American journal of clinical pathology
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Am. J. Clin. Pathol. · Jul 2010
A novel thromboelastographic score to identify overt disseminated intravascular coagulation resulting in a hypocoagulable state.
Thromboelastography (TEM) yields a multitude of data that are complicated to analyze. We evaluated its value in identification of global coagulopathy in overt disseminated intravascular coagulation (DIC). We studied 21 patients, each with International Society for Haemostasis and Thrombosis scores of 5 or more (compatible with overt DIC) and less than 5 (suggestive of nonovert DIC), who underwent whole blood nonadditive TEM. ⋯ Individual TEM parameters correlated variably with conventional tests. Their combination into a cohesive TEM score possibly better captured the multiple hemostatic derangements occurring in DIC. The TEM score may bring objectivity to the analysis of TEM data.
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Am. J. Clin. Pathol. · Jul 2010
Case ReportsAutopsy findings in eight patients with fatal H1N1 influenza.
A novel H1N1 influenza A virus emerged in April 2009, and rapidly reached pandemic proportions. We report a retrospective observational case study of pathologic findings in 8 patients with fatal novel H1N1 infection at the University of Michigan Health Systems (Ann Arbor) compared with 8 age-, sex-, body mass index-, and treatment-matched control subjects. Diffuse alveolar damage (DAD) in acute and organizing phases affected all patients with influenza and was accompanied by acute bronchopneumonia in 6 patients. ⋯ Cytophagocytosis was seen in all influenza-related cases. The autopsy findings in our patients with novel H1N1 influenza resemble other influenza virus infections with the exception of prominent thrombosis and hemophagocytosis. The possibility of hemophagocytic syndrome should be investigated in severely ill patients with H1N1 infection.
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Elevated levels of circulating procoagulants like tissue factor may increase the risk of systemic coagulation activation, thrombin generation, and consumptive coagulopathy. I measured procoagulant activity in plasma by using a clot-based assay that incorporated normal plasma to replace missing factors, corn trypsin inhibitor to block contact activation, factor VIIa to improve sensitivity to tissue factor activity, and anti-tissue factor antibodies to measure tissue factor-specific activity. Procoagulant activity was evaluated in 58 trauma patients. ⋯ In control subjects, tissue factor activity was below the detection limit of the assay. Tissue factor activity was 3- to 4-fold higher in trauma patients with coagulopathy vs patients without coagulopathy (P = .002). Trauma patients with coagulopathy have increased circulating tissue factor activity.
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Am. J. Clin. Pathol. · Apr 2010
Comparative StudyComparison of plasma with whole blood prothrombin time and fibrinogen on the same instrument.
We compared plasma with whole blood (WB) international normalized ratio (INR) and fibrinogen using the same instrument and reagents. WBINRs were 50% higher than plasma INRs. After increasing the WB sample volume 40% and adjusting the International Sensitivity Index, WBINRs were similar to plasma INRs [adjusted WBINR = 0.99(plasma INR) - 0.02; r(2) = 0.98; n = 155], but the average difference in WB vs plasma INR was 4-fold higher than duplicate plasma INRs. ⋯ Accurate WB fibrinogen measurements required a mathematical hematocrit correction. We conclude that WBINR and fibrinogen assays can be performed on point-of-care or automated analyzers, but sample volume must be adjusted to account for hematocrit. Accuracy is limited by variations in hematocrit with worsening accuracy for samples with high INRs or low fibrinogen levels.
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Am. J. Clin. Pathol. · Mar 2010
Platelet count and prothrombin time help distinguish thrombotic thrombocytopenic purpura-hemolytic uremic syndrome from disseminated intravascular coagulation in adults.
Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) and disseminated intravascular coagulation (DIC) may have identical manifestations in adults. Because TTP-HUS is 90% fatal without plasma exchange, prompt diagnosis is essential. ⋯ A platelet count of less than 20 x 10(3)/microL (20 x 10(9)/L) and a PT within 5 seconds of the upper limit of the reference interval had a specificity of 92% for TTP-HUS. Our data confirm that readily available laboratory assays in the proper clinical scenario can increase the likelihood of TTP-HUS over DIC.