Tracing the Lines: A Review of Viscoelastography for Emergency Medicine Clinicians

Approaches to Precision-based Anticoagulation management in the critically Ill

Anticoagulant therapy is commonly associated with a high incidence of avoidable adverse events, especially in the acute care setting. This has led to several initiatives by key national health care stakeholders, including specific attention to The Joint Commission's National Patient Safety Goals, to improve anticoagulation management. The subject of special populations has long been identified as challenging by clinicians with the use of anticoagulants. This is driven in part by numerous variables that can contribute to hard outcomes such as bleeding, thrombosis, length of stay, hospital re-admission, morbidity, and mortality. Despite the notable effort to improve the use of anticoagulants with numerous clinical trials, guidelines, guidance statements, and other sources of published evidence, notable difficulties continue to challenge practitioners in managing this class of medications. This is especially the case with very diverse critically ill populations where countless variables exist, many of which were never explored in trials or have historically been frequently excluded. Trials evaluating anticoagulation therapy often can only account for small portions of variables that may affect thrombosis and hemostasis, and study methods often do not reflect the constantly changing dynamic conditions seen in unique critically ill patients. Clinicians providing care to the numerous critically ill populations are faced with conditions that lead to relatively small therapeutic windows, which makes designing safe optimal anticoagulation management plans difficult when dealing with complex patients and mechanical support devices. The approach to crafting a successful management plan for anticoagulant therapy must incorporate the numerous variables that are continuously assessed and revised during the patient's time in the intensive care unit. We explore considerations and approaches when developing, assessing, and implementing an individualized or precision-based management plan that involves the use of anticoagulants in the critically ill. The skills and thought process provided will assist clinicians in managing this unique, variable, and challenging population.

A Review of Thromboelastography for Nurses

BACKGROUND

Thromboelastography is a viscoelastic test with multiple potential advantages over conventional coagulation tests in various disease states. Thromboelastography rapidly provides qualitative and quantitative information related to a patient's coagulation status.

OBJECTIVE

To describe recent studies of the use of thromboelastography in various clinical states and how thromboelastography is used in coagulation management.

METHODS

A literature review using the MEDLINE and PubMed databases was conducted. The updated methodology for integrated reviews by Whittemore and Knafl was followed. Coauthors evaluated separate areas that were independently reviewed by other coauthors to ensure appropriateness for inclusion.

RESULTS

The use of thromboelastography for various clinical conditions with challenging hemostatic profiles has increased. This integrative review covers the use of thromboelastography in patients with trauma, medication-induced coagulopathy, acute and chronic liver failure, and cardiothoracic surgery. Potential future directions are also discussed.

DISCUSSION

Thromboelastography has numerous potential benefits over conventional coagulation tests for assessing coagulation status in patients in various clinical states. Nurses can support clinical decisions to use the most appropriate test for their patients.

CONCLUSIONS

Each team member should be involved in assessing the usefulness of thromboelastography. Critical care nurses and the multidisciplinary team must identify patients in whom its use is warranted, interpret the results, and provide appropriate interventions in response to the results and clinical status of the patient.

Practical Guide for Anticoagulant and Antiplatelet Reversal in Clinical Practice

In recent years, anticoagulant and antiplatelet use have increased over the past years for the prevention and treatment of several cardiovascular conditions. Due to the rising use of antithrombotic medications and the complexity of specific clinical cases requiring such therapies, bleeding remains the primary concern among patients using antithrombotics. Direct oral anticoagulants (DOACs) include rivaroxaban, apixaban, edoxaban, and betrixaban. Direct thrombin inhibitors (DTIs) include argatroban, bivalirudin, and dabigatran. DOACs are associated with lower rates of fatal, life-threatening, and significant bleeding risks compared to those of warfarin. The immediate reversal of these agents can be indicated in an emergency setting. Antithrombotic reversal recommendations are still in development. Vitamin K and prothrombin complex concentrate (PCCs) can be used for warfarin reversal. Andexanet alfa and idarucizumab are specific reversal agents for DOACs and DTIs, respectively. Protamine sulfate is the solely approved reversal agent for unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH). However, there are no specific reversal agents for antiplatelets. This article aims to provide a practical guide for clinicians regarding the reversal of anticoagulants and antiplatelets in clinical practice based on the most recent studies.

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.

Real-time monitoring of intravenous thrombolysis in acute ischemic stroke using rotational thromboelastometry: a feasibility pilot study

Introduction

Rotational thromboelastometry (ROTEM) records whole blood coagulation in vitro. Data on dynamic changes of clot patterns during intravenous thrombolysis (IVT) in acute ischemic stroke is scarce. We investigated the feasibility of ROTEM as a potential point-of-care assessment tool for IVT.

Methods

In this prospective pilot study, patients with acute stroke symptoms received IVT. Whole blood coagulation was tracked on the ROTEM analyzer. Blood samples were analyzed before, and then 2, 15, 30 and 60 min after beginning IVT. In vitro clots (iCLs) were described by their maximum clot firmness (MCF), the time needed to reach MCF (MCF-t), as well as the area under the curve (AR10). National Institutes of Health Stroke Scale (NIHSS) was used as early clinical outcome parameter.

Results

We analyzed 288 iCLs from 12 patients undergoing IVT. In all iCLs, an early fibrinolysis (91% within the first 10 min) was detected during IVT. Three different curve progression patterns were observed: a low-responder pattern with a continuous clot increase, a high-responder pattern with a sustained clot decrease or total clotting suppression and an intermediate-responder pattern with alternating clot characteristics. There was a difference among these groups in early clinical outcome (AR10 and MCF each p = 0.01, MCF-t p = 0.02, Kruskal–Wallis Test).

Conclusion

The fibrinolysis patterns determined using ROTEM allow for the monitoring of IVT in patients with acute ischemic stroke. This pilot study found a correlation between the in vitro fibrinolysis patterns and early clinical outcomes. These findings support a potential for individualization of IVT in the future.

Use of Thromboelastography and Rotational Thromboelastometry in Otolaryngology: A Narrative Review

In the field of otolaryngology—head and neck surgery (ENT), coagulopathies present unique diagnostic and therapeutic challenges. In both hyper- and hypocoagulable patients, management of coagulopathies requires intricate attention to the nature of hemostatic competence. Common coagulation tests (CCTs) offer only a snapshot of hemostatic competence and do not provide a clear insight into the patient’s real-time hemostatic condition. Viscoelastic tests (VETs) offer a holistic and concurrent picture of the coagulation process. Although VETs have found prominent utilization in hepatic transplants, obstetrics, and emergent surgical settings, they have not been fully adopted in the realm of otolaryngology. The objective of this manuscript is to provide an overview of the literature evaluating the current utilization and possible future uses of VETs in the field of otolaryngology. The authors performed a comprehensive literature search of the utilization of VETs in otolaryngology and identified applicable studies that included descriptions of viscoelastic testing. Twenty-five studies were identified in this search, spanning topics from head and neck oncology, microvascular free flap reconstruction, obstructive sleep apnea, adenotonsillectomy, facial trauma, and epistaxis. The applicability of VETs has been demonstrated in head and neck oncology and microvascular free flap management, although their pervasiveness in practice is limited. Underutilization of VETs in the field of otolaryngology may be due to a lack of familiarity of the tests amongst practitioners. Instead, most otolaryngologists continue to rely on CCTs, including PT, PTT, INR, CBC, fibrinogen levels, and thrombin time. Learning to perform, interpret, and skillfully employ VETs in clinical and operative practice can greatly improve the management of coagulopathic patients who are at increased risk of bleeding or thrombosis.

The pathophysiology of sepsis - 2021 update: Part 2, organ dysfunction and assessment

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

This is the second article in a 2-part series discussing the pathophysiology of sepsis. Part 1 of the series reviewed the immunologic response and overlapping pathways of inflammation and coagulation that contribute to the widespread organ dysfunction. In this article (part 2), major organ systems and their dysfunction in sepsis are reviewed, with discussion of scoring systems used to identify patterns and abnormal vital signs and laboratory values associated with sepsis.

SUMMARY

Sepsis is a dysregulated host response to infection that produces significant morbidity, and patients with shock due to sepsis have circulatory and cellular and metabolic abnormalities that lead to a higher mortality. Cardiovascular dysfunction produces vasodilation, reduced cardiac output and hypotension/shock requiring fluids, vasopressors, and advanced hemodynamic monitoring. Respiratory dysfunction may require mechanical ventilation and attention to volume status. Renal dysfunction is a frequent manifestation of sepsis. Hematologic dysfunction produces low platelets and either elevation or reduction of leucocytes, so consideration of the neutrophil:lymphocyte ratio may be useful. Procoagulant and antifibrinolytic activity leads to coagulation that is stimulated by inflammation. Hepatic dysfunction manifest as elevated bilirubin is often a late finding in sepsis and may cause reductions in production of essential proteins. Neurologic dysfunction may result from local endothelial injury and systemic inflammation through activity of the vagus nerve.

CONCLUSION

Timely recognition and team response with efficient use of therapies can improve patient outcome, and pharmacists with a complete understanding of the pathophysiologic mechanisms and treatments are valuable members of that team.

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.

Successful Use of Aspirin, Apixaban, and Viscoelastography in a Patient with Severe COVID Disease and Allergy to Porcine Products

Coagulation abnormalities are frequently described in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Common thromboprophylaxis and anticoagulation treatment strategies include the use of heparinoid therapy. We describe a 57-year-old woman with an allergy to porcine products that was started on apixaban for anticoagulation therapy given her allergy profile and need for venous thromboembolism prophylaxis. Apixaban and aspirin therapy were optimized with the support of serial viscoelastography and platelet function assays. Our patient experienced respiratory failure requiring intubation for 7 days but was successfully weaned to room air, tolerated a regular diet, and ultimately discharged to home after a 17-day hospital course. Here we report the safe and successful use of aspirin, apixaban, and viscoelastography for COVID-19-associated coagulopathy.