Rational and design of the T-STORHM Study: A prospective randomized trial comparing fresh whole blood to blood components for acutely bleeding trauma patients

The first two years of the use of low titer group O whole blood during French Military overseas operations: A retrospective study

BACKGROUND

On the battlefield, hemorrhage is the main cause of potentially preventable death. To reduce mortality due to hemorrhagic injuries, the French Military Medical Service (FMMS) has deployed low titer group O whole blood (LTOWB) since June 2021 during operation BARKHANE in the Sahel-Saharan strip. Questions persist regarding the circumstances under which the FMMS employs LTOWB during overseas operations.

STUDY DESIGN

We performed a retrospective analysis of all LTOWB transfused by the FMMS during overseas operations in the Sahel-Saharan strip between June 1, 2021, and June 1, 2023. Information was collected from battlefield forward transfusion sheets.

RESULTS

Over the 2-year study period, 40 units of LTOWB were transfused into 25 patients. Of the 25 patients, 18 were combat casualties and seven were transfused for non-trauma surgery. Of the 40 units of LTOWB transfused, 22 were provided during Role 2 care, 11 during tactical medical evacuation (MEDEVAC), and seven in light and mobile surgical units. Among combat casualties, LTOWB was the first blood product transfused in 13 patients. In combat casualties, 6 h post-trauma, the median ratio of plasma: red blood cells (RBCs) was 1.5, and the median equivalent platelet concentrate (PC) transfused was 0.17. No immediate adverse events related to LTOWB transfusion were reported.

CONCLUSION

LTOWB is transfused by the FMMS during overseas operations from the tactical MEDEVAC until Role 2 care. Deployment of LTOWB by the FMMS enables an early high-ratio plasma/RBC transfusion and an early platelet transfusion for combat casualties.

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.

Development of a national out-of-hospital transfusion protocol: a modified RAND Delphi study

BACKGROUND

Early resuscitation with blood components or products is emerging as best practice in selected patients with trauma and medical patients; as a result, out-of-hospital transfusion (OHT) programs are being developed based on limited and often conflicting evidence. This study aimed to provide guidance to Canadian critical care transport organizations on the development of OHT protocols.

METHODS

The study period was July 2021 to June 2022. We used a modified RAND Delphi process to achieve consensus on statements created by the study team guiding various aspects of OHT in the context of critical care transport. Purposive sampling ensured representative distribution of participants in regard to geography and relevant clinical specialties. We conducted 2 written survey Delphi rounds, followed by a virtual panel discussion (round 3). Consensus was defined as a median score of at least 6 on a Likert scale ranging from 1 ("Definitely should not include") to 7 ("Definitely should include"). Statements that did not achieve consensus in the first 2 rounds were discussed and voted on during the panel discussion.

RESULTS

Seventeen subject experts participated in the study, all of whom completed the 3 Delphi rounds. After the study process was completed, a total of 39 statements were agreed on, covering the following domains: general oversight and clinical governance, storage and transport of blood components and products, initiation of OHT, types of blood components and products, delivery and monitoring of OHT, indications for and use of hemostatic adjuncts, and resuscitation targets of OHT.

INTERPRETATION

This expert consensus document provides guidance on OHT best practices. The consensus statements should support efficient and safe OHT in national and international critical care transport programs.

Transfusion management in the trauma patient

PURPOSE OF REVIEW

Transfusion of blood products is lifesaving in the trauma ICU. Intensivists must be familiar with contemporary literature to develop the optimal transfusion strategy for each patient.

RECENT FINDINGS

A balanced ratio of red-blood cells to plasma and platelets is associated with improved mortality and has therefore become the standard of care for resuscitation. There is a dose-dependent relationship between units of product transfused and infections. Liquid and freeze-dried plasma are alternatives to fresh frozen plasma that can be administered immediately and may improve coagulation parameters more rapidly, though higher quality research is needed. Trauma induced coagulopathy can occur despite a balanced transfusion, and administration of prothrombin complex concentrate and cryoprecipitate may have a role in preventing this. In addition to balanced ratios, viscoelastic guidance is being increasingly utilized to individualize component transfusion. Alternatively, whole blood can be used, which has become the standard in military practice and is gaining popularity at civilian centers.

SUMMARY

Hemorrhagic shock is the leading cause of death in trauma. Improved resuscitation strategy has been one of the most important contemporary advancements in trauma care and continues to be a key area of clinical research.

Step by step transfusion timeline and its challenges in trauma: A retrospective study in a level one trauma center

BACKGROUND

Hemorrhagic shock is the leading cause of preventable early death in trauma patients. Transfusion management is guided by international guidelines promoting early and aggressive transfusion strategies. This study aimed to describe transfusion timelines in a trauma center and to identify key points to performing early and efficient transfusions.

METHODS

This is a monocentric retrospective study of 108 severe trauma patients, transfused within the first 48 h and hospitalized in an intensive care unit between January 2017 and May 2019.

RESULTS

One hundred and eight patients were transfused with 1250 labile blood products. Half of these labile blood products were transfused within 3 h of admission and consumed by 26 patients requiring massive transfusion (≥4 red blood cells [RBC] within 1 h). Among these, the median delay from patient's admission to labile blood products prescription was -11 min (-34 to -1); from admission to delivery of labile blood products was 1 min (-20 to 16); and from admission to first transfusion was 20 min (7-37) for RBC, 26 min (13-38) for plasma, and 72 min (51-103) for platelet concentrates. The anticipated prescription of labile blood products and the use of massive transfusion packs and lyophilized plasma units were associated with earlier achievement of high transfusion ratios.

CONCLUSION

This study provides detailed data on the transfusion timelines and composition, from prescription to initial transfusion. Transfusion anticipation, use of preconditioned transfusion packs including platelets, and lyophilized plasma allow rapid and high-ratio transfusion practices in severe trauma patients.

There and Back Again: The Once and Current Developments in Donor-Derived Platelet Products for Products for Hemostatic Therapy

Over 100 years ago, Duke transfused whole blood to a thrombocytopenic patient to raise the platelet count and prevent bleeding. Since then, platelet transfusions have undergone numerous modifications from whole blood-derived platelet-rich plasma to apheresis-derived platelet concentrates. Similarly, the storage time and temperature have changed. The mandate to store platelets for a maximum of 5-7 days at room temperature has been challenged by recent clinical trial data, ongoing difficulties with transfusion-transmitted infections, and recurring periods of shortages, further exacerbated by the COVID-19 pandemic. Alternative platelet storage approaches are as old as the first platelet transfusions. Cold-stored platelets may offer increased storage times (days) and improved hemostatic potential at the expense of reduced circulation time. Frozen (cryopreserved) platelets extend the storage time to years but require storage at -80 °C and thawing before transfusion. Lyophilized platelets can be powder-stored for years at room temperature and reconstituted within minutes in sterile water but are probably the least explored alternative platelet product to date. Finally, whole blood offers the hemostatic spectrum of all blood components but has challenges, such as ABO incompatibility. While we know more than ever before about the in vitro properties of these products, clinical trial data on these products are accumulating. The purpose of this review is to summarize the findings of recent preclinical and clinical studies on alternative, donor-derived platelet products.

Prehospital Whole Blood Transfusion Programs in Norway

BACKGROUND

Prehospital management of severe hemorrhage has evolved significantly in Norwegian medical emergency services in the last 10 years. Treatment algorithms for severe bleeding were previously focused on restoration of the blood volume by administration of crystalloids and colloids, but now the national trauma system guidelines recommend early balanced transfusion therapy according to remote damage control resuscitation principles.

MATERIALS AND METHODS

This survey describes the implementation, utilization, and experience of the use of low titer group O whole blood (LTOWB) and blood components in air ambulance services in Norway. Medical directors from all air ambulance bases in Norway as well as the blood banks that support LTOWB were invited to participate.

RESULTS

Medical directors from all 13 helicopter emergency medical services (HEMS) bases, the 7 search and rescue (SAR) helicopter bases, and the 4 blood banks that support HEMS with LTOWB responded to the survey. All HEMS and SAR helicopter services carry LTOWB or blood components. Four of 20 (20%) HEMS bases have implemented LTOWB. A majority of services (18/20, 90%) have a preference for LTOWB, primarily because LTOWB enables early balanced transfusion and has logistical benefits in time-critical emergencies and during prolonged evacuations.

CONCLUSION

HEMS services and blood banks report favorable experiences in the implementation and utilization of LTOWB. Prehospital balanced blood transfusion using whole blood is feasible in Norway.

Hemostatic Resuscitation in Children

Trauma is a major source of morbidity and mortality for children worldwide; life-threatening hemorrhage is a primary cause of preventable death. Essential interventions in children with life-threatening hemorrhage include hemostatic resuscitation and mechanical control of bleeding. Herein we review pediatric hemostatic resuscitation, a strategy that addresses both hemorrhagic shock and the coagulopathic complications described in patients with major hemorrhage. Some components of hemostatic resuscitation may include: early and aggressive resuscitation with blood products, minimizing crystalloid and hemodilution, antifibrinolytic adjuncts such as tranexamic acid, and the novel use of low-titer group O whole-blood (LTOWB) transfusion in injured children. The following selection of important publications address the current state of hemostatic resuscitation strategies in pediatric trauma patients as well as the remaining knowledge gaps and areas for further research.

Whole Blood Transfusion: Past, Present, and Future

Transfusion of whole blood largely was replaced by component therapy in the 1970s and 1980s. The recent military operations in Iraq and Afghanistan returned whole blood to military trauma care. Eventually, whole blood use was incorporated into some civilian trauma care. It has been utilized in several other civilian populations as well. Trials to compare whole blood to component therapy are ongoing.

The rebirth of the cool: a narrative review of the clinical outcomes of cold stored low titer group O whole blood recipients compared to conventional component recipients in trauma

There has been renewed interest in the use of low titer group O whole blood (LTOWB) for the resuscitation of civilian casualties. LTOWB offers several advantages over conventional components such as providing balanced resuscitation in one bag that contains less additive/preservative solution than an equivalent volume of conventional components, is easier and faster to transfuse than multiple components, avoids blood product ratio confusion, contains cold stored platelets, and reduces donor exposures. The resurgence in its use in the resuscitation of civilian trauma patients has led to the publication of an increasing number of studies on its use, primarily amongst adult recipients but also in pediatric patients. These studies have indicated that hemolysis does not occur amongst adult and pediatric non-group O recipients of a modest quantity of LTOWB. The published studies to date on mortality have shown conflicting results with some demonstrating a reduction following LTOWB transfusion while most others have not shown a reduction; there have not been any studies to date that have found significantly increased overall mortality amongst LTOWB recipients. Similarly, when other clinical outcomes, such as venous thromboembolism, sepsis, hospital or intensive care unit lengths of stay are evaluated, LTOWB recipients have not demonstrated worse outcomes compared to conventional component recipients. While definitive proof of the trends in these morbidity and mortality outcomes awaits confirmation in randomized controlled trials, the evidence to date indicates the safety of transfusing LTOWB to injured civilians.

Viscoelastic monitoring in trauma resuscitation

BACKGROUND

Traumatic injury results in both physical and physiologic insult. Successful care of the trauma patient depends upon timely correction of both physical and biochemical injury. Trauma-induced coagulopathy is a derangement of hemostasis and thrombosis that develops rapidly and can be fatal if not corrected. Viscoelastic monitoring (VEM) assays have been developed to provide rapid, accurate, and relatively comprehensive depictions of an individual's coagulation profile. VEM are increasingly being integrated into trauma resuscitation guidelines to provide dynamic and individualized guidance to correct coagulopathy.

STUDY DESIGN AND METHODS

We performed a narrative review of the search terms viscoelastic, thromboelastography, thromboelastometry, TEG, ROTEM, trauma, injury, resuscitation, and coagulopathy using PubMed. Particular focus was directed to articles describing algorithms for management of traumatic coagulopathy based on VEM assay parameters.

RESULTS

Our search identified 16 papers with VEM-guided resuscitation strategies in adult patients based on TEG, 12 such protocols in adults based on ROTEM, 1 protocol for children based on TEG, and 2 protocols for children based on ROTEM.

CONCLUSIONS

This review presents evidence to support VEM use to detect traumatic coagulopathy, discusses the role of VEM in trauma resuscitation, provides a summary of proposed treatment algorithms, and discusses pending questions in the field.

Guidelines for Reporting Trial Protocols and Completed Trials Modified Due to the COVID-19 Pandemic and Other Extenuating Circumstances: The CONSERVE 2021 Statement

IMPORTANCE

Extenuating circumstances can trigger unplanned changes to randomized trials and introduce methodological, ethical, feasibility, and analytical challenges that can potentially compromise the validity of findings. Numerous randomized trials have required changes in response to the COVID-19 pandemic, but guidance for reporting such modifications is incomplete.

OBJECTIVE

As a joint extension for the CONSORT and SPIRIT reporting guidelines, CONSERVE (CONSORT and SPIRIT Extension for RCTs Revised in Extenuating Circumstances) aims to improve reporting of trial protocols and completed trials that undergo important modifications in response to extenuating circumstances.

EVIDENCE

A panel of 37 international trial investigators, patient representatives, methodologists and statisticians, ethicists, funders, regulators, and journal editors convened to develop the guideline. The panel developed CONSERVE following an accelerated, iterative process between June 2020 and February 2021 involving (1) a rapid literature review of multiple databases (OVID Medline, OVID EMBASE, and EBSCO CINAHL) and gray literature sources from 2003 to March 2021; (2) consensus-based panelist meetings using a modified Delphi process and surveys; and (3) a global survey of trial stakeholders.

FINDINGS

The rapid review yielded 41 673 citations, of which 38 titles were relevant, including emerging guidance from regulatory and funding agencies for managing the effects of the COVID-19 pandemic on trials. However, no generalizable guidance for all circumstances in which trials and trial protocols might face unanticipated modifications were identified. The CONSERVE panel used these findings to develop a consensus reporting guidelines following 4 rounds of meetings and surveys. Responses were received from 198 professionals from 34 countries, of whom 90% (n = 178) indicated that they understood the concept definitions and 85.4% (n = 169) indicated that they understood and could use the implementation tool. Feedback from survey respondents was used to finalize the guideline and confirm that the guideline's core concepts were applicable and had utility for the trial community. CONSERVE incorporates an implementation tool and checklists tailored to trial reports and trial protocols for which extenuating circumstances have resulted in important modifications to the intended study procedures. The checklists include 4 sections capturing extenuating circumstances, important modifications, responsible parties, and interim data analyses.

CONCLUSIONS AND RELEVANCE

CONSERVE offers an extension to CONSORT and SPIRIT that could improve the transparency, quality, and completeness of reporting important modifications to trials in extenuating circumstances such as COVID-19.

Whole truths but half the blood: Addressing the gap between the evidence and practice of pre-hospital and in-hospital blood product use for trauma resuscitation

BACKGROUND

In recent years, several studies have demonstrated the efficacy of using pre-hospital blood product and in-hospital whole blood for trauma resuscitation. While some observations suggest an encouraging uptake of this evidence by emergency medical service (EMS) agencies and trauma centers, a nationwide characterization of blood product utilization for bleeding trauma patients remains unknown. The objective of this study is to determine nationwide estimates of pre-hospital blood product and in-hospital whole blood utilization for trauma resuscitation.

STUDY DESIGN AND METHODS

All adult trauma patients reported to the National Emergency Medical Services Information System (NEMSIS) dataset 2019 were included. Proportions of patients who received any pre-hospital blood product were calculated. The American College of Surgeons (ACS) Trauma Quality Programs (TQP) databases 2015-2017 and first quarter of 2020 were used to calculate the proportion of ACS-verified trauma centers that transfused whole blood.

RESULTS

Among a total of 3,058,804 pre-hospital trauma patients, only 313 (0.01%) received any blood transfusion; 208 (0.21%) patients with systolic blood pressure (SBP) ≤90 mmHg and 121 (0.67%) patients with SBP ≤90 mmHg and heart rate ≥120 beats per minute received any blood product. The proportion of ACS-verified trauma centers transfusing whole blood increased from 16.7% (45/269) in 2015 to 24.5% (123/502) in first quarter of 2020.

DISCUSSION

Despite strong evidence and recommendations, pre-hospital utilization of blood products for trauma resuscitation remains low. Additionally, while the overall in-hospital whole blood use also remains low, its use has increased at ACS-verified trauma centers over the past 5 years.

Blood product needs and transfusion timelines for the multisite massive Paris 2015 terrorist attack: A retrospective analysis

OBJECTIVE

Hemorrhage is the leading cause of death after terrorist attack, and the immediacy of labile blood product (LBP) administration has a decisive impact on patients' outcome. The main objective of this study was to evaluate the transfusion patterns of the Paris terrorist attack victims, November 13, 2015.

METHODS

We performed a retrospective analysis including all casualties admitted to hospital, aiming to describe the transfusion patterns from admission to the first week after the attack.

RESULTS

Sixty-eight of 337 admitted patients were transfused. More than three quarters of blood products were consumed in the initial phase (until November 14, 11:59 PM), where 282 packed red blood cell (pRBC) units were transfused along with 201 plasma and 25 platelet units, to 55 patients (16% of casualties). Almost 40% of these LBPs (134 pRBC, 73 plasma, 8 platelet units) were transfused within the first 6 hours after the attack. These early transfusions were massive transfusion (MT) for 20 (6%) of 337 patients, and the average plasma/red blood cell ratio was 0.8 for MT patients who received 366 (72%) of 508 LBPs.The median time from admission to pRBC transfusion was 57 (25-108) minutes and 208 (52-430) minutes for MT and non-MT patients, respectively. These same time intervals were 119 (66-202) minutes and 222 (87-381) minutes for plasma and 225 (131-289) minutes and 198 (167-230) minutes for platelets.

CONCLUSION

Our data suggest that improving transfusion procedures in mass casualty setting should rely more on shortening the time to bring LBP to the bedside than in increasing the stockpile.

LEVEL OF EVIDENCE

Epidemiological study, Therapeutic IV.

Fresh whole blood from walking blood banks for patients with traumatic hemorrhagic shock: A systematic review and meta-analysis

BACKGROUND

Whole blood is optimal for resuscitation of traumatic hemorrhage. Walking Blood Banks provide fresh whole blood (FWB) where conventional blood components or stored, tested whole blood are not readily available. There is an increasing interest in this as an emergency resilience measure for isolated communities and during crises including the coronavirus disease 2019 pandemic. We conducted a systematic review and meta-analysis of the available evidence to inform practice.

METHODS

Standard systematic review methodology was used to obtain studies that reported the delivery of FWB (PROSPERO registry CRD42019153849). Studies that only reported whole blood from conventional blood banking were excluded. For outcomes, odds ratios (ORs) and 95% confidence interval (CI) were calculated using random-effects modeling because of high risk of heterogeneity. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation system.

RESULTS

Twenty-seven studies published from 2006 to 2020 reported >10,000 U of FWB for >3,000 patients (precise values not available for all studies). Evidence for studies was "low" or "very low" except for one study, which was "moderate" in quality. Fresh whole blood patients were more severely injured than non-FWB patients. Overall, survival was equivalent between FWB and non-FWB groups for eight studies that compared these (OR, 1.00 [95% CI, 0.65-1.55]; p = 0.61). However, the highest quality study (matched groups for physiological and injury characteristics) reported an adjusted OR of 0.27 (95% CI, 0.13-0.58) for mortality for the FWB group (p < 0.01).

CONCLUSION

Thousands of units of FWB from Walking Blood Banks have been transfused in patients following life-threatening hemorrhage. Survival is equivalent for FWB resuscitation when compared with non-FWB, even when patients were more severely injured. Evidence is scarce and of relative low quality and may underestimate potential adverse events. Whereas Walking Blood Banks may be an attractive resilience measure, caution is still advised. Walking Blood Banks should be subject to prospective evaluation to optimize care and inform policy.

LEVEL OF EVIDENCE

Systematic/therapeutic, level 3.

Quality of Platelets in Stored Whole Blood

Transfusion of whole blood rather than blood components is gaining popularity. It is easy to use, with one transfusion product to administer rather than 3, and is held at one storage temperature. It only contains anticoagulant-preservative solution, while components contain various storage solutions, which in theory may induce dilution coagulopathy. In this review, the quality of platelets in stored whole blood is summarized. In cold-stored whole blood, the platelet count declines by 1% to 2% per day. The responsiveness to various agonists declines during the storage time, but this appears to have a limited impact on clotting time or on clot strength as measured with thromboelastography. Animal studies have confirmed that platelets from stored whole blood participate equally well in clot formation. The recovery of platelets in stored whole blood is acceptable during at least 15 days of storage. The survival of platelets after transfusion is only 1 day, but this is likely to be sufficient for the intended patient group requiring massive transfusions, as the platelets are rapidly consumed in the wound area. In addition to the logistic benefits, there are drawbacks, most importantly having a sufficiently large inventory with an acceptable outdating rate, particularly since massive transfusions are rare, while requiring a lot of whole blood. The positive experience of the United States military with whole blood transfusion is often brought forward for introduction in the civilian blood bank, but patients with trauma are only a small fraction of the civilian population requiring massive transfusions. It needs to be determined whether in the resourceful environment of the hospital, these patients benefit from whole blood transfusions. Optimization of whole blood storage, with focus on platelet quality, needs to be performed to allow extension of the storage time beyond 15 days to a point where the number of units in inventory and outdating can be balanced.