Expired blood transfusion and mortality outcomes in combat trauma patients.

BACKGROUND: Expired blood can be transfused if clinically indicated but outcome data do not exist. We hypothesized that modestly outdated blood can effectively support a hemorrhaging patient until surgical control is achieved. This study assessed whether expired blood was associated with mortality in combat trauma patients. STUDY DESIGN AND METHODS: A retrospective analysis of Armed Services Blood Program and Department of Defense Trauma Registry databases evaluated combat casualty records (2001-2023). The intervention of interest was transfusion of at least one unit of whole blood (WB), red blood cells (RBC), or platelets within one week past expiration. The outcome of interest was mortality at discharge. A control cohort that only received in-date blood was matched to the treatment cohort for logistic regression analysis. RESULTS: One hundred patients received expired RBCs (86), WB (11), and platelets (3). Mortality at discharge was 11.6% for expired RBC recipients and 13.4% for the control cohort (p = .97). After adjustment for injury severity, expired RBCs were not associated with mortality (OR = 0.40 [95% CI, 0.14-1.16]; p = .09). Of 10 patients who received the most expired RBCs by volume or storage duration, two were deceased at discharge. All 14 expired WB and platelet recipients were alive at discharge, but sample sizes were underpowered for regression analysis. DISCUSSION: Transfusion of modestly outdated RBCs was not associated with mortality in combat trauma patients. Expired WB and platelet recipients did well, but sample sizes were too small to draw significant conclusions. Expired blood should be further investigated for possible use in extenuating circumstances.

Massive transfusion protocol reactivation as a novel marker of physician team under-triage after injury.

BACKGROUND: Large trauma centers have protocols for the assessment of injury and triaging of care with attempts to over-triage to ensure adequate care for all patients. We noted that a significant number of patients undergo a second massive transfusion protocol (MTP) activation in the first 24 h of care and conducted a retrospective cohort study of patients involved over a 3-year period. METHODS: Transfusion service records of MTP activations 2019-2021 were linked to Trauma Registry records and divided into cohorts receiving a single versus a reactivation of the MTP. Time of activation and amounts of blood products issued were linked to demographic, injury severity, and outcome data. Categorical and continuous data were compared between cohorts with chi-squared, Fisher's, and Wilcoxan tests as appropriate, and multivariable regression models were used to seek interactions (p < .05). RESULTS: MTP activation was recorded for 1884 acute trauma patients over our 3-year study period, 142 of whom (7.5%) had reactivation. Factors associated with reactivation included older age (46 vs. 40 years), higher injury severity score (ISS, 27 vs. 22), leg injuries, and presentation during morning shift change (5-7 a.m., 3.3% vs. 7.7%). Patients undergoing MTP reactivation used more RBCs (5 U vs. 2 U) and had more ICU days (3 vs. 2). CONCLUSIONS: Older patients and those presenting during shift change are at risk for failure to recognize their complex injury patterns and under-triage for trauma care. The fidelity and granularity of transfusion service records can provide unique opportunities for quality assessment and improvement in trauma care.

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.

The safety of ABO minor incompatible platelets transfusions using a rapid infuser.

BACKGROUND: Administering platelets through a rapid infuser is proven to be safe. However, the clinical significance of infusing ABO-incompatible platelets with red blood cells (RBCs) in a rapid infuser remains unclear. There is a theoretical risk that isoagglutinin in the plasma of a platelet unit can interact with RBCs and induce hemolysis. MATERIALS AND METHODS: Seven in vitro studies were performed including five cases (type A RBCs and type O platelets) and two controls (type A RBCs and platelets). Anti-A titers were measured in platelet units. An RBC unit and a platelet unit were mixed in the rapid infuser reservoir and incubated for 30 min. The primary outcome was the presence of hemolysis based on the following parameters: free hemoglobin concentration, hemolysis check, direct antiglobulin test (DAT), and direct agglutination. RESULTS: The post-mix DAT was positive for IgG in all test samples (5/5), and weakly positive for complement in 3/5. The changes in free Hb in test cases between measured and calculated post-mix spanned -2.2 to +3.4 mg/dL. Post-mix hemolysis check was negative in 3/5 and slightly positive in 2/5 cases, with no significant differences compared to the control case. Anti-A titers ranged from 16 to 512 and were not associated with hemolysis. All samples were negative for direct agglutination. CONCLUSION: Our study suggested that mixing ABO-incompatible platelets with RBCs in a rapid infuser does not induce in vitro hemolysis. These findings support the use of rapid infusers regardless of platelet compatibility in support of hemostatic resuscitation.

Novel method for determining when a field-collected donor unit is sufficiently full.

BACKGROUND: Whole blood (WB) collections can occur downrange for immediate administration. An important aspect of these collections is determining when the unit is sufficiently full. This project tested a novel method for determining when a field collection is complete. METHODS: The amount of empty space at the top of WB units, destined to become LTOWB or separated into components, that were collected at blood centers or hospitals was measured by holding a WB unit off the ground and placing the top of a piece of string where the donor tubing entered the bag. The string was marked where it intersected the top of the column of blood in the bag and measured from the top. The WB units were also weighed. RESULTS: A total of 15 different bags, two of which were measured in two different filling volumes, from 15 hospitals or blood centers were measured and weighed. The most commonly used blood bag, Terumo Imuflex SP, had a median string length of 9 mm (range: 2-24 mm) and weighed a median of 565.1 g (range: 524.8-636.7 g). CONCLUSION: Pieces of string can be precut to the appropriate length depending on the type of bag before a mission where field WB collections might be required and a mark placed on the bag before the collection commences to indicate when the unit is full.

Effects of pre-freeze pathogen reduction with riboflavin and UV light on red cells stored post-thaw in AS-3 additive solution.

BACKGROUND: Pathogen reduction technology (PRT) may improve the safety of RBCs for transfusion. As the Czech Republic considers PRT, we asked what effects riboflavin and UV light PRT pre-freezing has on the post-thaw recovery and properties of cryopreserved RBCs (CRBCs) after deglycerolization and liquid storage. STUDY DESIGN AND METHODS: 24 Group O whole blood (WB) units were leukoreduced and then treated with riboflavin and UV light PRT (Mirasol, Terumo BCT, USA) before cryopreservation (T-CRBC); 20 similarly-collected units were untreated controls (C-CRBC). Units were processed to RBCs and then cryopreserved with 40% glycerol (wt/vol), frozen at -80°C, stored >118 days, reconstituted as deglycerolized RBC units in AS-3, and stored at 4 ± 2°C for 21 days. One treated unit sustained massive hemolysis during the post-thaw wash process and was removed from data analysis. The remaining units were assessed pre-PRT, post-PRT, and post-thaw-wash on days 0, 7, 14, and 21 for hematocrit, volume, hemoglobin per transfusion unit, pH, % hemolysis, hemoglobin in the supernatant, potassium, phosphorus, NH3 , osmolality, ATP, and 2,3-diphosphoglycerate. RESULTS: PRT with leukoreduction caused a 5% loss of RBC followed by a 24% freeze-thaw-wash related loss for a total 28% loss but treated units contained an average of 45 g of hemoglobin, meeting European Union guidelines for CRBC. T-CRBCs displayed higher post-wash hemolysis, potassium, and ammonia concentrations, and lower ATP at the end of storage. CONCLUSIONS: Cryopreserved RBCs from Riboflavin and UV light-treated WB meet the criteria for clinical use for 7 days after thawing and provide additional protection against infectious threats.

Age, admission platelet count, and mortality in severe isolated traumatic brain injury: A retrospective cohort study.

BACKGROUND: We asked whether patients >50 years of age with acute traumatic brain injury (TBI) present with lower platelet counts and whether lower platelet counts are independently associated with mortality. METHODS: We combined trauma registry and laboratory data on a retrospective cohort of all patients ≥18 years of age admitted to our Level 1 US regional trauma center 2015-2021 with severe (Head Abbreviated Injury Score [AIS] ≥3), isolated (all other AIS <3) TBI who had a first platelet count within 1 h of arrival. Age and platelet count were assessed continuously and as groups (age 18-50 vs. >50, platelet normals, and at conventional transfusion thresholds). Outcomes such as mean admission platelet counts and in-hospital mortality were assessed categorically and with logistic regression. RESULTS: Of 44,056 patients, 1298 (3%, median age: 52 [IQR 33,68], 76.1% male) met all inclusion criteria with no differences between younger and older age groups for (ISS; 18 [14,26] vs. 17 [14,26], p = .22), New ISS (NISS; 29 [19,50] vs. 28 [17,50], p = .36), or AIS-Head (4 [3,5] vs. 4 [3,5]; p = .87). Patients aged >50 had lower admission platelet counts (219,000 ± 93,000 vs. 242,000 ± 76,000/µL; p < .001) and greater in-hospital mortality (24.5% vs. 15.6%, p < .001) than those 18-50. In multivariable regression, firearms injuries (OR9.08), increasing age (OR1.004), NISS (OR1.007), and AIS-Head (OR1.05), and decreasing admission platelet counts (OR0.998) were independently associated with mortality (p < .001-.041). Platelet transfusion in the first 4 h of care was more frequent among older patients (p < .001). CONCLUSIONS: Older patients with TBI had lower admission platelet counts, which were independently associated with greater mortality.

Transfusion of ABO-group identical red blood cells following uncrossmatched transfusion does not lead to higher mortality in civilian trauma patients.

BACKGROUND: Questions persist about the safety of switching non-group O recipients of group O uncrossmatched red blood cells (RBC) or low titer group O whole blood (LTOWB) to ABO-identical RBCs during their resuscitation. METHODS: The database of an earlier nine-center study of transfusing incompatible plasma to trauma patients was reanalyzed. The patients were divided into three groups based on 24-h RBC transfusion: (1) group O patients who received group O RBC/LTOWB units (control group, n = 1203), (2) non-group O recipients who received only group O units (n = 646), (3) non-group O recipients who received at least one unit of group O and non-group O units (n = 562). Fixed marginal effect of receipt of non-O RBC units on 6- and 24-h and 30-day mortality was calculated. RESULTS: The non-O patients who received only group O RBCs received fewer RBC/LTOWB units and had slightly but significantly lower injury severity score compared to control group; non-group O patients who received both group O and non-O units received significantly more RBC/LTOWB units and had a slightly but significantly higher injury severity score compared to control group. In the multivariate analysis, the non-O patients who received only group O RBCs had significantly higher mortality at 6-h compared to the controls; the non-group O recipients of O and non-O RBCs did not demonstrate higher mortality. At 24-h and 30-days, there were no differences in survival between the groups. CONCLUSION: Providing non-group O RBCs to non-group O trauma patients who also received group O RBC units is not associated with higher mortality.

Cryopreservation of apheresis platelets treated with riboflavin and UV light.

BACKGROUND: Pathogen reduction technology (PRT) is increasingly used in the preparation of platelets for therapeutic transfusion. As the Czech Republic considers PRT, we asked what effects PRT may have on the recovery and function of platelets after cryopreservation (CP), which we use in both military and civilian blood settings. STUDY DESIGN AND METHODS: 16 Group O apheresis platelets units were treated with PRT (Mirasol, Terumo BCT, USA) before freezing; 15 similarly collected units were frozen without PRT as controls. All units were processed with 5-6% DMSO, frozen at - 80 °C, stored > 14 days, and reconstituted in thawed AB plasma. After reconstitution, all units were assessed for: platelet count, mean platelet volume (MPV), platelet recovery, thromboelastography, thrombin generation time, endogenous thrombin potential (ETP), glucose, lactate, pH, pO2, pCO2, HCO3, CD41, CD42b, CD62, Annexin V, CCL5, CD62P, and aggregates > 2 mm and selected units for Kunicki score. RESULTS: PRT treated platelet units had lower platelet number (247 vs 278 ×109/U), reduced thromboelastographic MA (38 vs 62 mm) and demonstrated aggregates compared to untreated platelets. Plasma coagulation functions were largely unchanged. CONCLUSIONS: Samples from PRT units showed reduced platelet number, reduced function greater than the reduced number would cause, and aggregates. While the platelet numbers are sufficient to meet the European standard, marked platelets activation with weak clot strength suggest reduced effectiveness.

Ultramassive Transfusion for Trauma in the Age of Hemostatic Resuscitation: A Retrospective Single-Center Cohort From a Large US Level-1 Trauma Center, 2011-2021.

BACKGROUND: Uncontrolled bleeding is a leading cause of death in trauma. In the last 40 years, ultramassive transfusion (UMT; ≥20 units of red blood cells [RBCs]/24 hours) for trauma has been associated with 50% to 80% mortality; the question remains as to whether the increasing number of units transfused in urgent resuscitation is a marker of futility. We asked whether the frequency and outcomes of UMT have changed in the era of hemostatic resuscitation. METHODS: We performed a retrospective cohort study of all UMTs in the first 24 hours of care over an 11-year period at a major US level-1 adult and pediatric trauma center. UMT patients were identified, and a dataset was built by linking blood bank and trauma registry data, then reviewing individual electronic health records. Success in achieving hemostatic proportions of blood products was estimated as (units of plasma + apheresis-platelets-in-plasma + cryoprecipitate-pools + whole blood]/[all units given] ≥0.5. Demographics, injury type (blunt or penetrating), severity (Injury Severity Score [ISS]), severity pattern (Abbreviated Injury Scale score for head [AIS-Head] ≥4), admitting laboratory, transfusion, selected emergency department interventions, and discharge status were assessed using χ2 tests of categorical association, the Student t-test of means, and multivariable logistic regression. P <.05 was considered significant. RESULTS: Among 66,734 trauma admissions from April 6, 2011 to December 31, 2021, we identified 6288 (9.4%) who received any blood products in the first 24 hours, 159 of whom received UMT (0.23%; 154 aged 18-90 + 5 aged 9-17), 81% in hemostatic proportions. Overall mortality was 65% (n = 103); mean ISS = 40; median time to death, 6.1 hours. In univariate analyses, death was not associated with age, sex, or more RBC units transfused beyond 20 but was associated with blunt injury, increasing injury severity, severe head injury, and failure to receive hemostatic blood product ratios. Mortality was also associated with decreased pH and evidence of coagulopathy at admission, especially hypofibrinogenemia. Multivariable logistic regression showed severe head injury, admission hypofibrinogenemia and not receiving a hemostatic resuscitation proportion of blood products as independently associated with death. CONCLUSIONS: One in 420 acute trauma patients at our center received UMT, a historically low rate. A third of these patients lived, and UMT was not itself a marker of futility. Early identification of coagulopathy was possible, and failure to give blood components in hemostatic ratios was associated with excess mortality.

How we built a hospital-based community whole blood program.

BACKGROUND: Whole blood (WB) is an attractive product for prehospital treatment of hemorrhagic shock and for initial in-hospital resuscitation of patients likely to require massive transfusion. Neither our regional blood provider nor our hospital blood bank had recent experience collecting or using WB, so we developed a stepwise process to gather experience with WB in clinical practice. METHODS: When our Transfusion Committee suggested a WB program, we worked with our regional blood provider to collect cold-stored, leukoreduced, low-titer anti-A, and anti-B group O RhD positive WB (low-titer group O WB [LTOWB]) and worked with our city Fire Department to integrate it into prehospital care. This work required planning, development of protocols, writing software for blood bank and electronic medical records, changes in paramedic scope of practice, public information, training of clinicians, and close clinical follow-up. RESULTS: Between June 2019 and December 2021, we received 2269 units of LTOWB and transfused 2220 units; 24 (1%) were wasted, two were withdrawn, and 23 were in stock at the end of that time. Most (89%) were transfused to trauma patients. Usage has grown from 48 to 120 units/month, covers all 5 Fire Districts in the county, and represents about » of all hospital trauma blood product use. CONCLUSIONS: Developing a WB program is complex but can be started slowly, including both pre-hospital and hospital elements, and expanded as resources and training progress. The investments of time, effort, and funding involved can potentially improve care, save blood bank and nursing effort, and reduce patient charges.

Providing whole blood for an urban paramedical ambulance system.

INTRODUCTION: Hemorrhage is the second leading cause of death among urban trauma patients, and the provision of prehospital blood-based resuscitation can be lifesaving. We developed an efficient system to support blood-based resuscitation by an urban advanced life support ambulance system. METHODS: We worked with our state health department for permission for fire department paramedics to initiate blood transfusion and built protocols for field whole blood resuscitation. Our regional trauma center transfusion service provided 2 units of O positive, low-titer, leukoreduced whole blood in an internally monitored and sealed ice box weighing 10 pounds to the fire department paramedic supervisor. When notified, the supervisor transported the blood to the sites of anticipated need. Total blood use and wastage were recorded. RESULTS: Following two public hearings, we obtained state-wide approval for the initiation of emergency uncrossmatched blood transfusion by paramedics. Over a 1-year period beginning August 27, 2019, 160 units of whole blood were made available for use, and 51 units were transfused to 39 patients, 30 of whom were trauma patients. Other recipients include patients in shock from massive gastrointestinal, peripartum, or other suspected bleeding. Unused units were returned to the providing transfusion service after 1 week and used for hospital patient care without loss. The estimated cost of providing blood per mission was $0.28 and per patient transfused was $1138. CONCLUSIONS: With appropriate attention to detail, it is possible to provide whole blood to an urban paramedical ambulance system with efficient blood component usage, minimal blood wastage, and low cost.

Blood product availability in the Washington state trauma system.

BACKGROUND: Early transfusion can prolong life in injured patients awaiting definitive hemorrhage control. We conducted a community resources assessment of blood product availability at hospitals within the Washington State (WA) Regional Trauma System, with the expectation that a minority of Level IV and V centers would have blood products routinely available for use in resuscitation. METHODS: We designed a questionnaire soliciting information on routinely available unit quantities of red blood cells (RBC), plasma, platelets, cryoprecipitate, and/or whole blood and submitted this questionnaire electronically to the 82 WA designated trauma centers (Levels I-V). Non-responders were contacted directly by telephone. The study was conducted in September and October 2021. US 2020 census data were used to correlate results with local population densities. RESULTS: First-round contact netted responses from 57 (70%) centers; the remaining centers provided information via telephone, for a 100% final response. Packed RBC were available in 79 of the 82 centers (96%; range 6-220 units); plasma, 62 centers (76%, range 1-100 units); platelets, 40 centers (49%, range 1-8 units); cryoprecipitate, 45 centers (55%, range 1-20 units). Whole blood was only available at the Level I center. Three Level V centers, located in 2 of the 8 WA state trauma regions, reported no routine blood availability. The two trauma regions affected represent 12% of the state's population and more than a third of its geographic area. CONCLUSIONS: Within the WA regional trauma system, blood products are wide, if unevenly, available. Large urban/rural disparities in availability exist that should be explored.

Rate of D-alloimmunization in trauma does not depend on the number of RhD-positive units transfused: The BEST collaborative study.

BACKGROUND: Evidence indicates the life-saving benefits of early blood product transfusion in severe trauma resuscitation. Many of these products will be RhD-positive, so understanding the D-alloimmunization rate is important. METHODS: This was a multicenter, retrospective study whereby injured RhD-negative patients between 18-50 years of age who received at least one unit of RhD-positive red blood cells (RBC) or low titer group O whole blood (LTOWB) during their resuscitation between 1 January, 2010 through 31 December, 2019 were identified. If an antibody detection test was performed ≥14 days after the index RhD-positive transfusion then basic demographic information was collected, including whether the patient became D-alloimmunized. The overall D-alloimmunization rate, and the rate stratified by the number of units transfused, were calculated. RESULTS: Data were collected from nine institutions. Five institutions reported fewer than 10 eligible patients each and were excluded. From the remaining four institutions, all from the USA, there were 235 eligible patients; 77 (random effects estimate: 32.7%; 95% CI: 19.1-50.1%) became D-alloimmunized. Three of the institutions reported D-alloimmunization rates ≥38.6%, while the remaining institution's rate was 12.2%. In both random and fixed-effects models, the rate of D-alloimmunization was not significantly different between those who received one RhD-positive unit and those who received multiple RhD-positive units. CONCLUSION: In this large, multicenter study of injured patients, the overall rate of D-alloimmunization fell within the range previously reported. The rate of D-alloimmunization did not increase as the number of transfused RhD-positive units increased. These data can help to inform RhD type selection decisions.

Platelet Transfusion and Outcomes After Massive Transfusion Protocol Activation for Major Trauma: A Retrospective Cohort Study.

BACKGROUND: Incorporation of massive transfusion protocols (MTPs) into acute major trauma care has reduced hemorrhagic mortality, but the threshold and timing of platelet transfusion in MTP are controversial. This study aimed to describe early (first 4 hours) platelet transfusion practice in a setting where platelet counts are available within 15 minutes and the effect of early platelet deployment on in-hospital mortality. Our hypothesis in this work was that platelet transfusion in resuscitation of severe trauma can be guided by rapid turnaround platelet counts without excess mortality. METHODS: We examined MTP activations for all admissions from October 2016 to September 2018 to a Level 1 regional trauma center with a full trauma team activation. We characterized platelet transfusion practice by demographics, injury severity, and admission vital signs (as shock index: heart rate/systolic blood pressure) and laboratory results. A multivariable model assessed association between early platelet transfusion and mortality at 4 hours, 24 hours, and overall in-hospital, with P <.001. RESULTS: Of the 11,474 new trauma patients admitted over the study period, 469 (4.0%) were massively transfused (defined as ≥10 units of red blood cells [RBCs] in 24 hours, ≥5 units of RBC in 6 hour, ≥3 units of RBC in 1 hour, or ≥4 units of total products in 30 minutes). 250 patients (53.0%) received platelets in the first 4 hours, and most early platelet transfusions occurred in the first hour after admission (175, 70.0%). Platelet recipients had higher injury severity scores (mean ± standard deviation [SD], 35 ± 16 vs 28 ± 14), lower admission platelet counts (189 ± 80 × 10 9 /L vs 234 ± 80 × 10 9 /L; P < .001), higher admission shock index (heart rate/systolic blood pressure; 1.15 ± 0.46 vs 0.98 ± 0.36; P < .001), and received more units of red cells in the first 4 hours (8.7 ± 7.7 vs 3.3 ± 1.6 units), 24 hours (9 ± 9 vs 3 ± 2 units), and in-hospital (9 ± 8 vs 3 ± 2 units) than nonrecipients (all P < .001). We saw no difference in 4-hour (8% vs 7.8%; P = .4), 24-hour (16.4% vs 10.5%; P = .06), or in-hospital mortality (30.4% vs 23.7%; P = .1) between platelet recipients and nonrecipients. After adjustment for age, injury severity, head injury, and admission physiology/laboratory results, early platelet transfusion was not associated with 4-hour, 24-hour, or in-hospital mortality. CONCLUSIONS: In an advanced trauma care setting where platelet counts are available within 15 minutes, approximately half of massively transfused patients received early platelet transfusion. Early platelet transfusion guided by protocol-based clinical judgment and rapid-turnaround platelet counts was not associated with increased mortality.

Drivers of blood use in paediatric trauma: A retrospective cohort study.

OBJECTIVES: We asked whether age or injury severity drives blood use patterns in paediatric trauma. BACKGROUND: Transfusion for paediatric trauma care is complicated by known developmental differences in coagulation and injury patterns. METHODS/MATERIALS: We linked 10 years of Trauma Registry and blood bank data, 2011-2020, for all acute trauma patients aged <18 treated at a large US Level 1 adult and paediatric trauma centre. We assessed age, injury severity and mechanism for association with any blood use, use within the first 4 h of care, and resuscitation balance, using grouped-age Chi-square and multivariable regression models. RESULTS: Of 60 066 acute trauma arrivals at our centre in the study period, 7979 (13.3%) met inclusion criteria. Median age (IQR) was (7.6[2.4-14.5]); 6230(78.1%) were < 15 years old; 590(7.4%) received any blood products; and 128(1.6%) died. Among the 5842(73.2%) patients with impact-related injury, 2023(34.6%) met standards for severe injury (New Injury Severity Score [NISS] ≥ 16); 541(9.3%) were transfused, 171(31.6%) in the first 4 h and 72(13.3%) using ≥3 units of products in the first hour. Firearms injuries were the most severe, most likely to be transfused urgently, using balanced resuscitation, and to die (p < 0.001 for all). Multivariable logistic regression showed any blood use as strongly associated with NISS (Odds Ratio 1.124832; p < 0.0001; 95% CI 1.11-1.13) but not with age (OR 0.98; p = 0.07; 95% CI 0.96-1.00). CONCLUSION: Transfusion in the care of acute paediatric trauma is uncommon (<10% of injured minors in our cohorts received any blood products), and injury severity, particularly firearms injury-not age-drove transfusion.

Advances in hemorrhage control resuscitation.

PURPOSE OF REVIEW: Despite significant advances in trauma management over the last twenty years, uncontrolled hemorrhage remains the leading cause of preventable death in trauma. We review recent changes affecting hemorrhage control resuscitation. RECENT FINDINGS: Early blood product usage has become well established as a standard of care in trauma hemorrhage control. To enable this, low titer group A liquid plasma and group O whole blood are increasingly utilized. Single donor apheresis platelets have now replaced pooled donor platelets in the USA and are often pathogen reduced, which has implications for trauma resuscitation. Further work is examining timing and dosing of tranexamic acid and the debate in factor concentrate usage in trauma induced coagulopathy continues to evolve. The 'Stop the bleed' campaign has highlighted how important the use of hemostatic dressings are in hemorrhage control, as too is the expanded use of endovascular aortic occlusion. We highlight the ongoing research into desmopressin use and the undetermined significance of ionized calcium levels in trauma. Finally, we discuss our own hospital experience with coagulation testing and the paucity of evidence of improved outcomes with viscoelastic testing. SUMMARY: Improving trauma coagulopathy diagnostics and hemorrhage control are vital if we are to decrease the mortality associated with trauma.

Evidence-Based and Clinically Relevant Outcomes for Hemorrhage Control Trauma Trials.

OBJECTIVE: To address the clinical and regulatory challenges of optimal primary endpoints for bleeding patients by developing consensus-based recommendations for primary clinical outcomes for pivotal trials in patients within 6 categories of significant bleeding, (1) traumatic injury, (2) intracranial hemorrhage, (3) cardiac surgery, (4) gastrointestinal hemorrhage, (5) inherited bleeding disorders, and (6) hypoproliferative thrombocytopenia. BACKGROUND: A standardized primary outcome in clinical trials evaluating hemostatic products and strategies for the treatment of clinically significant bleeding will facilitate the conduct, interpretation, and translation into clinical practice of hemostasis research and support alignment among funders, investigators, clinicians, and regulators. METHODS: An international panel of experts was convened by the National Heart Lung and Blood Institute and the United States Department of Defense on September 23 and 24, 2019. For patients suffering hemorrhagic shock, the 26 trauma working-group members met for almost a year, utilizing biweekly phone conferences and then an in-person meeting, evaluating the strengths and weaknesses of previous high quality studies. The selection of the recommended primary outcome was guided by goals of patient-centeredness, expected or demonstrated sensitivity to beneficial treatment effects, biologic plausibility, clinical and logistical feasibility, and broad applicability. CONCLUSIONS: For patients suffering hemorrhagic shock, and especially from truncal hemorrhage, the recommended primary outcome was 3 to 6-hour all-cause mortality, chosen to coincide with the physiology of hemorrhagic death and to avoid bias from competing risks. Particular attention was recommended to injury and treatment time, as well as robust assessments of multiple safety related outcomes.

Economical provision of blood components for critical patient transport across a large geographic area.

BACKGROUND: Rapid air transport of critically injured patients to sites of appropriate care can save lives. The provision of blood products on critical care transport flights may save additional lives by starting resuscitation earlier. METHODS: Our regional trauma center transfusion service provided 2 units of O-negative red blood cells and 2 units of A low-titer anti-B liquid plasma in an internally monitored and sealed eutectic box weighing 10.4 pounds to eight air bases once weekly. Flight crews were instructed to transfuse plasma units first. Unused blood was returned to the transfusion service. Total blood use and wastage were recorded. RESULTS: Over a 6-year period, ≈ 7400 blood components were provided, and >1000 were used by the air transport service in patient care. Plasma units were 57% of all units given. Unused units were returned to the providing transfusion service and used in hospital patient care with <3% loss. Estimated cost of providing blood per mission was $63 and per patient transfused was $1940. CONCLUSIONS: With appropriate attention to detail, it is possible to provide life-saving blood components to aeromedical transport services across a large geographic area with efficient blood component usage, minimal blood wastage, and low cost.