New Uses for Thromboelastography and Other Forms of Viscoelastic Monitoring in the Emergency Department: A Narrative Review

Hemostasis Testing in the Emergency Department: A Narrative Review

Routine laboratory screening is typically performed at initial evaluation of the vast majority of presentations to the emergency department (ED). These laboratory results are crucial to the diagnostic process, as they may influence up to 70% of clinical decisions. However, despite the usefulness of biological assessments, many tests performed are inappropriate or of doubtful clinical relevance. This overutilization rate of laboratory testing in hospitals, which represents a significant medical-economic burden, ranges from 20 to 67%, with coagulation tests at the top of the list. While reviews frequently focus on nonintensive care units, there are few published assessments of emergency-specific interventions or guidelines/guidance to date. The aim of this review is to highlight current recommendations for hemostasis evaluation in the emergency setting with a specific analysis of common situations leading to ED admissions, such as suspected venous thrombosis or severe bleeding. We revisit the evidence related to the assessment of patient's hemostatic capacity based on comprehensive history taking and physical examination as well as best practice recommendations for blood sample collection to ensure the reliability of results. This review also includes an examination of various currently available point of care tests and a comprehensive discussion on indications, limitations, and interpretation of these tests.

The Management of COVID-19-Related Coagulopathy: A Focus on the Challenges of Metabolic and Vascular Diseases

The course of COVID-19 is highly dependent on the associated cardiometabolic comorbidities of the patient, which worsen the prognosis of coronavirus infection, mainly due to systemic inflammation, endothelium dysfunction, and thrombosis. A search on the recent medical literature was performed in five languages, using the PubMed, Embase, Cochrane, and Google Scholar databases, for the review of data regarding the management of patients with a high risk for severe COVID-19, focusing on the associated coagulopathy. Special features of COVID-19 management are presented, based on the underlying conditions (obesity, diabetes mellitus, and cardiovascular diseases), emphasizing the necessity of a modern, holistic approach to thromboembolic states. The latest findings regarding the most efficient therapeutic approaches are included in the article, offering guidance for medical professionals in severe, complicated cases of SARS-CoV-2 infection. We can conclude that severe COVID-19 is closely related to vascular inflammation and intense cytokine release leading to hemostasis disorders. Overweight, hyperglycemia, cardiovascular diseases, and old age are important risk factors for severe outcomes of coronavirus infection, involving a hypercoagulable state. Early diagnosis and proper therapy in complicated SARS-CoV-2-infected cases could reduce mortality and the need for intensive care during hospitalization in patients with cardiometabolic comorbidities.

Evaluation of a Newly Implemented Critical Thromboelastography (TEG) Value Callback System

OBJECTIVES

Thromboelastography (TEG) measures whole blood coagulation kinetics in real time and is useful in guiding blood product transfusion. At our institution, providers have immediate remote access to TEG results. However, some critical values are occasionally missed. Our patient blood management program implemented a critical TEG value callback system to improve patient management and blood product utilization.

METHODS

This retrospective, observational study assessed the data of trauma and critical care patients preimplementation (n = 20) and postimplementation (n = 100) of the callback system. Provider responses to callbacks and changes in TEG parameters after subsequent testing were compared between the two groups.

RESULTS

In response to callbacks, 42% provided appropriate management and 42% ordered a repeat TEG vs 28% and 33% in the historical group (P < .0001 and P = .0002, respectively). Following callback, 90% of the TEG parameters in the study group showed an improvement vs 57% in the control group (P = .011).

CONCLUSIONS

The increase in appropriate management and the improvement in TEG parameters upon repeat testing in the study group compared to the control group demonstrate the efficacy of the TEG callback system. Further studies are needed to evaluate the callback system effect on patient outcome.

Study on the Predictive Value of Thromboelastography in Early Neurological Deterioration in Patients with Primary Acute Cerebral Infarction

Objective

To investigate the predictive value of thromboelastography for the occurrence of early neurological deterioration (END) in patients with primary acute cerebral infarction (ACI).

Methods

150 patients who were hospitalized in the department of neurology of our hospital from September 2020 to September 2021 and were clearly diagnosed with primary ACI by head CT and head magnetic resonance imaging (MRI) were selected and divided into END and non-END groups according to the change in National Institute of Health Stroke Scale (NIHSS) score within 72 h of admission. The general baseline data and laboratory indexes of the first examination at admission were compared between the two groups, and the factors that may affect the occurrence of END were determined by univariate analysis and multivariate logistic regression analysis, and the predictive value of thromboelastography on the occurrence of END after ACI was analyzed by applying the receiver operating characteristic (ROC) curve.

Results

Time to onset, baseline NIHSS score, percentage of diabetes, white blood cell (WBC) levels, C-reactive protein (CRP), and apolipoprotein B (Apo B) levels were higher in the END group than in the non-END group (P < 0.05); coagulation reaction time (RT) (3.97 ± 1.16 vs. 5.49 ± 1.03) and kinetic time (KT) (1.32 ± 0.67 vs. 1.82 ± 0.58) were lower in the END group than in the non-END group (P < 0.05). Inthe END group (P < 0.05) diabetes, baseline NHISS score, CRP level, Apo B level, and RT were independent risk factors for the development of END in patients with ACI (P < 0.05). The AUC of RT to predict the occurrence of END in patients with ACI was 0.855 (95% CI: 0784 to 0925, P = 0.001), with a sensitivity of 81.70% and specificity of 78.00% when the optimal cut-off value was 0.597.

Conclusion

NIHSS score at admission, CRP, apolipoprotein B, RT shortening, and diabetes mellitus were independent risk factors for the development of END in ACI patients; RT shortening in TEG was predictive of END in ACI patients.

Updates on Novel Non-Replacement Drugs for Hemophilia

Over the last decade, the world of hemophilia has experienced an unprecedented therapeutic advance, thanks to the progress in bioengineering technologies, leading to the introduction of drugs with novel mechanisms of action based on restoring thrombin generation or coagulation factor VIII mimicking. Apart from the bispecific monoclonal antibody emicizumab, already approved for patients with severe hemophilia A with and without inhibitors, novel non-replacement drugs designed to reduce the treatment burden of patients with hemophilia A or B with or without inhibitors are undergoing evaluation in clinical trials. Thanks to their innovative mechanism of action and subcutaneous administration, these drugs promise to provide effective bleeding protection together with improved adherence and improve health-related quality of life for patients with hemophilia. On the other hand, rare thromboembolic events have been reported with some of these drugs and warrant continuous post-marketing surveillance and investigation of predisposing factors, although the overall safety profile of most of these drugs is good. Finally, new challenges need to be faced in the clinical and laboratory monitoring of the hemostatic status in patients treated with these innovative therapies. In this review, we provide an update on the available data on novel non-replacement drugs currently undergoing evaluation in clinical trials for patients with hemophilia.

The Applicability of Thromboelastography in Acute Ischemic Stroke: A Literature Review

Acute ischemic stroke (AIS) due to cerebral artery occlusion is often treated by thrombolytics or antithrombotic drugs. Thromboelastography (TEG) is a noninvasive test that provides a dynamic overview of the coagulation process. TEG may help guide thrombolytic and antithrombotic therapy in AIS. This article aims to highlight the potential use of TEG in AIS patients by reviewing available studies. We conducted a literature review, including PubMed and Cochrane library databases. The following keywords were used to find relevant studies: thromboelastography, TEG, acute ischemic stroke, stroke, coagulopathy, antiplatelet, and anticoagulant treatment. We identified 142 papers and after abstract review, we included 24 studies in this report. TEG identified a hypercoagulable state in AIS patients represented by short R, K, and greater α: angle in all papers included. Modification of TEG parameters induced by intravenous thrombolysis was inconsistent but prolonged lysis (increased LY30) and weaker clots (lower maximum amplitude) were most frequent. TEG detected hypo-coagulopathy induced by dual antiplatelet therapy as well as antiplatelet drug resistance, with ticagrelor and aspirin having greater inhibition of platelet activity. A prolonged R-value seems to be the most reliable TEG parameter in detecting the anticoagulant effect of factor Xa inhibitor treatment. TEG might represent a useful point-of-care test for emergency decision-making in AIS patients and a tool for individualized treatment options. This hypothesis needs validation in a large cohort of prospectively studied AIS patients.

The Applicability of Thromboelastography in Acute Ischemic Stroke: A Literature Review

Acute ischemic stroke (AIS) due to cerebral artery occlusion is often treated by thrombolytics or antithrombotic drugs. Thromboelastography (TEG) is a noninvasive test that provides a dynamic overview of the coagulation process. TEG may help guide thrombolytic and antithrombotic therapy in AIS. This article aims to highlight the potential use of TEG in AIS patients by reviewing available studies. We conducted a literature review, including PubMed and Cochrane library databases. The following keywords were used to find relevant studies: thromboelastography, TEG, acute ischemic stroke, stroke, coagulopathy, antiplatelet, and anticoagulant treatment. We identified 142 papers and after abstract review, we included 24 studies in this report. TEG identified a hypercoagulable state in AIS patients represented by short R, K, and greater α: angle in all papers included. Modification of TEG parameters induced by intravenous thrombolysis was inconsistent but prolonged lysis (increased LY30) and weaker clots (lower maximum amplitude) were most frequent. TEG detected hypo-coagulopathy induced by dual antiplatelet therapy as well as antiplatelet drug resistance, with ticagrelor and aspirin having greater inhibition of platelet activity. A prolonged R-value seems to be the most reliable TEG parameter in detecting the anticoagulant effect of factor Xa inhibitor treatment. TEG might represent a useful point-of-care test for emergency decision-making in AIS patients and a tool for individualized treatment options. This hypothesis needs validation in a large cohort of prospectively studied AIS patients.

Which Septic Shock Patients With Non-Overt DIC Progress to DIC After Admission? Point-of-Care Thromboelastography Testing

BACKGROUND

Disseminated intravascular coagulation (DIC) is a life-threatening complication of septic shock; however, risk factors for its development after admission are unknown. Thromboelastography (TEG) can reflect coagulation disturbances in early non-overt DIC that are not detected by standard coagulation tests. This study investigated the risk factors including TEG findings as early predictors for DIC development after admission in septic shock patients with non-overt DIC.

METHODS

This retrospective observation study included 295 consecutive septic shock patients with non-overt DIC at admission between January 2016 and December 2019. DIC was defined as an International Society on Thrombosis and Hemostasis (ISTH) score ≥ 5. The primary outcome was non-overt DIC at admission that met the ISTH DIC criteria within 3 days after admission.

RESULTS

Of the 295 patients with non-overt DIC, 89 (30.2%) developed DIC after admission. The DIC group showed a higher ISTH score and 28-day mortality rate than the non-DIC group (2 vs. 3, P < 0.001; 13.6% vs. 27.0%, P = 0.008, respectively). The DIC rate increased with the ISTH score (7.7%, 13.3%, 15.8%, 36.5%, and 61.4% for scores of 0, 1, 2, 3, and 4, respectively). Among TEG values, the maximum amplitude (MA) was higher in the non-DIC group (P < 0.001). On multivariate analysis, an MA < 64 mm was independently associated with DIC development (odds ratio, 2.311; 95% confidence interval, 1.298-4.115).

CONCLUSIONS

DIC more often developed among those with admission ISTH scores ≥ 3 and was associated with higher mortality rates. An MA < 64 mm was independently associated with DIC development in septic shock patients.

Prevalence and Trajectory of COVID-19-Associated Hypercoagulability Using Serial Thromboelastography in a South African Population

Introduction

The coagulation abnormalities resulting from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been attributed to inflammation and subsequent cytokine storm. Thromboelastography (TEG) is a point-of-care test used to assess clot formation and degradation in whole blood and is an indicator of the overall real-time coagulopathic state of the patient.

Methods

A single-centre, prospective, observational cohort study was conducted in South Africa, analysing the coagulation patterns of 41 patients with hypoxia related to SARS-CoV-2 using serial thromboelastography (TEG) on admission, after 48 hours, and at resolution of hypoxia/day 10. Results: Two-thirds (n = 26) were women. The median age was 61 (IQR 50–67), and the majority (88%) were Black patients. Almost half (22) of the patients were critically ill and ventilated, with median SOFA and SAPS2 scores of 3 and 22 (IQR2-4 and 18–30), respectively. The prevalence of hypercoagulability was 0.54 (95% CI 0.46–0.62), whilst 29/41 (0.71, CI 0.64–0.78)) met the definition of hypofibrinolysis. Differences between the hypercoagulable (HC) and non-hypercoagulable groups remained apparent at 48 hours after anticoagulation. At this time point, the K time was significantly lower (p ˂ 0,01), and the α-angle (p ˂ 0,01) and maximum amplitude (MA) (p ˂ 0,01) were significantly higher in the HC cohort. At resolution of hypoxia, or day 10, only MA was significantly higher in the hypercoagulable group compared to the non-hypercoagulable group (p = 0.01). The initial impairment in fibrinolysis (Ly30), α angle, and MA were significantly associated with mortality, with p values of 0.006, 0.031, and 0.04, respectively.

Conclusions

In this South African population, hypercoagulability was a highly prevalent phenomenon in COVID-19 disease. It was typified by hypofibrinolysis and a persistently elevated MA, despite anticoagulation therapy.