Red Blood Cell Transfusion in European Neonatal Intensive Care Units, 2022 to 2023.

Importance: Red blood cell (RBC) transfusions are frequently administered to preterm infants born before 32 weeks of gestation in the neonatal intensive care unit (NICU). Two randomized clinical trials (Effects of Transfusion Thresholds on Neurocognitive Outcomes of Extremely Low-Birth-Weight Infants [ETTNO] and Transfusion of Prematures [TOP]) found that liberal RBC transfusion thresholds are nonsuperior to restrictive thresholds, but the extent to which these results have been integrated into clinical practice since publication in 2020 is unknown. Objective: To describe neonatal RBC transfusion practice in Europe. Design, Setting, and Participants: This international prospective observational cohort study collected data between September 1, 2022, and August 31, 2023, with a 6-week observation period per center, from 64 NICUs in 22 European countries. Participants included 1143 preterm infants born before 32 weeks of gestation. Exposure: Admission to the NICU. Main Outcomes and Measures: Study outcome measures included RBC transfusion prevalence rates, cumulative incidence, indications, pretransfusion hemoglobin (Hb) levels, volumes, and transfusion rates, Hb increment, and adverse effects of RBC transfusion. Results: A total of 1143 preterm infants were included (641 male [56.1%]; median gestational age at birth, 28 weeks plus 2 days [IQR, 26 weeks plus 2 days to 30 weeks plus 2 days]; median birth weight, 1030 [IQR, 780-1350] g), of whom 396 received 1 or more RBC transfusions, totaling 903 transfusions. Overall RBC transfusion prevalence rate during postnatal days 1 to 28 was 3.4 transfusion days per 100 admission days, with considerable variation across countries, only partly explained by patient mix. By day 28, 36.5% (95% CI, 31.6%-41.5%) of infants had received at least 1 transfusion. Most transfusions were given based on a defined Hb threshold (748 [82.8%]). Hemoglobin levels before transfusions indicated for threshold were below the restrictive thresholds set by ETTNO in 324 of 729 transfusions (44.4%) and TOP in 265 of 729 (36.4%). Conversely, they were between restrictive and liberal thresholds in 352 (48.3%) and 409 (56.1%) transfusions, respectively, and above liberal thresholds in 53 (7.3%) and 55 (7.5%) transfusions, respectively. Most transfusions given based on threshold had volumes of 15 mL/kg (470 of 738 [63.7%]) and were administered over 3 hours (400 of 738 [54.2%]), but there was substantial variation in dose and duration. Conclusions and Relevance: In this cohort study of very preterm infants, most transfusions indicated for threshold were given for pretransfusion Hb levels above restrictive transfusion thresholds evaluated in recent trials. These results underline the need to optimize practices and for implementation research to support uptake of evidence.

Supplemental Iron and Recombinant Erythropoietin for Anemia in Infants Born Very Preterm: A Survey of Clinical Practice in Europe.

OBJECTIVES: To survey practices of iron and recombinant human erythropoietin (rhEpo) administration to infants born preterm across Europe. STUDY DESIGN: Over a three-month period, we conducted an online survey in 597 neonatal intensive care units (NICUs) of 18 European countries treating infants born with a gestational age (GA) <32 weeks. RESULTS: 343 NICUs (response rate 56·3%) completed the survey. Almost all (97·7%) NICUs routinely supplement enteral iron, and 74·3% of respondents to all infants born <32 weeks' GA. 65·3% of NICUs routinely evaluate erythropoiesis and iron parameters beyond day 28 after birth. Most NICUs initiate iron supplementation at postnatal age of two weeks and stop after 6 (34·3%) or 12 months (34·3%). Routine use of rhEpo was reported in 22·2% of NICUs, and in individual cases in 6·9%. RhEpo was mostly administered subcutaneously (70·1%) and most frequently at a dose of 250 U/kg 3 times a week (44·3%), but the dose varied greatly between centers. CONCLUSION: This survey highlights wide heterogeneity in evaluating erythropoietic activity and iron deficiency in infants born preterm. Variation in iron supplementation during infancy likely reflects an inadequate evidence base. Current evidence on the efficacy and safety profile of rhEpo is only poorly translated into clinical practice. This survey demonstrates a need for standards to optimize patient blood management in anemia of prematurity.

Desmopressin for prevention of bleeding for thrombocytopenic, critically ill patients undergoing invasive procedures: A randomised, double-blind, placebo-controlled feasibility trial.

Thrombocytopenic patients have an increased risk of bleeding when undergoing invasive procedures. In a multicentre, phase II, blinded, randomised, controlled feasibility trial, critically ill patients with platelet count 100 × 109/L or less were randomised 1:1 to intravenous desmopressin (0.3 µg/kg) or placebo before an invasive procedure. Forty-three participants (18.8% of those eligible) were recruited, with 41 eligible for analysis. Post-procedure bleeding occurred in one of 22 (4.5%) in the placebo arm and zero of 19 in the desmopressin arm. Despite liberal inclusion criteria, there were significant feasibility challenges recruiting patients in the critical care setting prior to invasive procedures.

Trauma induced coagulopathy is limited to only one out of four shock induced endotheliopathy (SHINE) phenotypes among moderate-severely injured trauma patients: an exploratory analysis.

BACKGROUND: Trauma induced coagulopathy remains to be an important cause of high transfusion requirements and mortality and shock induced endotheliopathy (SHINE) has been implicated. METHODS: European multicenter observational study of adult trauma patients with injury severity score ≥ 16 arriving within 2 h from injury to the trauma centers. Admission blood samples obtained were used for analysis of the SHINE biomarkers (syndecan-1, soluble thrombomodulin, adrenaline) and extensive analysis of coagulation, -and fibrinolytic factors together with collection of clinical data. Hierarchical clustering of the SHINE biomarkers was used to identify the SHINE phenotypes. RESULTS: The 313 patients clustered into four SHINE phenotypes. Phenotype 2, having the highest glycocalyx shedding, encompassing 22% of the whole cohort, had severe coagulopathy with lower levels of prothrombin, FV, IX, X, XI and severe hyperfibrinolysis with higher plasmin - alpha 2-antiplasmin (PAP) - and tPA levels and lower alpha2 - antiplasmin levels. This phenotype had significantly higher transfusion requirements and higher mortality (39% vs. 23%, 15% and 14%) but similar injury severity score (ISS) compared to the others phenotypes. CONCLUSIONS: Hierarchical clustering identified four SHINE phenotype in a cohort of trauma patients. Trauma induced coagulopathy was confined to only one of the SHINE phenotypes, encompassing 22% of the total cohort. This phenotype was characterized by severe hypocoagulability and hyperfibrinolysis, which translated to significantly higher transfusion requirements and higher mortality compared to the other SHINE phenotypes with similar injury severity, warranting further investigation.

The impact of different doses of oral iron supplementation during pregnancy: a pilot randomized trial.

The burden of iron-deficiency anemia remains significant during pregnancy. Oral iron is first-line medication, but there is uncertainty about a range of factors including adherence and side-effects of different doses. We conducted a pilot randomized trial to investigate the impact of different doses of oral iron supplementation started early in pregnancy, in non-anemic women, for four main outcomes; recruitment and protocol compliance, adherence, maintenance of maternal hemoglobin and side-effects. Participants at antenatal clinic visits were allocated to one of three trial arms, in a 1:1:1 ratio, as 200mg ferrous sulphate daily, alternate days or three-times per week, with follow-up to delivery. Baseline characteristics of 300 recruited participants were well matched between trial arms. The mean proportion of tablets taken as expected per participant was 82.5% overall (72.3%, 89.6% and 84.5% for the daily, alternate days and three-times a week arm, respectively). There was a lower overall adherence rate in the daily arm (47%) compared with alternate days (62%) and three times per week (61%). Reduction in hemoglobin between randomization and 28 weeks appeared smaller for the daily arm. A range of side-effects were commonly reported at baseline before starting interventions, and by later antenatal visits. Many side effects of iron overlapped with normal pregnancy symptoms. A daily iron dosing schedule might give the best opportunity for delivering an adequate iron load during pregnancy in non-anemic women. Further randomized trials powered on clinical outcomes are needed to establish the clinical effectiveness of oral iron supplementation to prevent iron deficiency anemia. (ISRCTN12911644).

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.

Impact of patient demographics on treatment outcomes in AML: a population-based registry in England, 2013-2020.

ABSTRACT: We report 1- and 5-year survival after acute myeloid leukemia (AML) diagnosis and early mortality within 30 days of systemic anticancer therapy (SACT) treatments, using national cancer registry data in England. Patients aged 18 to 99 years diagnosed between 2013 and 2020 were included. Overall survival (OS) was calculated using Kaplan-Meier methodology, and adjusted hazard ratios (aHRs; adjusted for intensity of treatment, age at diagnosis, sex, ethnicity, socioeconomic deprivation, comorbidity, and year of diagnosis) using Cox proportional hazards regression. Odds of 30-day mortality (adjusted odds ratios [aORs], adjusted for aforementioned characteristics), along with performance status and body mass index, were calculated using logistic regression. Among 17 107 patients identified, older age and comorbidity were associated with worse survival. Asian and Black patients had better survival than White patients: 5-year OS of 34.6%, 29.7%, and 17.8%, respectively; aHR of 0.86; (95% confidence interval [CI], 0.77-0.96) Asian vs White, and 0.84 (95% CI, 0.73-0.96) Black vs White. Socioeconomic deprivation was associated with worse survival. Overall, 7906 (46.2%) patients were documented as having received SACT. Thirty-day mortality was lower for patients receiving intensive rather than nonintensive SACT. After adjustment for cofactors, the risk was higher in those treated intensively (aOR, 0.74; 95% CI, 0.60-0.92). We show that ethnicity and socioeconomic status affects outcomes in AML. Further work is needed to understand how these effects may differ in different health care settings, and whether this because of effects on disease biology, responsiveness to treatment, or drug toxicity. Selection of intensive vs nonintensive treatment should be based on individual patient factors, balancing improved long-term survival against higher early mortality.

Clinical Practice Guideline for Red Blood Cell Transfusion Thresholds in Very Preterm Neonates.

Importance: Red blood cell (RBC) transfusion is a common medical intervention to treat anemia in very preterm neonates; however, best transfusion practices, such as thresholds, remain uncertain. Objective: To develop recommendations for clinicians on the use of RBC transfusions in very preterm neonates. Evidence Review: An international steering committee reviewed evidence from a systematic review of 6 randomized clinical trials (RCTs) that compared high vs low hemoglobin-based or hematocrit-based transfusion thresholds. The steering committee reached consensus on certainty-of-evidence ratings and worked with a panel from stakeholder organizations on reviewing the evidence. With input from parent representatives and the stakeholder panel, the steering committee used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to develop recommendations. Findings: A systematic review of 6 RCTs encompassing 3483 participants (1759 females [51.3%]; mean [SD] age range, 25.9-29.8 [1.5-3.0] weeks) was used as the basis of the recommendations. The ranges for higher hemoglobin concentration (liberal) vs lower hemoglobin concentration (restrictive) threshold study arms were similar across the trials. However, specific thresholds differed based on the severity of illness, which was defined using variable criteria in the trials. There was moderate certainty of evidence that low transfusion thresholds likely had little to no difference in important short-term and long-term outcomes. The recommended hemoglobin thresholds varied on the basis of postnatal week and respiratory support needs. At postnatal weeks 1, 2, and 3 or more, for neonates on respiratory support, the recommended thresholds were 11, 10, and 9 g/dL, respectively; for neonates on no or minimal respiratory support, the recommended thresholds were 10, 8.5, and 7 g/dL, respectively (to convert hemoglobin to grams per liter, multiply by 10.0). Conclusions and Relevance: This consensus statement recommends a restrictive RBC transfusion strategy, with moderate certainty of evidence, for preterm neonates with less than 30 weeks' gestation.

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.

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.

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.