Thromboelastography and Rotational Thromboelastometry use in trauma

Utility of Global Hemostatic Assays in Patients with Bleeding Disorders of Unknown Cause

Bleeding disorder of unknown cause (BDUC) is a diagnosis of exclusion after exhaustive evaluation of plasmatic coagulation and platelet function. This review explores the utility of global hemostatic assays as confirmatory tests and in elucidating the pathophysiology of BDUC. Unlike traditional hemostatic tests that focus on coagulation factors, global assays are conducted both in plasma and also whole blood. These assays provide a more comprehensive understanding of the cell-based model of coagulation, aid in the identification of plasmatic factor abnormalities that may reduce hemostatic capacity, and allow for the assessment of impaired platelet-endothelial interactions under shear stress, as well as hyperfibrinolytic states. While clinical tests such as skin bleeding time and global assays such as PFA-100 exhibit limited diagnostic capacity, the role of viscoelastic testing in identifying hemostatic dysfunction in patients with BDUC remains unclear. Thrombin generation assays have shown variable results in BDUC patients; some studies demonstrate differences compared with healthy controls or reference values, whereas others question its clinical utility. Fibrinolysis assessment in vitro remains challenging, with studies employing euglobulin clot lysis time, plasma clot lysis time, and fluorogenic plasmin generation yielding inconclusive or conflicting results. Notably, recent studies suggest that microfluidic analysis unveils shear-dependent platelet function defects in BDUC patients, undetected by conventional platelet function assays. Overall, global assays might be helpful for exploring underlying hemostatic impairments, when conventional hemostatic laboratory tests yield no results. However, due to limited data and/or discrepant results, further research is needed to evaluate the utility of global assays as screening tools.

Higher Doses of Calcium Associated With Survival in Trauma Patients

INTRODUCTION

Calcium is required for coagulation, cardiac output, and peripheral vascular resistance. Between 85% and 94% of trauma patients treated with massive blood transfusion develop hypocalcemia.1 The aim of this study is to evaluate the relationship between increased intravenous calcium administration during massive transfusion and improved survival of trauma patients.

METHODS

We performed a retrospective analysis of trauma patients who received massive transfusion over a 2-y period. Doses of elemental calcium administered per unit of blood product transfused were calculated by calcium to blood product ratio (CBR). Chi-square test evaluated association between coagulopathy and 30-d mortality. Two-sample t-test evaluated association between CBR and coagulopathy. Bivariate regression analysis evaluated association between CBR and blood products transfused per patient. Multivariable logistic regression analysis, controlling for age, sex, coagulopathy, and Injury Severity Score evaluated the association between CBR and mortality.

RESULTS

The study included 77 patients. Coagulopathy was associated with increased 30-d mortality (P < 0.05). Patients who survived had higher CBR than those who died (P < 0.05). CBR was associated with a significant reduction in total blood products transfused per patient (P < 0.05). CBR was not associated with coagulopathy (P = 0.24). Multivariable logistic regression analysis demonstrated that Injury Severity Score ≥16, coagulopathy and decreased CBR were significant predictors of mortality (P < 0.05). CBR above 50 mg was a predictor of survival (P < 0.05).

CONCLUSIONS

Higher doses of calcium given per blood product transfused were associated with improved 30-d survival and decreased blood product transfusions.

CG02N Analyzer Accurately Measures Fibrinogen Level in Whole Blood in the Presence of Low- or High-Dose Heparin

Rapid fibrinogen (Fbg) evaluation is important in patients with massive bleeding during severe trauma and those undergoing major surgery. However, there are only a few studies on the point-of-care Fbg analyzer. In this study, we aimed to investigate the accuracy of Fbg level measured using CG02N, with whole blood contained in lithium-heparinized syringes with two different concentrations of heparin. Blood samples were collected in lithium-heparinized tubes, namely PREZA-PAK®II (low-dose heparin group [LG], 7 IU/mL) and Pro-Vent® Plus (high-dose heparin group [HG], 70.5 IU/mL). The Fbg levels in LG and HG were compared with those of citrated plasma Fbg (standard-Fbg). Strong correlations with respect to the Fbg level were observed between standard-Fbg and LG or HG (r = 0.968, p < 0.0001; r = 0.970, p < 0.0001, respectively). We demonstrated that the Fbg level in whole-blood samples was accurately assessed by CG02N and not affected by low- or high-dose heparin.

Neutralization, by a polyspecific antivenom, of the coagulopathy induced by the venom of Bothrops asper: Assessment by standard coagulation tests and rotational thromboelastometry in a murine model

Venom-induced consumption coagulopathy and thrombocytopenia are common and potentially severe manifestations of viperid snakebite envenoming since they contribute to local and systemic hemorrhage. Therefore, the assessment of the efficacy of antivenoms to neutralize coagulopathic and thrombocytopenic toxins should be part of the preclinical evaluation of these drugs. To evaluate the efficacy of the polyvalent (Crotalinae) antivenom produced in Costa Rica, in this study we have used a mouse model of coagulopathy and thrombocytopenia induced by the venom of Bothrops asper, based on the bolus intravenous (i.v.) injection of venom. When venom and antivenom were incubated before injection, or when antivenom was administered i.v. immediately after venom injection, venom-induced hemostatic alterations were largely abrogated. We also studied the recovery rate of clotting parameters in conditions where antivenom was administered when mice were coagulopathic. Some parameters recovered more rapidly in antivenom-treated mice than in control envenomed animals, but others showed a spontaneous recovery without antivenom. This is due to a rapid clearance of plasma venom levels in these experimental conditions. This implies that models based on the bolus i.v. injection of venom have limitations for assessing the effect of antivenom in the recovery of clotting alterations once coagulopathy has developed. It is suggested that alternative models should be developed based on a slower systemic absorption of venom. Overall, our findings provide a protocol for the preclinical evaluation of antivenoms and demonstrate that the polyvalent antivenom is effective in neutralizing the toxins of B. asper venom responsible for coagulopathy and thrombocytopenia.

Emerging technology for early detection and management of postpartum hemorrhage to prevent morbidity

Despite advances in hemorrhage detection and management, postpartum hemorrhage remains the single leading cause of maternal death worldwide. Within the United States, hemorrhage is the leading cause of maternal death on the day of delivery and within the first week after delivery. Blood transfusion after hemorrhage represents a large proportion of severe maternal morbidity during and after delivery. Blood loss during delivery has historically been assessed visually by inspecting soiled pads, linens, and laparotomy sponges. These methods underestimate the volume of blood loss by as much as 40%, becoming increasingly inaccurate as blood loss increases. Young, healthy obstetrical patients compensate for blood loss via peripheral vasoconstriction, maintaining heart rate and blood pressure in a normal range until over 1 L of blood has been lost. A significant decrease in blood pressure along with marked tachycardia (>120 bpm) may not be seen until 30% to 40% of blood volume has been lost, or 2.0 to 2.6 L in a healthy term pregnant patient, after which the patient may rapidly decompensate. In resource-poor settings especially, the narrow window between the emergence of significant vital sign abnormalities and clinical decompensation may prove catastrophic. Once hemorrhage is detected, decisions regarding blood product transfusion are routinely made on the basis of inaccurate estimates of blood loss, placing patients at risk of underresuscitation (increasing the risk of hemorrhagic shock and end-organ damage) or overresuscitation (increasing the risk of transfusion reaction, fluid overload, and alloimmunization). We will review novel technologies that have emerged to assist both in the early and accurate detection of postpartum hemorrhage and in decisions regarding blood product transfusion.

Coronary Revascularization in Patients With Cancer

Purpose of review

The treatment of coronary artery disease (CAD) in cancer patients is an evolving landscape. Recent data emphasizes the importance of aggressive management of cardiovascular risk factors and diseases in improving cardiovascular health in this unique group of patients regardless of cancer type or stage.

Recent findings

Novel cancer therapeutics such as immune therapies and proteasome inhibitors have been associated with CAD. Recent stent technologies may safely allow for shorter duration (< 6 months) of dual antiplatelet therapy post-percutaneous coronary interventions. Intracoronary imaging may be useful in the decision making process in terms of stent positioning and healing.

Summary

Large registry studies have partially filled a gap left by the lack of randomized controlled trials in the treatment of CAD in cancer patients. Cardio-oncology is gaining traction as a major sub-specialty in the cardiology field given the release of the first European Society of Cardiology - Cardio-oncology guidelines in 2022.

Viscoelastic testing: an illustrated review of technology and clinical applications

Viscoelastic testing (VET), including thromboelastography and thromboelastometry, provides a rapid and comprehensive picture of whole blood coagulation dynamics and hemostasis that can be reviewed and evaluated at the point-of-care. This technology is over 50 years old; however, over the past few years, there has been a significant increase in research examining the use of VET. Best practice guidelines for the use of VET exist in both the United States and Europe, particularly for elective cardiac surgery, although recommendations for implementation are somewhat limited in some clinical areas by the lack of studies constituting high-grade evidence. Other challenges to implementation surround validation of the technology in some care settings as well as lack of training. Nevertheless, there is a wide range of potential clinical applications, such as treating coagulopathies in liver disease and transplant surgery, critical care, as well as within obstetrical hemorrhage. In this illustrated review, we provide an overview of viscoelastic testing technology (also called viscoelastic hemostatic assays) and describe how the assays can be used to provide a broad overview of hemostasis from clot formation to clot lysis, while highlighting the contribution of coagulation factors and platelets. We then summarize the major clinical applications for viscoelastic testing, including more recent applications, such as in COVID-19. Each section describes the clinical context, and key publications, followed by a representative algorithm and key guidelines.

Association between Functional Parameters of Coagulation and Conventional Coagulation Tests in the Setting of Fluid Resuscitation with Balanced Crystalloid or Gelatine: A Secondary Analysis of an In Vivo Prospective Randomized Crossover Study

Functional point-of-care tests (POCTs) have evolved into useful tools for diagnosing disorders of blood coagulation and fibrinolysis. We aimed to describe the in vivo association between standard and functional parameters of coagulation and fibrinolysis in the setting of acute hemodilution induced by an infusion of balanced crystalloid or synthetic gelatine solutions. This prospective randomized crossover in vivo study included healthy male volunteers aged 18–30 years. Enrolled participants were randomly assigned to receive either the Optilyte^® or Geloplasma^® infusion. Laboratory analysis included conventional coagulation parameters and rotational thromboelastometry (ROTEM) assays. A total of 25 healthy Caucasian males were included. ROTEM viscoelastic assays presented moderate to strong correlations with conventional coagulation tests, regardless of the fluid type utilized. Irrespectively of the extent of hemodilution, significant correlations remained unaffected. The strongest associations were found between the ROTEM clot formation and clot strength and the fibrinogen concentration and platelet count, and between the ROTEM clotting time and the APTT and PT. This in vivo experimental study in healthy male volunteers demonstrated that ROTEM may be used as a credible alternative to standard laboratory tests to assess blood coagulation and fibrinolysis in the setting of fluid resuscitation with both crystalloid and colloid solutions. The study was registered online in the ClinicalTrials.gov database (NCT05148650).

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.

Combining Heparin and a FX/Xa Aptamer to Reduce Thrombin Generation in Cardiopulmonary Bypass and COVID-19

Known limitations of unfractionated heparin (UFH) have encouraged the evaluation of anticoagulant aptamers as alternatives to UFH in highly procoagulant settings such as cardiopulmonary bypass (CPB). Despite progress, these efforts have not been totally successful. We take a different approach and explore whether properties of an anticoagulant aptamer can complement UFH, rather than replace it, to address shortcomings with UFH use. Combining RNA aptamer 11F7t, which targets factor X/Xa, with UFH (or low molecular weight heparin) yields a significantly enhanced anticoagulant cocktail effective in normal and COVID-19 patient blood. This aptamer-UFH combination (1) supports continuous circulation of human blood through an ex vivo membrane oxygenation circuit, as is required for patients undergoing CPB and COVID-19 patients requiring extracorporeal membrane oxygenation, (2) allows for a reduced level of UFH to be employed, (3) more effectively limits thrombin generation compared to UFH alone, and (4) is rapidly reversed by the administration of protamine sulfate, the standard treatment for reversing UFH clinically following CPB. Thus, the combination of factor X/Xa aptamer and UFH has significantly improved anticoagulant properties compared to UFH alone and underscores the potential of RNA aptamers to improve medical management of acute care patients requiring potent yet rapidly reversible anticoagulation.

In Vivo Effects of Balanced Crystalloid or Gelatine Infusions on Functional Parameters of Coagulation and Fibrinolysis: A Prospective Randomized Crossover Study

Prudent administration of fluids helps restore or maintain hemodynamic stability in the setting of perioperative blood loss. However, fluids may arguably exacerbate the existing coagulopathy. We sought to investigate the influence of balanced crystalloid and synthetic gelatine infusions on coagulation and fibrinolysis in healthy volunteers. This prospective randomized crossover study included 25 males aged 18–30 years. Infusions performed included 20 mL/kg of a balanced crystalloid solution (Optilyte^®) or 20 mL/kg of gelatine 26.500 Da (Geloplasma^®) in a random order over a period of 2 weeks. Laboratory analysis included conventional coagulation parameters and rotational thromboelastometry (ROTEM) assays. We confirmed a decrease in fibrinogen concentration and the number of platelets, and prolongation of PT after infusions. Compared to baseline values, differences in the ROTEM assays’ results after infusions signified the decrease in coagulation factors and fibrinogen concentration, causing impaired fibrin polymerization and clot structure. The ROTEM indicator of clot lysis remained unaffected. In the case of both Optilyte^® and Geloplasma^®, the results suggested relevant dilution. Gelatine disrupted the process of clot formation more than balanced crystalloid. Infusions of both crystalloid and saline-free colloid solutions causing up to 30% blood dilution cause significant dilution of the coagulation factors, platelets, and fibrinogen. However, balanced crystalloid infusion provides less infusion-induced coagulopathy compared to gelatine.

Point-of-Care Viscoelastic Tests in the Management of Obstetric Hemorrhage

Obstetric hemorrhage remains the leading cause of maternal morbidity and mortality worldwide. Thromboelastography and rotational thromboelastometry are laboratory methods of assessing the kinetics of blood clot formation through real-time measurement of viscoelastic clot strength and may aid in management of severe hemorrhage. Although first described more than 70 years ago, viscoelastic testing devices are now available that allow for rapid point-of-care use of this technology to aid in real-time management of blood product replacement in cases of severe hemorrhage. These devices can be used to visually estimate multiple facets of hemostasis-coagulation, platelet function, and fibrinolysis-within 10-20 minutes. They have been used successfully in cardiac surgery, trauma, and liver transplantation and have potential for use in management of obstetric hemorrhage. Goals with their use include targeted transfusion of blood and its components for specific coagulation deficiencies. To date, however, published experiences with the use of these viscoelastic tests for obstetric hemorrhage have been limited. Because of the increasing use of the point-of-care tests by anesthesiologists, surgeons, and intensivists, the purpose of this report is to familiarize obstetricians with the technology involved and its use in severe hemorrhage complicating pregnancy.

The heparinase-linked differential time method allows detection of heparin potency in whole blood with high sensitivity and dynamic range

Anticoagulation therapy with heparin is an effective treatment against thrombosis. Heparin tends to cause spontaneous bleeding and requires regular monitoring during therapy. Most high-sensitivity heparin sensors have focused on the concentration detection in clarified buffer solution. However, the pharmacodynamics of heparin vary depending on individual patient or disease, while potency detection with high sensitivity and dynamic range outperforms concentration detection in clinical diagnosis. In this study, a novel heparinase-linked differential time (HLDT) method was established with a two-zone of Graphene modified Carbon (GR-C) sensor, which was utilized to evaluate heparin potency in whole blood. It was based on electrochemical measurement of clotting time shifting associated with presence or absence of heparinase. Heparinase inhibits the anticoagulant ability of heparin by forming a heparin-antithrombin-thrombin complex during coagulation. And the intensity and peak time of electrochemical current were associated with thrombin activity and clotting on the electrode. The results demonstrated that the sensor had high selectivity for heparin potency in 10 μL of whole blood with a detection limit of 0.1 U/mL, and the linear detection range was 0.1-5 U/mL. The coefficient of variation (CV) of the peak time was less than 5%, and linear correlation between the GR-C sensor and the TEG-5000 instrument was 0.987. Thus, the HLDT method has better clinical application due to its good repeatability, high sensitivity and wide range in heparin potency evaluation.

Thromboelastography determined dynamics of blood coagulation and its correlation with complications and outcomes in patients with coronavirus disease 2019

BACKGROUND

Coronavirus disease 2019 (COVID-19) causes abnormalities in the hemostatic system, collectively known as COVID-associated coagulopathy. The dynamics of clot formation are best discerned by whole-blood viscoelastic tests, such as thromboelastography (TEG). We aimed to assess the various abnormalities seen on TEG and explored the predictors of outcomes in these patients.

METHODS

Thromboelastography was performed for 28 patients with COVID-19 using an automated thromboelastogram. The hemostatic condition was categorized as hypercoagulable in 17 (63%), hypocoagulable in 2 (7%), and normal in 8 (30%) based on TEG variables, such as reaction time , time until clot reaches a fixed strength, alpha angle, maximum amplitude, and clotting index. Laboratory parameters and clinical outcomes were compared between hypercoagulable and normal groups.

RESULTS

Twenty-seven patients with a median age of 50 years (interquartile range, 40-60 years), male-to-female ratio of 0.9:1, median C-reactive protein of 25.7 (10.9-108.8) mg/L, serum ferritin of 693 (317-1031) µg/L, and albumin 2.9 (2.6-3.3) g/dL were included. The median prothrombin time/international normalized ratio and activated partial thromboplastin time were within normal range in the hypercoagulable and normal groups. The severity of COVID-19 was mild in 6 (22.2%), moderate in 2 (7.4%), and severe in 19 (70.4%) patients. Twenty-eight-day mortality among patients with hypocoagulable and hypercoagulable states was higher than normal coagulation status. (log-rank test, P = .002).

CONCLUSIONS

Hypercoagulable state, together with a severe inflammatory state, is common in patients with COVID-19, despite thromboprophylaxis. TEG assesses coagulation status better than conventional coagulation tests. Coagulation abnormalities are associated with poor outcomes.

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.

Safety and efficacy of thromboelastography guidance of antifibrinolytic therapy in trauma patients: An observational cohort analysis

Background:

Tranexamic acid (TXA) is an antifibrinolytic therapy intended to decrease blood loss and improve hemostasis in traumatic hemorrhage. Viscoelastic assays, such as thromboelastography (TEG), allow for the identification of a patient's specific hemostasis. The purpose of this research study was to explore the safety and efficacy of TEG-guided antifibrinolytic therapy in trauma patients.

Methods:

This study was a retrospective review of trauma patients meeting institution-specific inclusion criteria for TXA. Patients were assigned to fibrinolytic groups per TEG LY30 data. Safety outcomes (24-h mortality, overall in-hospital mortality, and thromboembolic events) were compared between patients who did or did not receive TXA and within fibrinolytic groups. Mortality outcomes were adjusted for baseline Injury Severity Score (ISS). Secondary aims included blood product utilization, length of hospital, and intensive care unit stay.

Results:

Hypofibrinolysis was the most common fibrinolytic phenotype. Adjusting for ISS, there were no significant differences in mortality. A 30.7% thromboembolism incidence was identified in the TXA group compared to 16.6% not receiving TXA (P = 0.26), with 72.7% of these patients experiencing fibrinolytic shutdown.

Conclusions:

There were no differences in 24-h mortality, all-cause mortality, or secondary outcomes. The difference in thromboembolic rates between patients receiving TXA and those who did not, while not statistically significant, poses clinical concern.

Changes in the coagulation parameters in dogs with protein-losing enteropathy between before and after treatment

Protein-losing enteropathy (PLE) is known to induce hypercoagulability and resultant thromboembolism in dogs. We hypothesized that hypercoagulability would improve if remission was obtained in dogs with PLE after treatment. This study aimed to evaluate the changes in the coagulation parameters after treatment in dogs diagnosed with PLE. As coagulation parameters, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, thrombin-antithrombin complex (TAT), D-dimer, and antithrombin (AT) were measured. In addition to these parameters, rotational thromboelastometry (ROTEM), which evaluates the comprehensive coagulation and fibrinolysis reactions of whole blood, was conducted and the data of clotting time (CT), clot formation time (CFT), α angle (α), maximum clot firmness (MCF) and lysis index at 60 min (LI60) were obtained. Eleven of the 14 dogs diagnosed with PLE were classified as responders to the treatment based on the changes in their plasma albumin (ALB) concentration after treatment. Significant increase in CFT and decrease of α and MCF indicating the resolution of hypercoagulability were found after treatment in responder dogs; however, there was no significant change in the coagulation and fibrinolysis parameters other than those measured by ROTEM. This study demonstrated that the hypercoagulability detected by ROTEM was significantly improved after treatment in dogs with PLE.

Fibrinolysis and bleeding of unknown cause

Patients with bleeding of unknown cause (BUC) present with a variety of mild to moderate bleeding symptoms, but no hemostatic abnormalities can be found. Hyperfibrinolysis is rarely evaluated as the underlying cause for bleeding in clinical practice, and well-established global assays for abnormal fibrinolysis are lacking. Few patients with definitive fibrinolytic disorders, including α2-antiplasmin deficiency, plasminogen activator inhibitor 1 deficiency, or Quebec platelet disorder, have been reported. This review aims to summarize data on established fibrinolytic disorders and to discuss assessments of fibrinolysis in prior bleeding cohorts. Furthermore, we review available global tests with the potential to measure fibrinolysis, such as turbidity fibrin clot assays and rotational thromboelastometry, and their relevance in the workup of patients with BUC. We conclude that, due to the lack of adequate global tests, hyperfibrinolysis might be an underdiagnosed cause for a bleeding disorder. The diagnosis of hyperfibrinolytic bleeding disorders would improve patient care as effective treatment with antifibrinolytic agents is available.

Prognostic Factors and Overall Survival After Pericardiocentesis in Patients With Cancer and Thrombocytopenia

Background: Pericardiocentesis is an important diagnostic and therapeutic tool for cancer-associated pericardial effusion. Limited safety and outcomes data exists regarding the management of malignancy-related pericardial effusion in patients with thrombocytopenia.

Objectives: Our study aimed to analyze prognostic factors and overall survival (OS) after pericardiocentesis in thrombocytopenic cancer patients.

Methods and Results: A retrospective review of 136 thrombocytopenic cancer patients who underwent primary percutaneous pericardiocentesis was performed. Degree of thrombocytopenia was classified by platelet count recorded on day of pericardiocentesis: 75–149 × 10³ cells/μL (41%); 50–74 × 10³ cells/μL (10%); 25–49 × 10³ cells/μL (24%); <25 × 10³ cells/μL (25%). Median OS was 2.6 months and median follow-up was 37.4 months. Kaplan-Meier survival analysis showed significant OS differences among thrombocytopenia severity groups (p = 0.023), and worse OS with platelets <100 vs. ≥100 × 10³ cells/μL (p = 0.031). By univariate analysis, thrombocytopenia severity was associated with increased risk of death (HR 0.993; 95% CI 0.989–0.997; p = 0.002). Poor prognostic factors for OS were advanced cancer, malignant effusion, elevated international normalized ratio (INR), quantity of platelet transfusions, and platelet transfusion resistance. However, thrombocytopenia severity became insignificant for OS (p = 0.802), after adjusting for advanced cancer and INR.

Conclusions: For patients with malignancy-related large pericardial effusion and thrombocytopenia, pericardiocentesis is a feasible intervention and should be considered due to low complication rates. There is no absolute contraindication to pericardiocentesis in case of hemodynamic instability, even with severe thrombocytopenia.

Hematotoxic Snakebite Victim with Trauma: The Role of Guided Transfusion, Rotational Thromboelastometry, and Tranexamic Acid

Hematotoxic snake bite is a leading cause of mortality in South India. However, it is rare for the emergency physician to encounter a patient with trauma associated with snakebite. Management of such a patient differs substantially from the routine management of either a trauma patient or a snakebite victim. A 59-y-old man was bitten by a snake, after which he lost consciousness, fell, and sustained facial trauma. He was rushed to the emergency department within 30 min and was discovered to have ongoing oromaxillofacial bleeding. His respiratory distress and gasping respirations warranted orotracheal intubation and ventilation. He was treated with anti-snake venom and underwent viscoelastometry-guided transfusion to correct coagulopathy. Hemostasis was achieved after administration of tranexamic acid and bilateral posterior nasal packing. Imaging studies revealed craniomaxillofacial trauma with intracranial hemorrhage. He underwent a delayed mandibular repair. Judicious, guided fluid management, adequate nutrition, and prompt weaning off the ventilator allowed early discharge of the patient from the hospital. The minimal weakness present in his left lower limb at the time of discharge had improved by the time of follow-up. This report shows the utility of early and rapid anti-snake venom in envenomated victims with coagulopathy. The role of cryoprecipitate, tranexamic acid, and viscoelastometric testing needs further exploration in specific hematotoxic snakebites.

Initial clinical experience with the Quantra QStat System in adult trauma patients

Background

Whole blood viscoelastic testing (VET) devices are routinely used in a variety of clinical settings to assess hemostasis. The Quantra QStat System is a cartridge-based point of care VET device that measures changes in clot stiffness during coagulation and fibrinolysis using ultrasound detection of resonance. The objective of this study was to assess the ability of the Quantra QStat System to detect coagulopathies in trauma patients.

Methods

A multicenter observational study was conducted on adult subjects at two level 1 trauma centers. For each subject, whole blood samples were drawn upon arrival to the emergency department and again, in some cases, after administration of blood products and/or antifibrinolytics. Samples were analyzed on the Quantra in parallel to ROTEM delta. The QStat cartridge provides measures of Clot Time (CT), Clot Stiffness (CS), Fibrinogen and Platelet Contributions to clot stiffness (FCS and PCS), and Clot Stability to Lysis (CSL). Data analyses included linear regression of Quantra and ROTEM parameters and an assessment of the concordance of the two devices for the assessment of hyperfibrinolysis.

Results

A total of 56 patients were analyzed. 42% of samples had a low QStat CS value suggestive of an hypocoagulable state. The low stiffness values could be attributed to either low PCS, FCS or combination. Additionally, 13% of samples showed evidence of hyperfibrinolysis based on the QStat CSL parameter. Samples analyzed with ROTEM assays showed a lower prevalence of low CS and hyperfibrinolysis based on EXTEM and FIBTEM results. The correlation of CS, FCS and CT versus equivalent ROTEM parameters was strong with r-values of 0.83, 0.79 and 0.79, respectively.

Discussion

This first clinical experience with the Quantra in trauma patients showed that the QStat Cartridge was strongly correlated with ROTEM parameters and that it could detect coagulopathies associated with critical bleeding.

Level of evidence

Diagnostic test, Level II.

Thromboelastography Better Reflects Hemostatic Abnormalities in Cirrhotics Compared With the International Normalized Ratio

GOAL

The goal of this study was to describe potential key differences in thromboelastography (TEG) variables in hospitalized cirrhotics compared with a healthy population, identify patterns of hematologic disturbance with disease progression, and assess the value of traditional tests such as international normalized ratio (INR) and platelet count to determine coagulopathy in cirrhotics.

BACKGROUND

TEG, a functional assay of coagulation, has emerged as a useful tool for predicting bleeding risk in cirrhosis.

STUDY

Hospitalized cirrhotics who received a TEG before any blood products between January 2017 and February 2018 at a liver transplant center were included. Reaction time (r-time), coagulation time (k-time), angle-rate of clot polymerization (α) and maximum clot strength (maximum amplitude) were measured with kaolin-activated citrated blood TEG assays.

RESULTS

A total of 106 cirrhotic patients (Child-Turcotte-Pugh A, B, C; n=25, 25, 56) were identified for comparison against data from 53 healthy controls. TEG parameters in cirrhotics were statistically different from controls. Mean INR and platelet count for all cirrhotics were largely outside the normal reference range, contrary to TEG parameters which demonstrated parameters mostly within the normal reference ranges. The r-time, k-time, and α values in the cirrhotics progressively increased and maximum amplitude values progressively decreased as the liver disease progressed. Regression analysis showed no significant correlations between INR and r-time across any Child-Turcotte-Pugh class (r=0.01, 0.18, 0.23; P=0.95, 0.39, 0.08, respectively).

CONCLUSIONS

Although cirrhotics had TEG parameters within normal ranges, there was a propensity for decreased clot formation as liver function worsened. Importantly, the INR did not correlate with TEG parameters in cirrhotic patients, and given the precarious hemostatic balance in these patients, a TEG may be a better predictor of bleeding risk.

Post-TBI splenectomy may exacerbate coagulopathy and platelet activation in a murine model

INTRODUCTION

Traumatic brain injury (TBI) induces acute hypocoagulability, subacute hypercoagulability, and persistently elevated risk for thromboembolic events. Splenectomy is associated with increased mortality in patients with moderate or severe TBI. We hypothesized that the adverse effects of splenectomy in TBI patients may be secondary to the exacerbation of pathologic coagulation and platelet activation changes.

METHODS

An established murine weight-drop TBI model was utilized and a splenectomy was performed immediately following TBI. Sham as well as TBI and splenectomy alone mice were used as injury controls. Mice were sacrificed for blood draws at 1, 6, and 24 h, as well as 7 days post-TBI. Viscoelastic coagulation parameters were assessed by rotational thromboelastometry (ROTEM) and platelet activation was measured by expression of P-selectin via flow cytometry analysis of platelet rich plasma samples.

RESULTS

At 6 h following injury, TBI/splenectomy demonstrated hypocoagulability with prolonged clot formation time (CFT) compared to TBI alone. By 24 h following injury, TBI/splenectomy and splenectomy mice were hypercoagulable with a shorter CFT, a higher alpha angle, and increased MCF, despite a lower percentage of platelet contribution to clot compared to TBI alone. However, only the TBI/splenectomy continued to display this hypercoagulable state at 7 days. While TBI/splenectomy had greater P-selectin expression at 1-h post-injury, TBI alone had significantly greater P-selectin expression at 24 h post-injury compared to TBI/splenectomy. Interestingly, P-selectin expression remained elevated only in TBI/splenectomy at 7 days post-injury.

CONCLUSION

Splenectomy following TBI exacerbates changes in the post-injury coagulation state. The combination of TBI and splenectomy induces an acute hypocoagulable state that could contribute to an increase in intracranial bleeding. Subacutely, the addition of splenectomy to TBI exacerbates post-injury hypercoagulability and induces persistent platelet activation. These polytrauma effects on coagulation may contribute to the increased mortality observed in patients with combined brain and splenic injuries.

Data-driven Development of ROTEM and TEG Algorithms for the Management of Trauma Hemorrhage: A Prospective Observational Multicenter Study

OBJECTIVE

Developing pragmatic data-driven algorithms for management of trauma induced coagulopathy (TIC) during trauma hemorrhage for viscoelastic hemostatic assays (VHAs).

BACKGROUND

Admission data from conventional coagulation tests (CCT), rotational thrombelastometry (ROTEM) and thrombelastography (TEG) were collected prospectively at 6 European trauma centers during 2008 to 2013.

METHODS

To identify significant VHA parameters capable of detecting TIC (defined as INR > 1.2), hypofibrinogenemia (< 2.0 g/L), and thrombocytopenia (< 100 x10/L), univariate regression models were constructed. Area under the curve (AUC) was calculated, and threshold values for TEG and ROTEM parameters with 70% sensitivity were included in the algorithms.

RESULTS

A total of, 2287 adult trauma patients (ROTEM: 2019 and TEG: 968) were enrolled. FIBTEM clot amplitude at 5 minutes (CA5) had the largest AUC and 10 mm detected hypofibrinogenemia with 70% sensitivity. The corresponding value for functional fibrinogen (FF) TEG maximum amplitude (MA) was 19 mm. Thrombocytopenia was similarly detected using the calculated threshold EXTEM-FIBTEM CA5 30 mm. The corresponding rTEG-FF TEG MA was 46 mm. TIC was identified by EXTEM CA5 41 mm, rTEG MA 64 mm (80% sensitivity). For hyperfibrinolysis, we examined the relationship between viscoelastic lysis parameters and clinical outcomes, with resulting threshold values of 85% for EXTEM Li30 and 10% for rTEG Ly30.Based on these analyses, we constructed algorithms for ROTEM, TEG, and CCTs to be used in addition to ratio driven transfusion and tranexamic acid.

CONCLUSIONS

We describe a systematic approach to define threshold parameters for ROTEM and TEG. These parameters were incorporated into algorithms to support data-driven adjustments of resuscitation with therapeutics, to optimize damage control resuscitation practice in trauma.

Thromboelastography versus standard coagulation testing in the assessment and reversal of coagulopathy among cirrhotics: a systematic review and meta-analysis

The utility of thromboelastography/thromboelastometry currently has unvalidated clinical benefit in the assessment and reversal of coagulopathy among cirrhotic patients as compared to standard coagulation testing. A novel systematic review and meta-analysis was conducted in order to assess pooled outcome data among patients receiving thromboelastography/thromboelastometry as compared to standard coagulation testing. As compared to standard coagulation testing, there was a significant reduction in the number of patients requiring pRBC, platelet, and fresh frozen plasma transfusions among thromboelastography/thromboelastometry group with pooled OR 0.53 (95% CI 0.32-0.85; P = 0.009), 0.29 (95% CI 0.12-0.74; P = 0.009), and 0.19 (95% CI 0.12-0.31; P < 0.00001), respectively. Similarly, there was a significant reduction in number of pRBC, platelet, and fresh frozen plasma units transfused in the thromboelastography/thromboelastometry group with pooled MD -1.53 (95% CI -2.86 to -0.21; P = 0.02), -0.57 (95% CI -1.06 to -0.09; P = 0.02), and -2.71 (95% CI -4.34 to -1.07; P = 0.001), respectively. There were significantly decreased total bleeding events with pooled OR 0.54 (95% CI 0.31-0.94; P = 0.03) and amount of intraoperative bleeding during liver transplantation with pooled MD -1.46 (95% CI -2.49 to -0.44; P = 0.005) in the thromboelastography/thromboelastometry group. Overall, there was no significant difference in mortality between groups with pooled OR 0.91 (95% CI 0.63-1.30; P = 0.60). As compared to standard coagulation testing, a thromboelastography/thromboelastometry-guided approach to the assessment and reversal of cirrhotic coagulopathy improves overall number of patients exposed to blood product transfusions, quantity of transfusions, and bleeding events.

Identifying Hemostatic Thresholds in Cancer Patients Undergoing Coronary Angiography Based on Platelet Count and Thromboelastography

Objectives: To evaluate the role of platelet count and thromboelastogram (TEG) in the treatment of thrombocytopenic cancer patients with suspected coronary artery disease (CAD).

Background: Cancer patients with CAD and thrombocytopenia are often treated non-invasively (i.e., without coronary angiography when clinically indicated) due to perceived high risk of bleeding. We sought to evaluate coagulability based on TEG and determine if platelet count and TEG could predict bleeding risk/mortality among cancer patients undergoing coronary angiography (CA).

Methods: Baseline demographics, platelet count, and TEG parameters were recorded among cancer patients that underwent CA and had a concomitant TEG. Logistic regression and univariate proportional hazards regression analysis were performed to determine the impact of platelet count and coagulability on 24-month overall survival (OS).

Results: All patients with platelet count <20,000/mm³ and nearly all patients with platelet count 20,000–49,000/mm³ were hypocoagulable based on TEG results. In contrast, nearly all patients with platelet counts of 50,000–99,999/mm³ had normal TEG results and OS similar to those with platelet counts of ≥100,000/mm³. Coagulability based on TEG was not associated with OS. However, a platelet count of <50,000/mm³ was associated with worse 24-month OS (hazard ratio = 2.76; p = 0.0072) when compared with a platelet count of ≥100,000/mm³. No major bleeding complications were observed in all groups.

Conclusion: The majority of cancer patients with platelet counts of <50,000/mm³ were hypocoagulable based on TEG and had worse OS at 24 months. The relatively normal TEGs in the >50,000/mm³ groups, as well as the improved survival, suggest that with appropriate clinical indication and risk/benefit assessment, a cut-off of 50,000/mm³ platelets can be considered for CA in cancer patients.

Clinical utility of rotational thromboelastometry in detecting hemostatic disorders

Hemostasis represents an equilibrium between procoagulant and anticoagulant processes, but once this balance is shifted to one side, it leads to coagulopathy presented by pathological bleeding or thrombosis. Many conditions could cause coagulopathy. The most common are sepsis, severe traumas and malignancies. Widely used conventional coagulation tests (CCTs), focused only on clot initiation, are primary used to detect hypocoagulability. Viscoelastographic tests (VET), like rotational thromboelastometry (ROTEM), can detect problems in different stages of coagulation, from initiation thought clot elongation and propagation, to the clot lysis and might reveal both, hypercoagulability and hypocoagulability. Rotational thromboelastometry have gained popularity in the care of patients with TIC, as a tool to guide transfusion support. Nowadays it is widely used in other medical specialties, as well. Several studies in septic patients pointed out hypocoagulable ROTEM pattern as a predictor of poor prognosis. Additionally, there is great interest of ROTEM usage in malignancies, although limited research is currently available. It suggests ROTEM have the ability to identify a patient in high risk of thrombosis. Further investigation trough randomized studies is needed to confirm ROTEM utility and to help in making a consensus about its use in different medical occasions.

Relationship of Coagulopathy and Platelet Dysfunction to Transfusion Needs After Traumatic Brain Injury

BACKGROUND

Coagulopathy and platelet dysfunction commonly develop after traumatic brain injury (TBI). Thromboelastography (TEG) and platelet function assays (PFAs) are often performed at the time of admission; however, their roles in assessing post-TBI coagulopathy have not been investigated. We hypothesized that compared to blunt TBI, penetrating TBI would (1) demonstrate greater coagulopathy by TEG, (2) be associated with abnormal PFA results, and (3) require more blood product transfusions.

METHODS

We performed a retrospective study of patients admitted to the neuroscience intensive care unit of a level 1 trauma center from 2013 to 2015 with head Abbreviated Injury Scale ≥3. Patients were compared by mechanism of injury (blunt vs. penetrating). Admission demographics, injury characteristics, and laboratory parameters were evaluated. VerifyNow^® Aspirin and P2Y12 tests were used for platelet function analysis.

RESULTS

Five hundred and thirty-four patients were included in the analysis. There were no differences between groups in platelet count or international normalized ratio; however, patients with penetrating TBI were more coagulopathic by TEG, with all of the TEG parameters being significantly different except for R time. Patients with penetrating head trauma were not more likely than their blunt counterparts to have abnormal PFA results, and PFA results did not correlate with any TEG parameter in either group. The penetrating cohort received more units of blood products in the first 4 and 24 h than the blunt cohort.

CONCLUSIONS

Patients presenting with penetrating TBI demonstrated increased coagulopathy compared to those with blunt TBI as measured by TEG and need for transfusion. PFA results did not correlate with TEG findings in this population.

Thromboelastography for the Orthopaedic Surgeon

Evaluation of coagulation is vital in the care of the orthopaedic patients, particularly in the subspecialties of trauma, spine, arthroplasty, and revision surgery resulting from blood loss and coagulopathies. Although conventional tests (prothrombin time/international normalized ratio, activated partial thromboplastin time, platelet count, and fibrinogen) are most commonly used, others like thromboelastography (TEG) are also available to the orthopaedic surgeons. TEG is a blood test developed in the 1950s, which provides a snapshot of a patient's coagulation profile by evaluating clot formation and lysis. Recently, TEG has been used to assess traumatic coagulopathy. The coagulation parameters measured by the TEG are reaction time (R-time), time to reach a certain clot strength (K-value), speed of fibrin build up (α-angle), maximum clot amplitude, and percentage decrease of clot in 30 minutes (LY30). Using these values, traumatologists have developed a better, faster, and more accurate overview of a patient's resuscitation and more successfully direct blood product use. However, many orthopaedic surgeons-despite performing surgical procedures that risk notable blood loss and postoperative clotting complications-are unaware of the existence of the TEG blood test and the critical information it provides. Increasing awareness of the TEG among orthopaedic surgeons could have a notable effect on numerous aspects of musculoskeletal care.

Complement component 5 does not interfere with physiological hemostasis but is essential for Escherichia coli-induced coagulation accompanied by Toll-like receptor 4

There is a close cross-talk between complement, Toll-like receptors (TLRs) and coagulation. The role of the central complement component 5 (C5) in physiological and pathophysiological hemostasis has not, however, been fully elucidated. This study examined the effects of C5 in normal hemostasis and in Escherichia coli-induced coagulation and tissue factor (TF) up-regulation. Fresh whole blood obtained from six healthy donors and one C5-deficient individual (C5D) was anti-coagulated with the thrombin inhibitor lepirudin. Blood was incubated with or without E. coli in the presence of the C5 inhibitor eculizumab, a blocking anti-CD14 monoclonal antibody (anti-CD14) or the TLR-4 inhibitor eritoran. C5D blood was reconstituted with purified human C5. TF mRNA was measured by quantitative polymerase chain reaction (qPCR) and monocyte TF and CD11b surface expression by flow cytometry. Prothrombin fragment 1+2 (PTF1·2) in plasma and microparticles exposing TF (TF-MP) was measured by enzyme-linked immunosorbent assay (ELISA). Coagulation kinetics were analyzed by rotational thromboelastometry and platelet function by PFA-200. Normal blood with eculizumab as well as C5D blood with or without reconstitution with C5 displayed completely normal biochemical hemostatic patterns. In contrast, E. coli-induced TF mRNA and TF-MP were significantly reduced by C5 inhibition. C5 inhibition combined with anti-CD14 or eritoran completely inhibited the E. coli-induced monocyte TF, TF-MP and plasma PTF1·2. Addition of C5a alone did not induce TF expression on monocytes. In conclusion, C5 showed no impact on physiological hemostasis, but substantially contributed to E. coli-induced procoagulant events, which were abolished by the combined inhibition of C5 and CD14 or TLR-4.

The role of coagulopathy on clinical outcome following traumatic brain injury in children: analysis of 66 consecutive cases in a single center institution

INTRODUCTION

Head injury is a significant economic, social, and medical problem in developing countries and remains one of the leading causes of pediatric morbidity and mortality. The association of traumatic brain injury and coagulopathy in children is linked with an increase in mortality and poor functional outcomes. However, its impact on long-term outcome has not been discussed in the literature so far.

OBJECTIVES

The aim of this paper was to investigate the effect of coagulopathy diagnosed by routine laboratory tests on neurological outcome following traumatic brain injury in children.

METHODS

A retrospective review was carried out using medical records of children with a traumatic brain injury admitted at a level I trauma center, between January 2013 and December 2016, submitted to any neurosurgical procedures. Statistical analysis was performed accordingly to identify factors predicting unfavorable or favorable outcomes at 1- and 6-month follow-ups. Data regarding age, gender, trauma mechanism, Glasgow Coma Scale at admission and at discharge, highest and lowest stable intracranial pressure, serum glucose and coagulation assessment, radiological findings, and length of stay were analyzed.

RESULTS

We identified 66 children with surgical head trauma. Mean age was 10.9 years (ranges from 3 months to 17 years), with male predominance (77.3%). Common mechanisms were road traffic accidents (66.7%), falls (19.7%), and blunt trauma (10.6%). Brain edema was detected in 68.2% of the patients, surgical fractures or intracranial bleeding in 75.8%. ICP monitoring was performed in 24.2% of the patients, and of these, 18.7% underwent consecutive decompressive craniectomy. Mean length of in-patient treatment was 16.3 ± 28.2 days. At 1- and 6-month follow-ups, favorable outcome was detected in 71.2 and 78.7% of the patients, respectively. The mortality rate was 12.1%. Routine coagulation assessments such as prothrombin time, fibrinogen levels, and thrombocyte count upon admission were potential prognostic variables identified.

CONCLUSIONS

The present study concluded that a trauma-related coagulopathy is an important predictor of unfavorable neurological outcome following TBI in pediatric patients. Initial GCS score, age, and neuroradiological findings, such as severe brain edema and different types of intracranial bleeding, correlated with GOS in the first 6 months following TBI. Sustained intracranial hypertension also predicted unfavorable outcome and death in this series.

Review: The Perioperative Use of Thromboelastography for Liver Transplant Patients

Thromboelastography (TEG) is a viscoelastic test that allows rapid evaluation of clot formation and fibrinolysis from a sample of whole blood. TEG is increasingly utilized to guide blood product resuscitation in surgical patients and transfusions for liver transplant patients. Patients with severe liver failure have significant derangement of their clotting function due to impaired production of procoagulant and anticoagulant factors. Traditional coagulation studies are limited by the short time needed for the result and provide little information about the dynamics and strength of clot formation. In addition, traditional coagulation studies do not correlate well with bleeding episodes and may lead to over-transfusion of various blood products. Evidence is less robust regarding the use of TEG for transfusion management decisions in severe liver failure patients awaiting, undergoing, or immediately after liver transplant surgery. However, the available evidence suggests that systematic implementation of TEG rather than traditional coagulation studies results in the administration of fewer blood products without increased mortality or complications. The purpose of this study is to review the literature regarding the use of TEG in liver failure patients prior to liver transplant, intraoperatively, and postoperatively. Additional high-quality randomized controlled studies should be performed to evaluate the use of TEG to guide transfusion decisions, particularly in the postoperative period following liver transplantation.

Hemostatic Management of Trauma-Induced Coagulopathy

Trauma-induced coagulopathy is a primary factor in many trauma-related fatalities. Management hinges upon rapid diagnosis of coagulation abnormalities and immediate administration of appropriate hemostatic agents. Use of crystalloids and packed red blood cells has traditionally been the core of trauma resuscitation, but current massive transfusion protocols include combination therapy with fresh frozen plasma and predefined ratios of platelets to packed red blood cells, limiting crystalloid administration. Hemostatic agents such as tranexamic acid, prothrombin complex concentrate, fibrinogen concentrate, and, in cases of refractory bleeding, recombinant activated factor VIIa may also be warranted. Goal-directed resuscitation using viscoelastic tools allows specific component-centered therapy based on individual clotting abnormalities that may limit blood product use and thromboembolic risks and may lead to reduced mortality. Because of the complex management of patients with trauma-induced coagulopathy, critical care nurses must be familiar with the pathophysiology, acute diagnostics, and pharmacotherapeutic options used to treat these patients.

iTACTIC - implementing Treatment Algorithms for the Correction of Trauma-Induced Coagulopathy: study protocol for a multicentre, randomised controlled trial

BACKGROUND

Traumatic injury is the fourth leading cause of death globally. Half of all trauma deaths are due to bleeding and most of these will occur within 6 h of injury. Haemorrhagic shock following injury has been shown to induce a clotting dysfunction within minutes, and this early trauma-induced coagulopathy (TIC) may exacerbate bleeding and is associated with higher mortality and morbidity. In spite of improved resuscitation strategies over the last decade, current transfusion therapy still fails to correct TIC during ongoing haemorrhage and evidence for the optimal management of bleeding trauma patients is lacking. Recent publications describe increasing the use of Viscoelastic Haemostatic Assays (VHAs) in trauma haemorrhage; however, there is insufficient evidence to support their superiority to conventional coagulation tests (CCTs).

METHODS/DESIGN

This multicentre, randomised controlled study will compare the haemostatic effect of an evidence-based VHA-guided versus an optimised CCT-guided transfusion algorithm in haemorrhaging trauma patients. A total of 392 adult trauma patients will be enrolled at major trauma centres. Participants will be eligible if they present with clinical signs of haemorrhagic shock, activate the local massive haemorrhage protocol and initiate first blood transfusion. Enrolled patients will be block randomised per centre to either VHA-guided or CCT-guided transfusion therapy in addition to that therapy delivered as part of standard care, until haemostasis is achieved. Patients will be followed until discharge or 28 days. The primary endpoint is the proportion of subjects alive and free of massive transfusion (less than 10 units of red blood cells) at 24 h. Secondary outcomes include the effect of CCT- versus VHA-guided therapy on organ failure, total hospital and intensive care lengths of stay, health care resources needed and mortality. Surviving patients will be asked to complete a quality of life questionnaire (EuroQol EQ-5D^TM) at day 90.

DISCUSSION

CCTs have traditionally been used to detect TIC and monitor response to treatment in traumatic major haemorrhage. The use of VHAs is increasing, but limited evidence exists to support the superiority of these technologies (or comparatively) for patient-centred outcomes. This knowledge gap will be addressed by this trial.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02593877 . Registered on 15 October 2015. Trial sponsor Queen Mary University of London The contact person of the above sponsor organisation is: Dr. Sally Burtles, Director of Research Services and Business Development, Joint Research Management Office, QM Innovation Building, 5 Walden Street, London E1 2EF; phone: 020 7882 7260; Email: sponsorsrep@bartshealth.nhs.uk Trial sites Academic Medical Centre, Amsterdam, The Netherlands Kliniken der Stadt Köln gGmbH, Cologne, Germany Rigshospitalet (Copenhagen University Hospital), Copenhagen, Denmark John Radcliff Hospital, Oxford, United Kingdom Oslo University Hospital, Oslo, Norway The Royal London Hospital, London, United Kingdom Centre for Trauma Sciences, Blizard Institute, Queen Mary University of London, London, United Kingdom Health Economics Research Centre, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom Sites that are planning to start recruitment in mid/late 2017 Nottingham University Hospitals, Queen's Medical Centre, Nottingham, United Kingdom University of Kansas Hospital (UKH), Kansas City, MO, USA Protocol version: 3.0/14.03.2017 (Additional file 1).

Viscoelastic Studies: Effective Tools for Trauma and Surgical Resuscitation Efforts

Trauma-induced coagulopathy (TIC) is an abrupt disruption of all hemostatic components of coagulation resulting from severe tissue injury and hypoperfusion. The effective management of TIC has remained elusive to clinicians using traditional laboratory methods, challenging efforts to improve outcomes related to uncontrolled bleeding. Recent initiatives have aimed to reduce TIC-associated morbidity and mortality, further invoking trauma experts to explore innovative modalities in the field of viscoelastic studies, such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM). These tests are able to guide proper blood product administration more effectively during trauma and surgical resuscitation compared with conventional laboratory tests. Although TEG and ROTEM are similar tests, inherent differences in their features produce variation in output results. This article calls on the perioperative clinician to evaluate TEG and ROTEM tests and consider their implementation based on the benefits of their application to clinical practice.

The impact of early thromboelastography directed therapy in trauma resuscitation

Background

Conventional coagulation tests do not provide an accurate representation of the complex nature of trauma induced coagulopathy. Thrombelastography provides a prompt global overview of all dynamic sequential aspects of trauma induced coagulopathy. The objective of this study was to evaluate the impact of using thrombelastography on blood products utilization, crystalloids utilization, hospital, and intensive care using length of stay, and cost savings.

Methods

We retrospectively reviewed 134 patients (May of 2012 to February of 2015) meeting Class I trauma activation. Outcome data was compared between two groups: patients prior to thrombelastography implementation (n = 87) and patients with thrombelastography guided trauma resuscitation (n = 47). Blood product usage was compared for three time periods: first 4 h, the next 20 h, and first 24 h.

Results

For the first 24 h of treatment, patients with thrombelastography guided trauma resuscitation had lower packed red blood cells (p = 0.0022) and fresh frozen plasma (p = 0.0474), but higher jumbo pack platelets (p = 0.0476) utilization when compared to the patients prior to thrombelastography implementation. There was no statistical significant difference in the utilization of crystalloids for any of the three time intervals. Patients with thrombelastography guided trauma resuscitation had a shorter hospital length of stay (p = 0.0011) and intensive care unit length of stay (p = 0.0059) than the patients prior to thrombelastography implementation. Cost savings in blood products transfusion were most pronounced in patients with penetrating injuries.

Discussion

Using visco-elastic tests to guide blood transfusion was first used for liver transplant patients and then applied to cardiovascular surgery and trauma. Similar to other studies, this study showed using visco-elastic tests for trauma patietns corresponded to an overall reduction in the use of packed red blood cells and fresh frozen plasma during the first 24 hours of resuscitation. In addition, this study showed using visco-elastic tests corresponded to a significant reduction in both hospital and intensive care unit length of stay.

Conclusion

This study demonstrates that Thrombelastography guided trauma resuscitation decreases the overall transfusion requirements of packed red blood cells and fresh frozen plasma. However, given the nature of under-recognized jumbo pack platelets dysfunction in the conventional laboratory parameters, jumbo pack platelets utilization is higher when following Thrombelastography directed resuscitation. The utilization of Thrombelastography corresponded to a reduction in hospital length of stay, intensive care unit length of stay and cost of transfused blood products.

Electronic supplementary material

The online version of this article (10.1186/s13049-017-0443-4) contains supplementary material, which is available to authorized users.

Flow, Liver, Flow: A Retrospective Analysis of the Interplay of Liver Disease and Coagulopathy in Chronic Subdural Hematoma

BACKGROUND

Chronic subdural hematoma (cSDH) is a common neurosurgical ailment, particularly in elderly patients. A recent study uncovered an association between liver disease and recurrence in patients with cSDH. Here, we explored that relationship to identify recurrence predictors in at-risk patients.

OBJECTIVE

We hypothesized that the association between liver disease and recurrence was attributable to coagulopathy secondary to liver disease.

METHODS

We retrospectively reviewed all patients with cSDH treated with burr-hole drainage by 2 surgeons between 2007 and 2015. Comorbidities and laboratory findings for each patient were examined by Pearson χ² analysis or Mann-Whitney U tests.

RESULTS

We identified 261 cSDH in 215 patients. Patients were a mean age of 65.6 years, and 72% were male. Sixteen patients with cSDH required repeat surgery (6.1%). There were 123 coagulopathic patients (47.1%), and 14 with liver disease (5.4%), all of whom were coagulopathic (P < 0.001). Coagulopathic patients with liver disease were more likely to experience recurrence than patients with coagulopathy alone (relative risk = 4.09, P = 0.019). Patients with liver disease had significantly elevated prothrombin time (P = 0.013) and reduced platelet counts (P < 0.001). Platelets also were reduced in coagulopathic patients with liver disease, as compared with those with coagulopathy alone (P = 0.002). Thrombocytopenia remained significant in a multivariate analysis (P < 0.001).

CONCLUSIONS

Liver disease is significantly associated with the recurrence of cSDH. Although coagulopathy alone does not predict recurrence, patients with coagulopathy and liver disease are at greater risk for recurrence than those with coagulopathy alone. Liver disease effects are reflected in certain hematologic laboratory values.

Monitoring the coagulation status of trauma patients with viscoelastic devices

Coagulopathy is a physiological response to massive bleeding that frequently occurs after severe trauma and is an independent predictive factor for mortality. Therefore, it is very important to grasp the coagulation status of patients with severe trauma quickly and accurately in order to establish the therapeutic strategy. Judging from the description in the European guidelines, the importance of viscoelastic devices in understanding the disease condition of patients with traumatic coagulopathy has been widely recognized in Europe. In the USA, the ACS TQIP Massive Transfusion in Trauma Guidelines proposed by the American College of Surgeons in 2013 presented the test results obtained by the viscoelastic devices, TEG® 5000 and ROTEM®, as the standard for transfusion or injection of blood plasma, cryoprecipitate, platelet concentrate, or anti-fibrinolytic agents in the treatment strategy for traumatic coagulopathy and hemorrhagic shock. However, some studies have reported limitations of these viscoelastic devices. A review in the Cochrane Library published in 2015 pointed out the presence of biases in the abovementioned reports in trauma patients and the absence of a quality study in this field thus far. A quality study on the relationship between traumatic coagulopathy and viscoelastic devices is needed.

Role of Coagulation Factor Concentrates in the Operating Room

The use of fresh frozen plasma, cryoprecipitate, and platelets has been the mainstay of approaches to correct coagulopathies that can arise in the perioperative setting. Limitations include the time delay from obtaining results of coagulation screens to the availability of thawed fresh frozen plasma and the potential of fluid overload. With advances in both global haemostatic testing and concentrates of coagulation factors, there are increasing opportunities for innovative practice. However, there remains a paucity of studies that can provide good quality, unbiased evidence. These issues are elaborated here to form the basis for future study.

The Utility of Viscoelastic Testing in Patients Undergoing IR Procedures

Whole-blood viscoelastic testing can identify patient-specific coagulation disturbances, allowing for targeted repletion of necessary coagulation factors and differentiation between coagulopathy and surgical bleeding that requires intervention. Viscoelastic testing complements standard coagulation tests and has been shown to decrease transfusion requirements and improve survival in bleeding patients. Viscoelastic testing also can be used to predict bleeding and improve the care of patients undergoing interventional radiology (IR) procedures.

The effect of hyperglycemia on blood coagulation: In vitro, observational healthy-volunteer study using rotational thromboelastometry (ROTEM)

We performed a study to investigate whether contamination of hemostasis samples with a glucose-containing solution might generate spurious results in rotational thromboelastometry (ROTEM) tests.Venous blood was taken from 12 healthy volunteers and divided into 4 specimen bottles, which were contaminated with different concentrations (0%, 5%, 10%, and 20%) of glucose solution.Significant lengthening of INTEMCT was observed in the 10% and 20% groups compared with baseline values (7.7% and 9%, P = 0.041 and P = 0.037, respectively). INTEMCFT increased by 20.1% in the 20% group (P = 0.005). INTEMα-angle and INTEMMCF decreased by 3.9% and 2.7%, respectively, in the 20% group (P = 0.010 and P = 0.049, respectively). EXTEMCFT was prolonged significantly, by 10.2%, 15.5%, and 25.6%, in the 5%, 10%, and 20% groups, respectively (P = 0.004, P < 0.001, and P < 0.001, respectively). EXTEMα-angle decreased significantly by 1.9%, 3.2%, and 4.0% in the 5%, 10%, and 20% groups, respectively (P = 0.014, P = 0.001, and P = 0.005, respectively). EXTEMMCF decreased by 3.4% in the 20% group (P = 0.023). FIBTEMMCF decreased by 9.2% and 17.5% in the 10% and 20% groups, respectively (P = 0.019 and P = 0.021, respectively). A significant correlation was observed between standard glucose solution contamination in the specimens and percentage variation of EXTEMCFT, EXTEMMCF, and FIBTEMMCF.To obtain accurate data from the ROTEM test regarding the hemostatic status of patients, specimens with suspected or known contamination should not be analyzed.

An in vitro analysis of the effect of acidosis on coagulation in chronic disease states - a thromboelastograph study

Thrombosis is a complication of many chronic illnesses. Chronic obstructive pulmonary disease (COPD) and diabetes mellitus are common medical conditions frequently associated with a hypercoagulable state. Acidaemia has been shown to reduce coagulation. COPD and diabetes mellitus during acute deterioration can present with a severe acidaemia. The impact of this acidaemia on coagulation is poorly studied. Patients presenting with a diagnosis of diabetic ketoacidosis or type II respiratory failure from COPD and a pH of less than 7.2 were included in our study. A coagulation screen and a thromboelastograph (TEG) were performed on admission and 24 hours later. The mean pH on admission was 7.07 and mean base excess was -16.3. The activated partial thromboplastin time was associated with pH change but remained within the normal range (26-41 s). All other coagulation and TEG parameters failed to show evidence of association (p>0.05). In the two models of non-haemorrhagic acidosis investigated, coagulation was not altered by the changes in pH. More work is needed to understand the complex relationship between factors affecting coagulation in individual disease processes.