophylactic platelet transfusions are administered with the goal of enhancing hemostasis, increasing evidence supports critical nonhemostatic roles for platelets related to innate and adaptive immunity, inflammation, and angiogenesis, which may impact patient responses and outcomes. Here we review several recent studies conducted in adult or pediatric patients that highlight the limitations in our current understanding of prophylactic platelet transfusion. Together, these studies underscore the need for additional research, especially in the form of robust randomized clinical trials and integrating additional parameters beyond the platelet count. Future research at the basic, translational, and clinical levels will best define the optimal role for prophylactic transfusion across the lifespan and its broader impact on health and disease.

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.

Do anemia treatments improve quality of life and physical function in patients with myelodysplastic syndromes (MDS)? A systematic review.

Anemia is common in Myelodysplastic Syndromes (MDS). Different anemia treatments have been tested in clinical studies, but the full impact on patients' health-related quality of life (HRQoL) and physical function is unknown. The main aim of this review was to assess whether improvements in anemia are associated with changes in HRQoL/physical function. Twenty-six full-text publications were identified, enrolling 2211 patients: nine randomized trials (RCTs), fourteen non-randomized studies of interventions and three cross-sectional studies. Interventions included: growth factors/erythropoiesis-stimulating agents (n = 14), red cell transfusion (n = 9), erythroid maturation agents (n = 1), or a combination (n = 2). Five RCTs reported no changes in HRQoL despite erythroid response to the intervention, raising the question of whether anemia treatment alone can effectively improve HRQoL. Many studies were considered at high risk of bias for assessing HRQoL. There is a pressing need for future clinical trials to better define the nature of the relationship between anemia and HRQoL/functional outcomes.