Management of Trauma-Induced Coagulopathy with Thrombelastography

Management of Bleeding Diathesis in Elective and Orthopaedic Trauma: A Review

There is a general need among orthopaedic surgeons for practical advice on managing patients with bleeding disorders. Appropriate diagnosis and management of these disorders is paramount once discovered before, during, or after the patient's surgical course. Bleeding disorders disrupt the body's ability to control bleeding, commonly through platelet function and blood clotting. Normally, the vessel contracts and retracts once disruption of blood vessels occurs, limiting blood loss. Blood platelets adhere to exposed collagen, aggregate at the site, and obstruct blood loss. Because platelet aggregates are temporary, blood clotting is needed to back up the platelet plug and provide a milieu for the healing process that completes the hemostatic events. Disorders that interfere with any of these events can result in hemorrhage, drainage, or rebleeding. Bleeding disorders are a group of conditions, either hereditary or acquired, marked by abnormal or excessive bleeding and/or bruising. The most effective methods for assessing coagulation disorders include a detailed history and a series of blood tests. Clinical examination findings are notable but may be less specific. If a surgical patient has a bleeding disorder discovered preoperatively, postoperatively, or intraoperatively, treatments exist with medications, surgical management, interventional radiology procedures, and replacement therapy.

The role of factor XIII in patient blood management

Factor XIII (FXIII), a plasma transglutaminase, is a coagulation factor that plays a crucial role in blood clotting and patient blood management. The studies have demonstrated that FXIII targets a wide range of additional substrates that have an important role in hemostasis, especially in posttraumatic patients, patients undergoing surgery or obstetrics, being involved in wound healing and tissue repair. Morover, FXIII deficiency has also been described and an extensive research has shown that FXIII deficiency is a rare coagulopathy that leads to longer bleeding time, perioperative and postoperative complications and slower wound healing. Present article aims to overview the diverse functions of FXIII and to highlight its role in patient blood management.

Characterising practice patterns of human derived, lyophilized coagulation concentrates within the trauma quality improvement program registry

OBJECTIVES

We seek to describe the current practice pattern use of prothrombin complex concentrate (PCC) and fibrinogen concentrate (FC) in trauma patients.

BACKGROUND

Trauma-induced coagulopathy (TIC) and endotheliopathy of trauma (EOT) contribute significantly to mortality from traumatic haemorrhage. FC, and 4-factor PCC are potential treatments for EOT and TIC, respectively.

MATERIALS AND METHODS

We obtained data from the Trauma Quality Improvement Program (TQIP) registry and identified patients who received either PCC or FC using procedural codes. We used descriptive statistics to characterise practice patterns of these products.

RESULTS

There were 6 714 002 total encounters within the TQIP from 2017 to 2022, of which 10 589 received PCC and 3009 received FC. Of the recipients, there were 35 that received both products. There were 44 that received both. The median age of PCC recipients was 77 (69-84) with 19 patients <15 years of age with the youngest being 2 years of age. There was a general upward trend in the number of facilities with documented use of PCC: 155/744, 168/766, 189/764, 206/780, 234/795, and 235/816, respectively. The median age of FC recipients was 57 (32-75) with 48 patients <15 years of age with the youngest being 1 year of age. There was a minor downward trend in the number of facilities that had documented use of FC: 55, 44, 39, 32, 38 and 40.

CONCLUSIONS

The administration of PCC and FC remains uncommon, although there appears to be an upward trend of PCC use. Most PCC use appeared to be for anticoagulation reversal in the setting of head trauma. Data guiding the use of these products are necessary as these products become more recognised as adjuncts to traumatic haemorrhage control.

Fluid resuscitation in trauma: What you need to know

ABSTRACT

There have been numerous changes in resuscitation strategies for severely injured patients over the last several decades. Certain strategies, such as aggressive crystalloid resuscitation, have largely been abandoned because of the high incidence of complications and worsening of trauma-induced coagulopathy. Significant emphasis has been placed on restoring a normal coagulation profile with plasma or whole blood transfusion. In addition, the importance of the lethal consequences of trauma-induced coagulopathy, such as hyperfibrinolysis, has been easily recognized by the use of viscoelastic testing, and its treatment with tranexamic acid has been extensively studied. Furthermore, the critical role of early intravenous calcium administration, even before blood transfusion administration, has been emphasized. Other adjuncts, such as fibrinogen supplementation with fibrinogen concentrate or cryoprecipitate and prothrombin complex concentrate, are being studied and incorporated in some of the institutional massive transfusion protocols. Finally, balanced blood component transfusion (1:1:1 or 1:1:2) and whole blood have become commonplace in trauma centers in North America. This review provides a description of recent developments in resuscitation and a discussion of recent innovations and areas for future investigation.

A Contemporary Review of Blood Transfusion in Critically Ill Patients

Blood transfusion is a common therapeutic intervention in hospitalized patients. There are numerous indications for transfusion, including anemia and coagulopathy with deficiency of single or multiple coagulation components such as platelets or coagulation factors. Nevertheless, the practice of transfusion in critically ill patients has been controversial mainly due to a lack of evidence and the need to consider the appropriate clinical context for transfusion. Further, transfusion carries many risk factors that must be balanced with benefits. Therefore, transfusion practice in ICU patients has constantly evolved, and we endeavor to present a contemporary review of transfusion practices in this population guided by clinical trials and expert guidelines.

Using microfluidic shear to assess transfusion requirements in trauma patients

Background

Viscoelastic assays have widely been used for evaluating coagulopathies but lack the addition of shear stress important to in vivo clot formation. Stasys technology subjects whole blood to shear forces over factor-coated surfaces. Microclot formation is analyzed to determine clot area (CA) and platelet contractile forces (PCFs). We hypothesize the CA and PCF from this novel assay will provide information that correlates with trauma-induced coagulopathy and transfusion requirements.

Methods

Blood samples were collected on adult trauma patients from a single-institution prospective cohort study of high-level activations. Patient and injury characteristics, transfusion data, and outcomes were collected. Thromboelastography, coagulation studies, and Stasys assays were run on paired samples collected at admission. Stasys CA and PCFs were quantified as area under the curve calculations and maximum values. Normal ranges for Stasys assays were determined using healthy donors. Data were compared using Kruskal-Wallis tests and simple linear regression.

Results

From March 2021 to January 2023, 108 samples were obtained. Median age was 37.5 (IQR 27.5-52) years; patients were 77% male. 71% suffered blunt trauma, 26% had an Injury Severity Score of ≥25. An elevated international normalized ratio significantly correlated with decreased cumulative PCF (p=0.05), maximum PCF (p=0.05) and CA (p=0.02). Lower cumulative PCF significantly correlated with transfusion of any products at 6 and 24 hours (p=0.04 and p=0.05) as well as packed red blood cells (pRBCs) at 6 and 24 hours (p=0.04 and p=0.03). A decreased maximum PCF showed significant correlation with receiving any transfusion at 6 (p=0.04) and 24 hours (p=0.02) as well as transfusion of pRBCs, fresh frozen plasma, and platelets in the first 6 hours (p=0.03, p=0.03, p=0.03, respectively).

Conclusions

Assessing coagulopathy in real time remains challenging in trauma patients. In this pilot study, we demonstrated that microfluidic approaches incorporating shear stress could predict transfusion requirements at time of admission as well as requirements in the first 24 hours.

Level of evidence

Level II.

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.

Trauma-induced coagulopathy: What you need to know

ABSTRACT

Trauma-induced coagulopathy (TIC) is a global inflammatory state accompanied by coagulation derangements, acidemia, and hypothermia, which occurs after traumatic injury. It occurs in approximately 25% of severely injured patients, and its incidence is directly related to injury severity. The mechanism of TIC is multifaceted; proposed contributing factors include dysregulation of activated protein C, increased tPA, systemic endothelial activation, decreased fibrinogen, clotting factor consumption, and platelet dysfunction. Effects of TIC include systemic inflammation, coagulation derangements, acidemia, and hypothermia. Trauma-induced coagulopathy may be diagnosed by conventional coagulation tests including platelet count, Clauss assay, international normalized ratio, thrombin time, prothrombin time, and activated partial thromboplastin time; viscoelastic hemostatic assays such as thrombelastography and rotational thrombelastography; or a clinical scoring system known as the Trauma Induced Coagulopathy Clinical Score. Preventing TIC begins in the prehospital phase with early hemorrhage control, blood product resuscitation, and tranexamic acid therapy. Early administration of prothrombin complex concentrate is also being studied in the prehospital environment. The mainstays of TIC treatment include hemorrhage control, blood and component transfusions, and correction of abnormalities such as hypocalcemia, acidosis, and hypothermia.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Fatal motorcycle straddle injury consolidated with traumatic testicular dislocation: A case report

Straddle injuries are those to the perineum region brought on by straddling or riding over something, such as a horse, vehicle, or other object. The motorcycle fuel tank or handlebars are primarily responsible for the typical injury to the perineum area in motorcycle accidents. Motorcycle straddle injury usually manifest as abrasions to the scrotum or penis, and severe cases can cause pelvic fractures or even testicular dislocation. Because these injuries are usually closed with unclear internal damage, diagnosis presents a significant challenge and can easily lead to misdiagnosis. However, pelvic fractures and the bleeding and nerve damage associated with perineal injury are often fatal, and testicular dislocation can also have serious consequences for patients. Therefore, a clear diagnosis and timely treatment are crucial for patients with this type of injury. This article reports the case of a motorcycle rider who died 4 h after a traffic accident with only minor surface injury visible, showing only bruising in the waist and scrotum. A forensic examination revealed multiple fractures throughout the patient's body, with a slightly more severe pelvic fracture and testicular dislocation on the left side in the left inguinal area. This article analyzes the cause of death and related issues in this case, aiming to provide assistance to clinical physicians and forensic practitioners and to emphasize the importance of handling straddle injury in treatment and related investigations to avoid serious consequences.

Bothrops atrox and Bothrops lanceolatus Venoms In Vitro Investigation: Composition, Procoagulant Effects, Co-Factor Dependency, and Correction Using Antivenoms

Bothrops venoms are rich in enzymes acting on platelets and coagulation. This action is dependent on two major co-factors, i.e., calcium and phospholipids, while antivenoms variably neutralize venom-related coagulopathy effects. Our aims were (i) to describe the composition of B. atrox and B. lanceolatus venoms; (ii) to study their activity on the whole blood using rotational thromboelastometry (ROTEM); (iii) to evaluate the contribution of calcium and phospholipids in their activity; and (iv) to compare the effectiveness of four antivenoms (Bothrofav™, Inoserp™ South America, Antivipmyn™ TRI, and PoliVal-ICP™) on the procoagulant activity of these two venoms. Venom composition was comparable. Both venoms exhibited hypercoagulant effects. B. lanceolatus venom was completely dependent on calcium but less dependent on phospholipids than B. atrox venom to induce in vitro coagulation. The four antivenoms neutralized the procoagulant activity of the two venoms; however, with quantitative differences. Bothrofav™ was more effective against both venoms than the three other antivenoms. The relatively similar venom-induced effects in vitro were unexpected considering the opposite clinical manifestations resulting from envenomation (i.e., systemic bleeding with B. atrox and thrombosis with B. lanceolatus). In vivo studies are warranted to better understand the pathophysiology of systemic bleeding and thrombosis associated with Bothrops bites.

Severe Trauma-Induced Coagulopathy: Molecular Mechanisms Underlying Critical Illness

Trauma remains one of the leading causes of death in adults despite the implementation of preventive measures and innovations in trauma systems. The etiology of coagulopathy in trauma patients is multifactorial and related to the kind of injury and nature of resuscitation. Trauma-induced coagulopathy (TIC) is a biochemical response involving dysregulated coagulation, altered fibrinolysis, systemic endothelial dysfunction, platelet dysfunction, and inflammatory responses due to trauma. The aim of this review is to report the pathophysiology, early diagnosis and treatment of TIC. A literature search was performed using different databases to identify relevant studies in indexed scientific journals. We reviewed the main pathophysiological mechanisms involved in the early development of TIC. Diagnostic methods have also been reported which allow early targeted therapy with pharmaceutical hemostatic agents such as TEG-based goal-directed resuscitation and fibrinolysis management. TIC is a result of a complex interaction between different pathophysiological processes. New evidence in the field of trauma immunology can, in part, help explain the intricacy of the processes that occur after trauma. However, although our knowledge of TIC has grown, improving outcomes for trauma patients, many questions still need to be answered by ongoing studies.

Alternative blood products in trauma

PURPOSE OF REVIEW

Hemorrhage and trauma-induced coagulopathy cause significant morbidity and mortality in trauma patients. Although blood products are the cornerstone of resuscitation, these resources are scarce, necessitating alternatives. This review examines the use of alternative blood products in trauma as well as the literature supporting their use.

RECENT FINDINGS

There is no single true blood product alternative. In recent years, there has been great progress in understanding trauma-induced pathophysiology and blood component alternatives. Products such as tranexamic acid and prothrombin complex concentrate have become well established and are frequently utilized in trauma centers, and many more alternatives are still undergoing further research and development.

SUMMARY

Stabilization of hemorrhage and resuscitation is priority in trauma-induced coagulopathy treatment. Alternative products such as tranexamic acid, recombinant factors, prothrombic complex concentrate, fibrinogen concentrates, and desmopressin may also be considered based on the clinical context. Viscoelastic hemostatic assays such as rotational thromboelastometry and thromboelastography can help guide these efforts. Following initial stabilization, additional interventions such as iron supplementation, erythropoietin stimulating agents, and vitamin D may help with chronic sequela.

Persistent fibrinolysis shutdown is associated with increased mortality in traumatic pancreatic injury

PURPOSE

The features of fibrinolytic system modifications and their relationship with prognosis are still unknown in traumatic pancreatic injury. The object of this prospective cohort research was to identify fibrinolytic characteristics in patients with pancreatic trauma and to identify the correlation to mortality.

METHOD

A prospective screening of traumatic pancreatic injury patients was done for five years. The fibrinolytic status of patients was determined by thromboelastography (TEG). The percentage reduction in clot strength 30 min (LY30) after the time of maximal clot strength was utilized to distinguish the fibrinolytic phenotype of individuals, including fibrinolytic shutdown (SD), physiologic fibrinolysis (PHYS) and hyperfibrinolysis (HF). Two cohorts, transient fibrinolytic shutdown (TSD) and persistent fibrinolytic shutdown (PSD), were divided according to whether fibrinolytic shutdown persisted within one week. Demographics, injury severity, characteristics of pancreatic injury, treatment, and outcomes were compared.

RESULT

A total of 180 cases enrolled, aged 42(interquartile range 32-51) years, 88% males, 97% were blunt trauma. The median ISS was 19(IQR 10-25), and 76% were AAST grade III to V (high-grade). At admission, there were 159 cases of SD (88%), 15 cases of PHYS (8%) while 6 cases of HF (3%). Of these, the TSD cohort included 54 patients (34%), while the PSD cohort included 105 patients (66%). Compared with the TSD cohort, the PSD cohort had more severe injury (ISS 21[IQR 12-27] vs 16[IQR 9-22], p = 0.006) and a higher proportion of AAST high-grade (83% vs 67%, p = 0.035). Persistent fibrinolytic shutdown was associated with operative treatment (odds ratio [OR] 3.111; 95%CI 1.146-8.447; p = 0.026), associated intra-abdominal injury (OR 8.331; 95% CI 1.301-53.336; p = 0.025) and admission LY30 (OR 0.016; 95% CI 0.002 - 0.120; p < 0.001). It was an independent predictor of mortality (adjusted odds ratio [AOR] 4.674; 95% CI 1.03 to 21.14; p = 0.045).

CONCLUSION

Fibrinolytic shutdown especially persistence of this phenotype is more common in traumatic pancreatic injury than PHYS and HF, which related with mortality. Risk factors including LY30 at admission, intra-abdominal injury and operative treatment were associated with the persistent fibrinolytic shutdown. Sheltered the patients from these risk factors seems to be beneficial, which need to be confirmed by further large-scale studies.

Admission maximum amplitude-reaction time ratio: Association between thromboelastography values predicts poor outcome in injured children

INTRODUCTION

Thromboelastography (TEG)-derived maximum amplitude-reaction time (MA-R) ratio that accounts for both hypocoagulable and hypercoagulable changes in coagulation is associated with poor outcomes in adults. The relationship between these TEG values and outcomes has not been studied in children.

METHODS

In a retrospective cohort study, a level I pediatric trauma center database was queried for children younger than 18 years who had a TEG assay on admission between 2016 and 2020. Demographics, injury characteristics, and admission TEG values were recorded. The MA-R ratio was calculated and divided into quartiles. Main outcomes included mortality, transfusion within 24 hours of admission, and thromboembolism. A logistic regression model was generated adjusting for age, Injury Severity Score, injury mechanism, admission shock, and Glasgow Coma Scale.

RESULTS

In total, 657 children were included, of which 70% were male and 75% had blunt mechanism injury. The median (interquartile range) age was 11 (4-14) years, the median (interquartile range) Injury Severity Score was10 (5-22), and in-hospital mortality was 7% (n = 45). Of these patients, 17% (n = 112) required transfusion. Most R and MA values were within normal limits. On unadjusted analysis, the lowest MA-R ratio quartile was associated with increased mortality (15% vs. 4%, 5%, and 4%, respectively; p < 0.001) and increased transfusion need (26% vs. 12%, 16%, and 13%, respectively; p = 0.002) compared with higher quartiles. In the logistic regression models, a low MA-R ratio was independently associated with increased in-hospital mortality (odds ratio [95% confidence interval], 4.4 [1.9-10.2]) and increased need for transfusion within 24 hours of admission (odds ratio [95% confidence interval], 2.0 [1.2-3.4]) compared with higher MA-R ratio. There was no association between MA-R ratio and venous thromboembolic events (venous thromboembolic event rate by quartile: 4%, 2%, 1%, and 3%).

CONCLUSION

Although individual admission TEG values are not commonly substantially deranged in injured children, the MA-R ratio is an independent predictor of poor outcome. Maximum amplitude-reaction time ratio may be a useful prognostic tool in pediatric trauma; validation is necessary.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Measurement of Blood Viscoelasticity Using Thromboelastography

Thromboelastography (TEG) was the first viscoelastic test (VET), invented in Germany in 1948 by Dr. Hartert, and which evaluates the hemostatic competence of whole blood. Thromboelastography was introduced before the activated partial thromboplastin time (aPTT), which was devised in 1953. TEG was not widely used until the introduction of a cell-based model of hemostasis (1994) showing the importance of platelets and tissue factor in hemostasis. Nowadays, VET has become an essential method for assessing hemostatic competence in cardiac surgery, liver transplantation, and trauma. TEG has undergone several modifications, but the concept on which the original TEG was based (cup and pin technology) remained in up to the TEG 5000 analyzer (Haemonetics, Braintree, MA). A new generation of thromboelastography, TEG 6s (Haemonetics, Boston, MA), that assesses blood viscoelastic properties by resonance technology has recently been developed. This newer methodology represents a cartridge-based, automated assay aimed to improve on historical TEG performance and precision. In the present chapter, we will review the advantages and limitations of TEG 5000 and TEG 6s systems as well as factors that affect TEG and which must be considered when interpreting TEG tracings.

Transfusion management in the trauma patient

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Changes in Thrombelastography in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease and the Relationship with Lung Function

Purpose

To analyze the changes in thrombelastography (TEG) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the relationship with indicators related to lung function.

Methods

100 patients with AECOPD admitted to our hospital from May 2021 to May 2022 were selected as the AE group, and another 80 patients with a stable phase of COPD in the same period were selected as the SP group. Fresh blood specimens were collected from both groups, and TEG-related indicators (R value, K value, α-angle, MA value) were measured using the TEG technique, and lung function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) were measured using a lung function meter, and the correlation between TEG-related indicators and lung function-related indicators was analyzed.

Results

Patients in the AE group had lower R and K values and higher α-angle and MA values than those in the SP group, all with statistically significant differences (P < 0.05). Patients in the AE group had lower FEV1, FVC, FEV1/FVC, and FEV1% levels than those in the SP group, all with statistically significant differences (P < 0.05). Correlation analysis showed that the R value in TEG of AECOPD patients was positively correlated with pulmonary function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = 0.565, 0.529, 0.447, 0.527, all P < 0.001); K value was positively correlated with pulmonary function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = 0.512, 0.567, 0.459, 0.439, all P < 0.001); α-angle was inversely correlated with pulmonary function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = -0.498, -0.372, -0.408, -0.424, all P < 0.001); MA value was inversely correlated with lung function-related indicators (FEV1, FVC, FEV1/FVC, FEV1%) (r = -0.459, -0.429, -0.394, -0.403, all P < 0.001).

Conclusion

There is a correlation between TEG-related indicators and lung function-related indicators in AECOPD patients, both of which can guide the diagnosis and treatment process of the disease and are worthy of clinical promotion. The clinical registration number is EA2021086.

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.

Snake Venom Hydrogels as a Rapid Hemostatic Agent for Uncontrolled Bleeding

Uncontrolled bleeding from traumatic injury remains the leading cause of preventable death with loss of balance between blood clotting (coagulation) and blood clot breakdown (fibrinolysis). A major limitation of existing hemostatic agents is that they require a functioning clotting system to control the bleeding and are largely based on gauze delivery scaffolds. Herein, a novel rapid wound sealant, composed of two recombinant snake venom proteins, the procoagulant ecarin, to rapidly initiate blood clotting and the antifibrinolytic textilinin, to prevent blood clot breakdown within a synthetic thermoresponsive hydrogel scaffold is developed. In vitro, it is demonstrated that clotting is rapidly initiated with only nanomolar concentrations of venom protein and clot breakdown is effectively inhibited by textilinin. A stable clot is formed within 60 s compared to normal clot formation in 8 min. In vivo studies reveal that the snake venom hydrogel rapidly controls warfarin-induced bleeding, reducing the bleed volume from 48% to 12% and has demonstrated immune compatibility. A new class of hemostatic agents that achieve formation of rapid and stable blood clots even in the presence of blood thinners is demonstrated here.

Cold-stored platelets are effective in an in vitro model of massive transfusion protocol assessed by rotational thromboelastometry

BACKGROUND

Platelets are a key component of massive transfusion in treating actively bleeding patients. While optimized for prophylactic transfusions, the effectiveness of the current standard room temperature stored platelets (RPs) in treating actively bleeding patients is not clear. Cold-stored platelets (CPs) have been shown to have superior hemostatic functions and the potential to extend shelf life. In this study, we explored the effect of using CPs versus RPs in an in vitro transfusion model based on the massive transfusion protocol.

STUDY DESIGN AND METHODS

RPs or CPs were combined with RBCs and plasma in a 1:1:1 volume ratio to make transfusion packages. Whole blood was collected and then either diluted to 20% hematocrit or mixed with tPA (8.8 μg/ml). By volume, 70% of transfusion package was mixed with 30% whole blood to simulate massive transfusions and analyzed by rotational thromboelastometry. Transfusion package supernatant was analyzed for PAI-1 activity as well.

RESULTS

Both transfusion packages restored the clot characteristics of hemodiluted or hyperfibrinolytic whole blood. Specifically, only transfusion packages made with CPs significantly reduced the maximum clot lysis of hyperfibrinolytic whole blood. PAI-1 activity in CPs transfusion packages were also significantly higher.

DISCUSSION

Transfusion packages containing cold-stored platelets may be able to restore the blood hemostatic profile of bleeding patients. In addition, transfusion packages made from CPs may provide additional benefit of resisting hyperfibrinolysis in bleeding patients. In trauma where post-transfusion platelet recovery is less of a concern, CPs are a viable option to restore hemostasis.

Full-length plasma skeletal muscle myosin isoform deficiency is associated with coagulopathy in acutely injured patients

BACKGROUND

Skeletal muscle myosin (SkM) molecules are procoagulant both in vitro and in vivo. The association of plasma SkM isoforms with blood coagulability and hemostatic capacity has not been defined.

OBJECTIVES

We hypothesized that coagulopathy in acutely injured patients is associated with procoagulant plasma SkM heavy chain levels.

METHODS

To test this hypothesis, citrated whole blood and plasma from 104 trauma patients were collected and studied to obtain data for rapid thrombelastography, international normalized ratios, and plasma SkM levels. Coagulability parameters were dichotomized by the threshold for the hypercoagulable trauma-induced coagulopathy.

RESULTS

Lower plasma full-length SkM heavy chain (full-SkM) levels were associated with higher international normalized ratio values (>1.3) (p = .03). The full-SkM levels were also associated with a lower rate of clot propagation (thrombelastography angle <65°) (p = .004), and plasma full-SkM levels were positively correlated with the thrombelastography angle (r2  = .32, p = .0007). The trauma patient group with the lower plasma full-SkM levels showed an association with lower clot strength (maximum amplitude <55 mm) (p = .002), and plasma full-SkM levels positively correlated with maximum amplitude (r2  = .27, p = .005). Hyperfibrinolysis was associated with significantly decreased full-SkM levels (p = .03). Trauma patients who required red blood cells and fresh frozen plasma transfusions had lower plasma full-SkM levels compared with those without transfusions (p = .04 and .02, respectively).

CONCLUSIONS

In acutely injured trauma patients, lower levels of plasma full-SkM levels are linked to hypocoagulability in trauma-induced coagulopathy, implying that SkM plays a role in the hemostatic capacity in trauma patients and may contribute to trauma-induced coagulopathy.

Disseminated intravascular coagulation and its immune mechanisms

Disseminated intravascular coagulation (DIC) is a syndrome triggered by infectious and noninfectious pathologies characterized by excessive generation of thrombin within the vasculature and widespread proteolytic conversion of fibrinogen. Despite diverse clinical manifestations ranging from thrombo-occlusive damage to bleeding diathesis, DIC etiology commonly involves excessive activation of blood coagulation and overlapping dysregulation of anticoagulants and fibrinolysis. Initiation of blood coagulation follows intravascular expression of tissue factor or activation of the contact pathway in response to pathogen-associated or host-derived, damage-associated molecular patterns. The process is further amplified through inflammatory and immunothrombotic mechanisms. Consumption of anticoagulants and disruption of endothelial homeostasis lower the regulatory control and disseminate microvascular thrombosis. Clinical DIC development in patients is associated with worsening morbidities and increased mortality, regardless of the underlying pathology; therefore, timely recognition of DIC is critical for reducing the pathologic burden. Due to the diversity of triggers and pathogenic mechanisms leading to DIC, diagnosis is based on algorithms that quantify hemostatic imbalance, thrombocytopenia, and fibrinogen conversion. Because current diagnosis primarily assesses overt consumptive coagulopathies, there is a critical need for better recognition of nonovert DIC and/or pre-DIC states. Therapeutic strategies for patients with DIC involve resolution of the eliciting triggers and supportive care for the hemostatic imbalance. Despite medical care, mortality in patients with DIC remains high, and new strategies, tailored to the underlying pathologic mechanisms, are needed.

Variations in clot phenotype following injury: The MA-R ratio and fragile clots

INTRODUCTION

Trauma-induced coagulopathy is a continuum ranging from hypercoagulable to hypercoagulable phenotypes. In single-center studies, the maximum amplitude (MA) to r-time (R) (MA-R) ratio has identified a phenotype of injured patients with high mortality risk. The purpose of this study was to determine the relationship between MA-R and mortality using multicenter data and to investigate fibrinogen consumption in the development of this specific coagulopathy phenotype.

METHODS

Using the Pragmatic Randomized Optimal Platelet and Plasma Ratios data set, patients were divided into blunt and penetrating injury cohorts. MA was divided by R time from admission thromboelastogram to calculate MA-R. MA-R was used to assess odds of early and late mortality using multivariable models. Multivariable models were used to assess thrombogram values in both cohorts. Refinement of the MA-R cut point was performed with Youden index. Repeat multivariable analysis was performed with a binary CRITICAL and NORMAL MA-R.

RESULTS

In initial analysis, MA-R quartiles were not associated with mortality in the penetrating cohort. In the blunt cohort, there was an association between low MA-R and early and late mortality. A refined cut point of 11 was identified (CRITICAL: MA-R, ≤11; NORMAL: MA-R, >11). CRITICAL MA-R was associated with mortality in both penetrating and blunt subgroups. In further injury subgroup analysis, CRITICAL patients had significantly decreased fibrinogen levels in the blunt subgroup only. In both blunt and penetrating injury, there was no difference in time to initiation of thrombin burst (lagtime). However, both endogenous thrombin potential and peak thrombin levels were significantly lower in CRITICAL patients.

CONCLUSIONS

MA-R identifies a trauma-induced coagulopathy phenotype characterized in blunt injury by impaired thrombin generation that is associated with early and late mortality. The endotheliopathy and tissue factor release likely plays a role in the cascade of impaired thrombin burst, possible early fibrinogen consumption and the weaker clot identified by MA-R.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

Sangre total leucorreducida y filtro ahorrador de plaquetas preserva su función hemostática por 21 días: ¿La resucitación hemostática podría ser una realidad en Colombia?

Introducción. La resucitación hemostática es una estrategia para compensar la pérdida sanguínea y disminuir el impacto de la coagulación inducida por trauma. Debido a que la disponibilidad de transfundir una razón equilibrada de hemocomponentes es difícil de lograr en el entorno clínico, la sangre total ha reaparecido como una estrategia fisiológica, con ventajas logísticas, que le permiten ser accesible para iniciar tempranamente la resucitación hemostática. El objetivo de este estudio fue evaluar las propiedades celulares, coagulantes y viscoelásticas de la sangre total almacenada por 21 días. Métodos. Las unidades de sangre total fueron obtenidas de 20 donantes voluntarios sanos. Se procesaron mediante un sistema de leucorreducción ahorrador de plaquetas y fueron almacenadas en refrigeración (1-6°C) sin agitación. Se analizaron los días 0, 6, 11 y 21. Las bolsas fueron analizadas para evaluar las líneas celulares, niveles de factores de coagulación y propiedades viscoelásticas mediante tromboelastografía. Resultados. El conteo eritrocitario y la hemoglobina se mantuvieron estables. El conteo de plaquetas tuvo una reducción del 50 % al sexto día, pero se mantuvo estable el resto del seguimiento. Los factores de coagulación II-V-VII-X, fibrinógeno y proteína C se mantuvieron dentro del rango normal. La tromboelastografía mostró una prolongación en el tiempo del inicio de la formación del coágulo, pero sin alterar la formación final de un coágulo estable. Conclusiones. La sangre total leucorreducida y con filtro ahorrador de plaquetas conserva sus propiedades hemostáticas por 21 días. Este es el primer paso en Colombia para la evaluación clínica de esta opción, que permita hacer una realidad universal la resucitación hemostática del paciente con trauma severo.

Reference Values of Thromboelastometry Parameters in Healthy Term Neonates Using NATEM in Cord Blood Samples

Background: ROTEM assay has gained increasing acceptance as a method for rapid and specific coagulation pathway assessment. However, its use in the neonatal population remains limited since reference ranges have not yet been established. Aims: (1) to determine reference ranges for healthy term neonates of ROTEM parameters using non-activated assay (NATEM) in cord blood samples; (2) to assess whether delivery mode, gender, gestational age, birth weight and blood group (ABO and Rhesus) of the neonate, coagulation disorder and anticoagulant medication of the mother have an impact on NATEM parameters. Methods: NATEM assay was conducted in cord blood samples of 189 term neonates without any medical history. Results: Reference ranges (2.5th and 97.5th percentiles) are established for clotting time (CT), clot formation time (CFT), α-angle, clot amplitude at 5, 10 and 20 min (A5, A10, A20), maximum clot firmness (MCF), lysis index at 30 and 60 min (LI30, LI60, %) and maximum clot elasticity (MCE). Reference ranges for NATEM are CT 182-499 s, CFT 63-176 s, α-angle 58-78°, A5 28-52 mm, A10 37-61 mm, A20 42-66 mm, MCF 43-67 mm, LI30 97-100%, LI60 87-98% and MCE 75-203. Male neonates appear to be more hypocoagulable than females. Conclusions: We demonstrate reference ranges for healthy term neonates in NATEM assay that could be used as a reference group for future studies of neonates with an underlying pathology.

Pro-Con Debate: Viscoelastic Hemostatic Assays Should Replace Fixed Ratio Massive Transfusion Protocols in Trauma

Major trauma patients at risk of traumatic coagulopathy are commonly treated with early clotting factor replacement to maintain hemostasis and prevent microvascular bleeding. In the United States, trauma transfusions are often dosed by empiric, low-ratio massive transfusion protocols, which pair plasma and platelets in some ratio relative to the red cells, such as the "1:1:1" combination of 1 units of red cells, 1 unit of plasma, and 1 donor's worth of pooled platelets. Empiric transfusion increases the rate of overtransfusion when unnecessary blood products are administered based on a formula and not on at patient's hemostatic profile. Viscoelastic hemostatic assays (VHAs) are point-of-care hemostatic assays that provided detailed information about abnormal clotting pathways. VHAs are used at many centers to better target hemostatic therapies in trauma. This Pro/Con section will address whether VHA guidance should replace empiric fixed ratio protocols in major trauma.

Evaluation of direct oral anticoagulant use on thromboelastography in an emergency department population

BACKGROUND

Direct oral anticoagulant (DOAC) use presents a challenge to all providers involved in emergency care of patients since widely accepted laboratory tests to assess the level of anticoagulation for such medications are lacking. Viscoelastic tests such as thromboelastography (TEG) tests are increasingly used throughout major trauma centers to help guide resuscitation efforts in patients presenting with trauma and/or hemorrhagic shock.

OBJECTIVE

The primary outcome compared TEG parameters between emergency department trauma patients reporting DOAC therapy and known normal TEG parameter values. The secondary outcome evaluated patients who reported time of last known DOAC dose within a preferred time frame of <12 h for once daily dosing DOAC therapy or < 6 h for twice daily dosing DOAC therapy.

METHODS

This single-center, retrospective cohort study assessed TEG values in patients receiving DOAC therapy and compared these to institution TEG ranges considered normal. TEG values of reaction time (R time), kinetics (K), alpha angle (AA), maximum amplitude (MA), and percent lysis in 30 min (LY30) were collected for patients reporting DOAC therapy.

RESULTS

40 patients were included in this study. 19 patients reported apixaban therapy and 21 reported rivaroxaban therapy. 5 (12.5%) patients had an elevated R time and 1 (2.5%) patient had a reduced MA. All other TEG values did not suggest hypocoagulability. For the secondary outcome assessing patients reporting last known dose within the preferred time frame, only the R time was elevated in 2 (14.3%) patients. Lastly, in a subgroup analysis of patients with elevated low-molecular-weight heparin (LMWH) orAnti- Xa levels, the R time was the only parameter affected in 25% of patients.

CONCLUSION

TEG values were typically not affected by rivaroxaban or apixaban use in an emergency department trauma population suggesting that TEG is not sensitive for Xa inhibitor detection and should not be relied upon for assessing anticoagulation in such settings.

A Systematic Review of Thromboelastography Utilization in Vascular and Endovascular Surgery

OBJECTIVE

Thromboelastography (TEG) is diagnostic modality that analyzes real-time blood coagulation parameters. Clinically, TEG primarily allows for directed blood component resuscitation among patients with acute blood loss and coagulopathy. The utilization of TEG has been widely adopted in among other surgical specialties; however, its use in vascular surgery is less prominent. We aimed to provide an up-to-date review of TEG utilization in vascular and endovascular surgery.

METHODS

Using PRISMA guidelines, a literature review with the Medical Subject Headings (MeSH) terms "TEG and arterial events", "TEG and vascular surgery", "TEG and vascular", "TEG and endovascular surgery", "TEG and endovascular", "TEG and peripheral artery disease", "TEG and prediction of arterial events", "TEG and prediction of complications ", "TEG and prediction of thrombosis", "TEG and prediction of amputation", and "TEG and amputation" was performed in Cochrane and PubMed databases to identify all peer-reviewed studies of TEG utilization in vascular surgery, written between 2000-2021 in the English language. The free text and MeSH subheadings search terms included diagnosis, complications, physiopathology, surgery, mortality, and therapy to further restrict the articles. Studies were excluded if they were not in humans or pertaining to vascular or endovascular surgery. Additionally, case reports and studies with limited information regarding TEG utilization were excluded. Each study was independently reviewed by two researchers to assess for eligibility.

RESULTS

Of the 262 studies identified through the MeSH strategy, 15 studies met inclusion criteria and were reviewed and summarized. Literature on TEG utilization in vascular surgery spanned cerebrovascular disease (n=3), peripheral arterial disease (n=3), arteriovenous malformations (n=1), venous thromboembolic events (n=7), and perioperative bleeding and transfusion (n=1). In cerebrovascular disease, TEG may predict the presence and stability of carotid plaques, analyze platelet function before carotid stenting, and compare efficacy of antiplatelet therapy after stent deployment. In peripheral arterial disease, TEG has been used to predict disease severity and analyze the impact of contrast on coagulation parameters. In venous disease, TEG may predict hypercoagulability and thromboembolic events among various patient populations. Finally, TEG can be utilized in the postoperative setting to predict hemorrhage and transfusion requirements.

CONCLUSIONS

This systematic review provides an up-to-date summarization of TEG utilization in multiple facets of vascular and endovascular surgery.

Utilization and Efficacy of Resuscitation Endpoints in Trauma and Burn Patients: A Review Article

Shock is a sequelae in trauma and burn patients that substantially increases the risk for morbidity and mortality. The use of resuscitation endpoints allows for improved management of these patients, with the potential to prevent further morbidity/mortality. We conducted a review of the current literature on the efficacy of hemodynamic, metabolic, and regional resuscitation endpoints for use in trauma and burn patients. Hemodynamic endpoints included mean arterial pressure (MAP), heart rate (HR), urinary output (UO), compensatory reserve index (CRI), intrathoracic blood volume, and stroke volume variation (SVV). Metabolic endpoints measure cellular responses to decreased oxygen delivery and include serum lactic acid (LA), base deficit (BD), bicarbonate, anion gap, apparent strong ion difference, and serum pH. Mean arterial pressure, HR, UO, and LA are the most established markers of trauma and burn resuscitation. The evidence suggests LA is a superior metabolic endpoint marker. Newer resuscitation endpoint technologies such as point-of-care ultrasound (PoCUS), thromboelastography (TEG), and rotational thromboelastometry (ROTEM) may improve patient outcomes; however, additional research is needed to establish the efficacy in trauma and burn patients. The endpoints discussed have situational strengths and weaknesses and no single universal resuscitation endpoint has yet emerged. This review may increase knowledge and aid in guideline development. We recommend clinicians continue to integrate multiple endpoints with emphasis on MAP, HR, UO, LA, and BD. Future investigation should aim to standardize endpoints for each clinical presentation. The search for universal and novel resuscitation parameters in trauma and burns should also continue.

Early fixation strategies for high energy pelvic ring injuries - the Zurich algorithm

In isolated high energy pelvic ring injuries, early surgical and nonsurgical fixation belongs to the rescue tools required for rapid recovery. With the increasing use of pelvic binders on scene, these patients frequently arrive in a better condition at the level I trauma centre than without any measures of immobilisation. We describe our surgical tools to achieve rapid fixation within the first hours after arrival, taking into account if additional injuries or special stations are relevant.

Lower Mortality with Cryoprecipitate During Massive Transfusion in Penetrating but Not Blunt Trauma

BACKGROUND

Balanced blood product transfusion improves the outcomes of trauma patients with exsanguinating hemorrhage, but it remains unclear whether administering cryoprecipitate improves mortality. We aimed to examine the impact of early cryoprecipitate transfusion on the outcomes of the trauma patients needing massive transfusion (MT).

METHODS

All MT patients 18 years or older in the 2017 Trauma Quality Improvement Program (TQIP) were retrospectively reviewed. MT was defined as the transfusion of ≥10 units of blood within 24 hours. Propensity score analysis (PSA) was used to 1:1 match then compare patients who received and those who did not receive cryoprecipitate in the first 4 hours after injury. Outcomes included in-hospital mortality, 1-day mortality, in-hospital complications and transfusion needs at 24 hours.

RESULTS

Of 1,004,440 trauma patients, 1,454 MT patients received cryoprecipitate and 2,920 did not. After PSA, 877 patients receiving cryoprecipitate were matched to 877 patients who did not. In-hospital mortality was lower among patients who received cryoprecipitate (49.4% v. 54.9%, P = 0.022), as was 1-day mortality. Sub-analyses showed that mortality was lower with cryoprecipitate in patients with penetrating (37.5% versus. 48%, adjusted P = 0.008), but not blunt trauma (58.5% versus. 59.8%, adjusted P = 1.000). In penetrating trauma, the cryoprecipitate group also had lower 1-day mortality (21.8% versus. 38.6%, P <0.001) and a higher rate of hemorrhage control surgeries performed within 24 hours (71.4% versus. 63.3%, P = 0.018).

CONCLUSIONS

Cryoprecipitate in MT is associated with improved survival in penetrating, but not blunt, trauma. Randomized trials are needed to better define the role of cryoprecipitate in MT.

TEG® and ROTEM® Traces: Clinical Applications of Viscoelastic Coagulation Monitoring in Neonatal Intensive Care Unit

The concentration of the majority of hemostatic proteins differs considerably in early life, especially in neonates compared to adulthood. Knowledge of the concept of developmental hemostasis is an essential prerequisite for the proper interpretation of conventional coagulation tests (CCT) and is critical to ensure the optimal diagnosis and treatment of hemorrhagic and thrombotic diseases in neonatal age. Viscoelastic tests (VETs) provide a point-of-care, real-time, global, and dynamic assessment of the mechanical properties of the coagulation system with the examination of both cellular and plasma protein contributions to the initiation, formation, and lysis of clots. In this work, we provide a narrative review of the basic principles of VETs and summarize current evidence regarding the two most studied point-of-care VETs, thromboelastography (TEG®) and rotational thromboelastometry (ROTEM®), in the field of neonatal care. A literature analysis shows that viscoelastic hemostatic monitoring appears to be a useful additive technique to CCT, allowing targeted therapy to be delivered quickly. These tools may allow researchers to determine the neonatal coagulation profile and detect neonatal patients at risk for postoperative bleeding, coagulation abnormalities in neonatal sepsis, and other bleeding events in a timely manner, guiding transfusion therapies using the goal-oriented transfusion algorithm. However, diagnosis and treatment algorithms incorporating VETs for neonatal patients in a variety of clinical situations should be developed and applied to improve clinical outcomes. Further studies should be performed to make routinary diagnostic and therapeutic application possible for the neonatal population.

Viscoelastic monitoring in trauma resuscitation

BACKGROUND

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

STUDY DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Implementing thrombelastography: Experiences from a level I trauma institution

Viscoelastic hemostatic assays such as thrombelastography (TEG) and rotational thrombelastometry have proven to be important point-of-care tools in the management of acute traumatic hemorrhage. Despite the availability of prospective studies that have confirmed the utility of TEG in reducing transfusion requirements and mortality in bleeding patients when compared to conventional coagulation tests, many institutions run into barriers implementing these viscoelastic hemostatic assays due to concerns regarding cost and benefit. At our academic Level 1 trauma institution, the Division of Trauma, Critical Care, and Acute Care Surgery advocated for the addition of TEG to the clinical armamentarium of providers caring for injured patients and thus spearheaded the clinical implementation of TEG. With the approval of the central laboratory, the Division developed an extensive and well-trained team to run and interpret TEGs as well as perform machine validation and upkeep. The Division continues to perform point-of-care testing throughout the hospital today.

A Case Series of Thromboelastography-Guided Anticoagulation in COVID-19 Patients with Inherited and Acquired Hypercoagulable States

One of the complications of the novel coronavirus disease 2019 (COVID-19) is hypercoagulability. For this reason, patients presenting with COVID-19 are often put on therapeutic or intermediate anticoagulation upon hospitalization. A common issue of this anticoagulation is the progression to hypocoagulability resulting in hemorrhage. Therefore, monitoring the hemostatic integrity of critically ill COVID-19 patients is of utmost importance. In this case series, we present the cases of three coagulopathic COVID-19 patients whose anticoagulation was guided by thromboelastography (TEG). In each case, TEG permitted the clinical team to simultaneously prevent thrombotic and hemorrhagic events, a difficult task for COVID-19 patients admitted to the intensive care unit. The first two cases illustrate the utility of TEG to guide anticoagulant dosing for COVID-19 patients when the activated partial thromboplastin time (aPTT) is inaccurate. The first case was a severely ill COVID-19 patient with end-stage renal disease and a falsely elevated aPTT secondary to hypertriglyceridemia. The second case was a severely ill COVID-19 patient with chronic pulmonary disease who demonstrated a falsely elevated aPTT due to polycythemia and hemoconcentration. In both cases, TEG was sensitive to the hypercoagulability caused by the metabolic derangements which enabled the goal-directed titration of anticoagulants. The last case depicts a severely ill COVID-19 patient with an inherited factor V Leiden mutation who required abnormally high dosing to achieve therapeutic anticoagulation, guided by TEG. Hypercoagulopathic COVID-19 patients are difficult to anticoagulate without development of hypocoagulopathy. Treatment of these patients demands goal-directed therapy by diligent laboratory monitoring. This can be accomplished by the use of TEG coupled with aPTT to guide anticoagulation. This case series illustrates the necessity for active hemostatic monitoring of critically ill COVID-19 patients.

Euglobulin clot lysis time reveals a high frequency of fibrinolytic activation in trauma

Activation of the fibrinolytic system plays a central role in the host response to trauma. There is significant heterogeneity in the degree of fibrinolysis activation at baseline that is usually assessed by whole blood thromboelastography (TEG). Few studies have focused on plasma markers of fibrinolysis that could add novel insights into the frequency and mechanisms of fibrinolytic activation in trauma. Global fibrinolysis in plasma was assessed using a modified euglobulin clot lysis time (ECLT) assay in 171 major trauma patients and compared to commonly assessed analytes of fibrinolysis. The median ECLT in trauma patients was significantly shorter at 8.5 h (IQR, 1.3-19.5) compared to 19.9 h (9.8-22.6) in healthy controls (p < 0.0001). ECLT values ≤2.5th percentile of the reference range were present in 83 (48.5%) of trauma patients, suggesting increased fibrinolytic activation. Shortened ECLT values were associated with elevated plasmin-antiplasmin (PAP) complexes and free tissue plasminogen activator (tPA) levels in plasma. Sixteen (9.2%) individuals met the primary outcome for massive transfusion, here defined as the critical administration threshold (CAT) of 3 units of packed red cells in any 60-minute period within the first 24 h. In a univariate screen, plasma biomarkers associated with CAT included D-dimer (p < 0.001), PAP (p < 0.05), free tPA (p < 0.05) and ECLT (p < 0.05). We conclude that fibrinolytic activation, measured by ECLT, is present in a high proportion of trauma patients at presentation. The shortened ECLT is partially driven by high tPA levels and is associated with high levels of circulating PAP complexes. Further studies are needed to determine whether ECLT is an independent predictor of trauma outcomes.

Trauma-induced coagulopathy

Uncontrolled haemorrhage is a major preventable cause of death in patients with traumatic injury. Trauma-induced coagulopathy (TIC) describes abnormal coagulation processes that are attributable to trauma. In the early hours of TIC development, hypocoagulability is typically present, resulting in bleeding, whereas later TIC is characterized by a hypercoagulable state associated with venous thromboembolism and multiple organ failure. Several pathophysiological mechanisms underlie TIC; tissue injury and shock synergistically provoke endothelial, immune system, platelet and clotting activation, which are accentuated by the 'lethal triad' (coagulopathy, hypothermia and acidosis). Traumatic brain injury also has a distinct role in TIC. Haemostatic abnormalities include fibrinogen depletion, inadequate thrombin generation, impaired platelet function and dysregulated fibrinolysis. Laboratory diagnosis is based on coagulation abnormalities detected by conventional or viscoelastic haemostatic assays; however, it does not always match the clinical condition. Management priorities are stopping blood loss and reversing shock by restoring circulating blood volume, to prevent or reduce the risk of worsening TIC. Various blood products can be used in resuscitation; however, there is no international agreement on the optimal composition of transfusion components. Tranexamic acid is used in pre-hospital settings selectively in the USA and more widely in Europe and other locations. Survivors of TIC experience high rates of morbidity, which affects short-term and long-term quality of life and functional outcome.

Thromboelastography-Guided Anticoagulant Therapy for the Double Hazard of Thrombohemorrhagic Events in COVID-19: A Report of 3 Cases

Case series

Patients: Female, 72-year-old • Female, 55-year-old • Female, 43-year-old

Final Diagnosis: COVID provoked thromboembolism • COVID-19 • pulmonary embolism • rectus sheath hematoma

Symptoms: Cough • fever • shortness of breath

Medication: —

Clinical Procedure: —

Specialty: Critical Care Medicine • Diagnostics, Laboratory • Hematology • Infectious Diseases

Trauma-Induced Coagulopathy: Overview of an Emerging Medical Problem from Pathophysiology to Outcomes

Coagulopathy induced by major trauma is common, affecting approximately one-third of patients after trauma. It develops independently of iatrogenic, hypothermic, and dilutive causes (such as iatrogenic cause in case of fluid administration), which instead have a pejorative aspect on coagulopathy. Notwithstanding the continuous research conducted over the past decade on Trauma-Induced Coagulopathy (TIC), it remains a life-threatening condition with a significant impact on trauma mortality. We reviewed the current evidence regarding TIC diagnosis and pathophysiological mechanisms and summarized the different iterations of optimal TIC management strategies among which product resuscitation, potential drug administrations, and hemostatis-focused approaches. We have identified areas of ongoing investigation and controversy in TIC management.

Introduction of point-of-care ROTEM testing in the emergency department of an Australian level 1 trauma centre and its effect on blood product use

OBJECTIVE

To assess whether the introduction of point-of-care rotational thromboelastometry (ROTEM) analysis influences blood product transfusion and coagulation management in a modern Australian level 1 trauma centre.

METHODS

Retrospective blood transfusion data collection from all level 1 trauma patients with an Injury Severity Score (ISS) >12 presenting to the Royal Adelaide Hospital in 2016 and 2018. Evaluation of changes in blood product administration with the addition of point-of-care viscoelastic testing in the ED in 2018.

RESULTS

A total of 774 patients were analysed with 380 in 2016 and 394 in 2018. Almost a quarter of all 2018 trauma patients (93/394) had ROTEM performed within 24 h of ED arrival, 42% of these having an ISS >25. There was a significant increase in the number of patients receiving cryoprecipitate following the introduction of ROTEM (P = 0.01). In those receiving cryoprecipitate, there was a significant reduction in subsequent platelet and fresh frozen plasma use (P < 0.001). Overall, there was a reduction in expenditure on red cells, platelets and fresh frozen plasma from 2016 to 2018.

CONCLUSION

Point-of-care ROTEM was performed in a small proportion of patients, mainly those with a higher ISS. ROTEM introduction in the ED altered blood product transfusion practices for major trauma patients with an ISS >12, leading to a potentially safer transfusion strategy and cost savings for key blood products.

Associations of longitudinal D-Dimer and Factor II on early trauma survival risk

BACKGROUND

Trauma-induced coagulopathy (TIC) is a disorder that occurs in one-third of severely injured trauma patients, manifesting as increased bleeding and a 4X risk of mortality. Understanding the mechanisms driving TIC, clinical risk factors are essential to mitigating this coagulopathic bleeding and is therefore essential for saving lives. In this retrospective, single hospital study of 891 trauma patients, we investigate and quantify how two prominently described phenotypes of TIC, consumptive coagulopathy and hyperfibrinolysis, affect survival odds in the first 25 h, when deaths from TIC are most prevalent.

METHODS

We employ a joint survival model to estimate the longitudinal trajectories of the protein Factor II (% activity) and the log of the protein fragment D-Dimer ([Formula: see text]g/ml), representative biomarkers of consumptive coagulopathy and hyperfibrinolysis respectively, and tie them together with patient outcomes. Joint models have recently gained popularity in medical studies due to the necessity to simultaneously track continuously measured biomarkers as a disease evolves, as well as to associate them with patient outcomes. In this work, we estimate and analyze our joint model using Bayesian methods to obtain uncertainties and distributions over associations and trajectories.

RESULTS

We find that a unit increase in log D-Dimer increases the risk of mortality by 2.22 [1.57, 3.28] fold while a unit increase in Factor II only marginally decreases the risk of mortality by 0.94 [0.91,0.96] fold. This suggests that, while managing consumptive coagulopathy and hyperfibrinolysis both seem to affect survival odds, the effect of hyperfibrinolysis is much greater and more sensitive. Furthermore, we find that the longitudinal trajectories, controlling for many fixed covariates, trend differently for different patients. Thus, a more personalized approach is necessary when considering treatment and risk prediction under these phenotypes.

CONCLUSION

This study reinforces the finding that hyperfibrinolysis is linked with poor patient outcomes regardless of factor consumption levels. Furthermore, it quantifies the degree to which measured D-Dimer levels correlate with increased risk. The single hospital, retrospective nature can be understood to specify the results to this particular hospital's patients and protocol in treating trauma patients. Expanding to a multi-hospital setting would result in better estimates about the underlying nature of consumptive coagulopathy and hyperfibrinolysis with survival, regardless of protocol. Individual trajectories obtained with these estimates can be used to provide personalized dynamic risk prediction when making decisions regarding management of blood factors.

Assessing Plasmin Generation in Health and Disease

Fibrinolysis is an important process in hemostasis responsible for dissolving the clot during wound healing. Plasmin is a central enzyme in this process via its capacity to cleave fibrin. The kinetics of plasmin generation (PG) and inhibition during fibrinolysis have been poorly understood until the recent development of assays to quantify these metrics. The assessment of plasmin kinetics allows for the identification of fibrinolytic dysfunction and better understanding of the relationships between abnormal fibrin dissolution and disease pathogenesis. Additionally, direct measurement of the inhibition of PG by antifibrinolytic medications, such as tranexamic acid, can be a useful tool to assess the risks and effectiveness of antifibrinolytic therapy in hemorrhagic diseases. This review provides an overview of available PG assays to directly measure the kinetics of plasmin formation and inhibition in human and mouse plasmas and focuses on their applications in defining the role of plasmin in diseases, including angioedema, hemophilia, rare bleeding disorders, COVID-19, or diet-induced obesity. Moreover, this review introduces the PG assay as a promising clinical and research method to monitor antifibrinolytic medications and screen for genetic or acquired fibrinolytic disorders.

Coagulopathy as a Surrogate of Severity of Injury in Penetrating Brain Injury

Penetrating brain injury (PBI) is the most devastating type of traumatic brain injury. Development of coagulopathy in the acute setting of PBI, though common, remains of unclear significance as does its reversal. The aim of this study is to investigate the relationship between coagulopathy and clinical presentation, radiographical features, and outcome in civilian patients with PBI. Eighty-nine adult patients with PBI at a Level I trauma center in Chicago, Illinois who survived acute resuscitation and with available coagulation profile were analyzed. Coagulopathy was defined as international normalized ratio [INR] >1.3, platelet count <100,000 /μL, or partial thromboplastin time >37 sec. Median age (interquartile range; IQR) of our cohort was 27 (21-35) years, and 74 (83%) were male. The intent was assault in 74 cases (83%). The mechanism of PBI was gunshot wound in all patients. Forty patients (45%) were coagulopathic at presentation. In a multiple regression model, coagulopathy was associated with lower Glasgow Coma Scale (GCS)-Motor score (odds ratio [OR], 0.67; confidence interval [CI], 0.48-0.94; p = 0.02) and transfusion of blood products (OR, 3.91; CI, 1.2-12.5; p = 0.02). Effacement of basal cisterns was the only significant radiographical features associated with coagulopathy (OR, 3.34; CI, 1.08-10.37; p = 0.04). Mortality was found to be significantly more common in coagulopathic patients (73% vs. 25%; p < 0.001). However, in our limited sample, reversal of coagulopathy at 24 h was not associated with a statistically significant improvement in outcome. The triad of coagulopathy, low post-resuscitation GCS, and radiographical effacement of basal cisterns identify a particularly ominous phenotype of PBI. The role, and potential reversal of, coagulopathy in this group warrants further investigation.

Platelet Dysfunction after Traumatic Brain Injury: A Review

Coagulopathy is a known sequela of traumatic brain injury (TBI) and can lead to increased morbidity and mortality. Platelet dysfunction has been identified as one of several etiologies of coagulopathy following TBI and has been associated with poor outcomes. Regardless of whether the platelet dysfunction occurs as a direct consequence of the injury or because of pre-existing medical comorbidities or medication use, accurate detection and monitoring of response to therapy is key to optimal patient care. Platelet transfusion has been proposed as a potential therapeutic intervention to treat platelet dysfunction, with several studies using platelet function assays to monitor response. The development of increasingly precise diagnostic testing is providing enhanced understanding of the specific derangement in the hemostatic process, allowing clinicians to provide patient-specific treatment plans. There is wide variability in the currently available literature on the incidence and clinical significance of platelet dysfunction following TBI, which creates challenges with developing evidence-based management guidelines. The relatively high prevalence of platelet inhibitor therapy serves as an additional confounding factor. In addition, the data are largely retrospective in nature. We performed a literature review to provide clarity on this clinical issue. We reviewed 348 abstracts, and included 97 manuscripts in our final literature review. Based on the currently available research, platelet dysfunction has been consistently demonstrated in patients with moderate-severe TBI. We recommend the use of platelet functional assays to evaluate patients with TBI. Platelet transfusion directed at platelet dysfunction may lead to improved clinical outcome. A randomized trial guided by implementation science could improve the applicability of these practices.

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.

Arachidonic Acid-Dependent Pathway Inhibition in Platelets: its Role in Multiple Injury-Induced Coagulopathy and the Potential Mechanisms

BACKGROUND

Our previous study demonstrated the types of platelet dysfunction varied at early stage (∼3 h) in trauma-induced coagulopathy (TIC) caused by different types of injuries. And arachidonic acid (AA)-dependent pathway inhibition in platelet seemed to be specific for TIC caused by multiple injury (MI). The aim of this research was to further study AA-dependent pathway inhibition in platelets in a rat model of TIC caused by MI and to explore its potential mechanisms.

METHODS

Sprague-Dawley rat model of TIC caused by MI was established. We used thrombelastography with platelet mapping as a measure of platelet function to assess the inhibitory extent of AA-dependent activation pathway. Flow cytometry was used to determine the expression of activation-dependent granular protein P-selectin (CD62P). In addition, the plasma levels of 6-Keto-prostaglandin F1 alpha (6-Keto-PGF1α), Prostaglandin E2, and Thromboxane B2 were assessed by enzyme-linked immuno sorbent assay.

RESULTS

The inhibition rate of AA-dependent pathway after injury was significantly higher than that of control. The maximum amplitude decreased in the MI group, compared with that of control. The percentage of CD62P expression in the MI group was remarkably lower than that of control after AA treatment. The plasma concentrations of 6-Keto-PGF1α and PGE2 increased in the MI group.

CONCLUSION

Platelets inhibition was observed in TIC caused by MI at early stage after injury, which might be partially attributed to AA-dependent activation pathway dysfunction. The increase of plasma Prostacyclin and PGE2 levels may contribute to the inhibition process.

Application of a plasmin generation assay to define pharmacodynamic effects of tranexamic acid in women undergoing cesarean delivery

Essentials Tranexamic acid (TXA) is an antifibrinolytic drug used to reduce bleeding. Assaying plasmin generation (PG) in plasma detects clinically relevant TXA levels in vitro and ex vivo. 3.1-16.2 µg/mL TXA half-maximally inhibits PG in plasma from women undergoing cesarean delivery. PG velocity shows the strongest dose-relationship at low TXA concentrations (≤10 µg/mL). ABSTRACT: Background Tranexamic acid (TXA) is used to reduce bleeding. TXA inhibits plasmin(ogen) binding to fibrin and reduces fibrinolysis. TXA antifibrinolytic activity is typically measured by clot lysis assays; however, effects on plasmin generation (PG) are unclear due to a lack of tools to measure PG in plasma. Aims Develop an assay to measure PG kinetics in human plasma. Determine effects of TXA on PG and compare with fibrinolysis measured by rotational thromboelastometry (ROTEM). Methods We characterized effects of plasminogen, tissue plasminogen activator, fibrinogen, and α2 -antiplasmin on PG in vitro. We also studied effects of TXA on PG in plasma from 30 pregnant women administered intravenous TXA (5, 10, or 15 mg/kg) during cesarean delivery. PG was measured by calibrated fluorescence. PG parameters were compared with TXA measured by mass spectrometry and ROTEM of whole blood. Results The PG assay is specific for plasmin and sensitive to tissue plasminogen activator, fibrin(ogen), and α2 -antiplasmin. Addition of TXA to plasma in vitro dose dependently prolonged the clot lysis time and delayed and reduced PG. For all doses of TXA administered intravenously, the PG assay detected delayed time-to-peak (≤3 hours) and reduced the velocity, peak, and endogenous plasmin potential (≤24 hours) in plasma samples obtained after infusion. The PG time-to-peak, velocity, and peak correlated significantly with TXA concentration and showed less variability than the ROTEM lysis index at 30 minutes or maximum lysis. Conclusions The PG assay detects pharmacologically relevant concentrations of TXA administered in vitro and in vivo, and demonstrates TXA-mediated inhibition of PG in women undergoing cesarean delivery.

Whole blood for blood loss: hemostatic resuscitation in damage control

Hemorrhagic shock and its complications are a major cause of death among trauma patients. The management of hemorrhagic shock using a damage control resuscitation strategy has been shown to decrease mortality and improve patient outcomes. One of the components of damage control resuscitation is hemostatic resuscitation, which involves the replacement of lost blood volume with components such as packed red blood cells, fresh frozen plasma, cryoprecipitate, and platelets in a 1:1:1:1 ratio. However, this is a strategy that is not applicable in many parts of Latin America and other low-and-middle-income countries throughout the world, where there is a lack of well-equipped blood banks and an insufficient availability of blood products. To overcome these barriers, we propose the use of cold fresh whole blood for hemostatic resuscitation in exsanguinating patients. Over 6 years of experience in Ecuador has shown that resuscitation with cold fresh whole blood has similar outcomes and a similar safety profile compared to resuscitation with hemocomponents. Whole blood confers many advantages over component therapy including, but not limited to the transfusion of blood with a physiologic ratio of components, ease of transport and transfusion, less volume of anticoagulants and additives transfused to the patient, and exposure to fewer donors. Whole blood is a tool with reemerging potential that can be implemented in civilian trauma centers with optimal results and less technical demand.

Coagulopathy: Another side effect of coronavirus infection

Recently, coronavirus disease 2019 (COVID-19) has been considered as a major health problem around the globe. This severe acute respiratory syndrome has a bunch of features, such as high transmission rate, which are adding to its importance. Overcoming this disease relies on a complete understanding of the viral structure, receptors, at-risk cells or tissues, and pathogenesis. Currently, researches have shown that besides the lack of a proper anti-viral therapeutic method, complications provided by this virus are also standing in the way of decreasing its mortality rate. One of these complications is believed to be a hematologic manifestation. Commonly, three kinds of coagulopathies are detected in COVID-19 patients: disseminated intravascular coagulation (DIC), pulmonary embolism (PE), and deep vein thrombosis (DVT). In this paper, we have reviewed the relation between these conditions and coronavirus-related diseases pathogenesis, severity, and mortality rate.