Seminars in hematology
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Seminars in hematology · Jan 2004
ReviewChallenges for providing effective hemostasis in surgery and trauma.
Vascular injury, whether surgical or traumatic, triggers a complex series of regulatory events. The understanding of these events, their interdependence, and their effect on hemostasis and thrombosis, is slowly being unraveled. The current understanding of these processes is reviewed in this paper. ⋯ Hence, the initial treatment of patients with severe hemorrhage relies on improving the patient's physiological status and on basic surgical techniques. Should these efforts fail, then a number of topical hemostatic agents, selective inhibitors of fibrinolysis, and procoagulant molecules, such as recombinant factor VIIa, may be utilized. However, many of these agents have not yet been tested in clinical trials and studies are urgently needed to determine efficacy, safety, optimal dosage and time of administration.
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Seminars in hematology · Jan 2004
The Oklahoma Thrombotic Thrombocytopenic Purpura-Hemolytic Uremic Syndrome (TTP-HUS) Registry: a community perspective of patients with clinically diagnosed TTP-HUS.
The Oklahoma Thrombotic Thrombocytopenic Purpura-Hemolytic Uremic Syndrome (TTP-HUS) Registry enrolls all consecutive patients for whom plasma exchange treatment is requested for clinically diagnosed TTP-HUS within a defined geographic region. During 14.5 years, from January 1, 1989 until June 30, 2003, 301 patients have been enrolled; follow-up is complete on 300 patients. Clinical categories have been designated based on associated conditions and potential etiologies; presenting features and clinical outcomes have been defined to allow comparisons between groups. ⋯ The presenting features and clinical outcomes of patients with severe ADAMTS-13 deficiency were heterogeneous and not distinct from patients without severe ADAMTS-13 deficiency. These data suggest that severe ADAMTS-13 deficiency does not detect all patients who may be appropriately diagnosed with TTP-HUS and who may respond to plasma exchange treatment. Prospective data from consecutive patients are essential to translate new observations on pathogenesis into improved patient care.
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Seminars in hematology · Jan 2004
ReviewStrategies for minimizing blood loss in orthopedic surgery.
Several major orthopedic surgical procedures including hip arthroplasty, femoral osteotomy, and spinal fusion may result in significant blood loss and the need for allogeneic blood transfusions. Due to the heightened awareness of the potential deleterious effects of allogeneic blood product administration, several techniques have been evaluated to determine their efficacy in limiting perioperative blood loss. ⋯ These techniques include: general considerations, autologous transfusion therapy, intraoperative and postoperative blood salvage, pharmacologic manipulation of the coagulation cascade, and controlled hypotension. Undoubtedly, many of these techniques are effective alone; however, the goal of performing major orthopedic surgical procedures without the use of allogeneic blood products can only be accomplished by combining several of these techniques.
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Seminars in hematology · Jan 2004
ReviewThe management of coagulopathy and blood loss in liver surgery.
Liver surgery has long been associated with massive perioperative blood loss and high rates of postsurgery morbidity and mortality. Recent advances in our knowledge of hepatic segmental anatomy have led to the evolution of liver resection, and a growing awareness of the coagulopathy present in cirrhotic patients has produced a greater understanding of the factors influencing surgical hemostasis. ⋯ The potential role of recombinant factor VIIa (rFVIIa) in providing safe hemostasis during such procedures will also be explored. Today, due to careful monitoring and correction of coagulopathy, improved surgical techniques, and judicious patient selection, liver surgery is no longer a high-risk specialty with an unfavorable risk profile, but a safe and widely practiced procedure.
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Seminars in hematology · Jan 2004
von Willebrand factor-cleaving protease (ADAMTS-13) activity determination in the diagnosis of thrombotic microangiopathies: the Swiss experience.
Severe deficiency of von Willebrand factor (VWF)-cleaving protease (ADAMTS-13) activity (<5% of normal) is a specific finding for acute idiopathic thrombotic thrombocytopenic purpura (TTP), a disorder that presents as thrombocytopenia, microangiopathic hemolytic anemia, and often organ dysfunction such as neurological disturbances or renal failure, and fever. Between January 2001 and July 2003, ADAMTS-13 activity was determined in plasma samples of 396 consecutive patients referred to our laboratory for diagnostic purposes. Plasma samples with ADAMTS-13 activity less than 5% were in addition tested for the presence of inhibitory antibodies. ⋯ Forty-three (62%) patients with ADAMTS-13 activity less than 5% displayed inhibitory antibodies. Severe ADAMTS-13 deficiency was found in 60% of patients diagnosed with acute idiopathic TTP, but in none of 130 patients diagnosed with HUS or in any of the 14 patients with hematopoietic stem cell transplantation-associated TMA. Thus, plasma ADAMTS-13 activity less than 5% does not identify all patients clinically diagnosed with TTP, and severe ADAMTS-13 deficiency is not invariably associated with clinical manifestations of microvascular platelet clumping.