Seminars in thrombosis and hemostasis
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Sickle cell disease (SCD) is characterized by the presence of sickle hemoglobin, which has the unique property of polymerizing when deoxygenated. The pathophysiology of acute and chronic clinical manifestations of SCD have shown the central role of dense, dehydrated red cells in acute and chronic clinical manifestations of this pathology. ⋯ This review discusses, in the context of SCD, (1) abnormalities in the coagulation system, (2) perturbation of platelet activation and aggregation, (3) vascular endothelial dysfunction, (4) the contribution of cell inflammatory responses, and (5) the connection with nitric oxide metabolism. We also review the available studies on the therapeutic approaches in clinical management of hypercoagulability in SCD.
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Semin. Thromb. Hemost. · Apr 2011
Comparative StudyPrevention of venous thromboembolism: focus on mechanical prophylaxis.
Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a leading health-care problem whose pathogenesis is usually related to the so-called Virchow's triad and involves a variety of factors classified as inherited or acquired, predisposing, or triggers. The main goal of thromboprophylaxis is to reduce mortality and morbidity associated with VTE risk factors. Although striking evidence now indicates that the various pharmacological anticoagulant therapies can substantially lower the risk, this benefit might be offset by a small but definite risk of hemorrhage in some circumstances. ⋯ The main mechanism of action appears to be related to a milking (wavelike) effect to evacuate leg veins and reduce venous stasis because an effect on the enhancement of fibrinolysis remains unproven. Although the biological and clinical evidence suggests that graduate compression stockings are an effective, relatively cheap, and more comfortable thromboprophylactic measure, they appear less effective overall than intermittent pneumatic compression. In conclusion, although the preventive benefits of mechanical prophylaxis on VTE might be circumscribed to select medical and surgical settings, there appears to exist no clinical reason to discourage adoption of these measures when indicated.
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Semin. Thromb. Hemost. · Oct 2010
ReviewGlobal hemostasis in pregnancy: are we using thromboelastography to its full potential?
Pregnancy is a unique situation where significant physiological changes in all maternal organ systems take place. Most of these changes return to normal after delivery. During normal pregnancy the hemostatic balance changes in the direction of hypercoagulability, thus decreasing bleeding complications at time of delivery. ⋯ Despite the clear value as a test for monitoring hemostatic status of pregnancy-related complications, TEG is still underused for reasons such as poor awareness regarding the technique and interpretations, lack of full standardization, and the unavailability of large clinical studies. However, the fact remains that TEG is undoubtedly attractive to both researchers and clinicians, particularly in a point-of-care setting. We hope that much more investment is directed to TEG studies in both experimental and clinical fields to improve applications and promote use, especially with respect to clinical decision making in pregnancy-related complications.
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Semin. Thromb. Hemost. · Oct 2010
ReviewCoagulation abnormalities in the trauma patient: the role of point-of-care thromboelastography.
Current recommendations for resuscitation of the critically injured patient are limited by a lack of point-of-care (POC) assessment of coagulation status. Accordingly, the potential exists for indiscriminant blood component administration. Furthermore, although thromboembolic events have been described shortly after injury, the time sequence of post-injury coagulation changes is unknown. ⋯ Thromboelastography (TEG), a time-sensitive dynamic assay of the viscoelastic properties of blood, closely parallels the CBM, permitting timely, goal-directed restoration of hemostasis via POC monitoring of coagulation status. TEG-based therapy allows for goal-directed blood product administration in trauma, with potential avoidance of the complications resulting from overzealous component administration, as well as the ability to monitor post-injury coagulation status and thromboprophylaxis. This overview addresses coagulation status and thromboprophylaxis management in the trauma patient and the emerging role of POC TEG.
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Semin. Thromb. Hemost. · Oct 2010
ReviewClinical utility of thromboelastography: one size does not fit all.
Coagulation management requires the balancing of different components that contribute to clot formation. These components include the interactions between platelets, procoagulant, anticoagulant, and fibrinolytic factors. ⋯ In contrast, thromboelastography is a test that monitors the different phases of clot formation and lysis, providing the clinician with a tool for making informed therapeutic decisions. This review provides an overview of thromboelastography in the management of hypocoagulable and hypercoagulable conditions.