Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis
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Blood Coagul. Fibrinolysis · Sep 2008
A prospective analysis of heparin-platelet factor 4 antibodies in pregnant women treated with the low-molecular-weight heparin, dalteparin.
Indications for heparin during pregnancy are expanding. Heparin-induced thrombocytopenia caused by heparin-platelet factor 4 antibodies (HPF4-As), however, remains a serious concern. While up to 50% of cardiovascular surgical patients develop HPF4-As while receiving heparin, the rate of seroconversion is lower in medical patients, suggesting an impact of the patient population on the underlying immune response. ⋯ Throughout the study no thromboembolic event occurred, and in none of the patients was HPF4-As seroconversion noted. A prolonged drop in platelets to less than 50% from baseline was observed in one case (3%) after 35 weeks of treatment, which spontaneously resolved after child delivery. These findings suggest that long-term thromboprophylaxis with low-molecular-weight heparin is associated with a low rate of HPF4-As seroconversion in pregnancy.
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Blood Coagul. Fibrinolysis · Sep 2008
Safety and efficacy of lower-dose unfractionated heparin for prophylaxis of deep vein thrombosis and pulmonary embolism in an Asian population.
The objective of this study is to analyze the tolerance and efficacy of the subcutaneous administration of a reduced 2,500-unit low-dose unfractionated heparin given for an efficacious, yet Asian population-sensitive, prophylaxis for deep vein thrombosis and fatal pulmonary embolism. Eighty-seven Japanese patients were operated on either for abdominal or pelvic complications or both, as well as for gynecologic conditions including ovarian, cervical, and corpus cancers. Thirty-two of the patients were administered the experimental low dose of unfractionated calcium heparin for prophylaxis. ⋯ However, three (3/55; 6%) of the patients in the no-heparin group suffered a symptomatic pulmonary embolism, although none were fatal. There were no pulmonary embolism onsets in the heparin prophylaxis group. We feel that we have provided evidence that several serious complications, such as perisurgical hemorrhage, deep vein thrombosis, fatal pulmonary embolism, and increased postoperative recovery times, can be prevented by prophylaxis with 2,500-unit low-dose unfractionated heparin.
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Blood Coagul. Fibrinolysis · Sep 2008
Comparative StudyA comparison of kaolin-activated versus nonkaolin-activated thromboelastography in native and citrated blood.
Thromboelastography can be performed with native or citrated blood (a surrogate to native blood in healthy controls, surgical and cirrhotic patients). Activators such as kaolin are increasingly used to reduce the time to trace generation. To compare kaolin-activated thromboelastography with nonkaolin-activated thromboelastography of native and citrated blood in patients with liver disease, patients undergoing treatment with warfarin or low-molecular weight heparin and healthy volunteers. ⋯ For all thromboelastography parameters, correlation was poor (Spearman correlation coefficient < 0.70) between nonkaolin-activated and kaolin-activated thromboelastography, for both citrated and native blood. In healthy volunteers, in patients with liver disease and in those receiving anticoagulant treatment, there was a poor correlation between nonkaolin-activated and kaolin-activated thromboelastography. Kaolin-activated thromboelastography needs further validation before routine clinical use in these settings, and the specific methodology must be considered in comparing published studies.
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Blood Coagul. Fibrinolysis · Sep 2008
Comparative StudySpectrum of changes in endogenous thrombin potential due to heritable disorders of coagulation.
The modern thrombin generation tests describe different phases of generation of thrombin that is initiation, amplification and inhibition of thrombin generation as well as the integral amount of generated thrombin. We investigated 55 patients with congenital deficiencies of different coagulation factors and analysed the relationship between the nature and the concentration of clotting factors, with different parameters of thrombin generation curve that is lag time, peak, time to peak and the area under curve or endogenous thrombin potential. The endogenous thrombin potential was unaffected by severe deficiency of factors XI and XII, and reduced in factor IX, VII and factor V and VIII deficiencies. ⋯ Bleeding symptoms were restricted to epistaxis and ecchymosis when thrombin generation was more than 90% of the normal. In the cases of combined deficiency of factors V and VIII all the values were intermediate as they exhibit mild deficiencies of both factors V and VIII and correlated well with the clinical symptoms. Endogenous thrombin potential of inherited isolated deficiencies of coagulation factors may thus provide an interesting insight about involvement of the deficient factor(s) at different phases of thrombin generation.