Reappraising the concept of massive transfusion in trauma.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.INTRODUCTION: The massive-transfusion concept was introduced to recognize the dilutional complications resulting from large volumes of packed red blood cells (PRBCs). Definitions of massive transfusion vary and lack supporting clinical evidence. Damage-control resuscitation regimens of modern trauma care are targeted to the early correction of acute traumatic coagulopathy. The aim of this study was to identify a clinically relevant definition of trauma massive transfusion based on clinical outcomes. We also examined whether the concept was useful in that early prediction of massive transfusion requirements could allow early activation of blood bank protocols. METHODS: Datasets on trauma admissions over a 1 or 2-year period were obtained from the trauma registries of five large trauma research networks. A fractional polynomial was used to model the transfusion-associated probability of death. A logistic regression model for the prediction of massive transfusion, defined as 10 or more units of red cell transfusions, was developed. RESULTS: In total, 5,693 patient records were available for analysis. Mortality increased as transfusion requirements increased, but the model indicated no threshold effect. Mortality was 9% in patients who received none to five PRBC units, 22% in patients receiving six to nine PRBC units, and 42% in patients receiving 10 or more units. A logistic model for prediction of massive transfusion was developed and validated at multiple sites but achieved only moderate performance. The area under the receiver operating characteristic curve was 0.81, with specificity of only 50% at a sensitivity of 90% for the prediction of 10 or more PRBC units. Performance varied widely at different trauma centers, with specificity varying from 48% to 91%. CONCLUSIONS: No threshold for definition exists at which a massive transfusion specifically results in worse outcomes. Even with a large sample size across multiple trauma datasets, it was not possible to develop a transportable and clinically useful prediction model based on available admission parameters. Massive transfusion as a concept in trauma has limited utility, and emphasis should be placed on identifying patients with massive hemorrhage and acute traumatic coagulopathy.Published versio

Cell salvage and donor blood transfusion during cesarean section: A pragmatic, multicentre randomised controlled trial (SALVO)

BACKGROUND: Excessive haemorrhage at cesarean section requires donor (allogeneic) blood transfusion. Cell salvage may reduce this requirement. METHODS AND FINDINGS: We conducted a pragmatic randomised controlled trial (at 26 obstetric units; participants recruited from 4 June 2013 to 17 April 2016) of routine cell salvage use (intervention) versus current standard of care without routine salvage use (control) in cesarean section among women at risk of haemorrhage. Randomisation was stratified, using random permuted blocks of variable sizes. In an intention-to-treat analysis, we used multivariable models, adjusting for stratification variables and prognostic factors identified a priori, to compare rates of donor blood transfusion (primary outcome) and fetomaternal haemorrhage ≥2 ml in RhD-negative women with RhD-positive babies (a secondary outcome) between groups. Among 3,028 women randomised (2,990 analysed), 95.6% of 1,498 assigned to intervention had cell salvage deployed (50.8% had salvaged blood returned; mean 259.9 ml) versus 3.9% of 1,492 assigned to control. Donor blood transfusion rate was 3.5% in the control group versus 2.5% in the intervention group (adjusted odds ratio [OR] 0.65, 95% confidence interval [CI] 0.42 to 1.01, p = 0.056; adjusted risk difference -1.03, 95% CI -2.13 to 0.06). In a planned subgroup analysis, the transfusion rate was 4.6% in women assigned to control versus 3.0% in the intervention group among emergency cesareans (adjusted OR 0.58, 95% CI 0.34 to 0.99), whereas it was 2.2% versus 1.8% among elective cesareans (adjusted OR 0.83, 95% CI 0.38 to 1.83) (interaction p = 0.46). No case of amniotic fluid embolism was observed. The rate of fetomaternal haemorrhage was higher with the intervention (10.5% in the control group versus 25.6% in the intervention group, adjusted OR 5.63, 95% CI 1.43 to 22.14, p = 0.013). We are unable to comment on long-term antibody sensitisation effects. CONCLUSIONS: The overall reduction observed in donor blood transfusion associated with the routine use of cell salvage during cesarean section was not statistically significant. TRIAL REGISTRATION: This trial was prospectively registered on ISRCTN as trial number 66118656 and can be viewed on http://www.isrctn.com/ISRCTN66118656

Cell salvage and donor blood transfusion during Caesarean section: a pragmatic multicentre randomised controlled trial (SALVO)

Background: Excessive haemorrhage at caesarean section requires donor (allogeneic) blood transfusion. Cell 34 salvage may reduce this requirement. Methods and findings: We conducted a pragmatic randomised controlled trial (26 obstetric units; June 2013 through April 2016) of routine cell salvage use (intervention) vs. current standard of care without routine salvage use (control) in caesarean section among women at risk of haemorrhage. Randomisation was stratified, using random permuted blocks of variable sizes. In an intention-to-treat analysis, we used multivariable models, adjusting for stratification variables and prognostic factors identified a priori, to compare rates of donor blood transfusion (primary outcome) and fetomaternal haemorrhage ≥2ml in RhD-negative women with RhD-positive baby (a secondary outcome) between groups. Among 3028 women randomised (2990 analysed), 95.6% of 1498 assigned to intervention had cell salvage deployed (50.8% had salvaged blood returned; mean 259.9 ml) vs. 3.9% of 1492 assigned to control. Donor blood transfusion rates were 3.5% in the control group vs. 2.5% in intervention (adjusted odds ratio [OR] 0.65, 95% confidence interval [CI] 0.42 to 1.01, p=0.056; adjusted risk difference -1.03, 95% CI -2.13 to 0.06; number needed to treat [NNT] 97, at the lower limit of 95% confidence NNT was 47 and at the upper limit the number needed to harm was 1,667). In a planned subgroup analysis, the transfusion rate was 4.6% in women assigned to control vs. 3.0% in the intervention group among emergency caesareans (adjusted OR 0.58, 95% CI 0.34 to 0.99), whereas it was 2.2% vs. 1.8% among elective caesareans (adjusted OR 0.83, 95% CI 0.38 to 1.83) (interaction p=0.46). No case of amniotic fluid embolism was observed. Fetomaternal haemorrhage was higher with intervention (10.5% in control vs. 25.6% in intervention, adjusted OR 5.63, 95% CI 1.43 to 22.14, p=0.013). We are unable to comment on long-term antibody sensitisation effects. Conclusions: The overall reduction observed in donor blood transfusion associated with the routine use of cell salvage during caesarean section was not statistically significant

Blood transfusion: safety, optimisation and new advances

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Insights from developing and evaluating the NHS blood choices transfusion app to support junior and middle-grade doctor decision making against guidelines.

Objectives: To: 1. Develop a CE-marked smartphone App to support doctors' concordance with transfusion guidelines in non-bleeding adult patients, emphasising informed consent and anaemia management. 2. Test App accuracy and potential to improve user decisions. Background: Studies have shown inappropriate use of blood components and that most junior doctors own smartphones with medical apps. Methods: A multidisciplinary team developed App screens and logic through an iterative process based on national guidelines. Thirty medical or surgical transfusion scenarios were developed based on national guidelines and each sent to Consultant Haematologist experts in Transfusion Medicine. To obtain a clinical consensus and exclude ambiguous scenarios, their independent decisions and associated certainty were compared. The consensus clinical decision was then compared with guidance from the App. To explore potential App impact on simulated user decisions, 26 junior doctors responded to five transfusion scenarios before and after access to the App. Results: The Blood Choices App agreed with 91% (95% CI: 72%–99%) of expert decisions with a sensitivity of 100% (69% to 100%) and specificity of 85% (55%–98%). Excluding one malfunction scenario, the App had the potential to increase correct decisions by junior doctors from 83% (73%–90%) pre-App use to 96% (88%–99%) post (p-value 0.013), with 90% (67%–99%) saying they would use it in practice. Conclusions: Transfusion guidelines can be converted into an App with potential to improve guideline concordance. However, evaluating such Apps is essential to understand their limitations, detect malfunctions and prevent harm

Gaps in the evidence for prevention and treatment of maternal anaemia:a review of systematic reviews

<p>Abstract</p> <p>Background</p> <p>Anaemia, in particular due to iron deficiency, is common in pregnancy with associated negative outcomes for mother and infant. However, there is evidence of significant variation in management. The objectives of this review of systematic reviews were to analyse and summarise the evidence base, identify gaps in the evidence and develop a research agenda for this important component of maternity care.</p> <p>Methods</p> <p>Multiple databases were searched, including MEDLINE, EMBASE and <it>The Cochrane Library.</it> All systematic reviews relating to interventions to prevent and treat anaemia in the antenatal and postnatal period were eligible. Two reviewers independently assessed data inclusion, extraction and quality of methodology.</p> <p>Results</p> <p>27 reviews were included, all reporting on the prevention and treatment of anaemia in the antenatal (n = 24) and postnatal periods (n = 3). Using AMSTAR as the assessment tool for methodological quality, only 12 of the 27 were rated as high quality reviews. The greatest number of reviews covered antenatal nutritional supplementation for the prevention of anaemia (n = 19). Iron supplementation was the most extensively researched, but with ongoing uncertainty about optimal dose and regimen. Few identified reviews addressed anaemia management post-partum or correlations between laboratory and clinical outcomes, and no reviews reported on clinical symptoms of anaemia.</p> <p>Conclusions</p> <p>The review highlights evidence gaps including the management of anaemia in the postnatal period, screening for anaemia, and optimal interventions for treatment. Research priorities include developing standardised approaches to reporting of laboratory outcomes, and information on clinical outcomes relevant to the experiences of pregnant women.</p

The EHA Research Roadmap : Transfusion Medicine

International audienceTransfusion medicine is a broad discipline, encompassing not just use of blood components, but many areas of donor recruitment and safeguarding, apheresis, and novel cellular therapies. This roadmap provides a framework for discussion of research priorities in transfusion medicine moving forward. Although one could highlight many future research areas of direct relevance to donor and patient care, important themes remain centered on minimizing risks to patients and donors, and for the development of stratified or personalized transfusion strategies. It is clear that wide-scale genetic typing of donors and patients can now be delivered at low-cost, and the introduction of these technologies heralds a new era for transfusion medicine, which has been grounded in serological tests