Hematology
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The identification and management of coagulopathy is a critical component of caring for the severely injured patient. Notions of the mechanisms of coagulopathy in trauma patients have been supplanted by new insights resulting from close examination of the biochemical and cellular changes associated with acute tissue injury and hemorrhagic shock. ⋯ Mechanisms contributing to TIC include anticoagulation, consumption, platelet dysfunction, and hyperfibrinolysis. This review discusses current understanding of TIC mechanisms and their relative contributions to coagulopathy in the face of increasingly severe injury and highlights how they interact to produce coagulation system dysfunction.
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Applying the principles of evidence-based medicine to febrile neutropenia (FN) results in a more limited set of practices than expected. Hundreds of studies over the last 4 decades have produced evidence to support the following: (1) risk stratification allows the identification of a subset of patients who may be safely managed as outpatients given the right health care environment; (2) antibacterial prophylaxis for high-risk patients who remain neutropenic for ≥7 days prevents infections and decreases mortality; (3) the empirical management of febrile neutropenia with a single antipseudomonal beta-lactam results in the same outcome and less toxicity than combination therapy using aminoglycosides; (4) vancomycin should not be used routinely empirically either as part of the initial regimen or for persistent fever, but rather should be added when a pathogen that requires its use is isolated; (5) empirical antifungal therapy should be added after 4 days of persistent fever in patients at high risk for invasive fungal infection (IFI); the details of the characterization as high risk and the choice of agent remain debatable; and (6) preemptive antifungal therapy in which the initiation of antifungals is postponed and triggered by the presence, in addition to fever, of other clinical findings, computed tomography (CT) results, and serological tests for fungal infection is an acceptable strategy in a subset of patients. Many practical management questions remain unaddressed.
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The antiphospholipid syndrome (APS) is defined by venous or arterial thrombosis and/or pregnancy morbidity in patients with persistent presence of antiphospholipid antibodies (aPLs). Catastrophic APS is the most severe form of APS, which is associated with rapid development of microvascular thrombosis resulting in multiorgan failure in patients with aPLs. Patients with APS and catastrophic APS are recognized to have a high risk of recurrent thrombosis that can occur despite anticoagulant therapy. ⋯ Recognizing that patients with APS have different thrombotic risk profiles may assist clinicians in assessing the risks and benefits of anticoagulation. The optimal type, intensity, and duration of anticoagulation in the treatment of APS remain controversial, particularly for arterial thrombosis and recurrent thrombosis. Future studies that delineate thrombotic risk in APS and evaluate current and novel anticoagulants as well as nonanticoagulant therapies are required.
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Over the past century, blood banking and transfusion practices have moved from whole blood therapy to components. In trauma patients, the shift to component therapy was achieved without clinically validating which patients needed which blood products. Over the past 4 decades, this lack of clinical validation has led to uncertainty on how to optimally use blood products and has likely resulted in both overuse and underuse in injured patients. ⋯ In addition, studies have shown that resuscitating with plasma (instead of crystalloid) repairs the "endotheliopathy of trauma," or the systemic endothelial injury and dysfunction that lead to coagulation disturbances and inflammation. Data from the Trauma Outcomes Group, the Prospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study, and the ongoing Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial represent a decade-long effort to programmatically determine optimal resuscitation practices, balancing risk versus benefits. With injury as the leading cause of death in patients age 1 to 44 years and hemorrhage the leading cause of potentially preventable death in this group, high-quality data must be obtained to provide superior care to the civilian and combat injured.
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Low-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach, gastric MALT lymphoma, is associated with Helicobacter pylori infection. The eradication of H pylori using antibiotics is successful in 60% to 80% of affected patients. In contrast to the previous paradigm, we and other investigators have shown that a certain proportion of patients with H pylori-positive early-stage diffuse large B-cell lymphoma (DLBCL) of the stomach with histological evidence of MALT lymphoma, including high-grade transformed gastric MALT lymphoma and gastric DLBCL(MALT), achieved long-term complete pathological remission (pCR) after first-line H pylori eradication therapy, indicating that the loss of H pylori dependence and high-grade transformation are separate events in the progression of gastric lymphoma. ⋯ In conclusion, a wide range of H pylori-related gastric lymphomas have been identified. The use of antibiotics as the sole first-line therapy for early-stage gastric pure DLBCL requires validation in a prospective study. The clinical and biological significance of the CagA oncoprotein in the lymphomagenesis of gastric MALT lymphoma warrants further study.