Coagulation Concepts Update

Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
American Journal of Roentgenology (Impact Factor: 2.74). 12/2009; 193(6):1656-64. DOI: 10.2214/AJR.08.2191
Source: PubMed

ABSTRACT OBJECTIVE: Since the previous comprehensive radiology review on coagulation concepts that was done in 1990, many studies have been published in the medical and surgical literature that can guide the approach of a radiology practice. The purpose of this article is to provide an analysis of these works, updating the radiologist on proper use and interpretation of coagulation assessment tools, medications that modify the hemostatic system, and the use of transfusions prior to interventions. CONCLUSION: The basic tools for coagulation assessment have not changed; however, results from subspecialty research have suggested ways in which the use of these tools can be modified and streamlined to safely reduce time and expense for the patient and the health care system.

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    ABSTRACT: OBJECTIVE. The purpose of this study was to compare hematoma formation after breast core needle biopsy performed on patients undergoing and those not undergoing concurrent antithrombotic therapy. SUBJECTS AND METHODS. A prospective assessment of core needle biopsies (stereotactic, ultrasound guided, or MRI guided) performed on patients enrolled between September 2011 and July 2012 formed the basis of this study. Postprocedure mediolateral and craniocaudal mammograms were evaluated for the presence and size of hematomas. Patients were clinically evaluated for complications 24-48 hours after the procedure through telephone call or face-to-face consultation. Needle size, type of biopsy, and presence of hematoma and documented complications were correlated with use of antithrombotic agents (including aspirin, warfarin, clopidogrel, and daily nonsteroidal antiinflammatory medications). RESULTS. No clinically significant hematomas or bleeding complications were found. Eighty-nine of 617 (14.4%) non-clinically significant hematomas were detected on postprocedure mammograms. The probability of development of a non-clinically significant hematoma was 21.6% for patients taking antithrombotics and 13.0% for those not taking antithrombotics. Concurrent antithrombotic therapy and larger needle gauge were significant factors contributing to the probability of hematoma formation. The volume of the hematoma was not related to needle gauge or presence of antithrombotic therapy. CONCLUSION. No clinically significant hematomas were found. Because there are potential life-threatening risks to stopping antithrombotic therapy before breast biopsy, withholding antithrombotic therapy for core needle breast biopsy is not recommended because the incidence of non-clinically significant hematoma is low.
    American Journal of Roentgenology 07/2013; 201(1):215-22. DOI:10.2214/AJR.12.9930 · 2.74 Impact Factor
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    ABSTRACT: Transfusion in trauma is often empiric or based on traditional lab tests. Viscoelastic tests such as thromboelastography (TEG®) and rotational thromboelastometry (ROTEM®) have been proposed as superior to traditional lab tests. Due to the similarities between the two tests, general opinion seems to consider them equivalent with interchangeable interpretations. However, it is not clear whether the results can be similarly interpreted. This review evaluates the comparability between TEG and ROTEM and performs a descriptive review of the parameters utilized in each test in adult trauma patients. PUBMED database was reviewed using the keywords "thromboelastography" and "compare", between 2000 and 2011. Original studies directly comparing TEG® with ROTEM® in any area were retrieved. To verify the individual test parameter used in studies involving trauma patients, we further performed a review using the keywords "thromboelastography" and "trauma" in the PUBMED database. Only 4 studies directly compared TEG® with ROTEM®. One in liver transplantation found that transfusion practice could differ depending on the device in use. Another in cardiac surgery concluded that all measurements are not completely interchangeable. The third article using commercially available plasma detected clinically significant differences in the results from the two devices. The fourth one was a head-to-head comparison of the technical aspects. The 24 articles reporting the use of viscoelastic tests in trauma patients, presented considerable heterogeneity. Both tests are potentially useful as means to rapidly diagnose coagulopathy, guide transfusion and determine outcome in trauma patients. Differences in the activators utilized in each device limit the direct comparability. Standardization and robust clinical trials comparing the two technologies are needed before these tests can be widely recommended for clinical use in trauma.
    World Journal of Emergency Surgery 08/2012; 7 Suppl 1(Suppl 1):S3. DOI:10.1186/1749-7922-7-S1-S3 · 1.06 Impact Factor
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    ABSTRACT: Thromboelastography (TEG) measures the effects of antithrombotic agents by assessing global functional clotting status by evaluating the viscoelastic properties of in vitro clot formation. Recently, rapid TEG (r-TEG), which uses tissue factor in addition to standard kaolin to accelerate activation of the clotting cascade, has been proposed to obtain more immediate results. The correlation between results of TEG or r-TEG with international normalized ratio (INR) in patients on vitamin K antagonist (VKA) therapy has not been explored and represents the aim of this study. Patients on chronic therapy with VKAs (n = 100) were included in an observational prospective pharmacodynamic study. The correlation between TEG parameters, in particular markers of thrombus generation [Reaction time (R), maximum rate of thrombus generation (MRTG), and time to maximum rate of thrombus generation (TMRTG)], and INR values as well as the concordance between these parameters and therapeutic INR ranges were evaluated. In addition, in a subgroup of subjects (n = 17), the correlation of r-TEG parameters with TEG parameters and INR values was also assessed. No correlation was found between INR and TEG parameters of thrombus generation, in particular between INR and R (r = 0.189, p = 0.06), MRTG (r = -0.027, p = 0.79), and TMRTG (r = 0.188, p = 0.06). Further, no concordance was found between these parameters and recommended INR ranges. Significant Spearman correlations were found between INR and activated clotting time (rS = 0.546, p < 0.001), r-R (rS = 0.572, p = 0.017), and r-TMRTG (rS = 0.510, p = 0.037), but not r-MRTG (rS = 0.131, p = 0.617). Results were obtained in 24 ± 6 versus 12 ± 4 min with TEG and r-TEG, respectively (p < 0.001). In patients on chronic VKA therapy, TEG is not a useful tool to evaluate VKA anticoagulant effect, compared with standard INR measurements. However, r-TEG parameters of thrombus generation correlate with INR levels, suggesting a possible role of this assay for measuring more expeditiously anticoagulant treatment effects.
    Journal of Thrombosis and Thrombolysis 08/2014; DOI:10.1007/s11239-014-1130-1 · 2.04 Impact Factor