Pathophysiological Response to Trauma-Induced Coagulopathy: A Comprehensive Review

Disentangling the phenotypic patterns of hypertension and chronic hypotension

OBJECTIVE

2017 blood pressure (BP) categories focus on cardiac risk. We hypothesize that studying the balance between mechanisms that increase or decrease BP across the medical phenome will lead to new insights. We devised a classifier that uses BP measures to assign individuals to mutually exclusive categories centered in the upper (Htn), lower (Hotn) and middle (Naf) zones of the BP spectrum; and examined the epidemiologic and phenotypic patterns of these BP-categories.

METHODS

We classified a cohort of 832,560 deidentified electronic health records by BP-category; compared the frequency of BP-categories and four subtypes of Htn and Hotn by sex and age-decade; visualized the distributions of systolic, diastolic, mean arterial and pulse pressures stratified by BP-category; and ran Phenome-wide Association Studies (PheWAS) for Htn and Hotn. We paired knowledgebases for hypertension and hypotension and computed aggregate knowledgebase status (KB-status) indicating known associations. We assessed alignment of PheWAS results with KB-status for phecodes in the knowledgebase, and paired PheWAS correlations with KB-status to surface phenotypic patterns.

RESULTS

BP-categories represent distinct distributions within the multimodal distributions of systolic and diastolic pressure. They are centered in the upper, lower, and middle zones of mean arterial pressure and provide a different signal than pulse pressure. For phecodes in the knowledgebase, 85% of positive correlations align with KB-status. Phenotypic patterns for Htn and Hotn overlap for several phecodes and are separate for others. Our analysis suggests five candidates for hypothesis testing research, two where the prevalence of the association with Htn or Hotn may be under appreciated, three where mechanisms that increase and decrease blood pressure may be affecting one another's expression.

CONCLUSION

PairedPheWAS methods may open a phenome-wide path to disentangling hypertension and chronic hypotension. Our classifier provides a starting point for assigning individuals to BP-categories representing the upper, lower, and middle zones of the BP spectrum. 4.7 % of individuals matching 2017 BP categories for normal, elevated BP or isolated hypertension, have diastolic pressure < 60. Research is needed to fine-tune the classifier, provide external validation, evaluate the clinical significance of diastolic pressure < 60, and test the candidate hypotheses.

Hyperfibrinolysis: a crucial phenotypic abnormality of posttraumatic fibrinolytic dysfunction

Background

Traumatic fibrinolytic dysfunction is often categorized into 3 phenotypes based on the result of thromboelastography (TEG) lysis at 30 minutes (LY30): fibrinolysis shutdown, physiologic fibrinolysis, and hyperfibrinolysis. However, the molecular pathophysiology of fibrinolytic dysfunction and the association with clinical outcomes have not been fully evaluated.

Objectives

To assess whether posttraumatic fibrinolysis phenotypes identified by TEG correlate with levels of key fibrinolysis-related serum markers and with risk of mortality and hospital complications.

Methods

This is a secondary analysis of the Pragmatic, Randomized Optimal Platelet and Plasma Ratios trial. Patients were stratified according to the degree of fibrinolysis upon arrival using TEG LY30 values: low LY30, <0.8%; normal LY30, 0.81% to 0.9%; and high LY30, ≥3%. Serial values of molecular markers (0-72 hours after admission) and clinical outcomes were compared between fibrinolysis groups.

Results

A total of 547 patients were included (low LY30, 320; normal LY30, 108; high LY30, 119). The high LY30 group had higher tissue plasminogen activator and plasmin-antiplasmin values upon hospital arrival than the low LY30 or normal LY30 groups (P < .001, respectively). There was no significant difference in levels of tissue plasminogen activator, plasmin-antiplasmin, and plasminogen activator inhibitor 1 between the low LY30 and normal LY30 groups. The high LY30 group was associated with an increased risk of 24-hour and 30-day mortality, while there was no significant difference in mortality between the low LY30 and normal LY30 groups.

Conclusion

Our results suggest that hyperfibrinolysis is the most common form of traumatic fibrinolytic dysfunction and is associated with worse outcome.

A machine learning-based Coagulation Risk Index predicts acute traumatic coagulopathy in bleeding trauma patients

BACKGROUND

Acute traumatic coagulopathy (ATC) is a well-described phenomenon known to begin shortly after injury. This has profound implications for resuscitation from hemorrhagic shock, as ATC is associated with increased risk for massive transfusion (MT) and mortality. We describe a large-data machine learning-based Coagulation Risk Index (CRI) to test the early prediction of ATC in bleeding trauma patients.

METHODS

Coagulation Risk Index was developed using continuous vital signs (VSs) available during the first 15 minutes after admission at a single trauma center over 4 years. Data to compute the CRI were derived from continuous features of photoplethymographic and electrocardiographic waveforms, oximetry values, and blood pressure trends. Two groups of patients at risk for ATC were evaluated: critical administration threshold and patients who received an MT. Acute traumatic coagulopathy was evaluated in separate models and defined as an international normalized ratio (INR) >1.2 and >1.5 upon arrival. The CRI was developed using 2 years of cases for training and 2 years for testing. The accuracy of the models is described by area under the receiver operator curve with 95% confidence intervals.

RESULTS

A total of 17,567 patients were available for analysis with continuous VS data, 52.8% sustained blunt injury, 30.2% were female, and the mean age was 44.6 years. The ability of CRI to predict ATC in critical administration threshold patients was excellent. The true positive and true negative rates were 95.6% and 88.3%, and 94.9% and 89.2% for INR >1.2 and INR >1.5, respectively. The CRI also demonstrated excellent accuracy in patients receiving MT; true positive and true negative rates were 92.8% and 91.3%, and 100% and 88.1% for INR >1.2 and INR >1.5, respectively.

CONCLUSION

Using continuous VSs and large-data machine learning capabilities, the CRI accurately predicts early ATC in bleeding patients. Clinical application may guide early hemostatic resuscitation. Extension of this technology into the prehospital setting could provide earlier treatment of ATC.

LEVEL OF EVIDENCE

Retrospective, Prognostic Study; Level III.

A nomogram for predicting hemorrhagic shock in pediatric patients with multiple trauma

The timely detection and management of hemorrhagic shock hold paramount importance in clinical practice. This study was designed to establish a nomogram that may facilitate early identification of hemorrhagic shock in pediatric patients with multiple-trauma. A retrospective study was conducted utilizing a cohort comprising 325 pediatric patients diagnosed with multiple-trauma, who received treatment at the Children's Hospital, Zhejiang University School of Medicine, Zhejiang, China. For external validation, an additional cohort of 144 patients from a children's hospital in Taizhou was included. The model's predictor selection was optimized through the application of the Least Absolute  Shrinkage and Selection Operator (LASSO) regression. Subsequently, a prediction nomogram was constructed using multivariable logistic regression analysis. The performance and clinical utility of the developed model were comprehensively assessed utilizing various statistical metrics, including Harrell's Concordance Index (C-index), receiver operating characteristic (ROC) curve analysis, calibration curve analysis, and decision curve analysis (DCA). Multivariate logistic regression analysis identified systolic blood pressure (ΔSBP), platelet count, activated partial thromboplastin time (APTT), and injury severity score (ISS) as independent predictors for hemorrhagic shock. The nomogram constructed using these predictors demonstrated robust predictive capabilities, as evidenced by an impressive area under the curve (AUC) value of 0.963. The model's goodness-of-fit was assessed using the Hosmer-Lemeshow test (χ2 = 10.023, P = 0.209). Furthermore, decision curve analysis revealed significantly improved net benefits with the model. External validation further confirmed the reliability of the proposed predictive nomogram. This study successfully developed a nomogram for predicting the occurrence of hemorrhagic shock in pediatric patients with multiple trauma. This nomogram may serve as an accurate and effective tool for timely and efficient management of children with multiple trauma.

Multiomics Signatures of Coagulopathy in a Polytrauma Swine Model Contrasted with Severe Multisystem Injured Patients

Trauma-induced coagulopathy (TIC) is a leading contributor to preventable mortality in severely injured patients. Understanding the molecular drivers of TIC is an essential step in identifying novel therapeutics to reduce morbidity and mortality. This study investigated multiomics and viscoelastic responses to polytrauma using our novel swine model and compared these findings with severely injured patients. Molecular signatures of TIC were significantly associated with perturbed coagulation and inflammation systems as well as extensive hemolysis. These results were consistent with patterns observed in trauma patients who had multisystem injuries. Here, intervention using resuscitative endovascular balloon occlusion of the aorta following polytrauma in our swine model revealed distinct multiomics alterations as a function of placement location. Aortic balloon placement in zone-1 worsened ischemic damage and mitochondrial dysfunction, patterns that continued throughout the monitored time course. While placement in zone-III showed a beneficial effect on TIC, it showed an improvement in effective coagulation. Taken together, this study highlights the translational relevance of our polytrauma swine model for investigating therapeutic interventions to correct TIC in patients.

Association between albumin-corrected anion gap and in-hospital mortality of intensive care patients with trauma: A retrospective study based on MIMIC-Ⅲ and Ⅳ databases

BACKGROUND

To investigate the correlation between albumin-corrected anion gap(ACAG) within the first 24 hours of admission and in-hospital mortality in trauma patients in intensive care unit(ICU).

MATERIALS AND METHODS

We utilized the MIMIC-Ⅲ and MIMIC-Ⅳ databases to examine trauma patients admitted to the ICU. The relationship between ACAG and in-hospital mortality in trauma patients was analyzed using Receiver Operating Characteristic(ROC) curve, Kaplan-Meier (K-M) survival curve, and Cox regression model. Propensity score matching (PSM) and subgroup analysis were conducted to enhance stability and reliability of the findings. Mortality at 30-day and 90-day served as secondary outcomes.

RESULTS

The study enrolled a total of 1038 patients. The AUC for ACAG (0.701, 95%CI: 0.652-0.749) was notably higher than that for anion gap and albumin. The Log-rank test revealed that the optimal cut-off point of ACAG for predicting in-hospital mortality was determined to be 20.375mmol/L. The multivariate Cox regression analysis demonstrated an independent association between high ACAG level and a higher risk of in-hospital mortality (HR = 3.128, 95% CI: 1.615-6.059). After PSM analysis, a matched cohort consisting of 291 subjects was obtained. We found no signifcant interaction in most stratas. Finally, The in-hospital, 30-day, and 90-day survival rates in the high ACAG group exhibited a statistically decrease compared to those in the low ACAG group both pre- and post-matching.

CONCLUSION

The elevated level of ACAG was found to be independently associated with increased in-hospital mortality among trauma patients in the ICU.

Transfusion practice in Central Norway - a regional cohort study in patients suffering from major haemorrhage

BACKGROUND

In patients with major hemorrhage, balanced transfusions and limited crystalloid use is recommended in both civilian and military guidelines. This transfusion strategy is often applied in the non-trauma patient despite lack of supporting data. The aim of this study was to describe the current transfusion practice in patients with major hemorrhage of both traumatic and non-traumatic etiology in Central Norway, and discuss if transfusions are in accordance with appropriate massive transfusion protocols.

METHODS

In this retrospective observational cohort study, data from four hospitals in Central Norway was collected from 01.01.2017 to 31.12.2018. All adults (≥18 years) receiving massive transfusion (MT) and alive on admission were included. MT was defined as transfusion of ≥10 units of packed red blood cells (PRBC) within 24 hours, or ≥ 5 units of PRBC during the first 3 hours after admission to hospital. Clinical data was collected from the hospital blood bank registry (ProSang) and electronic patient charts (CareSuite PICIS). Patients undergoing cardiothoracic surgery or extracorporeal membrane oxygenation treatment were excluded.

RESULTS

A total of 174 patients were included in the study, of which 85.1% were non-trauma patients. Seventy-six per cent of all patients received plasma:PRBC in a ratio ≥ 1:2 (high ratio) and 59.2% of patients received platelets:PRBC in a ratio ≥ 1:2 (high ratio). 32.2% received a plasma:PRBC-ratio ≥ 1:1, and 23.6% platelet:PRBC-ratio ≥ 1:1. Median fluid infusion of crystalloids in all patients was 5750 mL. Thirty-seven per cent of all patients received tranexamic acid, 53.4% received calcium and fibrinogen concentrate was administered in 9.2%.

CONCLUSIONS

Most patients had a non-traumatic etiology. The majority was transfused with high ratios of plasma:PRBC and platelet:PRBC, but not in accordance with the aim of the local protocol (1:1:1). Crystalloids were administered liberally for both trauma and non-trauma patients. There was a lower use of hemostatic adjuvants than recommended in the local transfusion protocol. Awareness to local protocol should be increased.

Thrombotic microangiopathy after traumatic brain injury: A case report and review of the literature

Key Clinical Message

This case report supports that trauma can rarely cause thrombotic microangiopathy (TMA). Early recognition is important due to a high mortality of untreated TMA, but diagnosis can be delayed by attributing lab abnormalities as due to blood loss.

Abstract

Major trauma can provoke coagulopathy, ranging from hypo- to hypercoagulation. Thrombotic microangiopathy (TMA), characterized by hemolytic anemia, renal failure, thrombocytopenia, and intravascular hemolysis, results in bleeding tendency but also microvascular thrombosis. We report a rare case of isolated traumatic brain injury leading to TMA treated with plasmapheresis.

Outcomes of Local Versus Free Flaps for Reconstruction of the Proximal One-Third of the Leg

BACKGROUND

Reconstruction of the proximal one-third of the leg often requires soft tissue transfer to facilitate limb salvage. Tissue transfers are usually local or free flaps depending on wound dimensions, location, and surgeon preference. Historically, the proximal third of the leg was covered with pedicle flaps, but recently, we have used more free flaps in this position. Using data from a level 1 trauma center, we sought to evaluate outcomes of surgical management of proximal-third leg reconstruction across local and free flaps.

METHODS

This is an institutional review board-approved, retrospective chart review undertaken at LAC + USC Medical Center from 2007 to 2021. Patient history, demographics, flap characteristics, Gustilo-Anderson fracture classification, and outcomes were collected and analyzed in an internal database. Outcomes of interest included flap failure rates, postoperative complications, and long-term ambulatory status.

RESULTS

Among 394 lower extremity flaps placed, 122 flaps involved the proximal-third leg across 102 patients. Average age of patients was 42.8 ± 15.2 years; of note, the free flap cohort was significantly younger than the local flap cohort (P = 0.019). Ten local flaps suffered from infectious complications: osteomyelitis (n = 6) and hardware infection (n = 4), versus only 1 free flap that suffered from hardware infection; notably, these differences were not significant across cohorts. Free flaps had significantly more flap revisions (13.3%; P = 0.039) and overall flap complications (20.0%; P = 0.031) compared with local flaps; however, partial flap necrosis (4.9%) and flap loss (3.3%) were not significantly different across cohorts. Overall flap survival was 96.7%, and full ambulation was achieved in 42.2% of patients without significant differences across cohorts.

CONCLUSIONS

Our evaluation of proximal-third leg wounds demonstrates fewer infectious outcomes with free flaps compared with local flaps. There are multiple confounding variables; however, this finding may speak to the reliability of a robust free flap. Overall, there was no significant difference in patient comorbidities across flap cohorts with great overall flap survival. Ultimately, flap selection did not affect rates of flap necrosis, flap loss, or final ambulatory status.

Massive Trauma and Resuscitation Strategies

Massive trauma remains the leading cause of mortality among people aged younger than 45 years. In this review, we discuss the initial care and diagnosis of trauma patients followed by a comparison of resuscitation strategies. We discuss various strategies including use of whole blood and component therapy, examine viscoelastic techniques for management of coagulopathy, and consider the benefits and limitations of the resuscitation strategies and consider a series of questions that will be important for researchers to answer to provide the best and most cost-effective therapy for severely injured patients.

A nomogram for prediction of deep venous thrombosis risk in elderly femoral intertrochanteric fracture patients: A dual-center retrospective study

Objective

Deep venous thrombosis (DVT) of the lower extremity is a common perioperative complication of femoral intertrochanteric fracture. This study aimed to identify the risk factors of lower extremity deep vein thrombosis (DVT) in elderly femoral intertrochanteric fracture patients and establish a nomogram model.

Methods

From August 2014 to June 2021, a total of 1,652 femoral intertrochanteric fracture patients over the age of 65 were enrolled in our study. We distinguished independent risk factors by univariate and multivariate Cox analyses. A nomogram model was then built, and the discriminative and calibration of the model was evaluated through receiver operating characteristics (ROC) and calibration plots.

Results

A total of 378 patients developed DVT (292 in the training group, 86 in the validation group) while the remaining patients did not. According to the univariate and multivariate Cox analyses results, age (OR = 1.07, 95% CI: 1.04-1.10), fibrinogen (OR = 2.09, 95% CI: 1.68-2.60), D-dimer (OR = 1.33, 95% CI: 1.27-1.40), time from injury to admission (OR = 1.78, 95% CI: 1.55-2.05), functional status (OR = 4.21, 95% CI: 2.86-6.20), and diabetes (OR = 1.65, 95% CI: 1.10-2.48) were identified as independent risk factors of DVT. The ROC values for DVT of the training and validation group were 0.862 and 0.912, and the P-value of the Hosmer-Lemeshow calibration test was 0.767.

Conclusion

This nomogram model can be used to predict the probability of preoperative DVT in elderly patients with femoral intertrochanteric fracture and guide physician in perioperative thrombosis management.

Traumatized triad of complementopathy, endotheliopathy, and coagulopathy ˗ Impact on clinical outcomes in severe polytrauma patients

Complementopathy, endotheliopathy, and coagulopathy following a traumatic injury are key pathophysiological mechanisms potentially associated with multiple-organ failure (MOF) and mortality. However, the heterogeneity in the responses of complementopathy, endotheliopathy, and coagulopathy to trauma, the nature and extent of their interplay, and their relationship to clinical outcomes remain unclear. Fifty-four poly-trauma patients were enrolled and divided into three subgroups based on their ISS. Biomarkers in blood plasma reflecting complement activation, endothelial damage, and coagulopathy were measured starting from admission to the emergency department and at 3, 6, 12, 24, and 120 hours after admission. Comparative analyses showed that severely injured patients (ISS>24) were associated with longer days on mechanical ventilation, in the intensive care unit and hospital stays, and a higher incidence of hyperglycemia, bacteremia, respiratory failure and pneumonia compared to mildly (ISS<16) or moderately (ISS=16-24) injured patients. In this trauma cohort, complement was activated early, primarily through the alternative complement pathway. As measured in blood plasma, severely injured patients had significantly higher levels of complement activation products (C3a, C5a, C5b-9, and Bb), endothelial damage markers (syndecan-1, sTM, sVEGFr1, and hcDNA), and fibrinolytic markers (D-dimer and LY30) compared to less severely injured patients. Severely injured patients also had significantly lower thrombin generation (ETP and peak) and lower levels of coagulation factors (I, V, VIII, IX, protein C) than less severely injured patients. Complement activation correlated with endothelial damage and hypocoagulopathy. Logistic regression analyses revealed that Bb >1.57 μg/ml, syndecan-1 >66.6 ng/ml or D-dimer >6 mg/L at admission were associated with a higher risk of MOF/mortality. After adjusting for ISS, each increase of the triadic score defined above (Bb>1.57 µg/ml/Syndecan-1>66.6 ng/ml/D-dimer>6.0mg/L) was associated with a 6-fold higher in the odds ratio of MOF/death [OR: 6.83 (1.04-44.96, P=0.046], and a 4-fold greater in the odds of infectious complications [OR: 4.12 (1.04-16.36), P=0.044]. These findings provide preliminary evidence of two human injury response endotypes (traumatized triad and non-traumatized triad) that align with clinical trajectory, suggesting a potential endotype defined by a high triadic score. Patients with this endotype may be considered for timely intervention to create a pro-survival/organ-protective phenotype and improve clinical outcomes.

Utility of viscoelastic hemostatic assay to guide hemostatic resuscitation in trauma patients: a systematic review

Objective

Viscoelastic hemostatic assay (VHA) provides a graphical representation of a clot’s lifespan and reflects the real time of coagulation. It has been used to guide trauma resuscitation; however, evidence of the effectiveness of VHAs is still limited. This systematic review aims to summarize the published evidence to evaluate the VHA-guided strategy in resuscitating trauma patients.

Methods

The PubMed, Embase, and Web of Science databases were searched from their inception to December 13, 2021. Randomized controlled trials (RCTs) or observational studies comparing VHA-guided transfusion to controls in resuscitating trauma patients were included in this systematic review.

Results

Of the 7743 records screened, ten studies, including two RCTs and eight observational studies, met the inclusion criteria. There was great heterogeneity concerning study design, enrollment criterion, VHA device, VHA-guided strategy, and control strategy. Thrombelastography (TEG) was used as a guiding tool for transfusion in eight studies, and rotational thromboelastometry (ROTEM), and TEG or ROTEM were used in the other two studies. The overall risk of bias assessment was severe or mild in RCTs and was severe or moderate in observational studies. The main outcomes reported from the included studies were blood transfusion (n = 10), mortality (n = 10), hospital length of stay (LOS) (n = 7), intensive care unit LOS (n = 7), and cost (n = 4). The effect of the VHA-guided strategy was not always superior to the control. Most of the studies did not find significant differences in the transfusion amount of red blood cells (n = 7), plasma (n = 5), platelet (n = 7), cryoprecipitate/fibrinogen (n = 7), and mortality (n = 8) between the VHA-guided group and control group. Notable, two RCTs showed that the VHA-guided strategy was superior or equal to the conventional coagulation test-guided strategy in reducing mortality, respectively.

Conclusion

Although some studies demonstrated VHA-guided strategy probable benefit in reducing the need for blood transfusion and mortality when resuscitating trauma patients, the evidence is still not robust. The quality of evidence was primarily downgraded by the limited number of included studies and great heterogeneity and severe risk of bias in these. Further studies are strongly recommended.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-022-00454-8.

PEGylated Polyester Nanoparticles Trigger Adverse Events in a Large Animal Model of Trauma and in Naı̈ve Animals: Understanding Cytokine and Cellular Correlations with These Events

Intravenously infusible nanoparticles to control bleeding have shown promise in rodents, but translation into preclinical models has been challenging as many of these nanoparticle approaches have resulted in infusion responses and adverse outcomes in large animal trauma models. We developed a hemostatic nanoparticle technology that was screened to avoid one component of the infusion response: complement activation. We administered these hemostatic nanoparticles, control nanoparticles, or saline volume controls in a porcine polytrauma model. While the hemostatic nanoparticles promoted clotting as marked by a decrease in prothrombin time and both the hemostatic nanoparticles and controls did not active complement, in a subset of the animals, hard thrombi were found in uninjured tissues in both the hemostatic and control nanoparticle groups. Using data science methods that allow one to work across heterogeneous data sets, we found that the presence of these thrombi correlated with changes in IL-6, INF-alpha, lymphocytes, and neutrophils. While these findings might suggest that this formulation would not be a safe one for translation for trauma, they provide guidance for developing screening tools to make nanoparticle formulations in the complex milieux of trauma as well as for therapeutic interventions more broadly. This is important as we look to translate intravenously administered nanoparticle formulations for therapies, particularly considering the vascular changes seen in a subset of patients following COVID-19. We need to understand adverse events like thrombi more completely and screen for these events early to make nanomaterials as safe and effective as possible.

Factor XIII Measurement and Substitution in Trauma Patients after Admission to an Intensive Care Unit

Trauma patients admitted to an intensive care unit (ICU) may potentially experience a deficiency of coagulation factor thirteen (FXIII). In this retrospective cohort study conducted at a specialized trauma center, ICU patients were studied to determine the dependency of FXIII activity levels on clinical course and substitution with blood and coagulation products. A total of 189 patients with a median injury severity score (ISS) of 25 (16−36, IQR) were included. Abbreviated injury scores for extremities (r = −0.38, p < 0.0001) but not ISS (r = −0.03, p = 0.45) showed a negative correlation with initial FXIII levels. Patients receiving FXIII concentrate presented with a median initial FXIII level of 54 (48−59)% vs. 88 (74−108)%, p < 0.0001 versus controls; they had fewer ICU-free days: 17 (0−22) vs. 22 (16−24), p = 0.0001; and received higher amounts of red blood cell units: 5 (2−9) vs. 4 (1−7), p < 0.03 before, and 4 (2−7) vs. 1 (0−2), p < 0.0001 after FXIII substitution. Matched-pair analyses based on similar initial FXIII levels did not reveal better outcome endpoints in the FXIII-substituted group. The study showed that a low initial FXIII level correlated with the clinical course in this trauma cohort, but a substitution of FXIII did not improve endpoints within the range of the studied FXIII levels. Future prospective studies should investigate the utility of FXIII measurement and lower threshold values of FXIII, which trigger substitution in trauma patients.

PLATELET FUNCTION IN TRAUMA: IS CURRENT TECHNOLOGY IN FUNCTION TESTING MISSING THE MARK IN INJURED PATIENTS?

ABSTRACT

Platelets are subcellular anucleate components of blood primarily responsible for initiating and maintaining hemostasis. After injury to a blood vessel, platelets can be activated via several pathways, resulting in changed shape, adherence to the injury site, aggregation to form a plug, degranulation to initiate activation in other nearby platelets, and acceleration of thrombin formation to convert fibrinogen to fibrin before contracting to strengthen the clot. Platelet function assays use agonists to induce and measure one or more of these processes to identify alterations in platelet function that increase the likelihood of bleeding or thrombotic events. In severe trauma, these assays have revealed that platelet dysfunction is strongly associated with poor clinical outcomes. However, to date, the mechanism(s) causing clinically significant platelet dysfunction remain poorly understood. We review the pros, cons, and evidence for use of many of the popular assays in trauma, discuss limitations of their use in this patient population, and present approaches that can be taken to develop improved functional assays capable of elucidating mechanisms of trauma-induced platelet dysfunction. Platelet dysfunction in trauma has been associated with need for transfusions and mortality; however, most of the current platelet function assays were not designed for evaluating trauma patients, and there are limited data regarding their use in this population. New or improved functional assays will help define the mechanisms by which platelet dysfunction occurs, as well as help optimize future treatment.

Characteristics of blood plasma proteome changes associated with the hemorrhagic purpura of cosmonauts on the first day after long-term space missions

The interest in the role of the gravitational factor during landing after long-term space flights (SF) leads to the search for various innovative approaches to assessing the compliance of external changes observed by clinicians. The results of special research methods such as Omics technologies that may reflect physiological responses to the conditions created during landing are of great interest. Our purpose is to compare the blood plasma proteome changes associated with the trauma and endothelial dysfunction processes prior to launch and on the day of landing, as well as the groups of cosmonauts with and without the secondary hemorrhagic purpura. In our study, the concentrations of 125 plasma proteins in 18 Russian cosmonauts, measured using targeted proteomic analysis based on liquid chromatography and tandem mass spectrometry were analyzed. The results reveal the trends of 12 proteins participating in the processes that trigger hemorrhagic purpura under the effect of re-entry g-forces. Exposure to intense g-forces and return to the gravity are the key factors for external manifestations of changes in the body systems induced by a long-term stay in space microgravity. Our results may be useful for further research to experts in gravitational physiology, aviation and space medicine.

Integration of Metabolomics and Proteomics in Exploring the Endothelial Dysfunction Mechanism Induced by Serum Exosomes From Diabetic Retinopathy and Diabetic Nephropathy Patients

Background

The prevalence of diabetic microvascular diseases has increased significantly worldwide, the most common of which are diabetic nephropathy (DN) and diabetic retinopathy (DR). Microvascular endothelial cells are thought to be major targets of hyperglycemic damage, while the underlying mechanism of diffuse endothelial dysfunction in multiple organs needs to be further investigated.

Aim

The aim of this study is to explore the endothelial dysfunction mechanisms of serum exosomes (SExos) extracted from DR and DN (DRDN) patients.

Methods

In this study, human glomerular endothelial cells (HGECs) were used as the cell model. Metabolomics ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and proteomics tandem mass tag (TMT)-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) together with bioinformatics, the correlation analysis, and the joint pathway analysis were employed to discover the underlying mechanisms of endothelial dysfunction caused by patient's SExos.

Results

It can be assumed that serum exosomes extracted by DRDN patients might cause endothelial dysfunction mainly by upregulating alpha subunit of the coagulation factor fibrinogen (FIBA) and downregulating 1-methylhistidine (1-MH). Bioinformatics analysis pointed to an important role in reducing excess cysteine and methionine metabolism.

Conclusion

FIBA overexpression and 1-MH loss may be linked to the pathogenicity of diabetic endothelial dysfunction in DR/DN, implying that a cohort study is needed to further investigate the role of FIBA and 1-MH in the development of DN and DR, as well as the related pathways between the two proteins.

Thromboelastometry fails to detect autoheparinization after major trauma and hemorrhagic shock

BACKGROUND

Heparan sulfate is an integral component of the glycocalyx that provides an anticoagulant layer close to the endothelium. Hypoperfusion, inflammation, and sympathoadrenal activation following major trauma result in glycocalyx shedding and subsequent release of heparan sulfate into the bloodstream. The possible anticoagulant effect of this "autoheparinization" has been suggested as a potential driver of trauma-induced coagulopathy. We investigated whether thromboelastometry can be used to detect trauma-induced autoheparinization.

METHODS

This study comprised three parts. First, in a retrospective clinical study of 264 major trauma patients, the clotting time (CT) in the intrinsic activation (INTEM) and intrinsic activation plus heparinase (HEPTEM) assays were evaluated upon emergency room admission. Second, in an in vivo experimental rat model of hemorrhagic-traumatic shock, the release of heparan sulfate was investigated with INTEM and HEPTEM analyses of whole blood. Third, in vitro spiking of whole blood from healthy volunteers was undertaken to assess the effects of clinically relevant quantities of heparan sulfate and heparin on CT in the INTEM and HEPTEM assays.

RESULTS

In the first part, severe injury and hemorrhagic shock was not associated with any increases in INTEM CT versus HEPTEM CT. Part 2 showed that an approximate threefold increase in heparan sulfate resulting from hemorrhagic traumatic shock in rats did not prolong INTEM CT, and no significant differences between INTEM CT and HEPTEM CT were observed. Third, spiking of whole blood with heparan sulfate had no impact on INTEM CT, whereas heparin elicited significant prolongation of INTEM CT.

CONCLUSION

Despite structural similarity between heparan sulfate and heparin, the amounts of heparan sulfate shed in response to trauma did not exert an anticoagulant effect that was measurable by the intrinsically activated CT in thromboelastometry. The extent to which heparan sulfate contributes to trauma-induced coagulopathy has yet to be elucidated.

LEVEL OF EVIDENCE

Prognostic and Epidemiologic; Level III.

Trauma-induced coagulopathy: Mechanisms and clinical management

INTRODUCTION

Trauma-induced coagulopathy (TIC) is a form of coagulopathy unique to trauma patients and is associated with increased mortality. The complexity and incomplete understanding of TIC have resulted in controversies regarding optimum management. This review aims to summarise the pathophysiology of TIC and appraise established and emerging advances in the management of TIC.

METHODS

This narrative review is based on a literature search (MEDLINE database) completed in October 2020. Search terms used were "trauma induced coagulopathy", "coagulopathy of trauma", "trauma induced coagulopathy pathophysiology", "massive transfusion trauma induced coagulopathy", "viscoelastic assay trauma induced coagulopathy", "goal directed trauma induced coagulopathy and "fibrinogen trauma induced coagulopathy'.

RESULTS

TIC is not a uniform phenotype but a spectrum ranging from thrombotic to bleeding phenotypes. Evidence for the management of TIC with tranexamic acid, massive transfusion protocols, viscoelastic haemostatic assays (VHAs), and coagulation factor and fibrinogen concentrates were evaluated. Although most trauma centres utilise fixed-ratio massive transfusion protocols, the "ideal" transfusion ratio of blood to blood products is still debated. While more centres are using VHAs to guide blood product replacement, there is no agreed VHA-based transfusion strategy. The use of VHA to quantify the functional contributions of individual components of coagulation may permit targeted treatment of TIC but remains controversial.

CONCLUSION

A greater understanding of TIC, advances in point-of-care coagulation testing, and availability of coagulation factors and fibrinogen concentrates allows clinicians to employ a more goal-directed approach. Still, hospitals need to tailor their approaches according to available resources, provide training and establish local guidelines.

Postoperative hypoalbuminemia is an independent predictor of 1-year mortality after surgery for geriatric intertrochanteric femoral fracture: A retrospective cohort study

Preoperative hypoalbuminemia from malnutrition is associated with increased morbidity and mortality after geriatric hip fracture surgery. However, little is known regarding the correlation between postoperative hypoalbuminemia and mortality. This study aimed to evaluate whether postoperative hypoalbuminemia could predict 1-year mortality after intertrochanteric femoral fracture surgery in elderly patients.The medical records of 263 geriatric patients (age ≥65 years) who underwent intertrochanteric femoral fracture surgery between January 2013 and January 2016 in a single hospital were reviewed retrospectively. The patients were allocated to 2 groups based on lowest serum albumin levels within 2 postoperative days (≥3.0 g/dL [group 1, n = 46] and <3.0 g/dL [group 2, n = 217]. Data between the non-survival and survival groups were compared. Multivariable logistic regression analysis was conducted to identify the independent predictor for 1-year mortality.The 1-year mortality rate was 16.3% after intertrochanteric femoral fracture surgery. Multivariable logistic regression analysis revealed that postoperative hypoalbuminemia was significantly associated with 1-year mortality (adjusted odds ratio, 8.03; 95% confidence interval, 1.37-47.09; P = .021). The non-survival group showed a significantly increased incidence of postoperative hypoalbuminemia (95.4% vs 80.0%, P = .015) and intensive care unit admission (11.6% vs 2.7%, P = .020), older age (82.5 ± 5.8 years vs 80.0 ± 7.2 years, P = .032), lower body mass index (20.1 ± 3.2 kg/m2 vs 22.4 ± 3.8 kg/m2, P < .001), and increased amount of transfusion of perioperative red blood cells (1.79 ± 1.47 units vs 1.43 ± 2.08 units, P = .032), compared to the survival group.This study demonstrated that postoperative hypoalbuminemia is a potent predictor of 1-year mortality in geriatric patients undergoing intertrochanteric femoral fracture surgery. Therefore, exogenous albumin administration can be considered to improve postoperative outcomes and reduce the risk of mortality after surgery for geriatric hip fracture.

Personalized modulation of coagulation factors using a thrombin dynamics model to treat trauma-induced coagulopathy

Current trauma-induced coagulopathy resuscitation protocols use slow laboratory measurements, rules-of-thumb, and clinician gestalt to administer large volumes of uncharacterized, non-tailored blood products. These one-size-fits-all treatment approaches have high mortality. Here, we provide significant evidence that trauma patient survival 24 h after hospital admission occurs if and only if blood protein coagulation factor concentrations equilibrate at a normal value, either from inadvertent plasma-based modulation or from innate compensation. This result motivates quantitatively guiding trauma patient coagulation factor levels while accounting for protein interactions. Toward such treatment, we develop a Goal-oriented Coagulation Management (GCM) algorithm, a personalized and automated ordered sequence of operations to compute and specify coagulation factor concentrations that rectify clotting. This novel GCM algorithm also integrates new control-oriented advancements that we make in this work: an improvement of a prior thrombin dynamics model that captures the coagulation process to control, a use of rapidly-measurable concentrations to help predict patient state, and an accounting of patient-specific effects and limitations when adding coagulation factors to remedy coagulopathy. Validation of the GCM algorithm's guidance shows superior performance over clinical practice in attaining normal coagulation factor concentrations and normal clotting profiles simultaneously.

Influencing Factors and Prevention of Sepsis or Acute Kidney Injury in 85 Patients with Severe Trauma

Severe trauma can cause systemic reactions, leading to massive bleeding, shock, asphyxia, and disturbance of consciousness. At the same time, patients with severe trauma are at high risk of sepsis and acute renal injury. The occurrence of complications will increase the difficulty of clinical treatment, improve the mortality rate, and bring heavy physical and mental burdens and economic pressure to patients and their families. It is of great clinical significance to understand the high risk factors of sepsis and AKI and actively formulate prevention and treatment measures. In this study, the clinical data of 85 patients with severe trauma were analyzed by univariate and multivariate logistic regression to identify the risk factors leading to sepsis or AKI and analyze the prevention and treatment strategies. The results showed that multiple injuries, APACHE II score on admission, SOFA score on admission, and mechanical ventilation were independent influencing factors of sepsis in patients with severe trauma, while hemorrhagic shock, APACHE II score on admission, CRRT, and sepsis were independent influencing factors of AKI in patients with severe trauma. Severe trauma patients complicated with sepsis or AKI will increase the risk of death. In the course of treatment, prevention and intervention should be given as far as possible to reduce the incidence of complications.

Dose tranexamic acid reduce blood loss associated with simultaneous bilateral distal tibial tubercle-high tibial osteotomy?

Background

Simultaneous bilateral distal tibial tubercle high tibial osteotomy (SBDTT-HTO) can result in increased blood loss. The aim of this study is to evaluate the actual hemostatic effect of different tranexamic acid (TXA) treatment regimen in SBDTT-HTO.

Methods

We conducted a retrospective case–control study including 54 patients who underwent SBDTT-HTO. The single-dose group (n = 18) received 1 g of intravenous TXA 15–30 min before surgery, the two-dose group (n = 18) received an additional 1 g of intravenous TXA 6 h after surgery, and the multiple-dose group (n = 18) received an additional 1 g intravenous TXA per-day until discharge. Blood loss, hemoglobin levels, occurrence of any adverse events,functional analysis, quality of life, and pain assessmentswere compared among the three groups.

Results

The total blood loss, hidden blood loss, drainage volumes, and haemoglobin level in the multiple-dose group all occupy a significant advantage.(p < 0.05). In addition, better quality of life were observed in patients belonging to the multiple-dose group then single-dose group.(p < 0.05).

Conclusions

Based on our results, for patients undergoing SBDTT-HTO, sequential intravenous TXA administration can effectively and safely reduce blood loss,maintain postoperative Hb levels,and with the advantage of accelerating recovery.

Preparation, properties and application of graphene-based materials in tissue engineering scaffolds

Tissue engineering has great application prospect as an effective treatment for tissue and organ injury, functional reduction or loss. Bioactive tissues are reconstructed and damaged organs are repaired by the three elements including cells, scaffold materials and growth factors. Graphene-based composites can be used as reinforcing auxiliary materials for tissue scaffold preparation because of their large specific surface area, and good mechanical support. Tissue engineering scaffolds with graphene-based composites have been widely studied. Part of research have focused on the application of graphene-based composites in single tissue engineering; The basic principles of graphene materials used in tissue engineering are summarized in some researches. Some studies emphasized the key problems and solutions urgently needed to be solved in the development of tissue engineering, and discussed their application prospect. Some related studies mainly focused on the conductivity of graphene, and discussed the application of electroactive scaffolds in tissue engineering. In this review, the composite materials for preparing tissue engineering scaffolds are briefly described, which emphasizes the preparation methods, biological properties and practical applications of graphene-based composite scaffolds. The synthetic techniques with stressing solvent casting, electrospinning and 3D printing are introduced in detail. The mechanical, cell-oriented and biocompatible properties of graphene-based composite scaffolds in tissue engineering are analyzed and summarized. Their applications in bone tissue engineering, nerve tissue engineering, cardiovascular tissue engineering and other tissue engineering are summarized systematically. In addition, this work also looks forward to the difficulties and challenges in the future research, providing some references for the follow-up research of graphene-based composites in tissue engineering scaffolds.

Pathophysiology of Trauma-Induced Coagulopathy

There is no standard definition for trauma-induced coagulopathy (TIC). However, it could be defined as an abnormal hemostatic response secondary to trauma. The terms "early TIC" and "late TIC" have been recently suggested. "Early TIC" would refer to the inability to achieve effective hemostasis exacerbating an uncontrolled bleeding in a shocked patient with ischemia-reperfusion damage (bleeding phenotype) and takes place usually early after injury, whereas "late TIC" would represent a hypercoagulable state after surviving a severe tissue injury, that would contribute to thromboembolic events and multiorgan failure (MOF), (thrombotic phenotype), occurring typically hours after the trauma insult though it could be delayed for days. In addition, severe tissue injury when there is no associated shock could be followed by an early hypercoagulable state, representing an evolutionary maladaptive response of a physiologic mechanism created to increase clot formation and prevent bleeding. Therefore, TIC is not a uniform phenotype, ranging from bleeding to pro-thrombotic profiles. This current concept of TIC is mainly based on the recognition of TIC as a unique clotting disorder following trauma in which alterations in the endothelial function, fibrinolysis regulation and platelet behavior after major trauma are the main cornerstones.

Extracellular vesicle-associated procoagulant activity is highest the first 3 hours after trauma and thereafter declines substantially: A prospective observational pilot study

BACKGROUND

Trauma patients have high concentrations of circulating extracellular vesicles (EVs) following injury, but the functional role of EVs in this setting is only partly deciphered. We aimed to describe in detail EV-associated procoagulant activity in individual trauma patients during the first 12 hours after injury to explore their putative function and relate findings to relevant trauma characteristics and outcome.

METHODS

In a prospective observational study of 33 convenience recruited trauma patients, citrated plasma samples were obtained at trauma center admission and 2, 4, 6, and 8 hours thereafter. We measured thrombin generation from isolated EVs and the procoagulant activity of phosphatidylserine (PS)-exposing EVs. Correlation and multivariable linear regression analyses were used to explore associations between EV-associated procoagulant activity and trauma characteristics as well as outcome measures.

RESULTS

EV-associated procoagulant activity was highest in the first 3 hours after injury. EV-associated thrombin generation normalized within 7 to 12 hours of injury, whereas the procoagulant activity of PS-exposing EVs declined to a level right above that of healthy volunteers. Increased EV-associated procoagulant activity at admission was associated with higher New Injury Severity Score, lower admission base excess, higher admission international normalized ratio, prolonged admission activated partial thromboplastin time, higher Sequential Organ Failure Assessment score at day 0, and fewer ventilator-free days.

CONCLUSION

Our data suggest that EVs have a transient hypercoagulable function and may play a role in the early phase of hemostasis after injury. The role of EVs in trauma-induced coagulopathy and posttraumatic thrombosis should be studied bearing in mind this novel temporal pattern.

LEVEL OF EVIDENCE

Prognostic/epidemiologic, level V.

Benzodiazepines increase the likelihood of both infectious and thrombotic complications

INTRODUCTION

Benzodiazepines (BZDs) modulate peripheral γ-amino-butyric acid type A on macrophages causing immunomodulation. They inhibit proinflammatory cytokines increasing infections. Prior studies have also shown that infections can increase thrombotic complications. We sought to examine this relationship in trauma patients. We hypothesized that the presence of BZDs on admission urine drug screen (UDS) would increase rates of both complications.

METHODS

All patients submitted to the Pennsylvania Trauma Outcome Study database from 2003 to 2018 were queried. Those with a positive UDS for BZDs were analyzed. Infectious complications were defined as pneumonia, urinary tract infection, sepsis, wound, and soft tissue infection, and thrombotic complications were defined as presence of pulmonary embolism or deep vein thrombosis. Logistic regressions controlling for demographic and injury covariates assessed the adjusted impact of BZDs on infectious and thrombotic complications.

RESULTS

A total of 3,393 patients (2.08%) had infectious complications, and 3,048 (1.87%) had thrombotic complications. Furthermore, 33,260 patients (20.4%) had a positive UDS for BZDs on admission. Univariate analysis showed that those positive for BZDs had higher rates of infectious (3.33% vs. 1.76%, p < 0.001) and thrombotic (2.84% vs. 1.62%, p < 0.001) complications. Multivariate analysis revealed that BZDs significantly increased the odds of infectious and thrombotic complications. Patients who tested positive for BZDs and subsequently developed infection had increased odds (adjusted odds ratio, 1.65; p < 0.001) of developing thrombotic complications.

CONCLUSION

Trauma patients with a positive UDS for BZDs had higher odds of both infectious and thrombotic complications. Moreover, odds of thrombotic complications were higher in those with infections.

LEVEL OF EVIDENCE

Epidemiological, level III.

Fibrinogen in traumatic haemorrhage

PURPOSE OF REVIEW

Recent advances in the understanding of the pathophysiological processes associated with traumatic haemorrhage and trauma-induced coagulopathy (TIC) have resulted in improved outcomes for seriously injured trauma patients. However, a significant number of trauma patients still die from haemorrhage. This article reviews the role of fibrinogen in normal haemostasis, the effect of trauma and TIC on fibrinogen levels and current evidence for fibrinogen replacement in the management of traumatic haemorrhage.

RECENT FINDINGS

Fibrinogen is usually the first factor to reach critically low levels in traumatic haemorrhage and hypofibrinogenaemia after severe trauma is associated with increased risk of massive transfusion and death. It is postulated that the early replacement of fibrinogen in severely injured trauma patients can improve outcomes. There is, however, a paucity of evidence to support this, and in addition, there is little evidence to support or refute the effects of cryoprecipitate or fibrinogen concentrate for fibrinogen replacement.

SUMMARY

The important role fibrinogen plays in haemostasis and effective clot formation is clear. A number of pilot trials have investigated different strategies for fibrinogen replacement in severe trauma. These trials have formed the basis of several large-scale phase III trials, which, cumulatively will provide a firm evidence base to harmonise worldwide clinical management of severely injured trauma patients with major haemorrhage.

Evaluation of coagulation parameters in dogs with gallbladder mucoceles

BACKGROUND

Gallbladder mucocele (GBM) is a common biliary disorder in dogs. Limited information is available on the coagulation status of dogs with GBM.

HYPOTHESIS/OBJECTIVES

To determine patterns of coagulation alterations in dogs with GBM and correlate them with clinicopathologic abnormalities and ultrasonographic findings of disease severity.

ANIMALS

Twenty-three dogs with GBM identified on ultrasound examination were prospectively enrolled.

METHODS

At the time of GBM identification, blood and urine were collected for CBC, serum biochemical panel, urinalysis, prothrombin time, activated partial thromboplastin time (aPTT), factor VIII, protein C (PC), von Willebrand's factor (vWF), antithrombin activity, fibrinogen, D-dimers, and thromboelastrography (TEG). Gallbladder mucoceles were classified into ultrasound types 1 to 5. Medical records were reviewed for clinical presentation, underlying conditions and to determine if systemic inflammatory response syndrome (SIRS) was present.

RESULTS

Based on TEG parameters, maximal amplitude, and G, 19/23 (83%) of dogs with GBM had evaluations consistent with hypercoagulability. On plasma-based coagulation testing, dogs with GBM had increased total PC activity (20/23, 87%), fibrinogen (9/23, 39%), platelet count (9/23, 39%), and D-dimers (6/15, 40%) as well as prolongations in aPTT (9/22, 41%) and low vWF activity (5/21, 24%). No correlation was found between TEG G value and any coagulation or clinical pathology variables, ultrasound stage of GBM or disease severity as assessed by the presence of SIRS.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with ultrasonographically identified GBM have changes in whole blood kaolin-activated TEG supporting a hypercoagulable state although traditional plasma-based coagulation testing suggests that a complex state of hemostasis exists.

Increased resistance to fibrinolysis activation in patients with coronavirus disease 2019: a case series

We describe seven critically ill and seven noncritically ill patients with coronavirus disease 2019 infection. Two viscoelastic assays were performed with ClotPro technology, activated by extrinsic system test and recombinant tissue plasminogen activator challenge test. Coagulation profile presents a marked hypercoagulability with increased resistance to fibrinolysis, reflected by tissue plasminogen activator test. Our pathological observations show that the hypercoagulative status described in these patients is, at least partially, secondary to fibrinolysis shutdown.

Tranexamic acid use in severely injured patients, is it always appropriate?

Recently, it has been suggested that tranexamic acid should be administered only in those patients with hyperfibrinolysis determined using viscoelastic assays, as severely injured patients may present with fibrinolytic shutdown. However the last European guidelines on management of major bleeding and coagulopathy following trauma endorse the use of tranexamic acid to the trauma patient who is bleeding or at risk of significant hemorrhage as soon as possible without waiting for viscoelastic results. We present a severely blunt trauma patient treated with on-scene administration of tranexamic acid that developed immediate pulmonary embolism.

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.

Tranexamic acid use in severely injured patients, is it always appropriate?

Recently, it has been suggested that tranexamic acid should be administered only in those patients with hyperfibrinolysis determined using viscoelastic assays, as severely injured patients may present with fibrinolytic shutdown. However the last European guidelines on management of major bleeding and coagulopathy following trauma endorse the use of tranexamic acid to the trauma patient who is bleeding or at risk of significant hemorrhage as soon as possible without waiting for viscoelastic results. We present a severely blunt trauma patient treated with on-scene administration of tranexamic acid that developed immediate pulmonary embolism.

Hemostatic defects in massive transfusion: an update and treatment recommendations

INTRODUCTION

Acute hemorrhage is a global healthcare issue, and remains the leading preventable cause of death in trauma. Acute severe hemorrhage can be related to traumatic, peripartum, gastrointestinal, and procedural causes. Hemostatic defects occur early in patients requiring massive transfusion. Early recognition and treatment of hemorrhage and hemostatic defects are required to save lives and to achieve optimal patient outcomes.

AREAS COVERED

This review discusses current evidence and trials aimed at identifying the optimal treatment for hemostatic defects in hemorrhage and massive transfusion. Literature search included PubMed and Embase.

EXPERT OPINION

Patients with acute hemorrhage requiring massive transfusion commonly develop coagulopathy due to specific hemostatic defects, and accurate diagnosis and prompt correction are required for definitive hemorrhage control. Damage control resuscitation and massive transfusion protocols are optimal initial treatment strategies, followed by goal-directed individualized resuscitation using real-time coagulation monitoring. Distinct phenotypes exist in trauma-induced coagulopathy, including 'Bleeding' or 'Thrombotic' phenotypes, and hyperfibrinolysis vs. fibrinolysis shutdown. The trauma 'lethal triad' (hypothermia, coagulopathy, acidosis) has been updated to the 'lethal diamond' (including hypocalcemia). A number of controversies in optimal management exist, including whole blood vs. component therapy, use of factor concentrates vs. blood products, optimal use of tranexamic acid, and prehospital plasma and tranexamic acid administration.

Variations and obstacles in the use of coagulation factor concentrates for major trauma bleeding across Europe: outcomes from a European expert meeting

Purpose

Trauma is a leading cause of mortality, with major bleeding and trauma-induced coagulopathy (TIC) contributing to negative patient outcomes. Treatments for TIC include tranexamic acid (TXA), fresh frozen plasma (FFP), and coagulation factor concentrates (CFCs, e.g. prothrombin complex concentrates [PCCs] and fibrinogen concentrate [FCH]). Guidelines for TIC management vary across Europe and a clear definition of TIC is still lacking.

Methods

An advisory board involving European trauma experts was held on 02 February 2019, to discuss clinical experience in the management of trauma-related bleeding and recommendations from European guidelines, focusing on CFC use (mainly FCH). This review summarises the discussions, including TIC definitions, gaps in the guidelines that affect their implementation, and barriers to use of CFCs, with suggested solutions.

Results

A definition of TIC, which incorporates clinical (e.g. severe bleeding) and laboratory parameters (e.g. low fibrinogen) is suggested. TIC should be treated immediately with TXA and FCH/red blood cells; subsequently, if fibrinogen ≤ 1.5 g/L (or equivalent by viscoelastic testing), treatment with FCH, then PCC (if bleeding continues) is suggested. Fibrinogen concentrate, and not FFP, should be administered as first-line therapy for TIC. Several initiatives may improve TIC management, with improved medical education of major importance; generation of new and stronger data, simplified clinical practice guidance, and improved access to viscoelastic testing are also critical factors.

Conclusions

Management of TIC is challenging. A standard definition of TIC, together with initiatives to facilitate effective CFC administration, may contribute to improved patient care and outcomes.

Trauma-Induced Coagulopathy and Massive Bleeding: Current Hemostatic Concepts and Treatment Strategies

Hemorrhage after trauma remains a significant cause of preventable death. Trauma-induced coagulopathy (TIC) at the time of hospital admission is associated with an impaired outcome. Rather than a universal phenotype, TIC represents a complex hemostatic disorder, and standard coagulation tests are not designed to adequately reflect the complexity of TIC. Viscoelastic testing (VET) has gained increasing interest for the characterization of TIC because it provides a more comprehensive depiction of the coagulation process. Thus, VET has been established as a point-of-care-available hemostatic monitoring tool in many trauma centers. Damage-control resuscitation and early administration of tranexamic acid provide the basis for treating TIC. To improve survival, ratio-driven massive transfusion protocols favoring early and high-dose plasma transfusion have been implemented in many trauma centers around the world. Although plasma contains all coagulation factors and inhibitors, only high-volume plasma transfusion allows for adequate substitution of lacking coagulation proteins. However, high-volume plasma transfusion has been associated with several relevant risks. In some European trauma facilities, a more individualized hemostatic therapy concept has been implemented. The hemostatic profile of the bleeding patient is evaluated by VET. Subsequently, goal-directed hemostatic therapy is primarily based on coagulation factor concentrates such as fibrinogen concentrate or prothrombin complex concentrate. However, a clear difference in survival benefit between these two treatment strategies has not yet been shown. This concise review aims to summarize current evidence for different diagnostic and therapeutic strategies in patients with TIC.

Impact of a goal-directed factor-based coagulation management on thromboembolic events following major trauma

BACKGROUND

A factor-based coagulation management following major trauma is recommended as standard of care by the European Trauma Treatment Guidelines. However, concerns about the thromboembolic risk of this approach are still prevalent. Our study therefore aims to assess if such a haemostatic management is associated with an increased risk for thromboembolic events.

METHODS

In this retrospective observational study carried out at the University Hospital Zurich we compared two three-year periods before (period 1: 2005-2007) and after (period 2: 2012-2014) implementation of a factor-based coagulation algorithm. We included all adult patients following major trauma primarily admitted to the University Hospital Zurich. Thromboembolic events were defined as a new in-hospital appearance of any peripheral thrombosis, arterial embolism, pulmonary embolism, stroke or myocardial infarction. A logistic regression was performed to investigate the association of thromboembolic events with possible confounders such as age, sex, specific Abbreviated Injury Scale (AIS) subgroups, allogeneic blood products, and the coagulation management.

RESULTS

Out of 1138 patients, 772 met the inclusion criteria: 344 patients in period 1 and 428 patients in period 2. Thromboembolic events were present in 25 patients (7.3%) of period 1 and in 42 patients (9.8%) of period 2 (raw OR 1.39, 95% CI 0.83 to 2.33, p = 0.21). Only AIS extremities (adjusted OR 1.26, 95% CI 1.05 to 1.52, p = 0.015) and exposure to allogeneic blood products (adjusted OR 2.39, 95% CI 1.33 to 4.30, p = 0.004) were independently associated with thromboembolic events in the logistic regression, but the factor-based coagulation management was not (adjusted OR 1.60, 95% CI 0.90-2.86, p = 0.11).

CONCLUSION

There is no evidence that a goal-directed, factor-based coagulation management is associated with an increased risk for thromboembolic events following major trauma.