TXA combined with whole blood transfusion in trauma patients does not increase the risk of VTE but shock index does.

INTRODUCTION: Previous studies have demonstrated the benefits of tranexamic acid (TXA) administration in combination with packed red blood cell (PRBC) transfusion in trauma patients without increasing the risk of venous thromboembolism (VTE). However, the effect of TXA in combination with whole blood (WB) has not been studied. Injury, abbreviated injury severity scores (ISS and AIS) and the need for blood transfusions are historically associated with VTE. The objective of this study was to determine the relationship between VTE and the combination of TXA administration and transfusion of PRBCs vs. WB. METHODS: Our institutional trauma registry was queried for trauma patients between 2015 and 2022 who received either WB â€‹+ â€‹TXA or PRBC â€‹+ â€‹TXA either prehospital or within 4 â€‹h of arrival. Multivariate analysis was utilized to determine independent risk factors for VTE, which were defined as either a deep vein thrombosis (DVT) or a pulmonary embolism (PE). Model covariates included age, mechanism of injury (MOI), ISS, lower extremity AIS, comorbid conditions, and shock index (SI). Additional outcomes analyzed were hospital length of stay (LOS), ICU LOS, and ventilator days. RESULTS: Three hundred and five patients had complete data and were included in the analysis. Of those, 251 received WB â€‹+ â€‹TXA and 54 received PRBC â€‹+ â€‹TXA. A total of 34 patients were found to have VTE event (11.1 â€‹%); 28 (11.2 â€‹%) and 6 (11.1 â€‹%) from the WB â€‹+ â€‹TXA and PRBC â€‹+ â€‹TXA groups, respectively. An elevated pre-hospital SI was independently associated with increased VTE rate (OR 1.85, 95 â€‹% CI 1.07-3.20). WB transfusion, TXA administration, ISS, and MOI did not influence the rate of VTE. CONCLUSION: These data demonstrate that the combination of WB â€‹+ â€‹TXA administered to trauma patients has no higher risk of VTE than patients who receive PRBC â€‹+ â€‹TXA, a comparison that has not been studied clinically to date. Despite the pro thrombotic state enhanced by TXA and the decreased dilutional coagulopathy seen in WB resuscitation, there was no increased risk of VTE compared to TXA â€‹+ â€‹PRBC. There is no evidence that TXA combined with whole blood transfusion is associated with an increased risk of VTE. However, higher pre-hospital SI was associated with an elevated rate of VTE. These clinical features provide insight into patients who may be at an increased risk of developing VTE and may benefit from targeted prevention strategies.

Removing the barriers to prehospital blood: A roadmap to success.

ABSTRACT: This review describes the necessity, evolution, and current state of prehospital blood programs in the United States. Less than 1% of 9-1-1 ground emergency medical service agencies have been able to successfully implement prehospital blood transfusions as part of a resuscitation strategy for patients in hemorrhagic shock despite estimates that annually between 54,000 and 900,000 patients may benefit from its use. The use of prehospital blood transfusions as a tool for managing hemorrhagic shock has barriers to overcome to ensure it becomes widely available to patients throughout the United States. Barriers include (1) current state Emergency Medical Services clinicians' scope of practice limitations; (2) program costs and reimbursement of blood products; (3) no centralized data collection process for prehospital hemorrhagic shock and patient outcomes; (4) collaboration between prehospital agencies, blood suppliers, and hospital clinicians and transfusion service activities. The following article identifies barriers and a proposed roadmap to reduce death due to prehospital hemorrhage.

Emergency preparedness for mass casualty events: South Texas commentary on the development of a statewide emergency response system.

Mass casualty incidents (MCIs) are on the rise in the USA, and hemorrhage is the leading cause of preventable death in trauma. The need for rapid access to life-saving blood and blood products is essential for preventing death due to hemorrhage. It is well established that most major cities in the USA are underprepared to meet blood transfusion requirements in the event of an MCI. The South Texas Whole Blood Consortium sought to rectify this and vowed to be prepared to provide low-titer type O-positive whole blood (LTOWB) and blood components to the people who need it, where and when they need it. This system was able to transport 25 units of LTOWB and packed red blood cells almost 100 miles away to Uvalde Memorial Hospital within just 67 minutes after notification of an active shooter. The regional consortium has created a pool of dedicated LTOWB donors affectionately called Heroes in Arms who can be called on to instantly augment locoregional blood supply. Previously pregnant women have historically been excluded from donating plasma and LTOWB due to the increased rates of human leukocyte antigen (HLA) antibody (Ab) positivity, which is associated with transfusion-related acute lung injury. However, the South Texas Blood and Tissue Center in San Antonio had a large number of qualified, previously pregnant females desire to join the Heroes in Arms program prompting them to assess the feasibility of providing HLA Ab testing for this demographic and the results were promising. This is the first report of previously pregnant women being included in the pool for donation of LTOWB.

Walking blood bank: a plan to ensure self-sufficiency in an era of blood shortage.

Mass casualty incidents and massive transfusion requirements continue to plague the USA with hemorrhage remaining the number one cause of death in trauma. The unfortunate reality of numerous mass shootings in Southwest Texas has led to the need for a way in which to provide blood during these events as rapidly as it is required. Multiple agencies within the Southwest Texas system have united to help provide this life-saving blood to people when they need it most. This effort began with the development of a system for safe, efficient, and now widespread use of whole blood in the region. After demonstrating the success of delivering large quantities of blood during the Uvalde shooting, we have begun to develop a walking blood bank that is similar to what the miliary uses on the battlefield. The concept behind this initiative is to have a cohort of whole blood donors who are preselected to join the program which is now dubbed 'Heroes in Arms'. These donors will be called upon to donate whole blood during a massive transfusion event. Their blood will be rapidly screened prior to transfusion to the patient. This blood will still undergo the normal rigorous testing and, should any potentially transmissible diseases by discovered post-transfusion, the individual who received that product will be treated accordingly. Given the low rate of transmissible disease among this preselected population, combined with rapid screening prior to transfusion, the risk of a person receiving a transmissible disease is insignificant in comparison to the benefit of having blood to transfuse during hemorrhage. This model is a promising collaborative effort to provide in a timely and sufficient blood product in cases of major need which will consequently minimize the number of traumatically injured civilian patients who die from hemorrhage.

Commentary on gaps in prehospital trauma care: education and bioengineering innovations to improve outcomes in hemorrhage and traumatic brain injury.

Hemorrhage remains the leading cause of preventable death on the battlefield and the civilian arena. Many of these deaths occur in the prehospital setting. Traumatic brain injury also represents a major source of early mortality and morbidity in military and civilian settings. The inaugural HERETIC (HEmostatic REsuscitation and Trauma Induced Coagulopathy) Symposium convened a multidisciplinary panel of experts in prehospital trauma care to discuss what education and bioengineering advancements in the prehospital space are necessary to improve outcomes in hemorrhagic shock and traumatic brain injury. The panel identified several promising technological breakthroughs, including field point-of-care diagnostics for hemorrhage and brain injury and unique hemorrhage control options for non-compressible torso hemorrhage. Many of these technologies exist but require further advancement to be feasibly and reliably deployed in a prehospital or combat environment. The panel discussed shifting educational and training paradigms to clinical immersion experiences, particularly for prehospital clinicians. The panel discussed an important balance between pushing traditionally hospital-based interventions into the field and developing novel intervention options specifically for the prehospital environment. Advancing prehospital diagnostics may be important not only to allow more targeted applications of therapeutic options, but also to identify patients with less urgent injuries that may not need more advanced diagnostics, interventions, or transfer to a higher level of care in resource-constrained environments. Academia and industry should partner and prioritize some of the promising advances identified with a goal to prepare them for clinical field deployment to optimize the care of patients near the point of injury.

The impact of prehospital whole blood on hemorrhaging trauma patients: A multi-center retrospective study.

BACKGROUND: Whole blood (WB) use has become increasingly common in trauma centers across the United States for both in-hospital and prehospital resuscitation. We hypothesize that prehospital WB (pWB) use in trauma patients with suspected hemorrhage will result in improved hemodynamic status and reduced in-hospital blood product requirements. METHODS: The institutional trauma registries of two academic level I trauma centers were queried for all patients from 2015-2019 who underwent transfusion upon arrival to the trauma bay. Patients who were dead on arrival or had isolated head injuries were excluded. Demographics, injury and shock characteristics, transfusion requirements, including massive transfusion protocol (MTP) (>10 U in 24 hours) and rapid transfusion (CAT3+) and outcomes were compared between pWB and non-pWB patients. Significantly different demographic, injury characteristics and pWB were included in univariate followed by stepwise logistic regression analysis to determine the relationship with shock index (SI). Our primary objective was to determine the relationship between pWB and improved hemodynamics or reduction in blood product utilization. RESULTS: A total of 171 pWB and 1391 non-pWB patients met inclusion criteria. Prehospital WB patients had a lower median Injury Severity Score (17 vs. 21, p < 0.001) but higher prehospital SI showing greater physiologic disarray. Prehospital WB was associated with improvement in SI (-0.04 vs. 0.05, p = 0.002). Mortality and (LOS) were similar. Prehospital WB patients received fewer packed red blood cells, fresh frozen plasma, and platelets units across their LOS but total units and volumes were similar. Prehospital WB patients had fewer MTPs (22.6% vs. 32.4%, p = 0.01) despite a similar requirement of CAT3+ transfusion upon arrival. CONCLUSION: Prehospital WB administration is associated with a greater improvement in SI and a reduction in MTP. This study is limited by its lack of power to detect a mortality difference. Prospective randomized controlled trials will be required to determine the true impact of pWB on trauma patients. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Transfusion-related cost comparison of trauma patients receiving whole blood versus component therapy.

INTRODUCTION: With the emergence of whole blood (WB) in trauma resuscitation, cost-related comparisons are of significant importance to providers, blood banks, and hospital systems throughout the country. The objective of this study was to determine if there is a transfusion-related cost difference between trauma patients who received low titer O+ whole blood (LTO+WB) and component therapy (CT). METHODS: A retrospective review of adult and pediatric trauma patients who received either LTO+WB or CT from time of injury to within 4 hours of arrival was performed. Annual mean cost per unit of blood product was obtained from the regional blood bank supplier. Pediatric and adult patients were analyzed separately and were compared on a cost per patient (cost/patient) and cost per patient per milliliter (cost/patient/mL) basis. Subgroup analysis was performed on severely injured adult patients (Injury Severity Score, >15) and patients who underwent massive transfusion. RESULTS: Prehospital LTO+WB transfusion began at this institution in January 2018. After the initiation of the WB transfusion, the mean annual cost decreased 17.3% for all blood products, and the average net difference in cost related to component blood products and LTO+WB was more than $927,000. In adults, LTO+WB was associated with a significantly lower cost/patient and cost/patient/mL compared with CT at 4 hours ( p < 0.001), at 24 hours ( p < 0.001), and overall ( p < 0.001). In the severely injured subgroup (Injury Severity Score, >15), WB was associated with a lower cost/patient and cost/patient/mL at 4 hours ( p < 0.001), 24 hours ( p < 0.001), and overall ( p < 0.001), with no difference in the prehospital setting. Similar findings were true in patients meeting massive transfusion criteria, although differences in injury severity may account for this finding. CONCLUSION: With increased use of LTO+WB for resuscitation, cost comparison is of significant importance to all stakeholders. Low titer O+ WB was associated with reduced cost in severely injured patients. Ongoing analyses may improve resource utilization and benefit overall healthcare cost. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

The effects of hypocalcemia in severely injured pediatric trauma patients.

INTRODUCTION: The role of calcium is ubiquitous in human physiology. Emerging evidence suggests that the lethal triad be revised to include hypocalcemia (hypoCa) and thus be known as the lethal diamond . There are data showing that traumatic injury may result in hypoCa independent from the mechanism of calcium chelation by citrate-based blood preservatives. Minimal literature exists analyzing the role of hypoCa in pediatric trauma patients. We hypothesize that there is an independent association of hypoCa with increased blood product requirements and mortality. METHODS: A retrospective cohort study of severely injured pediatric trauma patients was conducted. Trauma registry data were collected from January 2016 to August 2021. Ionized calcium (iCa) levels were obtained from arrival blood draws. Subjects were categorized into two groups by a threshold iCa level of 1.00 mmol/L and compared. Shock Index Pediatric Adjusted scores were used to adjust for age-specific differences in vital signs. RESULTS: A total of 142 patients were compared, of which 46.5% were hypocalcemic (iCa <1.00 mmol/L). Patients were well matched in terms of demographics and injury severity. The hypocalcemic group had lower systolic blood pressure and a higher percentage of Shock Index Pediatric Adjusted-positive patients. Weight-adjusted transfusion volumes were significantly higher in the hypocalcemic group at both the 4-hour and 24-hour time points without a difference in prehospital transfusion requirements. There was no observed difference in early or in-hospital mortality. CONCLUSION: This study contributes to the body of literature regarding the association between hypoCa and traumatic injury in the pediatric population. Hypocalcemia was associated with increased blood product requirements without a difference in prehospital transfusion requirements, suggesting a possible independent association. Further prospective studies are needed to better understand this relationship. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Use of whole blood deployment programs for mass casualty incidents: South Texas experience in regional response and preparedness.

INTRODUCTION: Firearm-related deaths have become the leading cause of death in adolescents and children. Since the Sutherland Springs, TX mass casualty incident (MCI), the Southwest Texas Regional Advisory Council for trauma instituted a prehospital whole blood (WB) program and blood deployment program for MCIs. METHODS: The program was adopted statewide by the Texas Emergency Medical Task Force, of which Southwest Texas Regional Advisory Council is the lead for Emergency Medical Task Force 8. The recent active shooter MCI in Uvalde, TX was the first time the MCI blood deployment program had been used. To our knowledge, no other similar programs exist in this or any other country. RESULTS: On May 24, 2022, 19 children and 2 adults were killed at an MCI in Uvalde, TX. The MCI WB deployment protocol was initiated, and South Texas Blood and Tissue Center prepared 15 U of low-titer O-positive whole blood and 10 U of leukoreduced O packed cells. The deployed blood arrived at Uvalde Memorial Hospital within 67 minutes. One of the pediatric patients sustained multiple gunshots to the chest and extremities. The child was hypotensive and received 2 U of leukoreduced O packed cells, one at the initial hospital and another during transport. On arrival, the patient required 2 U of low-titer O-positive whole blood and underwent a successful hemorrhage control operation. The remaining blood was returned to South Texas Blood and Tissue Center for distribution. CONCLUSION: Multiple studies have shown the association of early blood product resuscitation and improved mortality, with WB being the ideal resuscitative product for many. The ongoing efforts in South Texas serve as a model for development of similar programs throughout the country to reduce preventable deaths. This event represents the first ever successful deployment of WB to the site of an MCI related to a school shooting in the modern era. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level V.

Use of Cold-Stored Whole Blood is Associated With Improved Mortality in Hemostatic Resuscitation of Major Bleeding: A Multicenter Study.

OBJECTIVE: The aim of this study was to identify a mortality benefit with the use of whole blood (WB) as part of the resuscitation of bleeding trauma patients. BACKGROUND: Blood component therapy (BCT) is the current standard for resuscitating trauma patients, with WB emerging as the blood product of choice. We hypothesized that the use of WB versus BCT alone would result in decreased mortality. METHODS: We performed a 14-center, prospective observational study of trauma patients who received WB versus BCT during their resuscitation. We applied a generalized linear mixed-effects model with a random effect and controlled for age, sex, mechanism of injury (MOI), and injury severity score. All patients who received blood as part of their initial resuscitation were included. Primary outcome was mortality and secondary outcomes included acute kidney injury, deep vein thrombosis/pulmonary embolism, pulmonary complications, and bleeding complications. RESULTS: A total of 1623 [WB: 1180 (74%), BCT: 443(27%)] patients who sustained penetrating (53%) or blunt (47%) injury were included. Patients who received WB had a higher shock index (0.98 vs 0.83), more comorbidities, and more blunt MOI (all P <0.05). After controlling for center, age, sex, MOI, and injury severity score, we found no differences in the rates of acute kidney injury, deep vein thrombosis/pulmonary embolism or pulmonary complications. WB patients were 9% less likely to experience bleeding complications and were 48% less likely to die than BCT patients ( P <0.0001). CONCLUSIONS: Compared with BCT, the use of WB was associated with a 48% reduction in mortality in trauma patients. Our study supports the use of WB use in the resuscitation of trauma patients.

Gaining or wasting time? Influence of time to operating room on mortality after temporary hemostasis using resuscitative endovascular balloon occlusion of the aorta.

BACKGROUND: The optimal candidates for resuscitative endovascular balloon occlusion of the aorta (REBOA) remains unclear. We hypothesized patients with delayed transfer to operating room (OR) would benefit from REBOA. METHODS: Using the 2016-2017 ACS-TQIP database, patients were divided based on the transfer time to OR: ≤1 h (early) and >1 h (delayed). In each group, patients who underwent REBOA in emergency department (ED-REBOA) were matched with those without REBOA (non-REBOA) using propensity scores, and survival to discharge was compared. RESULTS: Among 163,453 patients, 114 and 138 patients (38 and 46 ED-REBOA) were included in the early and delayed groups, respectively. Survival to discharge was comparable between ED-REBOA and non-REBOA patients in the early group (39.5% vs. 48.7%, p = 0.35), whereas it was higher in ED-REBOA patients in the delayed group (39.1% vs. 12.0%, p < 0.01). CONCLUSIONS: Patients with delayed transfer to OR >1 h benefited from REBOA.

Prehospital shock index and systolic blood pressure are highly specific for pediatric massive transfusion.

BACKGROUND: While massive transfusion protocols (MTPs) are associated with decreased mortality in adult trauma patients, there is limited research on the impact of MTP on pediatric trauma patients. The purpose of this study was to compare pediatric trauma patients requiring massive transfusion with all other pediatric trauma patients to identify triggers for MTP activation in injured children. METHODS: Using our level I trauma center's registry, we retrospectively identified all pediatric trauma patients from January 2015 to January 2018. Massive transfusion (MT) was defined as infusion of 40 mL/kg of blood products in the first 24 hours of admission. Patients missing prehospital vital sign data were excluded from the study. We retrospectively collected data including demographics, blood utilization, variable outcome data, prehospital vital signs, prehospital transport times, and Injury Severity Scores. Statistical significance was determined using Mann-Whitney U test and χ2 test. p Values of less than 0.05 were considered significant. RESULTS: Thirty-nine (1.9%) of the 2,035 pediatric patients met the criteria for MT. All-cause mortality in MT patients was 49% (19 of 39 patients) versus 0.01% (20 of 1996 patients) in non-MT patients. The two groups significantly differed in Injury Severity Score, prehospital vital signs, and outcome data.Both systolic blood pressure (SBP) of <100 mm Hg and shock index (SI) of >1.4 were found to be highly specific for MT with specificities of 86% and 92%, respectively. The combination of SBP of <100 mm Hg and SI of >1.4 had a specificity of 94%. The positive and negative predictive values of SBP of <100 mm Hg and SI of >1.4 in predicting MT were 18% and 98%, respectively. Based on positive likelihood ratios, patients with both SBP of <100 mm Hg and SI of >1.4 were 7.2 times more likely to require MT than patients who did not meet both of these vital sign criteria. CONCLUSION: Pediatric trauma patients requiring early blood transfusion present with lower blood pressures and higher heart rates, as well as higher SIs and lower pulse pressures. We found that SI and SBP are highly specific tools with promising likelihood ratios that could be used to identify patients requiring early transfusion. LEVEL OF EVIDENCE: Therapeutic/care management, level V.

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.

Timing of repair of blunt thoracic aortic injuries in the thoracic endovascular aortic repair era.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) is the preferred operative treatment of blunt thoracic aortic injuries (BTAIs). Its use is associated with improved outcomes compared with open surgical repair and nonoperative management. However, the optimal time from injury to repair is unknown and remains a subject of debate across different societal practice guidelines. The purpose of this study was to evaluate national trends in the management of BTAI, with a specific focus on the impact of timing of repair on outcomes. METHODS: Using the National Trauma Data Bank, we identified adult patients with BTAI between 2012 and 2017. Patients with prehospital or emergency department cardiac arrest or incomplete data sets were excluded from analysis. Patients were classified according to timing of repair: group 1, <24 hours; and group 2, ≥24 hours. The primary outcome evaluated was in-hospital mortality; secondary outcomes included overall hospital and intensive care unit length of stay. Multivariable logistic regression was performed to identify independent predictors of mortality. RESULTS: The analysis was completed for 2821 patients who underwent TEVAR for BTAI with known operative times. The overall mortality in the patient cohort was 8.4% (238/2821); 75% of patients undergoing TEVAR were repaired within 24 hours. Mortality was more than twofold greater in group 1 compared with group 2 (9.8% [207/2118] vs 4.4% [31/703]; P = .001). This mortality benefit persisted across injury severity groups and was independent of the presence of serious extrathoracic injuries. Logistic regression analysis, adjusting for age ≥65 years, Glasgow Coma Scale score ≤8, systolic blood pressure ≤90 mm Hg at admission, and serious extrathoracic injuries, showed a higher adjusted mortality in group 1 (odds ratio, 2.54; 95% confidence interval, 1.66-3.91; P = .001). CONCLUSIONS: The majority of patients with BTAI undergo endovascular repair within 24 hours of injury. Patients undergoing delayed repair have improved survival compared with those repaired within the first 24 hours of injury in spite of similar injury patterns and severity. In patients with BTAIs without signs of imminent rupture, delaying endovascular repair beyond 24 hours after injury should be considered.

Delays in Surgical Intervention and Temporary Hemostasis Using Resuscitative Endovascular Balloon Occlusion of the aorta (REBOA): Influence of Time to Operating Room on Mortality.

BACKGROUND: The optimal candidates for resuscitative endovascular balloon occlusion of the aorta (REBOA) remain unclear. We hypothesized that patients who experience delays in surgical intervention would benefit from REBOA. METHODS: Using the Japan Trauma Databank (2014-2019), patients transferred to the operating room (OR) within 3 h were identified. Patients treated with REBOA were matched with those without REBOA using propensity scores, and further divided based on the transfer time to OR: ≤ 1 h (early), 1-2 h (delayed), and >2 h (significantly-delayed). Survival to discharge was compared. RESULTS: Among 5258 patients, 310 underwent REBOA. In 223 matched pairs, patients treated with REBOA had improved survival (56.5% vs. 31.8%; p < 0.01), although in-hospital mortality was reduced by REBOA only in the delayed and significantly-delayed subgroups (HR = 0.43 [0.28-0.65] and 0.42 [0.25-0.71]). CONCLUSIONS: REBOA-treated trauma patients who experience delays in surgical intervention (>1 h) have improved survival.

Predictors of retained hemothorax in trauma: Results of an Eastern Association for the Surgery of Trauma multi-institutional trial.

BACKGROUND: The natural history of traumatic hemothorax (HTX) remains unclear. We aimed to describe outcomes of HTX following tube thoracostomy drainage and to delineate factors that predict progression to a retained hemothorax (RH). We hypothesized that initial large-volume HTX predicts the development of an RH. METHODS: We conducted a prospective, observational, multi-institutional study of adult trauma patients diagnosed with an HTX identified on computed tomography (CT) scan with volumes calculated at time of diagnosis. All patients were managed with tube thoracostomy drainage within 24 hours of presentation. Retained hemothorax was defined as blood-density fluid identified on follow-up CT scan or need for additional intervention after initial tube thoracostomy placement for HTX. RESULTS: A total of 369 patients who presented with an HTX initially managed with tube thoracostomy drainage were enrolled from 17 trauma centers. Retained hemothorax was identified in 106 patients (28.7%). Patients with RH had a larger median (interquartile range) HTX volume on initial CT compared with no RH (191 [48-431] mL vs. 88 [35-245] mL, p = 0.013) and were more likely to be older with a higher burden of thoracic injury. After controlling for significant differences between groups, RH was independently associated with a larger HTX on presentation, with a 15% increase in risk of RH for each additional 100 mL of HTX on initial CT imaging (odds ratio, 1.15; 95% confidence interval, 1.08-1.21; p < 0.001). Patients with an RH also had higher rates of pneumonia and longer hospital length of stay than those with successful initial management. Retained hemothorax was also associated with worse functional outcomes at discharge and first outpatient follow-up. CONCLUSION: Larger initial HTX volumes are independently associated with RH, and unsuccessful initial management with tube thoracostomy is associated with worse patient outcomes. Future studies should use this experience to assess a range of options for reducing the risk of unsuccessful initial management. LEVEL OF EVIDENCE: Therapeutic/care management study, level III.

The gut microbiome distinguishes mortality in trauma patients upon admission to the emergency department.

BACKGROUND: Traumatic injury can lead to a compromised intestinal epithelial barrier, decreased gut perfusion, and inflammation. While recent studies indicate that the gut microbiome (GM) is altered early following traumatic injury, the impact of GM changes on clinical outcomes remains unknown. Our objective of this follow-up study was to determine if the GM is associated with clinical outcomes in critically injured patients. METHODS: We conducted a prospective, observational study in adult patients (N = 67) sustaining severe injury admitted to a level I trauma center. Fecal specimens were collected on admission to the emergency department, and microbial DNA from all samples was analyzed using the Quantitative Insights Into Microbial Ecology pipeline and compared against the Greengenes database. α-Diversity and ß-diversity were estimated using the observed species metrics and analyzed with t tests and permutational analysis of variance for overall significance, with post hoc pairwise analyses. RESULTS: Our patient population consisted of 63% males with a mean age of 44 years. Seventy-eight percent of the patients suffered blunt trauma with 22% undergoing penetrating injuries. The mean body mass index was 26.9 kg/m. Significant differences in admission ß-diversity were noted by hospital length of stay, intensive care unit hospital length of stay, number of days on the ventilator, infections, and acute respiratory distress syndrome (p < 0.05). ß-Diversity on admission differed in patients who died compared with patients who lived (mean time to death, 8 days). There were also significantly less operational taxonomic units in samples from patients who died versus those who survived. A number of species were enriched in the GM of injured patients who died, which included some traditionally probiotic species such as Akkermansia muciniphilia, Oxalobacter formigenes, and Eubacterium biforme (p < 0.05). CONCLUSION: Gut microbiome diversity on admission in severely injured patients is predictive of a variety of clinically important outcomes. While our study does not address causality, the GM of trauma patients may provide valuable diagnostic and therapeutic targets for the care of injured patients. LEVEL OF EVIDENCE: Prognostic and epidemiological, level III.

Shock index and pulse pressure as triggers for massive transfusion.

BACKGROUND: Hemorrhage is the most common cause of preventable death in trauma patients. These mortalities might be prevented with prehospital transfusion. We sought to characterize injured patients requiring massive transfusion to determine the potential impact of a prehospital whole blood transfusion program. The primary goal of this analysis was to determine a method to identify patients at risk of massive transfusion in the prehospital environment. Many of the existing predictive models require laboratory values and/or sonographic evaluation of the patient after arrival at the hospital. Development of an algorithm to predict massive transfusion protocol (MTP) activation could lead to an easy-to-use tool for prehospital personnel to determine when a patient needs blood transfusion. METHODS: Using our Level I trauma center's registry, we retrospectively identified all adult trauma patients from January 2015 to August 2017 requiring activation of the MTP. Patients who were younger than 18 years, older than 89 years, prisoners, pregnant women, and/or with nontraumatic hemorrhage were excluded from the study. We retrospectively collected data including demographics, blood utilization, variable outcome data (survival, length of stay, intensive care unit days, ventilator days), prehospital vital signs, prehospital transport times, and Injury Severity Score. The independent-samples t test and χ test were used to compare the group who died to the group who survived. p < 0.05 was considered significant. Based on age and mechanism of injury, relative risk of death was calculated. Graphs were generated using Microsoft Excel software to plot patient variables. RESULTS: Our study population of 102 MTP patients had an average age of 42 years and average Injury Severity Score of 29, consisted of 80% males (82/102), and was 66% blunt trauma (67/102). The all-cause mortality was 67% (68/102). The positive predictive value of death for patients with pulse pressure of less than 45 and shock index of greater than 1 was 0.78 for all patients, but was 0.79 and 0.92 for blunt injury and elderly patients, respectively. CONCLUSIONS: Our data demonstrate a high mortality rate in trauma patients who require MTP despite short transport times, indicating the need for early intervention in the prehospital environment. Given our understanding that the most severely injured patients in hemorrhagic shock require blood resuscitation, this study demonstrates that this subset of trauma patients requiring massive transfusion can be identified in the prehospital setting. We recommend using Emergency Medical Services pulse pressure in combination with shock index to serve as a trigger for initiation of prehospital whole blood transfusion. LEVEL OF EVIDENCE: Therapeutic/care management, level V.

Outcomes after splenectomy in children: a 48-year population-based study.

PURPOSE: In children who have undergone splenectomy, there may be impaired immunologic function and an increased risk of infection. We aimed to define the long-term rate of and risk factors for post-splenectomy infection using a population-based cohort study. METHODS: All children (< 18 years) who underwent splenectomy from 1966 to 2011 in Olmsted County, MN were identified using the Rochester Epidemiology Project (REP). Descriptive statistics, Kaplan-Meier estimates, and Cox Proportional hazard ratios were performed to evaluate for risk factors associated with developing infection. RESULTS: Ninety patients underwent splenectomy and 46% were female. Indications included trauma (42%), benign hematologic disease (33%), malignancy (13%), and other (11%). Most were performed open. Vaccination was completed in (72%) for pneumococcal, H. influenza, and meningococcal vectors. Nineteen patients developed infection, and associated factors included non-traumatic, non-malignant disease [HR 4.83 (1.18-19.85)], and performance of multiple surgical procedures [HR 2.80 (1.09-7.21)]. Estimated survival free of infection rates at 15 and 20 years following surgery was both 97%. CONCLUSIONS: After splenectomy in children, most patients do not develop infection. Nearly three-quarters of patients were vaccinated with the lowest rates in patients that underwent a splenectomy for trauma. In patients who received multiple procedures during a splenectomy, the infection risk was higher.