The epidemiology and modern management of traumatic hemorrhage: US and international perspectives

Management of Suspected Peripheral Vascular Injuries in Orthopedic Trauma

OBJECTIVE

In orthopedic trauma, identification of extremity trauma combined with vascular injury is challenging. Missed diagnosis may result in amputation or even death. The purpose of this study was to investigate whether physical examination combined with handheld vascular ultrasound Doppler examination could be an effective method of screening for peripheral vascular injury and to explore the characteristics of vascular injuries in orthopedic trauma patients.

METHODS

Retrospective analysis of patients in the emergency department of orthopedic trauma in our hospital from January 2022 to October 2023. Physical examination combined with handheld vascular ultrasound Doppler examination was used as a screening method for suspected vascular injuries. Patients with suspected vascular injury would undergo further angiography and receive multidisciplinary treatment. Angiography was used as the gold standard for diagnosing vascular injuries. Patient demographics, mechanism of injury, location and type of injury, angiographic results, surgical notes, and early treatment outcome data were recorded.

RESULTS

A total of 55 cases (58 limb injuries) with suspected vascular injury were ultimately included. Angiography revealed that 53 cases (55 limbs, positive rate 94.8%) were considered to have confirmed vascular injuries. Forty-three were male (81.1%) and 10 were female (18.9%), with mean age 44.1 ± 16.6 years. The main mechanism of injury was traffic accident (30, 56.7%). Most common site of vascular injuries was knee joint (30/55, 54.5%), and popliteal artery (23, 47.9%) was the most commonly injured blood vessel. After multidisciplinary collaborative treatment, overall patient mortality was 3.8% (2/53), and limb survival rate among surviving patients was 81.1% (43/53) in our study.

CONCLUSION

In orthopedic trauma, "Hard signs" and "soft signs" combined with handheld vascular ultrasound Doppler examination were effective ways to screen for suspected vascular injuries. Most limbs had associated fractures or dislocations at the site of vascular injury. Collaboration of vascular surgery, microsurgery and orthopedic trauma may help improve patients' prognosis.

Development of a two-hit lethal liver injury model in swine

PURPOSE

Noncompressible truncal hemorrhage remains a leading cause of preventable death in the prehospital setting. Standardized and reproducible large animal models are essential to test new therapeutic strategies. However, existing injury models vary significantly in consistency and clinical accuracy. This study aims to develop a lethal porcine model to test hemostatic agents targeting noncompressible abdominal hemorrhages.

METHODS

We developed a two-hit injury model in Yorkshire swine, consisting of a grade IV liver injury combined with hemodilution. The hemodilution was induced by controlled exsanguination of 30% of the total blood volume and a 3:1 resuscitation with crystalloids. Subsequently, a grade IV liver injury was performed by sharp transection of both median lobes of the liver, resulting in major bleeding and severe hypotension. The abdominal incision was closed within 60 s from the injury. The endpoints included mortality, survival time, serum lab values, and blood loss within the abdomen.

RESULTS

This model was lethal in all animals (5/5), with a mean survival time of 24.4 ± 3.8 min. The standardized liver resection was uniform at 14.4 ± 2.1% of the total liver weight. Following the injury, the MAP dropped by 27 ± 8mmHg within the first 10 min. The use of a mixed injury model (i.e., open injury, closed hemorrhage) was instrumental in creating a standardized injury while allowing for a clinically significant hemorrhage.

CONCLUSION

This novel highly lethal, consistent, and clinically relevant translational model can be used to test and develop life-saving interventions for massive noncompressible abdominal hemorrhage.

Post-Reconstitution Hemostatic Stability Profiles of Canadian and German Freeze-Dried Plasma

Despite the importance of the hemostatic properties of reconstituted freeze-dried plasma (FDP) for trauma resuscitation, few studies have been conducted to determine its post-reconstitution hemostatic stability. This study aimed to assess the short- (≤24 h) and long-term (≥168 h) hemostatic stabilities of Canadian and German freeze-dried plasma (CFDP and LyoPlas) after reconstitution and storage under different conditions. Post-reconstitution hemostatic profiles were determined using rotational thromboelastometry (ROTEM) and a Stago analyzer, as both are widely used as standard methods for assessing the quality of plasma. When compared to the initial reconstituted CFDP, there were no changes in ROTEM measurements for INTEM maximum clot firmness (MCF), EXTEM clotting time (CT) and MCF, and Stago measurements for prothrombin time (PT), partial thromboplastin time (PTT), D-dimer concentration, plasminogen, and protein C activities after storage at 4 °C for 24 h and room temperature (RT) (22-25 °C) for 4 h. However, an increase in INTEM CT and decreases in fibrinogen concentration, factors V and VIII, and protein S activities were observed after storage at 4 °C for 24 h, while an increase in factor V and decreases in antithrombin and protein S activities were seen after storage at RT for 4 h. Evaluation of the long-term stability of reconstituted LyoPlas showed decreased stability in both global and specific hemostatic profiles with increasing storage temperatures, particularly at 35 °C, where progressive changes in CT and MCF, PT, PTT, fibrinogen concentration, factor V, antithrombin, protein C, and protein S activities were seen even after storage for 4 h. We confirmed the short-term stability of CFDP in global hemostatic properties after reconstitution and storage at RT, consistent with the shelf life of reconstituted LyoPlas. The long-term stability analyses suggest that the post-reconstitution hemostatic stability of FDP products would decrease over time with increasing storage temperature, with a significant loss of hemostatic functions at 35 °C compared to 22 °C or below. Therefore, the shelf life of reconstituted FDP should be recommended according to the storage temperature.

Diagnostic Adjunct Techniques in the Assessment of Hypovolemia: A Prospective Pilot Project

INTRODUCTION

Measuring the hypovolemic resuscitation end point remains a critical care challenge. Our project compared clinical hypovolemia (CH) with three diagnostic adjuncts: 1) noninvasive cardiac output monitoring (NICOM), 2) ultrasound (US) static IVC collapsibility (US-IVC), and 3) US dynamic carotid upstroke velocity (US-C). We hypothesized US measures would correlate more closely to CH than NICOM.

METHODS

Adult trauma/surgical intensive care unit patients were prospectively screened for suspected hypovolemia after acute resuscitation, excluding patients with burns, known heart failure, or severe liver/kidney disease. Adjunct measurements were assessed up to twice a day until clinical improvement. Hypovolemia was defined as: 1) NICOM: ≥10% stroke volume variation with passive leg raise, 2) US-IVC: <2.1 cm and >50% collapsibility (nonventilated) or >18% collapsibility (ventilated), 3) US-C: peak systolic velocity increase 15 cm/s with passive leg raise. Previously unknown cardiac dysfunction seen on US was noted. Observation-level data were analyzed with a Cohen's kappa (κ).

RESULTS

44 patients (62% male, median age 60) yielded 65 measures. Positive agreement with CH was 47% for NICOM, 37% for US-IVC and 10% for US-C. None of the three adjuncts correlated with CH (κ -0.045 to 0.029). After adjusting for previously unknown cardiac dysfunction present in 10 patients, no adjuncts correlated with CH (κ -0.036 to 0.031). No technique correlated with any other (κ -0.118 to 0.083).

CONCLUSIONS

None of the adjunct measurements correlated with CH or each other, highlighting that fluid status assessment remains challenging in critical care. US should assess for right ventricular dysfunction prior to resuscitation.

Is a Positive Prehospital FAST Associated with Severe Bleeding? A Multicenter Retrospective Study

INTRODUCTION

Severe hemorrhage is the leading cause of early preventable death in severe trauma patients. Delayed diagnosis is a poor prognostic factor, and severe hemorrhage prediction is essential. The aim of our study was to investigate if there was an association between the detection of peritoneal or pleural fluid on prehospital sonography for trauma and posttraumatic severe hemorrhage.

METHODS

We retrospectively studied data from records of thoracic or abdominal trauma patients managed in mobile intensive care units from January 2017 to December 2021 in four centers in France. Severe hemorrhage was defined as a condition necessitating transfusion of at least four packed red blood cells or surgical intervention/radioembolization for hemostasis within the first 24 h. Using a multivariate analysis, we investigated the predictive performance of focused assessment with sonography for trauma (FAST) alone or in combination with the five Red Flags criteria validated by Hamada et al.

RESULTS

Among the 527 patients analyzed, 371 (71%) were men, the mean age was 41 ± 19 years, and the Injury Severity Score was 11 (Interquartile range = [5; 22]). Seventy-three (14%) patients had severe hemorrhage - of whom 28 (38%) had a positive FAST, compared to 61 (13%) without severe hemorrhage (p < 0.01). For severe hemorrhage prediction, FAST had a sensitivity of 38% (95%CI = [27%; 50%]) and a specificity of 87% (95%CI = [83%; 90%]) (AUC = 0.62, 95%CI = [0.57; 0.68]). The comparison of the other outcomes between positive and negative FAST was: hemostatic procedure, 22 (25%) vs 28 (6%), p < 0.01; intensive care unit admission 71 (80%) vs 190 (43%), p < 0.01; mean length of hospital stay 11 [4; 27] vs 4 [0; 14] days, p = 0.02; 30-day mortality 13 (15%) vs 22 (5%), p < 0.01.

CONCLUSION

A positive FAST performed in the prehospital setting is associated with severe hemorrhage and all prognostic criteria we studied.

Tracking Research on Hemoglobin-Based Oxygen Carriers: A Scientometric Analysis and In-Depth Review

Numerous studies on the formulation and clinical applications of novel hemoglobin-based oxygen carriers (HBOCs) are reported in the scientific literature. However, there are fewer scientometric analysis related to HBOCs. Here, we illustrate recent studies on HBOCs using both a scientometric analysis approach and a scope review method. We used the former to investigate research on HBOCs from 1991 to 2022, exploring the current hotspots and research trends, and then we comprehensively analyzed the relationship between concepts based on the keyword analysis. The evolution of research fields, knowledge structures, and research topics in which HBOCs located are revealed by scientometric analysis. The elucidation of type, acting mechanism, potential clinical practice, and adverse effects of HBOCs helps to clarify the prospects of this biological agent. Scientometrics analyzed 1034 publications in this research field, and these findings provide a promising roadmap for further study.

The forgotten cohort-lessons learned from prehospital trauma death: a retrospective cohort study

BACKGROUND

Trauma related deaths remain a relevant public health problem, in particular in the younger male population. A significant number of these deaths occur prehospitally without transfer to a hospital. These patients, sometimes termed "the forgotten cohort", are usually not included in clinical registries, resulting in a lack of information about prehospitally trauma deaths. The aim of the present study was to compare patients who died prehospital with those who sustained life-threatening injuries in order to analyze and potentially improve prehospital strategies.

METHODS

This cohort study included all primary operations carried out by Switzerland's largest helicopter emergency medical service (HEMS) between January 1, 2011, and December 31, 2021. We included all adult trauma patients with life-threatening or fatal conditions. The outcome of this study is the vital status of the patient at the end of mission, i.e. fatal or life-threatening. Injury, rescue characteristics, and interventions of the forgotten trauma cohort, defined as patients with a fatal injury (NACA score of VII), were compared with life-threatening injuries (NACA score V and VI).

RESULTS

Of 110,331 HEMS missions, 5534 primary operations were finally analyzed, including 5191 (93.8%) life-threatening and 343 (6.2%) fatal injuries. More than two-thirds of patients (n = 3772, 68.2%) had a traumatic brain injury without a significant difference between the two groups (p > 0.05). Thoracic trauma (44.6% vs. 28.7%, p < 0.001) and abdominal trauma (22.2% vs. 16.1%, p = 0.004) were more frequent in fatal missions whereas pelvic trauma was similar between the two groups (13.4% vs. 12.9%, p = 0.788). Pneumothorax decompression rate (17.2% vs. 3.7%, p < 0.001) was higher in the forgotten cohort group and measures for bleeding control (15.2% vs. 42.7%, p < 0.001) and pelvic belt application (2.9% vs. 13.1% p < 0.001) were more common in the life-threating injury group.

CONCLUSION

Chest decompression rates and measures for early hemorrhage control are areas for potential improvement in prehospital care.

Retrospective value assessment of a dedicated, trauma hybrid operating room

BACKGROUND

In traumatic hemorrhage, hybrid operating rooms offer near simultaneous performance of endovascular and open techniques, with correlations to earlier hemorrhage control, fewer transfusions, and possible decreased mortality. However, hybrid operating rooms are resource intensive. This study quantifies and describes a single-center experience with the complications, cost-utility, and value of a dedicated trauma hybrid operating room.

METHODS

This retrospective cohort study evaluated 292 consecutive adult trauma patients who underwent immediate (<4 hours) operative intervention at a Level I trauma center. A total of 106 patients treated before the construction of a hybrid operating room served as historical controls to the 186 patients treated thereafter. Demographics, hemorrhage-control procedures, and financial data as well as postoperative complications and outcomes were collected via electronic medical records. Value and incremental cost-utility ratio were calculated.

RESULTS

Demographics and severity of illness were similar between cohorts. Resuscitative endovascular occlusion of the aorta was more frequently used in the hybrid operating room. Hemorrhage control occurred faster (60 vs. 49 minutes, p = 0.005) and, in the 4- to 24-hour postadmission period, required less red blood cell (mean, 1.0 vs. 0 U, p = 0.001) and plasma (mean, 1.0 vs. 0 U, p < 0.001) transfusions. Complications were similar except for a significant decrease in pneumonia (7% vs. 4%, p = 0.008). Severe complications (Clavien-Dindo classification, ≥3) were similar. Across the patient admission, costs were not significantly different ($50,023 vs. $54,740, p = 0.637). There was no change in overall value (1.00 vs. 1.07, p = 0.778).

CONCLUSION

The conversion of our standard trauma operating room to an endovascular hybrid operating room provided measurable improvements in hemorrhage control, red blood cell and plasma transfusions, and postoperative pneumonia without significant increase in cost. Value was unchanged.

LEVEL OF EVIDENCE

Economic/Value-Based Evaluations; Level III.

Survival and neurologic outcomes following aortic occlusion for trauma and hemorrhagic shock in a hybrid operating room

BACKGROUND

Outcomes following aortic occlusion for trauma and hemorrhagic shock are poor, leading some to question the clinical utility of aortic occlusion in this setting. This study evaluates neurologically intact survival following resuscitative endovascular balloon occlusion of the aorta (REBOA) versus resuscitative thoracotomy at a center with a dedicated trauma hybrid operating room with angiographic capabilities.

METHODS

This retrospective cohort analysis compared patients who underwent zone 1 aortic occlusion via resuscitative thoracotomy (n = 13) versus REBOA (n = 13) for blunt or non-thoracic, penetrating trauma and refractory hemorrhagic shock (systolic blood pressure less than 90 mmHg despite volume resuscitation) at a level 1 trauma center with a dedicated trauma hybrid operating room. The primary outcome was survival to hospital discharge. The secondary outcome was neurologic status at hospital discharge, assessed by Glasgow Coma Scale (GCS) scores.

RESULTS

Overall median age was 40 years, 27% had penetrating injuries, and 23% had pre-hospital closed-chest cardiopulmonary resuscitation. In both cohorts, median injury severity scores and head-abbreviated injury scores were 26 and 2, respectively. The resuscitative thoracotomy cohort had lower systolic blood pressure on arrival (0 [0-75] vs. 76 [65-99], p = 0.009). Hemorrhage control (systolic blood pressure 100 mmHg without ongoing vasopressor or transfusion requirements) was obtained in 77% of all REBOA cases and 8% of all resuscitative thoracotomy cases (p = 0.001). Survival to hospital discharge was greater in the REBOA cohort (54% vs. 8%, p = 0.030), as was discharge with GCS 15 (46% vs. 0%, p = 0.015).

CONCLUSIONS

Among patients undergoing aortic occlusion for blunt or non-thoracic, penetrating trauma and refractory hemorrhagic shock at a center with a dedicated, trauma hybrid operating room, nearly half of all patients managed with REBOA had neurologically intact survival. The high death rate in resuscitative thoracotomy and differences in patient cohorts limit direct comparison.

A double-edged sword of platelet-derived extracellular vesicles in tissues, injury or repair: The current research overview

Extracellular vesicles (EVs) are vesicular bodies with a double-layered membrane structure that are detached from the cell membrane or secreted by the cells. EVs secreted by platelets account for the main part in the blood circulation, which account for about 30% or even more. Many types of cells are regulated by PEVs, including endothelial cells, leukocytes, smooth muscle cells, etc. Nevertheless, despite the growing interest in the study of extracellular vesicles, there are still only a few studies on the role of PEVs. Therefore, this overview mainly focuses on one method of isolation and the functions of PEVs in tissues found so far, including promoting tissue repair and mediating tissue damage, which can be used for researchers to continue to explore the role of PEVs in other fields.

Mycobacterium vaccae protects against glucocorticoid resistance resulting from combined physical and psychosocial trauma in mice

Stress-related somatic and psychiatric disorders are often associated with a decline in regulatory T cell (Treg) counts and chronic low-grade inflammation. Recent preclinical evidence suggests that the latter is at least partly mediated by stress-induced upregulation of toll-like receptor (TLR)2 in newly generated neutrophils and polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), as well as glucocorticoid (GC) resistance in predominantly PMN-MDSCs following stress-induced upregulation of TLR4 expression. Here we show in mice exposed to the chronic subordinate colony housing (CSC) paradigm that repeated intragastric (i.g.) administrations of a heat-killed preparation of Mycobacterium vaccae NCTC 11659, a saprophytic microorganism with immunoregulatory properties, protected against the stress-induced reduction in systemic Tregs, increase in basal and LPS-induced in vitro splenocyte viability, as well as splenic in vitro GC resistance. Our findings further support the hypothesis that i.g. M. vaccae protects against CSC-associated splenic GC resistance via directly affecting the myeloid compartment, thereby preventing the CSC-induced upregulation of TLR4 in newly generated PMN-MDSCs. In contrast, the protective effects of i.g. M. vaccae on the CSC-induced upregulation of TLR2 in neutrophils and the subsequent increase in basal and LPS-induced in vitro splenocyte viability seems to be indirectly mediated via the Treg compartment. These data highlight the potential for use of oral administration of M. vaccae NCTC 11659 to prevent stress-induced exaggeration of inflammation, a risk factor for development of stress-related psychiatric disorders.

Artificial intelligence and machine learning for hemorrhagic trauma care

Artificial intelligence (AI), a branch of machine learning (ML) has been increasingly employed in the research of trauma in various aspects. Hemorrhage is the most common cause of trauma-related death. To better elucidate the current role of AI and contribute to future development of ML in trauma care, we conducted a review focused on the use of ML in the diagnosis or treatment strategy of traumatic hemorrhage. A literature search was carried out on PubMed and Google scholar. Titles and abstracts were screened and, if deemed appropriate, the full articles were reviewed. We included 89 studies in the review. These studies could be grouped into five areas: (1) prediction of outcomes; (2) risk assessment and injury severity for triage; (3) prediction of transfusions; (4) detection of hemorrhage; and (5) prediction of coagulopathy. Performance analysis of ML in comparison with current standards for trauma care showed that most studies demonstrated the benefits of ML models. However, most studies were retrospective, focused on prediction of mortality, and development of patient outcome scoring systems. Few studies performed model assessment via test datasets obtained from different sources. Prediction models for transfusions and coagulopathy have been developed, but none is in widespread use. AI-enabled ML-driven technology is becoming integral part of the whole course of trauma care. Comparison and application of ML algorithms using different datasets from initial training, testing and validation in prospective and randomized controlled trials are warranted for provision of decision support for individualized patient care as far forward as possible.

The PMN-MDSC - A key player in glucocorticoid resistance following combined physical and psychosocial trauma

Stress-associated somatic and psychiatric disorders are often linked to non-resolving low-grade inflammation, which is promoted at least in part by glucocorticoid (GC) resistance of distinct immune cell subpopulations. While the monocyte/macrophage compartment was in the focus of many clinical and preclinical studies, the role of myeloid-derived suppressor cells (MDSCs) in stress-associated pathologies and GC resistance is less understood. As GC resistance is a clear risk factor for posttraumatic complications in patients on intensive care, the exact interplay of physical and psychosocial traumatization in the development of GC resistance needs to be further clarified. In the current study we employ the chronic subordinate colony housing (CSC) paradigm, a well-characterized mouse model of chronic psychosocial stress, to study the role of myeloid cells, in particular of MDSCs, in innate immune activation and GC resistance following combined psychosocial and physical (e.g., bite wounds) trauma. Our findings support the hypothesis that stress-induced neutrophils, polymorphonuclear (PMN)-MDSCs and monocytes/monocyte-like (MO)-MDSCs get primed and activated locally in the bone marrow as determined by toll-like receptor (TLR)2 upregulation and increased basal and lipopolysaccharide (LPS)-induced in vitro cell viability. These primed and activated myeloid cells emigrate into the peripheral circulation and subsequently, if CSC is accompanied by significant bite wounding, accumulate in the spleen. Here, PMN-MDSCs and monocytes/MO-MDSCs upregulate TLR4 expression, which exclusively in PMN-MDSCs promotes NF-κB hyperactivation upon LPS-stimulation, thereby exceeding the anti-inflammatory capacities of GCs and resulting in GC resistance.

Survival and neurologic outcomes following aortic occlusion for trauma and hemorrhagic shock in a hybrid operating room

Background: Outcomes following aortic occlusion for trauma and hemorrhagic shock are poor, leading some to question the clinical utility of aortic occlusion in this setting. This study evaluates neurologically intact survival following resuscitative endovascular balloon occlusion of the aorta (REBOA) vs. resuscitative thoracotomy at a center with a dedicated trauma hybrid operating room with angiographic capabilities. Methods: This retrospective cohort analysis compared patients who underwent zone 1 aortic occlusion via resuscitative thoracotomy (n=13) vs. REBOA (n=13) for blunt or non-thoracic, penetrating trauma and refractory hemorrhagic shock (systolic blood pressure less than 90 mmHg despite volume resuscitation) at a level 1 trauma center with a dedicated, trauma hybrid operating room. The primary outcome was survival to hospital discharge. The secondary outcome was neurologic status at hospital discharge, assessed by Glasgow Coma Scale (GCS) scores. Results: Overall median age was 40 years, 27% had penetrating injuries, and 23% had pre-hospital closed-chest cardiopulmonary resuscitation. In both cohorts, median Injury Severity Scores and head Abbreviated Injury Scores were 26 and 2, respectively. The resuscitative thoracotomy cohort had lower systolic blood pressure on arrival (0 [0-75] vs. 76 [65-99], p=0.009). Hemorrhage control (systolic blood pressure 100 mmHg without ongoing vasopressor or transfusion requirements) was obtained in 77% of all REBOA cases and 8% of all resuscitative thoracotomy cases (p=0.001). Survival to hospital discharge was greater in the REBOA cohort (54% vs. 8%, p=0.030), as was discharge with GCS 15 (46% vs. 0%, p=0.015). Conclusions: Among patients undergoing aortic occlusion for blunt or non-thoracic, penetrating trauma and refractory hemorrhagic shock at a center with a dedicated, trauma hybrid operating room, nearly half of all patients managed with REBOA had neurologically intact survival. The high death rate in resuscitative thoracotomy and differences in patient cohorts limit direct comparison.

Blood Utilization and Thresholds for Mortality Following Major Trauma

INTRODUCTION

Blood loss is a hallmark of traumatic injury. Massive transfusion, historically defined as the replacement by transfusion of 10 units of packed red blood cells (PRBCs) in 4 h, is a response to uncontrolled hemorrhage. We sought to identify blood transfusion thresholds in which predicted mortality exceeds 50%.

METHODS

We analyzed the 2017-2019 National Trauma Database. Inclusion criteria included patients ≥18 y who received ≥1 unit of PRBCs. Statistical analysis included bivariate analysis, logistic regression for mortality, and adjusted predicted probability modeling was utilized.

RESULTS

We identified 61,676 patients for analysis. The 50% predicted mortality for all patients was 31 PRBC units. The 50% predicted mortality was 6 units of PRBCs for elderly trauma patients 80 y and older.

CONCLUSIONS

Blood remains as scarce resource in hospitals especially with trauma. Patients receiving a massive transfusion over a short period of time may exhaust blood bank supply with diminishing survival benefit. Surgeons should be judicious regarding continued blood usage once the 50% predicted mortality threshold is reached.

Autologous blood resuscitation for large animals in a research setting using the Hemafuse device: Preliminary data of device use for controlled and real-world hemorrhage

Introduction

New low-cost technologies are needed to salvage lost blood in low-resource settings and large animal laboratories. The Hemafuse device is a simple mechanical device that can recover lost blood during surgery. The aim of this study is to assess the feasibility of this device for resuscitating large animals with controlled and unintended hemorrhage and to provide device considerations for use in this context.

Methods

This study had two experimental components: (1) the Hemafuse device was kept on-shelf and used as needed to assess real-world use for unintended hemorrhage during experiments, and (2) animals underwent a controlled hemorrhage protocol, where four anesthetized swine underwent aortic and external jugular vein catheterization for pressure monitoring. Animals were hemorrhaged into the pelvis, and the Hemafuse device was used to suction the blood through a filter and pushed into a heparinized bag for subsequent retransfusion. Blood samples were collected at baseline, hemorrhage, within the device, and post-retransfusion and laboratory tests were performed.

Results

Animals that underwent controlled hemorrhage had a baseline mean arterial pressure of 83.6 ± 7.8 mmHg, and central venous pressure of 12.8 ± 1.9 mmHg, with expected changes throughout hemorrhage and resuscitation. Following resuscitation, pH was similar to baseline (7.39 ± 0.05 vs. 7.31 ± 0.03, p = 0.24). Lactate increased throughout the experiment with no significant differences after autotransfusion compared to baseline (2.7 ± 0.7 vs. 4.1 ± 1.4 mmol/L, p = 0.37). There were no significant changes in metabolic physiology. Compared to baseline, the hemoglobin (7.8 ± 2.4 vs. 7.3 ± 1.8 g/dL, p = 0.74), hematocrit (23% ± 6.9 vs. 21.3% ± 5.6, p = 0.71), and activated clotting time (268.5 ± 44.5 vs. 193 ± 24.6 s, p = 0.35) were similar after retransfusion. When used for unintended hemorrhage, the animals were resuscitated using the device with a mean time to retransfusion time of 128.7 ± 13.3 s and 100% survival throughout the experiment.

Conclusion

The Hemafuse device is feasible and efficacious for supporting large animal resuscitation. This is preliminary evidence that the device is a low-risk and low-cost off-the-shelf option for resuscitation using autologous blood with no significant effect on physiology post-retransfusion. We recommend that research laboratories consider the Hemafuse device for emergency use, particularly for highly invasive surgical laboratories where banked blood is not readily available.

Civilian vascular trauma, treatment and outcome at a level 1-trauma centre

BACKGROUND

Outcomes after vascular injuries in wartime are well documented, but studies on vascular injuries in a civilian European populations are scarce.

METHODS

A retrospective study on all adults admitted to a North-European level 1-trauma centre 2009-2018 with The Abbreviated Injury Scale-codes for non-iatrogenic vascular trauma (VT). Data were extracted from both national and regional trauma-registries, as well as patient charts. Patient demographics, mechanism, and location of vascular injury were registered as well as its treatment. Incidence and injury scores (ISS, NISS and TRISS) were calculated and overall survival (Kaplan-Meier) estimated.

RESULTS

Of 4042 trauma-patients, 68 (1.7%) (median age 44 years, 76% males) sustained 81 vascular injuries (69 arterial; 12 venous); 46 blunt and 22 (32%) penetrating injuries. The total incidence of vascular injuries was 1.45/100,000 inhabitants and did not change over the study-period (95% confidence interval 1.13-1.82). The injuries were located in thorax (n = 17), neck (n = 16) and abdominal region (n = 15); most of the blunt injuries followed traffic (n = 31) or falling accidents (n = 10), and with 17 of the 22 penetrating injuries due to stabbing. The median ISS and NISS-scores were 22 and 33, with 50 (74%) and 55 (81%) patients having scores > 15, respectively. Forty-three (63%) patients had open surgical repair and 8 (12%) received endovascular treatment. Twenty-one patients died within 30-days (31%), 33% and 27% after blunt and penetrating injuries, respectively. Half of the patients that died within 24 h sustained aortic injury.

CONCLUSIONS

Traumatic vascular injuries are rare in civilian settings and are less than 2% of major trauma admissions. These patients are often seriously injured and their treatment can be challenging with high 30-day mortality.

TRIAL REGISTRATION

Retrospectively registered.

Class of hemorrhagic shock is associated with progressive diastolic coronary flow reversal and diminished left ventricular function

Introduction: The relationship between coronary artery flow and left ventricular (LV) function during hemorrhagic shock remains unknown. The aim of this study was to quantify coronary artery flow directionality alongside left ventricular function through the four classes of hemorrhage shock. Methods: Following baseline data collection, swine were exsanguinated into cardiac arrest via the femoral artery using a logarithmic bleed, taking each animal through the four classes of hemorrhagic shock based on percent bleed (class I: 15%; class II: 15%-30%; class III: 30%-40%; class IV: >40%). Telemetry data, left ventricular pressure-volume loops, and left anterior descending artery flow tracings over numerous cardiac cycles were collected and analyzed for each animal throughout. Results: Five male swine (mean 72 ± 12 kg) were successfully exsanguinated into cardiac arrest. Mean left ventricular end-diastolic volume, end-diastolic pressure, and stroke work decreased as the hemorrhagic shock class progressed (p < 0.001). The proportion of diastole spent with retrograde coronary flow was also associated with class of hemorrhagic shock (mean 5.6% of diastole in baseline, to 63.9% of diastole in class IV; p < 0.0001), worsening at each class from baseline through class IV. Preload recruitable stroke work (PRSW) decreased significantly in classes II through IV (p < 0.001). Systemic Vascular Resistance (SVR) is associated with class of hemorrhage shock (p < 0.001). Conclusion: With progressive classes of hemorrhagic shock left ventricular function progressively decreased, and the coronary arteries spent a greater proportion of diastole in retrograde flow, with progressively more negative total coronary flow. Preload recruitable stroke work, a load-independent measure of inotropy, also worsened in severe hemorrhagic shock, indicating the mechanism extends beyond the drop in preload and afterload alone.

Plasma-based assays distinguish hyperfibrinolysis and shutdown subgroups in trauma-induced coagulopathy

BACKGROUND

Trauma patients with abnormal fibrinolysis have increased morbidity and mortality. Knowledge of mechanisms differentiating fibrinolytic phenotypes is important to optimize treatment. We hypothesized that subjects with abnormal fibrinolysis identified by whole blood viscoelastometry can also be distinguished by plasma thrombin generation, clot structure, fibrin formation, and plasmin generation measurements.

METHODS

Platelet-poor plasma (PPP) from an observational cross-sectional trauma cohort with fibrinolysis shutdown (% lysis at 30 minutes [LY30] < 0.9, n = 11) or hyperfibrinolysis (LY30 > 3%, n = 9) defined by whole blood thromboelastography were studied. Noninjured control subjects provided comparative samples. Thrombin generation, fibrin structure and formation, and plasmin generation were measured by fluorescence, confocal microscopy, turbidity, and a fluorescence-calibrated plasmin assay, respectively, in the absence/presence of tissue factor or tissue plasminogen activator (tPA).

RESULTS

Whereas spontaneous thrombin generation was not detected in PPP from control subjects, PPP from hyperfibrinolysis or shutdown patients demonstrated spontaneous thrombin generation, and the lag time was shorter in hyperfibrinolysis versus shutdown. Addition of tissue factor masked this difference but revealed increased thrombin generation in hyperfibrinolysis samples. Compared with shutdown, hyperfibrinolysis PPP formed denser fibrin networks. In the absence of tPA, the fibrin formation rate was faster in shutdown than hyperfibrinolysis, but hyperfibrinolysis clots lysed spontaneously; these differences were masked by addition of tPA. Tissue plasminogen activator-stimulated plasmin generation was similar in hyperfibrinolysis and shutdown samples. Differences in LY30, fibrin structure, and lysis correlated with pH.

CONCLUSION

This exploratory study using PPP-based assays identified differences in thrombin generation, fibrin formation and structure, and lysis in hyperfibrinolysis and shutdown subgroups. These groups did not differ in their ability to promote tPA-triggered plasmin generation. The ability to characterize these activities in PPP facilitates studies to identify mechanisms that promote adverse outcomes in trauma.

LEVEL OF EVIDENCE

Prognostic/Epidemiological; Level III.

Emerging Polymer Materials in Trackable Endovascular Embolization and Cell Delivery: From Hype to Hope

Minimally invasive endovascular embolization is a widely used clinical technique used for the occlusion of blood vessels to treat various diseases. Different occlusive agents ranging from gelatin foam to synthetic polymers such as poly(vinyl alcohol) (PVA) have been commercially used for embolization. However, these agents have some drawbacks, such as undesired toxicity and unintended and uncontrolled occlusion. To overcome these issues, several polymer-based embolic systems are under investigation including biocompatible and biodegradable microspheres, gelling liquid embolic with controlled occlusive features, and trackable microspheres with enhanced safety profiles. This review aims to summarize recent advances in current and emerging polymeric materials as embolization agents with varying material architectures. Furthermore, this review also explores the potential of combining injectable embolic agents and cell therapy to achieve more effective embolization with the promise of outstanding results in treating various devastating diseases. Finally, limitations and challenges in developing next-generation multifunctional embolic agents are discussed to promote advancement in this emerging field.

Zone 1 REBOA in a combat DCBI swine model does not worsen brain injury

BACKGROUND

Zone 1 resuscitative endovascular balloon occlusion of the aorta has been recommended for refractory shock after a dismounted complex blast injury for the austere combat scenario. While resuscitative endovascular balloon occlusion of the aorta should enhance coronary perfusion, there is a potential risk of secondary brain injury due to loss of cerebral autoregulation. We developed a combat casualty relevant dismounted complex blast injury swine model to evaluate the effects of resuscitative endovascular balloon occlusion of the aorta zone I on intracranial pressure and cerebral edema. We hypothesized that zone 1 aortic occlusion with resuscitative endovascular balloon occlusion of the aorta would increase mean arterial pressure transmitted in excessive intracranial pressure, thereby worsening brain injury.

METHODS

50 kg male Yorkshire swine were subjected to a combination dismounted complex blast injury model consisting of blast traumatic brain injury (50 psi, ARA Mobile Shock Laboratory), tissue injury (bilateral femur fractures), and hemorrhagic shock (controlled bleeding to a base deficit goal of 10 mEq/L). During the shock phase, pigs were randomized to no aortic occlusion (n = 8) or to 30 minutes of zone 1 resuscitative endovascular balloon occlusion of the aorta (zone 1 aortic occlusion group, n = 6). After shock, pigs in both groups received a modified Tactical Combat Casualty Care-based resuscitation and were monitored for an additional 240 minutes until euthanasia/death for a total of 6 hours. Intracranial pressure was monitored throughout, and brains were harvested for water content. Linear mixed models for repeated measures were used to compare mean arterial pressure and intracranial pressure between zone 1 aortic occlusion and no aortic occlusion groups.

RESULTS

After dismounted complex blast injury, the zone 1 group had a significantly higher mean arterial pressure during hemorrhagic shock compared to the control group (41.2 mm Hg vs 16.7 mm Hg, P = .002). During balloon occlusion, intracranial pressure was not significantly elevated in the zone 1 aortic occlusion group vs control, but intracranial pressure was significantly lower in the zone 1 group at the end of the observation period. In addition, the zone 1 aortic occlusion group did not have increased brain water content (zone 1 aortic occlusion: 3.95 ± 0.1g vs no aortic occlusion: 3.95 ± 0.3 g, P = .87). Troponin levels significantly increased in the no aortic occlusion group but did not in the zone 1 aortic occlusion group.

CONCLUSION

Zone 1 aortic occlusion using resuscitative endovascular balloon occlusion of the aorta in a large animal dismounted complex blast injury model improved proximal mean arterial pressure while not significantly increasing intracranial pressure during balloon inflation. Observation up to 240 minutes postresuscitation did not show clinical signs of worsening brain injury or cardiac injury. These data suggest that in a dismounted complex blast injury swine model, resuscitative endovascular balloon occlusion of the aorta in zone 1 may provide neuro- and cardioprotection in the setting of blast traumatic brain injury. However, longer monitoring periods may be needed to confirm that the neuroprotection is lasting.

The Utility of the Shock Index for Predicting Survival, Function and Health Status Outcomes in Major Trauma Patients: A Registry-Based Cohort Study

The shock index (SI; heart rate/systolic blood pressure) has been found to predict mortality in trauma patients. The aims of this study were to establish whether the SI improved the prediction of an existing model for both mortality and longer-term outcomes in major trauma patients. In total, 29,574 adult (>15 years) major trauma patients were included from the Victorian State Trauma Registry with a date of injury from July 2009 to June 2019. Outcomes of interest were survival to hospital discharge and function and health status at 6 months post-injury. Survival and function were analysed using measures of discrimination and calibration, whereas health status was assessed with R2 and MRSE measures. The area under the receiver operating characteristic curve (AUC) of the VSTR survival model improved when the SI was added (AUC 0.797 (0.787–0.807) versus AUC 0.807 (0.797–0.816), p < 0.001). For the prediction of functional outcome 6 months post-injury, the inclusion of the SI increased the AUC marginally (AUC 0.795 (0.786–0.803) versus AUC 0.799 (0.791–0.807), p < 0.001). When predicting in-hospital mortality and health status 6 months post-injury, including the SI resulted in a slightly better fit to the registry-risk adjustment model. In the future, external validation and the exploration of other models to improve prediction outcomes are warranted.

Fluid Resuscitation Aggravates the Cellular Injury in a Hemorrhagic Shock Model

<b><i>Background:</i></b> Resuscitation is the initial step for hemorrhagic shock. However, there is still controversy as to which fluid achieves the best results clinically and experimentally. <b><i>Aim:</i></b> It was aimed to investigate the effects of 0.9% NaCl (sodium chloride) and 6% HES (hydroxyethyl starch) on the kidney and blood environment. <b><i>Methods:</i></b> Twenty-four male Wistar rats were assigned as control, shock, and resuscitated (colloid: 6% HES and crystalloid: 0.9% NaCl) groups. Besides hemodynamics (mean arterial pressure and shock index) monitoring and kidney function evaluation, hemolysis, oxidative stress, inflammation, and glycocalyx degradation were evaluated in the plasma and kidney. <b><i>Results:</i></b> (1) Macrohemodynamics were successfully restored by both fluids. (2) Although 3 times more crystalloid volume was applied compared to the colloid resuscitation, similar hematocrit levels were found in both resuscitation strategies (32.8 ± 2.3 vs. 33.3 ± 1.0). (3) NaCl resuscitation led to increases in the hemolytic index, catalytic iron, and sialic acid compared to control, while HES administration increased the levels of malondialdehyde, ischemia-modified albumin, and sialic acid. (4) However, both fluid resuscitation strategies could inhibit inflammation and oxidative stress in the kidney and restore kidney function parameters. <b><i>Conclusion:</i></b> Although both NaCl and HES resuscitation showed protection of the kidney function against oxidative stress and inflammation, these fluids initiated the injury process.

Targeting repair of the vascular endothelium and glycocalyx after traumatic injury with plasma and platelet resuscitation

•

Endothelial glycocalyx shedding is a key instigator of the endotheliopathy of trauma.

•

Plasma and platelet transfusions preserve vascular integrity in pre-clinical models.

•

However, platelets may be less effective than plasma in preserving the glycocalyx.

Severely injured patients with hemorrhagic shock can develop endothelial dysfunction, systemic inflammation, and coagulation disturbances collectively known as the endotheliopathy of trauma (EOT). Shedding of the endothelial glycocalyx occurs early after injury, contributes to breakdown of the vascular barrier, and plays a critical role in the pathogenesis of multiple organ dysfunction, leading to poor outcomes in trauma patients. In this review we discuss (i) the pathophysiology of endothelial glycocalyx and vascular barrier breakdown following hemorrhagic shock and trauma, and (ii) the role of plasma and platelet transfusion in maintaining the glycocalyx and vascular endothelial integrity.

Clinical impact of a prehospital trauma shock bundle of care in South Africa

Introduction

Patients experiencing traumatic shock are at a higher risk for death and complications. We previously designed a bundle of emergency medical services traumatic shock care (“EMS-TruShoC”) for prehospital providers in resource-limited settings. We assess how EMS-TruShoC changes clinical outcomes of critically injured prehospital patients.

Methods

This is a quasi-experimental educational implementation of a simplified bundle of care using a pre-post design with a control group. The intervention was delivered to EMS providers in Western Cape, South Africa. Delta shock index (heart rate divided by systolic blood pressure, reported as change from the scene to facility arrival) from the 13 months preceding intervention were compared to the 13 months post-implementation. A difference-in-differences analysis examined the difference in mean shock index change between the groups.

Results

Data were collected from 198 providers who treated 770 severe trauma patients. The patient groups had similar demographic and clinical characteristics at baseline. Over all time-points, both groups had an increase in mean delta shock index (worsening shock), with the largest difference occurring 4-months post-implementation (0.047 change in control arm, 0.004 change in intervention arm; −0.043 difference-in-differences, P = 0.27). In pre-specified subgroup analyses, there was a statistically significant improvement in delta shock index in the intervention arm in patients with penetrating trauma cared for by basic providers immediately post-implementation (−0.372 difference-in-differences, P = 0.02).

Discussion

Overall, there was no significant difference in delta shock index between the EMS-TruShoC intervention versus control groups. However, significant improvement in shock index in one subgroup suggests the intervention may be more likely to benefit penetrating trauma patients and basic providers.

Challenges and Opportunities for Endovascular Treatment of Hemorrhage in Combat Casualty Care

ABSTRACT

The care of the hemorrhaging patient continues to evolve. The use of endovascular techniques to treat hemorrhage has increased significantly in civilian trauma care over the past 15 years and is identified as a major national trauma care research priority. Endovascular techniques are being increasingly employed to treat major thoracoabdominal arterial injuries and resuscitative endovascular balloon occlusion of the aorta is being adopted at trauma centers as a supportive adjunct to resuscitation in the exsanguinating patient. Emerging endovascular technology offers the opportunity to provide temporary or permanent control of non-compressible torso hemorrhage, which remains a vexing problem in combat casualty care. Endovascular advances have not been translated to the care of combat casualties to any significant degree, however. This review provides a summary and analysis of the gap between civilian endovascular hemorrhage control and combat casualty care practice to better align future research and development efforts.

The role of tricuspite annular plane systolic excursion as a marker of hypovolemia in healthy blood donor volunteers

AIM

The aim of this study is to compare the diameter of the inferior vena cava with tricuspid annular plane systolic excursion (TAPSE) measurement in order to determine the volume loss before and after blood donation in healthy volunteers.

METHODS

This Institutional Review Board-approved single center, prospective, cross-sectional study included 60 healthy blood donors donating in a tertiary care hospital's blood bank. After obtaining written consent, systolic, diastolic, and mean arterial blood pressures along with pulse rate of the donors were measured in sitting and supine positions by the attending physician, then, inferior vena cava (IVC) and TAPSE measurements were made before and after blood donation.

RESULTS

Statistically significant differences was found between standing systolic blood pressure and pulse rate, lying systolic blood pressure and pulse rate, IVC and TAPSE values before and after blood donation (p < 0.05). There was no difference between the other variables before and after blood donation.

CONCLUSION

Our study revealed that, low IVC and TAPSE values correlated in determining blood loss after blood donation. TAPSE may be useful to predict blood loss in early stages of hypovolemic shock.

Machine Learning Consensus Clustering Approach for Patients with Lactic Acidosis in Intensive Care Units

BACKGROUND

Lactic acidosis is a heterogeneous condition with multiple underlying causes and associated outcomes. The use of multi-dimensional patient data to subtype lactic acidosis can personalize patient care. Machine learning consensus clustering may identify lactic acidosis subgroups with unique clinical profiles and outcomes.

METHODS

We used the Medical Information Mart for Intensive Care III database to abstract electronic medical record data from patients admitted to intensive care units (ICU) in a tertiary care hospital in the United States. We included patients who developed lactic acidosis (defined as serum lactate ≥ 4 mmol/L) within 48 h of ICU admission. We performed consensus clustering analysis based on patient characteristics, comorbidities, vital signs, organ supports, and laboratory data to identify clinically distinct lactic acidosis subgroups. We calculated standardized mean differences to show key subgroup features. We compared outcomes among subgroups.

RESULTS

We identified 1919 patients with lactic acidosis. The algorithm revealed three best unique lactic acidosis subgroups based on patient variables. Cluster 1 (n = 554) was characterized by old age, elective admission to cardiac surgery ICU, vasopressor use, mechanical ventilation use, and higher pH and serum bicarbonate. Cluster 2 (n = 815) was characterized by young age, admission to trauma/surgical ICU with higher blood pressure, lower comorbidity burden, lower severity index, and less vasopressor use. Cluster 3 (n = 550) was characterized by admission to medical ICU, history of liver disease and coagulopathy, acute kidney injury, lower blood pressure, higher comorbidity burden, higher severity index, higher serum lactate, and lower pH and serum bicarbonate. Cluster 3 had the worst outcomes, while cluster 1 had the most favorable outcomes in terms of persistent lactic acidosis and mortality.

CONCLUSIONS

Consensus clustering analysis synthesized the pattern of clinical and laboratory data to reveal clinically distinct lactic acidosis subgroups with different outcomes.

Thrombin Generation Following Severe Trauma: Mechanisms, Modulators, and Implications for Hemostasis and Thrombosis

ABSTRACT

Thrombin is the central coagulation enzyme that catalyzes the conversion of fibrinogen to form insoluble fibrin blood clots. In vivo, thrombin production results from the concerted effort of plasma enzymatic reactions with essential contributions from circulating and vessel wall cells. The relative amount of thrombin produced directly dictates the structure and stability of fibrin clots; therefore, sufficient thrombin generation is essential for normal hemostasis to occur. Examination of thrombin generation phenotypes among severely injury trauma patients reveals important relationships between the potential for generating thrombin and risks of bleeding and thrombotic complications. Thus, understanding determinants of thrombin generation following traumatic injury is of high clinical importance. This review will focus on patterns and mechanisms of thrombin generation in severely injured patients, the role of fluid resuscitation in modulating thrombin generation and implications for outcomes.

Effects of Branched-chain Amino Acids on Nutritional Metabolism and Pharmacoeconomics in Patients with Severe Abdominal Trauma

OBJECTIVE

To observe the influences of branched-chain amino acids (BCAAs) on nutrition metabolism and prognosis of patients with severe abdominal trauma; at the same time, to analyze and evaluate the pharmacoeconomics of it.

METHODS

A total of 75 severe abdominal trauma patients were recruited from June 2016 to December 2017 and randomly divided into control group and observation group. After surgery and basic treatment, parenteral nutrition support therapy with iso-nitrogen and iso-calorie of both groups was administered. Meanwhile, an equivalent of 8.5% (18AA-II) and 10% (20AA) compound AA injection was administrated to the control and observation groups, respectively. The nitrogen balance, serum protein level and plasma amino spectrum of the patients were observed before and after treatment. Besides, the hospital stay, survival rate, complications, adverse reactions and hospitalization costs were also compared.

RESULTS

After a 7-day course treatment, the nitrogen balance level of the two groups was significantly improved, but no significant difference was found between them. In addition, the serum protein level and plasma amino spectrum of the two groups was generally improved when compared to before treatment. Compared with the control group, the level of albumin and transferrin in the observation group was improved significantly after treatment, while no difference in plasma amino spectrum was found between the two groups. Moreover, the cost analysis showed remarkably reduced hospitalization costs in the observation group.

CONCLUSION

To a certain degree, BCAAs could improve the nutritional metabolism and prognosis of patients with severe abdominal trauma, and have good cost-effectiveness.

Synthetic hydrogels as blood clot mimicking wound healing materials

Excessive bleeding-or hemorrhage-causes millions of civilian and non-civilian casualties every year. Additionally, wound sequelae, such as infections, are a significant source of chronic morbidity, even if the initial bleeding is successfully stopped. To treat acute and chronic wounds, numerous wound healing materials have been identified, tested, and adopted. Among them are topical dressings, such as gauzes, as well as natural and biomimetic materials. However, none of these materials successfully mimic the complex and dynamic properties of the body's own wound healing material: the blood clot. Specifically, blood clots exhibit complex mechanical and biochemical properties that vary across spatial and temporal scales to guide the wound healing response, which make them the ideal wound healing material. In this manuscript, we review blood clots' complex mechanical and biochemical properties, review current wound healing materials, and identify opportunities where new materials can provide additional functionality, with a specific focus on hydrogels. We highlight recent developments in synthetic hydrogels that make them capable of mimicking a larger subset of blood clot features: as plugs and as stimuli for tissue repair. We conclude that future hydrogel materials designed to mimic blood clot biochemistry, mechanics, and architecture can be combined with exciting platelet-like particles to serve as hemostats that also promote the biological wound healing response. Thus, we believe synthetic hydrogels are ideal candidates to address the clear need for better wound healing materials.

Fibrinogen inhibits microRNA-19b, a novel mechanism for repair of haemorrhagic shock-induced endothelial cell dysfunction

BACKGROUND

The benefits of plasma as an adjunct to the treatment of haemorrhagic shock are well established; however, the mechanism by which plasma modulates the endotheliopathy of trauma remains unclear. Our recent data demonstrated a novel role of microRNA-19b in post-haemorrhagic shock endothelial dysfunction via targeting of syndecan-1. Additionally, fibrinogen, as a key component of plasma or an isolated haemostatic protein, protects the endothelium by stabilizing syndecan-1. We therefore hypothesized that fibrinogen would inhibit microRNA-19b to mitigate the endotheliopathy of trauma in a murine model of haemorrhagic shock.

MATERIALS AND METHODS

C57BL/6J mice were subjected to haemorrhagic shock (mean arterial pressure 35±5 mmHg for 90 minutes) followed by resuscitation with lactated Ringer's, fresh frozen plasma, fibrinogen or no resuscitation. MicroRNA-19b and syndecan-1 mRNA were measured in lung tissue by qRT-PCR. Lungs were stained for histopathologic injury, and broncheoalveolar lavage was collected for protein as a permeability indicator.

RESULTS

Pulmonary microRNA-19b was increased after haemorrhagic shock and lactated Ringers, but reduced to sham levels by plasma and fibrinogen. Conversely, pulmonary syndecan-1 mRNA was downregulated by haemorrhagic shock and lactated Ringers, but returned to sham levels by plasma and fibrinogen. Plasma and fibrinogen-based resuscitation reduced lung injury compared to haemorrhagic shock and lactated Ringers while fibrinogen also reduced broncheoalveolar lavage protein.

DISCUSSION

We have demonstrated a novel mechanism by which fibrinogen, a key component of plasma and haemostatic agent, inhibits miR-19b, possibly by mitigating the endotheliopathy of trauma. Complete demonstration of the mechanism of fibrinogen inhibition of endotheliopathy via microRNA, however, remains to be elucidated. These findings support the early and empiric use of fibrinogen in post-haemorrhagic shock resuscitation.

Systematic review of the efficacy of a hybrid operating theatre in the management of severe trauma

Background

Hybrid operating theatres (OT) allow for simultaneous interventional radiology and operative procedures, serving as a one-stop facility for the treatment of severely injured patients. Several countries have adopted the use of the hybrid OT however their clinical impact in improving efficiency and quality of care remains unclear. This study systematically reviews the clinical impact of the hybrid OT for treatment of the severely injured.

Methods

A literature review of the PubMed, Embase and Cochrane databases was performed to identify all published articles in English, from 1st January 2000 to 31st December 2020, reporting on the impact of a hybrid OT for severe trauma. Articles were also reviewed for references of interest.

Results

Five studies reporting the clinical impact of the hybrid OT, in a total of 951 patients, were shortlisted. All were cohort studies that compared patient outcomes in the hybrid OT versus a conventional group. Out of 3 studies that assessed timeliness to intervention, one reported shorter time associated with the hybrid OT, while the other two reported no difference. Mortality outcomes were reported in 4 studies and showed no significant difference associated with treatment in the hybrid OT. Two studies revealed shorter total procedure times associated with the hybrid OT. Two out of 3 studies that evaluated blood transfusion requirements reported decreased transfusion rates in the hybrid OT group. Only 1 study examined complication rates and demonstrated morbidity benefits associated with the hybrid OT.

Conclusion

Establishment of a hybrid OT requires a significant capital investment as well as a highly functioning multi-disciplinary team. The cost–benefit ratio remains unclear. Future studies, preferably in the form of clinical trials, are required to evaluate its usefulness in improving timeliness to definitive haemorrhage control and outcomes in severe trauma.

Extracellular CIRP activates STING to exacerbate hemorrhagic shock

Stimulator of IFN genes (STING) activates TANK-binding kinase 1 (TBK1) and IFN regulatory factor 3 (IRF3) to produce type I IFNs. Extracellular cold-inducible RNA-binding protein (eCIRP) is released from cells during hemorrhagic shock (HS). We hypothesized that eCIRP activates STING to induce inflammation and acute lung injury (ALI) after HS. WT and STING^–/– mice underwent controlled hemorrhage by bleeding, followed by fluid resuscitation. Blood and lungs were collected at 4 hours after resuscitation. Serum ALT, AST, LDH, IL-6, and IFN-β were significantly decreased in STING^–/– mice compared with WT mice after HS. In STING^–/– mice, the levels of pTBK1 and pIRF3, and expression of TNF-α, IL-6, and IL-1β mRNAs and proteins in the lungs, were significantly decreased compared with WT HS mice. The 10-day mortality rate in STING^–/– mice was significantly reduced. I.v. injection of recombinant mouse CIRP (rmCIRP) in STING^–/– mice showed a significant decrease in pTBK1 and pIRF3 and in IFN-α and IFN-β mRNAs and proteins in the lungs compared with rmCIRP-treated WT mice. Treatment of TLR4^–/–, MyD88^–/–, and TRIF^–/– macrophages with rmCIRP significantly decreased pTBK1 and pIRF3 levels and IFN-α and IFN-β mRNAs and proteins compared with WT macrophages. HS increases eCIRP levels, which activate STING through TLR4/MyD88/TRIF pathways to exacerbate inflammation.

Penetrating injuries in Germany - epidemiology, management and outcome an analysis based on the TraumaRegister DGU®

Background

The management of penetrating wounds is a rare challenge for trauma surgeons in Germany and Central Europe as a result of the low incidence of this type of trauma. In Germany, penetrating injuries are reported to occur in 4–5 % of the severely injured patients who are enrolled in the TraumaRegister DGU® (trauma registry of the German Trauma Society). They include gunshot injuries, knife stab injuries, which are far more common, and penetrating injuries of other origin, for example trauma caused by accidents. The objective of this study was to assess the epidemiology and outcome of penetrating injuries in Germany, with a particular focus on the level of care provided by the treating trauma centre to gain more understanding of this trauma mechanism and to anticipate the necessary steps in the initial treatment.

Materials and methods

Since 2009, the TraumaRegister DGU® has been used to assess not only whether a trauma was penetrating but also whether it was caused by gunshot or stabbing. Data were taken from the standard documentation forms that participating German hospitals completed between 2009 and 2018. Excluded were patients with a maximum abbreviated injury scale (MAIS) score of 1 with a view to obtaining a realistic idea of this injury entity, which is rare in Germany.

Results

From 2009 to 2018, there were 1123 patients with gunshot wounds, corresponding to a prevalence rate of 0.5 %, and 4333 patients with stab wounds (1.8 %), which were frequently caused by violent crime. The high proportion of intentionally self-inflicted gunshot wounds to the head resulted in a cumulative mortality rate of 41 % for gunshot injuries. Stab wounds were associated with a lower mortality rate (6.8 %). Every fourth to fifth patient with a gunshot or stab wound presented with haemorrhagic shock, which is a problem that is seen during both the prehospital and the inhospital phase of patient management. Of the patients with penetrating injuries, 18.3 % required transfusions. This percentage was more than two times higher than that of the basic group of patients of the TraumaRegister DGU®, which consists of patients with a MAIS ≥ 3 and patients with a MAIS of 2 who died or were treated on the intensive care unit.

Conclusions

In Germany, gunshot and stab wounds have a low incidence and are mostly caused by violent crime or attempted suicides. Depending on the site of injury, they have a high mortality and are often associated with major haemorrhage. As a result of the low incidence of these types of trauma, further data and analyses are required in order to provide the basis for evaluating the long-term quality of the management of patients with stab or gunshot wounds.

Coagulopathy and its effect on treatment and mortality in patients with traumatic intracranial hemorrhage

BACKGROUND

The role of coagulopathy in patients with traumatic brain injury has remained elusive. In the present study, we aim to assess the prevalence of coagulopathy in patients with traumatic intracranial hemorrhage, their clinical features, and the effect of coagulopathy on treatment and mortality.

METHODS

An observational, retrospective single-center cohort of consecutive patients with traumatic intracranial hemorrhage treated at Helsinki University Hospital between 01 January and 31 December 2010. We compared clinical and radiological parameters in patients with and without coagulopathy defined as drug- or disease-induced, i.e., antiplatelet or anticoagulant medication at a therapeutic dose, thrombocytopenia (platelet count < 100 E9/L), international normalized ratio > 1.2, or thromboplastin time < 60%. Primary outcome was 30-day all-cause mortality. Logistic regression analysis allowed to assess for factors associated with coagulopathy and mortality.

RESULTS

Of our 505 patients (median age 61 years, 65.5% male), 206 (40.8%) had coagulopathy. Compared to non-coagulopathy patients, coagulopathy patients had larger hemorrhage volumes (mean 140.0 mL vs. 98.4 mL, p < 0.001) and higher 30-day mortality (18.9% vs. 9.7%, p = 0.003). In multivariable analysis, older age, lower admission Glasgow Coma Scale score, larger hemorrhage volume, and conservative treatment were independently associated with mortality. Surgical treatment was associated with lower mortality in both patients with and without coagulopathy.

CONCLUSIONS

Coagulopathy was more frequent in patients with traumatic intracranial hemorrhage presenting larger hemorrhage volumes compared to non-coagulopathy patients but was not independently associated with higher 30-day mortality. Hematoma evacuation, in turn, was associated with lower mortality irrespective of coagulopathy.

Fibrinogen Early In Severe Trauma studY (FEISTY): results from an Australian multicentre randomised controlled pilot trial

Background: Haemorrhage is a major cause of death in severe trauma. Fibrinogen plays a critical role in maintaining haemostasis in traumatic haemorrhage, and early replacement using fibrinogen concentrate (FC) or cryoprecipitate (Cryo) is recommended by several international trauma guidelines. Limited evidence supports one product over the other, with widespread geographic and institutional variation in practice. Two previous trials have investigated the feasibility of rapid FC administration in severely injured trauma patients, with conflicting results. Objective: To compare the time to fibrinogen replacement using FC or Cryo in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia. Design, setting, patients and interventions: A multicentre controlled pilot trial in which adult trauma patients with haemorrhage were randomly assigned (1:1) to receive FC or Cryo for fibrinogen replacement, guided by FIBTEM A5 (functional fibrinogen assessment at 5 minutes after clot formation, using rotational thromboelastometry). Main outcome measures: The primary outcome was time to commencement of fibrinogen replacement. Secondary outcomes included effects of the intervention on plasma fibrinogen levels and clinical outcomes including transfusion requirements and mortality. Results: Of the 100 randomly assigned patients, 62 were hypofibrinogenaemic and received the intervention (n = 37) or Cryo (n = 25). Median (interquartile range [IQR]) time to delivery of FC was 29 min (23-40 min) compared with 60 min (40-80 min) for Cryo (P = 0.0001). All 62 patients were hypofibrinogenaemic before receiving FC or Cryo (FC: median FIBTEM A5, 8 mm [IQR, 7-9 mm]; Cryo: median FIBTEM A5, 9 mm [IQR, 5-10 mm]). In the FC arm patients received a median of 3 g FC (IQR, 2-4 g), and in the Cryo arm patients received a median of 8 units of Cryo (IQR, 8-14 units). Restoration of fibrinogen levels was achieved in both arms after the intervention. Blood product transfusion, fluid resuscitation and thromboembolic complications were similar in both arms. Overall mortality was 15.3%, with more deaths in the FC arm. Conclusion: Fibrinogen replacement in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia was achieved substantially faster using FC compared with Cryo. Fibrinogen levels increased appropriately using either product. The optimal method for replacing fibrinogen in traumatic haemorrhage is controversial. Our results will inform the design of a larger trial powered to assess patient-centred outcomes.

Bicarbonate Ringer's solution for early resuscitation in hemorrhagic shock rabbits

Background

Fluid resuscitation is important for correcting hypovolemia. Isotonic crystalloids are the preferred solution for the initial clinical management of patients with multiple traumas. Bicarbonated Ringer’s solution (BRS), offering physiological levels of bicarbonate ions and electrolyte ions, can be used for supplementing missing extracellular fluid and correcting metabolic acidosis. We here investigated the effects of BRS on the resuscitation of hemorrhagic shock models and compared the resuscitation performance of three crystalloids, including BRS, acetated Ringer’s solution (ARS), and normal saline.

Methods

Thirty adult male New Zealand rabbits were randomly divided into five groups (n=6): a sham operation group (Sham group), an operation without fluid therapy group (Shock group), a BRS group, an ARS group, and a normal saline group (Saline group). The New Zealand rabbits experienced rapid bloodletting to shock status and maintained for 20 minutes except Sham group. The status of shock was maintained in the Shock group. The fluid was infused at a rate of 60 mL/kg per hour for 1.5 hours in three fluid therapy group. Measurement of vital signs, arterial blood gas tests, blood biochemistry, hematoxylin and eosin (HE) staining of lung tissue, TUNEL staining of the liver and kidney tissues, and analysis of intestinal flora were performed.

Results

The reduction in both base excess (BE) and bicarbonate ion (HCO₃^-) caused by acidosis in rabbits with hemorrhagic shock was significantly improved in the BRS group when compared with the Saline group at infusion for 30 minutes (T3) and 30 minutes after infusion (T5) (BRS group vs. Saline group, BE: at T3, −4.83±3.60 vs. −12.50±3.27 mmol/L, P<0.01; at T5, −3.67±4.37 vs. −11.00±2.76 mmol/L, P<0.01; HCO₃^-: at T3, 22.15±2.63 vs. 15.42±3.03 mmol/L, P<0.01; at T5, 23.15±2.9 vs. 16.23±3.07 mmol/L, P<0.01). Compared with Shock group, liver cell apoptosis due to hemorrhagic shock was relieved in both the BRS group and ARS group (BRS group vs. Shock group: 19.1±3.3 vs. 28.1±6.1, P<0.05; ARS group vs. Shock group: 19.8±5.4 vs. 28.1±6.1, P<0.05).

Conclusions

During resuscitation of hemorrhagic shock, BRS, a novel perioperative balanced crystalloid, is more effective than normal saline in maintaining acid-base balance and in protecting tissues and organs.

Massive Blood Transfusion for Trauma Score to Predict Massive Blood Transfusion in Trauma

Background

Massive blood loss is the most common cause of immediate death in trauma. A massive blood transfusion (MBT) score is a prediction tool to activate blood banks to prepare blood products. The previously published scoring systems were mostly developed from settings that had mature prehospital systems which may lead to a failure to validate in settings with immature prehospital systems. This research aimed to develop a massive blood transfusion for trauma (MBTT) score that is able to predict MBT in settings that have immature prehospital care.

Methods

This study was a retrospective cohort that collected data from trauma patients who met the trauma team activation criteria. The predicting parameters included in the analysis were retrieved from the history, physical examination, and initial laboratory results. The significant parameters from a multivariable analysis were used to develop a clinical scoring system. The discrimination was evaluated by the area under a receiver operating characteristic (AuROC) curve. The calibration was demonstrated with Hosmer–Lemeshow goodness of fit, and an internal validation was done.

Results

Among 867 patients, 102 (11.8%) patients received MBT. Four factors were associated with MBT: a score of 3 for age ≥60 years; 2.5 for base excess ≤–10 mEq/L; 2 for lactate >4 mmol/L; and 1 for heart rate ≥105 /min. The AuROC was 0.85 (95% CI: 0.78–0.91). At the cut point of ≥4, the positive likelihood ratio of the score was 6.72 (95% CI: 4.7–9.6, p < 0.001), the sensitivity was 63.6%, and the specificity was 90.5%. Internal validation with bootstrap replications had an AuROC of 0.83 (95% CI: 0.75–0.91).

Conclusions

The MBTT score has good discrimination to predict MBT with simple and rapidly obtainable parameters.

Pulse Arrival Time Is Associated With Hemorrhagic Volume in a Porcine Model: A Pilot Study

BACKGROUND

Hemorrhage is a major cause of preventable death worldwide, and early identification can be lifesaving. Pulse wave contour analysis has previously been used to infer hemodynamic variables in a variety of settings. We hypothesized that pulse arrival time (PAT), a form of pulse wave contour analysis which is assessed via electrocardiography (ECG) and photoplethysmography (PPG), is associated with hemorrhage volume.

METHODS

Yorkshire-Cross swine were randomized to hemorrhage (30 mL/kg over 20 minutes) vs. control. Continuous ECG and PPG waveforms were recorded with a novel monitoring device, and algorithms were developed to calculate PAT and PAT variability throughout the respiratory cycle, termed "PAT index" or "PAT_I." Mixed effects models were used to determine associations between blood loss and PAT and between blood loss and PAT_I to account for clustering within subjects and investigate inter-subject variability in these relationships.

RESULTS

PAT and PAT_I data were determined for ∼150 distinct intervals from five subjects. PAT and PAT_I were strongly associated with blood loss. Mixed effects modeling with PAT alone was substantially better than PAT_I alone (R2 0.93 vs. 0.57 and Akaike information criterion (AIC) 421.1 vs. 475.5, respectively). Modeling blood loss with PAT and PAT_I together resulted in slightly improved fit compared to PAT alone (R2 0.96, AIC 419.1). Mixed effects models demonstrated significant inter-subject variability in the relationships between blood loss and PAT.

CONCLUSIONS

Findings from this pilot study suggest that PAT and PAT_I may be used to detect blood loss. Because of the simple design of a single-lead ECG and PPG, the technology could be packaged into a very small form factor device for use in austere or resource-constrained environments. Significant inter-subject variability in the relationship between blood loss and PAT highlights the importance of individualized hemodynamic monitoring.

Determination of optimal deployment strategy for REBOA in patients with non-compressible hemorrhage below the diaphragm

Background

Non-compressible truncal hemorrhage (NCTH) is the leading cause of preventable death after trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) achieves temporary hemorrhage control, supporting cardiac and cerebral perfusion prior to definitive hemostasis. Aortic zone selection algorithms vary among institutions. We evaluated the efficacy of an algorithm for REBOA use.

Methods

A multicenter prospective, observational study conducted at six level 1 trauma centers over 12 months. Inclusion criteria were age >15 years with evidence of infradiaphragmatic NCTH needing emergent hemorrhage control within 60 min of ED arrival. An algorithm characterized by the results of focused assessment with sonography in trauma and pelvic X-ray was assessed post hoc for efficacy in a cohort of patients receiving REBOA.

Results

Of the 8166 patients screened, 78 patients had a REBOA placed. 21 patients were excluded, leaving 57 patients for analysis. The algorithm ensures REBOA deployment proximal to hemorrhage source to control bleeding in 98.2% of cases and accurately predicts the optimal REBOA zone in 78.9% of cases. If the algorithm was violated, bleeding was optimally controlled in only 43.8% (p=0.01). Three (75.0%) of the patients that received an inappropriate zone 1 REBOA died, two from multiple organ failure (MOF). All three patients that died with an inappropriate zone 3 REBOA died from exsanguination.

Discussion

This algorithm ensures proximal hemorrhage control and accurately predicts the primary source of hemorrhage. We propose a new algorithm that will be more inclusive. A zone 3 REBOA should not be performed when a zone 1 is indicated by the algorithm as 100% of these patients exsanguinated. MOF, perhaps from visceral ischemia in patients with an inappropriate zone 1 REBOA, may have been prevented with zone 3 placement or limited zone 1 occlusion time.

Level of evidence

Level III.

Revised Injury Severity Classification II (RISC II) is a predictor of mortality in REBOA-managed severe trauma patients

The evidence supporting the use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in severely injured patients is still debatable. Using the ABOTrauma Registry, we aimed to define factors affecting mortality in trauma REBOA patients. Data from the ABOTrauma Registry collected between 2014 and 2020 from 22 centers in 13 countries globally were analysed. Of 189 patients, 93 died (49%) and 96 survived (51%). The demographic, clinical, REBOA criteria, and laboratory variables of these two groups were compared using non-parametric methods. Significant factors were then entered into a backward logistic regression model. The univariate analysis showed numerous significant factors that predicted death including mechanism of injury, ongoing cardiopulmonary resuscitation, GCS, dilated pupils, systolic blood pressure, SPO2, ISS, serum lactate level and Revised Injury Severity Classification (RISCII). RISCII was the only significant factor in the backward logistic regression model (p < 0.0001). The odds of survival increased by 4% for each increase of 1% in the RISCII. The best RISCII that predicted 30-day survival in the REBOA treated patients was 53.7%, having a sensitivity of 82.3%, specificity of 64.5%, positive predictive value of 70.5%, negative predictive value of 77.9%, and usefulness index of 0.385. Although there are multiple significant factors shown in the univariate analysis, the only factor that predicted 30-day mortality in REBOA trauma patients in a logistic regression model was RISCII. Our results clearly demonstrate that single variables may not do well in predicting mortality in severe trauma patients and that a complex score such as the RISC II is needed. Although a complex score may be useful for benchmarking, its clinical utility can be hindered by its complexity.

Complement Deposition on the Surface of RBC After Trauma Serves a Biomarker of Moderate Trauma Severity: A Prospective Study

BACKGROUND

Activation of the complement system and complement deposition on red blood cells (RBCs) contribute to organ damage in trauma. We conducted a prospective study in subjects with traumatic injuries to determine the pattern of complement deposition on RBC and whether they are associated with clinical outcomes.

METHOD

A total of 124 trauma patients and 42 healthy controls were enrolled in this prospective study. RBC and sera were collected at 0, 6, 24, and 72 h from trauma patients and healthy controls during a single draw. Presence of C4d, C3d, C5b-9, phosphorylation of band 3 and production of nitric oxide were analyzed by flow cytometry.

RESULTS

RBC from trauma patients at all time points up to 24 h displayed significantly higher deposition of C4d on their RBC membrane as compared with healthy donors. Incubation of normal RBC with sera from trauma patients resulted in significant increase of C4d deposition (at 0, 6, 24, and 72 h), C5b-9 deposition (at 0 and 6 h), phosphorylation of band 3 (at 0 and 24 h), and nitric oxide production up to 24 h compared with sera from healthy subjects. Deposition of C4d and C5b-9 in patients with an Injury Severity Score (ISS) of 9 and above remained elevated up to 72 h.

CONCLUSIONS

Our study demonstrates that the presence of C4d, C3d, and C5b-9 on the surface of RBC is linked to increased phosphorylation of band 3 and increased production of nitric oxide. Deposition of C4d and C5b-9 decreased faster over course of 3-day study in subjects with ISS less than 9.

Clinical Impact of a Dedicated Trauma Hybrid Operating Room

BACKGROUND

Early hemorrhage control is essential to optimal trauma care. Hybrid operating rooms offer early, concomitant performance of advanced angiographic and operative hemostasis techniques, but their clinical impact is unclear. Herein, we present our initial experience with a dedicated, trauma hybrid operating room.

STUDY DESIGN

This retrospective cohort analysis of 292 adult trauma patients undergoing immediate surgery at a Level I trauma center compared patients managed after implementation of a dedicated, trauma hybrid operating room (n = 186) with historic controls (n = 106). The primary outcomes were time to hemorrhage control (systolic blood pressure ≥ 100 mmHg without ongoing vasopressor or transfusion requirements), early blood product administration, and complication.

RESULTS

Patient characteristics were similar between cohorts (age 41 years, 25% female, 38% penetrating trauma). The hybrid cohort had lower initial hemoglobin (10.2 vs 11.1 g/dL, p = 0.001) and a greater proportion of patients undergoing resuscitative endovascular balloon occlusion of the aorta (9% vs 1%, p = 0.007). Cohorts had similar case mixes and intraoperative consultation with cardiothoracic or vascular surgery (13%). Twenty-one percent of all hybrid cases included angiography. The interval between operating room arrival and hemorrhage control was shorter in the hybrid cohort (49 vs 60 minutes, p = 0.005). From 4 to 24 hours after arrival, the hybrid cohort had fewer red cell (0.0 vs 1.0, p = 0.001) and plasma transfusions (0.0 vs 1.0, p < 0.001). The hybrid cohort had fewer infectious complications (15% vs 27%, p = 0.009) and ventilator days (2.0 vs 3.0, p = 0.011), and similar in-hospital mortality (13% vs 10%, p = 0.579).

CONCLUSIONS

Implementation of a dedicated, trauma hybrid operating room was associated with earlier hemorrhage control and fewer early blood transfusions, infectious complications, and ventilator days.

Fibrin monomers and association with significant hemorrhage or mortality in severely injured trauma patients

BACKGROUND

Post-traumatic hemorrhage is still the leading cause of potentially preventable death in patients with severe trauma. Traumatic-induced coagulopathy has been described as a risk factor for significant hemorrhage and mortality in this population. Fibrin monomers (FMs) are a direct marker of thrombin action, and thus reflect coagulation activation. This study sought to determine the association of FMs levels at admission with significant hemorrhage and 28-day mortality after a severe trauma.

METHODS

We conducted a retrospective, observational study including all severe trauma patients admitted in a level-1 trauma center between January 2012 and December 2017. Patients with severe traumatic brain injury or previous anticoagulant / antiaggregant therapies were excluded. FMs measurements and standard coagulation test were taken at admission. Significant hemorrhage was defined as a hemorrhage requiring the transfusion of ≥ 4 Red Blood Cells units during the first 6 h. Multivariable analysis was applied to identify predictors of significant hemorrhage and a simple logistic regression analysis was applied to identify an association between FMs and 28-day mortality.

RESULTS

Overall, 299 patients were included. A total of 47 (16%) experienced a significant hemorrhage. The ROC curve demonstrated that FMs had a poor accuracy to predict the occurrence of significant hemorrhage with an AUC of 0.65 (0.57-0.74). The best threshold at 92.45 µg/ml had excellent sensitivity (87%) and negative predictive value (95%), but was not independently associated with significant hemorrhage (OR = 1.5; 95%CI (0.5-4.2)). The 28-day mortality rate was 5%. In simple logistic regression analysis, FMs values ≥109.5 µg/ml were significantly associated with 28-day mortality (unadjusted OR = 13.2; 95%CI (1.7-102)).

CONCLUSIONS

FMs levels at admission are not associated with the occurrence of a significant hemorrhage in patients with severe trauma. However, the excellent sensitivity and NPV of FMs could help to identify patients with a low risk of severe bleeding during hospital care. In addition, FMs levels ≥109.5 µg/ml might be predictive of 28-day mortality.

Role of microRNA-15a-5p/TNFAIP3-interacting protein 2 axis in acute lung injury induced by traumatic hemorrhagic shock

The present study aimed to investigate the role of microRNA (miR)-15a-5p in the pathogenesis of acute lung injury induced by traumatic hemorrhagic shock (THS), and to explore the underlying molecular mechanism. The expression level of miR-15a-5p was detected using reverse transcription-quantitative (RT-qPCR) and the association between miR-15a-5p and TNFAIP3-interacting protein 2 (TNIP2) was revealed using TargetScan and dual luciferase reporter assays. To investigate the effect of miR-15a-5p on THS-induced acute lung injury, a THS rat model was established. Lung capillary permeability and lung edema were then determined. Moreover, proinflammatory factors in the bronchoalveolar lavage fluid (BALF) and serum of the THS rat model were detected using ELISA. In addition, protein levels in the current study were measured via western blotting. It was revealed that miR-15a-5p was significantly upregulated in both patients with THS and samples from the THS rat model. TNIP2 represents a direct target of miR-15a-5p, and it was downregulated in both patients with THS and the THS rat model. Further analyses indicated that downregulation of miR-15a-5p significantly relieved acute lung injury induced by THS, evidenced by a decreased ratio of Evan's blue dye (EBD) in the BALF to EBD in plasma of THS rats, decreased lung permeability index and reduced lung wet/dry ratio. Inhibition of miR-15a-5p also decreased THS-induced upregulation of pro-inflammatory factors. Furthermore, the data revealed that THS-induced NF-κB activation in the lung tissues of rats was inhibited by miR-15a-5p knockdown. Moreover, it was demonstrated that all the effects of miR-15a-5p on THS rats were ablated following TNIP2 silencing. Taken together, the data of the current study indicate that miR-15a-5p downregulation serves a protective role in THS-induced acute lung injury via directly targeting TNIP2.