Thromb Haemostasis
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Hypoxia and ischaemia influence blood coagulation and fibrinolysis. This study has been made to determine whether human cardiopulmonary arrest causes fibrin formation and reduction of fibrinolysis. Serial levels of fibrinopeptide A (FPA), fibrinopeptide B beta 15-42 (FPB beta 15-42), D-dimer, tissue plasminogen activator antigen concentration (t-PA antigen), t-PA activity, plasminogen activator inhibitor-1 antigen concentration (PAI-1 antigen), and PAI-1 activity were determined in 63 patients with out-of-hospital cardiopulmonary arrest. ⋯ At 24 h after admission, PAI-1 antigen and PAI-1 activity were significantly increased (472.2 +/- 145.5 ng/ml; p < 0.001 and 103.6 +/- 36.1 IU/ml; p < 0.001, respectively). In conclusion, during and after CPR in patients with out-of-hospital cardiac arrest, massive fibrin generation with consecutive impairment of fibrinolysis were observed. These fibrin-mediated events may have some role in the derangement of vital organ function after cardiac arrest.
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Randomized Controlled Trial Clinical Trial
More effective suppression of hemostatic system activation in patients undergoing cardiac surgery by heparin dosing based on heparin blood concentrations rather than ACT.
This study was designed to determine whether the maintenance of higher than usual patient-specific heparin concentrations during cardiopulmonary bypass (CPB) was associated with more effective suppression of hemostasis system activation. Thirty-one patients scheduled for repeat cardiac surgery or combined procedures (i.e., coronary revascularization + valve repair/replacement) were consented and enrolled in this study. All patients received porcine heparin and protamine and were randomly assigned to monitoring of anticoagulation by either celite ACT alone (Control, n = 16) or by kaolin ACT combined with on-site measurements of whole blood heparin concentration (Intervention, n = 15). ⋯ Percent decrease in complement 3 was greater in the control group after protamine and bleeding times measured in the Intensive Care Unit were significantly more prolonged in this group. Maintenance of higher patient-specific heparin concentrations during CPB more effectively suppresses excessive hemostatic system activation than do standard heparin doses chosen based on measurement of ACT. These findings may explain, at least in part, the significant reduction in perioperative blood loss and blood product use when higher heparin concentrations are maintained.
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Antiphospholipid antibodies (aPL) characterize patients at risk for both arterial and venous thrombotic complications. Recently it has been recognized that the presence of plasma proteins such as beta 2-glycoprotein I(beta 2 GPI) and prothrombin are essential for the binding of aPL to phospholipids and that these proteins are probably the real target of aPL. The discovery of these new antigens for aPL introduces the possibility of new assays to detect the presence of aPL. ⋯ For venous thrombosis LAC is the strongest risk factor (OR 6.55; 95% CI 2.36-18.17), but ACA-IgM above 20 MPL units also appeared to be a significant (p = 0.0159) risk factor (OR 3.90; 95% CI 1.29-11.80). Furthermore, the presence of anti-beta 2GPI- and/or anti-prothrombin-antibodies in LAC positive patients (n = 60) does not increase the risk for thrombosis. The results showed that (i) the LAC assay correlates best with a history of both arterial and venous thrombosis and (ii) neither the anti-beta 2GPI ELISA nor the anti-prothrombin ELISA gives additional information for a thrombotic risk in SLE patients.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Risk factors for bleeding during treatment of acute venous thromboembolism.
Identification of risk factors for bleeding and prospective evaluation of two bleeding risk scores in the treatment of acute venous thromboembolism. ⋯ A small body surface area and malignancy were associated with a higher frequency of bleeding. The bleeding risk scores merely offer the clinician a general estimation of the risk of bleeding. In patients with a small body surface area or in patients with malignancy, it may be of interest to study whether limited dose reduction of the anticoagulant drug may cause less bleeding without affecting efficacy.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
A multicenter randomized double-blind study of enoxaparin compared with unfractionated heparin in the prevention of venous thromboembolic disease in elderly in-patients bedridden for an acute medical illness. The Enoxaparin in Medicine Study Group.
A multicenter, randomized double-blind study compared in two parallel groups the efficacy and safety of a low molecular weight heparin (LMWH) enoxaparin 20 mg once daily, with unfractionated heparin (UFH) 5000 IU twice daily, administered subcutaneously for 10 days, in the prevention of venous thrombosis disease in 442 hospitalized elderly patients bedridden for an acute medical illness. The main efficacy endpoint was defined as the occurrence of venous thrombosis, diagnosed by a daily fibrinogen uptake test, and/or documented clinical pulmonary embolism. Intention-to-treat analysis of efficacy showed that the incidence of venous thromboembolic events was low: 4.8% (10/207) in the LMWH group (9 episodes of isotopic venous thrombosis and one of scintigraphic pulmonary embolism), and 4.6% (10/216) in the UFH group (10 episodes of isotopic venous thrombosis). ⋯ During the study period, 15 patients (3.4%) died (7 in the LMWH group and 8 in the UFH group): 2 sudden deaths, one in each group including one case in which pulmonary embolism could not be excluded since no autopsy was performed, and 13 others deaths unrelated to the study treatments. Six patients (1.4%) presented a bleeding complication: 2 (0.9%) in the enoxaparin group (one major and one minor hemorrhage), and 4 (1.8%) in the UFH group (2 major and 2 minor hemorrhages). These results indicate that subcutaneous enoxaparin 20 mg once daily for 10 days is as effective and well tolerated as subcutaneous UFH 5000 IU twice daily in the prevention of venous thromboembolic disease in bedridden elderly in-patients presenting an acute medical illness.