PREFACE Global Hemostasis: New Approaches to Patient Diagnosis and Treatment Monitoring Welcome to this special issue of Seminars in Thrombosis and Hemostasis. Characteristically, each new issue is devoted to a particular theme of relevance to thrombosis and hemostasis. The current issue focuses on new approaches to patient diagnosis and treatment monitoring of global hemostasis. The concept and application of global hemo- stasis has been with us for some time and is now undergoing resurgence due to renewed interest and improved methodologies and instrumentation. This is perhaps best reflected by thromboelastography (TEG), which considers most aspects of hemostasis, including coagulation as well as the fibrinolytic components. Hence this methodology is the primary focus of the current issue. In addition, global hemostasis can be represented by other methodologies, such as thrombin generation and overall hemostasis potential, and a selection of articles covering these topics is also in- cluded in this issue. Standardization is critical when it comes to global hemostatic tests, particularly in clinical scenarios where decision making regarding diagnosis and management is of utmost importance. Accordingly, this issue includes a selection of articles that deal with standardization issues, quality assurance, and quality control from different perspectives. These approaches, for global hemostatic tests as well as other tests of hemostasis, validate test performance and ensure that results are correct. Because tissue factor is a key player in triggering hemostasis, this issue also provides an article discussing the contribution of tissue factor to global hemostatic assays. In the area of global hemo- stasis, animal studies have contributed greatly to our understanding of TEG and other global hemostatic assays and have highlighted the value of such studies at both clinical and experimental levels, so this issue also includes an overview of the veterinary experience for TEG. Some of the more critical areas for TEG are its utilization in trauma patients, pregnancy and its com- plications, and potentially in hemophilia monitoring. Accordingly, this issue offers selected articles in cover these specific areas. As guest editor for this issue, I hope you make the most of this ‘‘global dose’’ of hemostasis and find this update both profitable and enjoyable. Wegner and Popovsky 1 begin this issue with the critical statement that in hemostasis ‘‘one size does not fit all.’’ Indeed, using TEG (a vesicohemostatic assay [VHA] available since 1948) 2 is quite different than other conventional tests because it monitors the various phases of clot formation and lysis time from the time of initial clot formation, including the rate of clot develop- ment, maximum clot strength, and clot lysis. This provides the clinician with a tool for making informed therapeutic decisions. Currently, two VHA devices are available for clinical use, the TEG (Thromboelasto- graph; Haemoscope Corp., Niles, IL, USA) and the ROTEM (Rotation Thromboelastometer; Pentapharm GmbH, Munich, Germany). Both devices measure the changes in a clot’s physical properties by monitoring the movement of a pin suspended in activated blood, but with some small technical differences. 3 Sample types and other modifiers play a role in the speed and type of kinetics of generation of a clot including tissue factor, kaolin and corn trypsin inhibitor. In addition to the standard technique, the TEG-based PlateletMapping assay (Haemoscope Corp., Niles, IL) discussed by the authors has helped predict the bleeding risk in acute cases by measuring platelet responsiveness to adenosine diphosphate while the patient receives drugs like clopi- dogrel. 4 The article provides a rich overview of the clinical application of TEG in bleeding and thrombotic disorders and projects this to improved decisions regard- ing the appropriate treatment of those hemostatic ab- normalities. The article that follows by Chitlur and Lusher 5 discusses the first serious worldwide effort toward standardization of TEG with respect to preanalytical and analytical factors. Up until 2005, a major criticism of this technology was that it is not well standardized and that different investigators use different techniques and sample modifiers that make comparison of data difficult. 6,7 Chitlur and Lusher update us on the work in progress in this regard. The article explains how the international TEG/ROTEM Working Group was formulated and provoked interest in performing standardization exercises. Twelve laboratories from 1 Professor, Laurentian University- St. Lawrence College Collaborative Program, and Assistant Professor, Department of Anatomy and Cell Biology, Queen’s University, Kingston, Ontario, Canada. Global Hemostasis: New Approaches to Patient Diagnosis and Treatment Monitoring; Guest Editor, Maha Othman, M.D., Ph.D. Semin Thromb Hemost 2010;36:695–698. Copyright # 2010 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. DOI: http://dx.doi.org/10.1055/s-0030-1265285. ISSN 0094-6176. 695 Downloaded by: Northwestern University. Copyrighted material.