Use Of Viscoelastic Tests Research Articles

Should viscoelastic testing be a standard point-of-care test on all intensive care units?

Viscoelastic tests (VETs) have transformed assessment of haemostasis and transfusion practices in trauma, cardiac and liver transplantation centres. Impaired haemostasis is a common problem on the general intensive care unit (ICU), but routine use of VETs is rare. We have accordingly reviewed the evidence to determine whether there is evidence to support the use of VETs as a standard point of care test on all ICUs in assessing and managing patients. The benefits of using VETs in the management of major haemorrhage, namely faster identification of a coagulopathy, in particular early detection of fibrinolysis, and reduced transfusion requirements for blood products have been seen in the general ICU. Validation of treatments algorithms is now required to standardise practice. There is also emerging evidence to support the use of VETs to guide urgent treatment decisions in patients with a coagulopathy or in patients taking anti-coagulants or anti-platelet therapies. We recommend that departments independently review the feasibility of setting up a viscoelastic point of care service which considers the applicability to their patient cohort, the financial cost and the personnel required.

Fluid resuscitation in trauma: What you need to know.

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

PB0087 Use of Viscoelastic Tests in the Intensive Care Unit for the Evaluation of Haemostasis in SARS-COV-2 Infection

PB0087 Use of Viscoelastic Tests in the Intensive Care Unit for the Evaluation of Haemostasis in SARS-COV-2 Infection

Viscoelastic Testing on Venoarterial Extracorporeal Membrane Oxygenation: Need or Greed?

Extracorporeal life support (ECLS) is a life support modality that is being used in life-threatening cardiac and/or respiratory failure; in neonates, children, and adults. The risk of bleeding and other coagulation-related issues is unavoidable. Hence, while conducting ECLS, a patient-tailored approach is better than the generalized approach for bleeding management. There are no established guidelines for heparin use and its monitoring during ECLS in a bleeding patient on VA ECMO. Likewise, heparin and its adjuncts, though mentioned in the literature, have no consensus on what exact steps to follow in an adverse condition. Having a protocol for anticoagulation and its monitoring is of paramount importance in any center practicing ECLS. This review aims to seek the incidence of bleeding and thrombosis while on ECMO with the use of routine anticoagulant heparin and justify the need for the use of viscoelastic tests on VA ECMO.

Viscoelastic testing: Critical appraisal of new methodologies and current literature.

United States Food and Drug Administration (FDA)-approved viscoelastic testing (VET) methodologies have significantly changed in the last 10 years, with the availability of cartridge-based VET. Some of these cartridge-based methodologies use harmonic resonance-based clot detection. While VET has always allowed for the evaluation of real-time clot formation, cartridge-based VET provides increased ease of use as well as greater portability and robustness of results in out-of-laboratory environments. Here we review the use of VET in a variety of clinical contexts, including cardiac surgery, trauma, liver transplant, obstetrics, and hypercoagulable states such as COVID-19. As of now, high quality randomized trial evidence for new generation VET (TEG 6s, HemoSonics Quantra, ROTEM sigma) is limited. Nevertheless, the use of VET-guided transfusion algorithms appears to result in reduced blood usage without worsening of patient outcomes. Future work comparing the new generation VET instruments and continuing to validate clinically important cut-offs will help move the field of point-of-care coagulation monitoring forward and increase the quality of transfusion management in bleeding patients.

Non‐trauma uses of viscoelastic hemostatic assays in critical care: A narrative review and primer for pharmacists

AbstractThromboelastography (TEG) and rotational thromboelastometry (ROTEM) are point‐of‐care viscoelastic tests of whole blood that provide real‐time analyses of coagulation. TEG and ROTEM are often used to guide blood product administration in the trauma and surgical settings. These tests are increasingly being explored for their use in other disease states encountered in critically ill patients and in the management of antithrombotic medications. As the medication experts, pharmacists should be familiar with how to interpret and apply viscoelastic tests to disease state and medication management. The purpose of this narrative review is to provide a primer for pharmacists on viscoelastic tests and their interpretation and to explore non‐trauma indications for viscoelastic testing in critical care. Literature evaluating the use of TEG and ROTEM for patients with acute and chronic liver disease, ischemic and hemorrhagic stroke, myocardial infarction, cardiac arrest, coronavirus disease 2019, and extracorporeal membrane oxygenation are described. Current applications of viscoelastic tests by pharmacists and potential future roles of critical care pharmacists in expanding the use of viscoelastic tests are summarized.

The precision of ROTEM EXTEM is decreased in hypocoagulable blood: a prospective observational study

BackgroundThe use of viscoelastic tests is becoming increasingly popular. There is a paucity of validation of the reproducibility of varying coagulation states. Therefore, we aimed to study the coefficient of variation (CV) for the ROTEM EXTEM parameters clotting time (CT), clot formation time (CFT), alpha-angle and maximum clot firmness (MCF) in blood with varying degrees of coagulation strength. The hypothesis was that CV increases in states of hypocoagulability.MethodsCritically ill patients and patients subjected to neurosurgery at a university hospital during three separate periods were included. Each blood sample was tested in eight parallel channels, yielding the CVs for the tested variables. In 25 patients, the blood samples were analysed both at baseline and after dilution with albumin 5%, as well as after being spiked with fibrinogen, simulating weak and strong coagulation.ResultsIn total, 225 unique blood samples were collected from 91 patients. All samples were analysed in eight parallel ROTEM channels, resulting in 1,800 measurements. In hypocoagulable samples, defined as those with values outside the normal reference range, the CV of CT was higher (median (interquartile range)) (6.3% (5.1–9.5)) than for normocoagulable samples (5.1% (3.6–7.5)), p < 0.001. CFT showed no difference (p = 0.14), while the CV of alpha-angle was higher in hypocoagulable samples (3.6% (2.5–4.6)) than in normocoagulable samples (1.1% (0.8–1.6), p < 0.001. The CV of MCF was higher in hypocoagulable samples (1.8% (1.3–2.6)) than in normocoagulable samples (1.2% (0.9–1.7)), p < 0.001. The CV ranges for the different variables were as follows: CT: 1.2%–37%, CFT: 1.7%–30%, alpha-angle: 0.0%–17% and MCF: 0.0%–8.1%.ConclusionsCVs for the EXTEM ROTEM parameters CT, alpha-angle, and MCF increased in hypocoagulable blood compared to blood with normal coagulation, confirming the hypothesis for CT, alpha-angle, and MCF but not for CFT. Furthermore, the CVs for CT and CFT were much higher than those for alpha-angle and MCF. The results demonstrate that EXTEM ROTEM results from patients with weak coagulation should be interpreted with the notion of limited precision and that procoagulative treatment, based only on ROTEM EXTEM, should be given with some caution.

Diagnosis of disorders in the coagulation system, assessment of the risk of hemorrhagic complications in severe cirrhosis/liver diseases according to global screening tests of the hemostasis system and principles for their correction: guidelines

Hemostasis disorders in cirrhosis / severe liver disease are complex, as they affect both pro- and anticoagulant factors, as well as pro- and antifibrinolytic components. Most of the tests that are used in clinical practice to assess coagulation do not take into account the compensatory capabilities of this system as a whole. This document provides guidance for the optimal application and interpretation of global screening tests in the assessment of hemostasis in cirrhosis/severe liver disease, analysis of risk factor of spontaneous and perioperative hemorrhagic complications in these patients, and possible ways to correct them. Thrombocytopenia is one of the most common hematological abnormalities in cirrhosis/ severe liver disease. The frequency of thrombocytopenia in such patients at the stage of liver cirrhosis is 70%, at the pre-cirrhotic stage – 6%. The latest scientific data on the use of thrombopoietin receptor agonists in chronic liver diseases are presented: which patients are the best candidates for a such of therapy. The rationality and limitations in prescribing blood components to patients with liver cirrhosis/severe liver diseases are described. Emphasis is placed on the fact that a number of hemorrhagic complications develop for other non-coagulopathic reasons: decompensated portal hypertension, traumatization of a varicose vein with trophic wall disorders, etc. Data are presented on the use of viscoelastic tests to optimize the management of patients with liver cirrhosis, which simultaneously assess the four main known components of the hemostasis system: the coagulation cascade, platelets, anticoagulant mechanisms and the fibrinolysis system. These tests allow optimization of transfusion of blood components in such patients and should be further studied. Research in this very complex area of hepatology is ongoing and must continue.

Intraoperative transfusion management, antifibrinolytic therapy, coagulation monitoring and the impact on short-term outcomes after liver transplantation-A systematic review of the literature and expert panel recommendations.

Liver transplantation (LT) is frequently complicated by coagulopathy associated with end-stage liver disease (ESLD), that is, often multifactorial. The objective of this systematic review was to identify evidence based intraoperative transfusion and coagulation management strategies that improve immediate and short-term outcomes after LT. PRISMA-guidelines and GRADE-approach were followed. Three subquestions were formulated. (Q); Q1: transfusion management; Q2: antifibrinolytic therapy; and Q3: coagulation monitoring. Sixteen studies were included for Q1, six for Q2, and 10 for Q3. Q1: PRBC and platelet transfusions were associated with higher mortality. The use of prothrombin complex concentrate (PCC) and fibrinogen concentrate (FC) were not associated with reductions in intraoperative transfusion or increased thrombotic events. The use of cell salvage was not associated with hepatocellular carcinoma (HCC) recurrence or mortality. Cell salvage and transfusion education significantly decreased blood product transfusions. Q2: Epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA) were not associated with decreased blood product transfusion, improvements in patient or graft survival, or increases in thrombotic events. Q3: Viscoelastic testing (VET) was associated with decreased allogeneic blood product transfusion compared to conventional coagulation tests (CCT) and is likely to be cost-effective. Coagulation management guided by VET may be associated with increases in FC and PCC use. Q1: A specific blood product transfusion practice is not recommended (QOE; low | Recommendation; weak). Cell salvage and educational interventions are recommended (QOE: low | Grade of Recommendation: moderate). Q2: The routine use of antifibrinolytics is not recommended (QOE; low | Recommendation; weak). Q3: The use of VET is recommended (QOE; low-moderate | Recommendation; strong).

Implementing and sustaining Point of Care ROTEM® into a trauma activation protocol for the management of patients with traumatic injury: A mixed-methods study

BackgroundUp to 40% of patients with traumatic injury experience critical bleeding, many requiring transfusion of blood products. International transfusion guidelines recommend the use of viscoelastic testing to guide blood product replacement. We implemented a Point of Care ROTEM® blood test for trauma patients who present and initiate a trauma activation. ObjectivesThe aim of this study was to undertake an evaluation of the implementation data to identify factors which helped and hindered this new practice. MethodsA sequential mixed-methods design was conducted to evaluate intervention implementation. The intervention was designed with interprofessional collaboration and incorporated education and skills training supplemented with a decision aide. Patients aged ≥ 18 years who met the trauma activation criteria were included. Data collection occurred throughout the 21-month implementation period inclusive of initial roll out, maintenance and sustainability and include the number of ROTEM® blood tests taken and clinical characteristics of patients. Individual interviews were conducted with health professionals with experience of the intervention after the implementation period was complete. ResultsA total of 1570 eligible patients were included. The number of patients who had a ROTEM® blood test taken increased over time to 63%. The proportion of patients having a ROTEM® blood test obtained was higher for major trauma patients (n=162, 66.9%) who were admitted to the Intensive Care Unit. Regression analysis found trauma service presence on arrival and the sustainability phase of implementation increased the likelihood of having a ROTEM® taken. Qualitative data suggest that a more tailored approach to intervention implementation would assist with adoption. ConclusionImplementation of new practice requires careful planning and should be undertaken with input from end-users. Continuous evaluation is necessary to support ongoing implementation and sustainability. To ensure effective implementation occurs, complex interventions need to be made workable and integrated in everyday health care practice.

Massive Transfusion Activations in Non-Trauma Patients.

Massive transfusion activations (MTAs) are commonly used in the care of the trauma patient. However, MTA for trauma patients constitutes only a small fraction of MTA at our institution. The aim of this study was to characterize MTA in non-trauma patients to better understand how this strategy is employed at a larger tertiary hospital. All MTA involving non-trauma patients from January 2017 to April 2019 were reviewed. Patients with unclear indications for MTA were excluded. Data collected included patient demographics, reason for MTA, transfusion ratios, use of adjunctive antifibrinolytics, use of viscoelastic testing, and vasopressor administration at the time of MTA. There were 328 patients and 353 MTA identified over the study period. The mean age was 52.0years and 40.9% were male. Patients were most commonly under the care of a medical service (55.2%), while 25.3% were obstetric patients and 19.5% were surgical patients. Compliance with 1:1:1 transfusion ratios was low. Concomitant vasopressor use was high (70.8%), while antifibrinolytic agents (13.0%) and viscoelastic testing (19.0%) were used less commonly. The overall mortality of the study population was 56.1%. Massive transfusion activations are frequently used in non-trauma patients. There was a low rate of adherence to 1:1:1 transfusion ratios as well as utilization of adjuncts and tools that could allow for targeted resuscitation. Understanding practice patterns relating to MTA may allow for an opportunity for improvement.

The National Blood Shortage-An Impetus for Change.

The National Blood Shortage-An Impetus for Change.

Hemostasis testing in patients with liver dysfunction: Advantages and caveats.

Due to concomitant changes in pro- and anti-coagulant mechanisms, patients with liver dysfunction have a “rebalanced hemostasis”, which can easily be tipped toward either a hypo- or a hypercoagulable phenotype. Clinicians are often faced with the question whether patients with chronic liver disease undergoing invasive procedures or surgery and those having active bleeding require correction of the hemostasis abnormalities. Conventional coagulation screening tests, such as the prothrombin time/international normalized ratio and the activated partial thromboplastin time have been demonstrated to have numerous limitations in these patients and do not predict the risk of bleeding prior to high-risk procedures. The introduction of global coagulation assays, such as viscoelastic testing (VET), has been an important step forward in the assessment of the overall hemostasis profile. A growing body of evidence now suggests that the use of VET might be of significant clinical utility to prevent unnecessary infusion of blood products and to improve outcomes in numerous settings. The present review discusses the advantages and caveats of both conventional and global coagulation assays to assess the risk of bleeding in patients with chronic liver disease as well as the current role of transfusion and hemostatic agents to prevent or manage bleeding.

The Practicality of Viscoelastic Testing in Acute Hemorrhage to Guide Appropriate Transfusion Management

Abstract Introduction/Objective Acute hemorrhage often leads to multiple blood product transfusions and warrants efficient and dependable laboratory tests to elucidate the etiology for appropriate transfusion management. Conventional coagulation tests (aPPT, PT, INR, platelet count, fibrinogen) are inexpensive and have minimal labor requirements, but have slow turnaround times and may not accurately represent in vivo coagulopathies leading to inappropriate use of transfusion products, which in turn may lead to increased adverse events and mortality. Viscoelastic testing (VET) overcomes some of the disadvantages of conventional coagulation tests, but is not without its own limitations. This case study will summarize the advantages and disadvantages of VET by presenting two cases to highlight clinical situations in which VET is used and its impact on guiding management and clinical outcomes. Methods/Case Report We present 2 cases of acute hemorrhage to illustrate the importance of correct interpretation of VET in the appropriate clinical setting. Case 1 features a clinical situations in which TEG was misinterpreted due to lack of communication with the laboratory while Case 2 presents an acute hemorrhage situation in which Rapid TEG was used to guide transfusion strategy. While VET has many advantages in acute hemorrhage, clinicians must be aware of the disadvantages and the potential for misinterpretation of data. Results (if a Case Study enter NA) NA Conclusion VET is useful in acute hemorrhage if its functionality is understood and interpretation is correct. Appropriate use of VET may lead to effective transfusion management and improve clinical outcomes. However, it is imperative clinicians are aware of the limitations of VET when making clinical decisions. VET can only improve patient outcomes if it is used in the proper clinical situation and with proper interpretation of the data. Appropriate use of VET has the potential to improve transfusion management and ultimately lead to better patient outcomes.

Analysis of Viscoelastic Testing in Pediatric Patients Using the Pediatric Extracorporeal Membrane Oxygenation Outcomes Registry.

Use of viscoelastic tests (VETs), including thromboelastography (TEG) and rotational thromboelastometry (ROTEM), is increasing in the management of anticoagulation in extracorporeal membrane oxygenation (ECMO) patients. A retrospective review of data on 265 pediatric (<20 years old) ECMO patients who underwent VET and were submitted to the Pediatric ECMO Outcomes Registry (PEDECOR) was conducted to describe common coagulopathies in patients who underwent VET; associations between the VET parameters and traditional tests of coagulation; and comparisons in blood product usage in patients who underwent VET with those who did not. We calculated patient-level summary statistics and assessed differences between the groups using χ2 tests (categorical variables) and Kruskal-Wallis and Wilcoxon rank-sum tests (continuous variables). Viscoelastic test was utilized in 77% of patients in the analysis. Platelet dysfunction was the most common abnormality identified by TEG (30.8%) and ROTEM (9.7%). Bleeding patients who had VET performed received more cryoprecipitate transfusions than those who did not have VET (VET median = 9.7 ml/kg; interquartile range (IQR) = 4.3-22.0 ml/kg vs. no VET median = 5.1 ml/kg; IQR = 0-10.4 ml/kg; p = 0.0013). Given the growing use of VET in pediatric ECMO patients, further studies evaluating VET in managing complications as well as aiding in titration of anticoagulation therapy are needed.

Advances in anesthetic and obstetric management of patients with placenta accreta spectrum.

The incidence of placenta accreta spectrum is increasing and it is a leading cause of peripartum hysterectomy and massive postpartum hemorrhage. The purpose of the present article is to provide a contemporary overview of placenta accreta spectrum pertinent to the obstetric anesthesiologist. Recent changes in the terminology used to report invasive placentation were proposed to clarify diagnostic criteria and guidelines for use in clinical practice. Reduced morbidity is associated with scheduled preterm delivery in a center of excellence using a multidisciplinary team approach. Neuraxial anesthesia as a primary technique is increasingly being used despite the known risk of major bleeding. The use of viscoelastic testing and endovascular interventions may aid hemostatic resuscitation and improve outcomes. Accurate diagnosis and early antenatal planning among team members are essential. Obstetric anesthesiologists should be prepared to manage a massive hemorrhage, transfusion, and associated coagulopathy. Increasingly, viscoelastic tests are being used to assess coagulation status and the ability to interpret these results is required to guide the transfusion regimen. Balloon occlusion of the abdominal aorta has been proposed as an intervention that could improve outcomes in women with placenta accreta spectrum, but high-quality safety and efficacy data are lacking.

Application of Viscoelastic testing to the field of Otolaryngology Head and Neck Surgery: A Scoping Review

Background: &#x0D; In Otolaryngology Head and Neck Surgery (OHNS), hematologic management requires attention to the intricate nature of hemostatic competence. Elderly patients can experience drug induced coagulopathies. Strategies are needed in order to minimize hemorrhagic and thromboembolic risk and maximize positive outcomes. Viscoelastic tests (VETs) such as Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) have been used to guide blood component therapy. The purpose of this scoping review is to understand the utilization of VETs in OHNS. &#x0D; &#x0D; Methods: &#x0D; &#x0D; This scoping review included studies that discussed the utilization of VETs in the field of OHNS. The inclusion criteria was studies that discussed the application of VETs in Flap/Plastic Reconstruction, Facial Trauma/Resuscitation, Tonsillectomy, Obstructive Sleep Apnea (OSA), Epistaxis, Sinus Surgery, and HNC Resection. Studies that focused on general medical VET use were not included. &#x0D; &#x0D; Results: &#x0D; &#x0D; Fourteen articles met the study inclusion criteria from an initial pool of 45 articles. Seven articles discussed the use of VETs in free flap/reconstructive surgery, five articles explored use in HNC, two articles discussed use in facial trauma and resuscitation, one article mentioned use in OSA, and one article examined use in epistaxis. &#x0D; &#x0D; Conclusion and potential impact: &#x0D; &#x0D; Of the fourteen articles included, two articles found no clinically significant association between TEG parameters and flap loss or complications. Five studies found that TEG or ROTEM helpful in predicting coagulation clotting, a prothrombotic state, or a hyperfibrinolytic state in free flap and HNC patients. For facial trauma and HNC cancer patients two different studies found ROTEM helpful in guiding blood component resuscitation. Using the TEG, one study demonstrated a hypercoagulable state in OSA patients. This review encourages wider use of VETs in OHNS in order to monitor hemostasis and improve surgical outcomes. Further research is necessary to better understand how VETs can tailor hematologic management of OHNS patients.

Comparison of the Quantra QPlus System With Thromboelastography in Cardiac Surgery

Use of viscoelastic testing, such as thromboelastography (TEG), is recommended in cardiac surgery to monitor coagulation and to guide the transfusion of blood products. The Quantra QPlus System is a novel point-of-care platform that uses ultrasonic pulses to characterize dynamic changes in viscoelastic properties of a blood sample during coagulation. Despite the ability to assess similar aspects of clot formation, limited studies addressing the interchangeability of viscoelastic testing parameters exist. The primary aim of the present study was to assess the correlation and agreement between Quantra and TEG5000 results using blood samples from cardiac surgery patients. Tertiary care, academic medical center. Prospective observational study. Twenty-eight patients undergoing elective cardiac surgery undergoing cardiopulmonary bypass were evaluated. Perioperative blood samples were collected and assessed using Quantra, and results were compared with TEG and conventional coagulation testing. Method comparison analysis demonstrated that Quantra parameters (Quantra clot time, clot stiffness, and fibrinogen contribution to clot stiffness) significantly correlated with TEG R and TEG G after induction of anesthesia, during cardiopulmonary bypass, and after rewarming (rs = 0.83, rs = 0.84, and rs = 0.73, respectively). However, Quantra parameters demonstrated poor agreement compared with equivalent TEG5000 parameters. The Quantra QPlus System significantly correlated with TEG5000, suggesting that this test may be used in a similar clinical context. Despite the strength of correlation between Quantra and TEG parameters, measurements are not interchangeable.

Assessment of platelet function utilizing viscoelastic testing.

Assessment of platelet function utilizing viscoelastic testing.

Viscoelastic testing in pediatric patients.

A tailored transfusion algorithm based on viscoelastic testing in the perioperative period or in trauma patients is recommended by guidelines for bleeding management. Bleeding management strategies in neonates and children are mostly extrapolated from the adult experience, as published evidence in the youngest age group is scarce. This manuscript is intended to give a structured overview of what has been published on the use of viscoelastic testing to guide bleeding management in neonates and children. Several devices that use either the traditional viscoelastic method or resonance viscoelastography technology are on the market. Reference ranges for children have been evaluated in only some of them. As most of the hemostasis maturation processes can be observed during the first year of life, adult reference ranges for viscoelastic testing could be applied over the age of 1 year. The majority of the published trials in children are based on retrospective analyses describing the correlation between viscoelastic testing and standard laboratory testing or focusing on the prediction of bleeding. Clinically more relevant studies in pediatric patients undergoing cardiac surgery have demonstrated that the implementation of a transfusion algorithm based on viscoelastic testing has significantly reduced transfusion requirements and that this approach has enabled a rapid detection of coagulation disorders in the presence of excessive bleeding. Although further studies are urgently needed, experts have reviewed the use of a transfusion algorithm based on viscoelastic testing in children as a feasible approach, as it has been shown to improve bleeding management and rationalize blood product transfusion.