Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis
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Blood Coagul. Fibrinolysis · Mar 2010
Discard volume necessary for elimination of heparin flush effect on thromboelastography.
Heparin is commonly used to prevent obstruction of indwelling arterial catheters with blood clots. It is known to affect the outcomes of analysis of coagulation parameters with thromboelastography (TEG); therefore, it has been recommended to neutralize its effect with heparinase. However, heparinase may also neutralize the effect of low molecular weight heparin and endogenous heparinoids present in critically ill patients and thus yields unreliable results. ⋯ This was obvious from an increase in alpha angle and maximal amplitude of the measured clot and a decrease in R and time to maximal amplitude of the measured clot (P < 0.001). However, values obtained after discarding 4, 5 and 10 ml of blood did not differ markedly. To obtain valid information about TEG parameters, it is necessary to discard volume of at least 4 ml of blood (i.e., five times the volume of catheter dead space).
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Blood Coagul. Fibrinolysis · Mar 2010
Hypocoagulability, as evaluated by thrombelastography, at admission to the ICU is associated with increased 30-day mortality.
Thrombelastography (TEG), a cell-based whole blood assay, may better reflect haemostatic competence than conventional coagulation assays and this was therefore evaluated including the clot forming parameters: R, angle and maximal amplitude in patients at ICU admission. This was a prospective, observational study of patients admitted to a general ICU at a tertiary care university hospital with an expected stay of more than 24 h. Blood samples for TEG and standard coagulation analysis were obtained at admission. ⋯ Hypocoagulability at admission as evaluated by TEG was an independent risk factor for 30-day mortality [adjusted odds ratio (OR) 3.5; 95% confidence interval (CI) 1.7-7.1]. Hypocoagulability as evaluated by TEG was frequent at admission in general ICU patients and associated with a higher rate of ventilator treatment, higher rate of renal replacement therapy and a higher use of blood products. Hypocoagulability is an independent risk factor for 30-day mortality.
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Blood Coagul. Fibrinolysis · Mar 2010
Case ReportsCerebral venous thrombosis initially presenting with left occipital hemorrhage and headache.
Cerebral venous thrombosis (CVT) can be difficult to diagnose because of its wide spectrum of clinical manifestations. In the present article, we report a 58-year-old man coming to our emergency department presenting with left temporal throbbing headache and right hemianopia. Computed tomography of the brain revealed acute hemorrhages over the left occipital area. ⋯ He received anticoagulant therapy for 6 months and the headache subsided. We feel that a high index of clinical suspicion is needed to diagnose an intracerebral hemorrhage in an uncommon site caused by CVT, even if risk factors of CVT are not present, so that appropriate treatment can be initiated as promptly as possible. Failure to recognize the signs of CVT could result in inappropriate management and suboptimal secondary prophylaxis strategies, which could affect the patient's clinical outcome.
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Blood Coagul. Fibrinolysis · Jan 2010
Randomized Controlled TrialLow-molecular-weight heparin and unfractionated heparin in prophylaxis against deep vein thrombosis in critically ill patients undergoing major surgery.
The objective of the present study was to compare the efficacy and safety of low-dose unfractionated heparin (UFH) and a low-molecular-weight heparin (LMWH) as prophylaxis against venous thromboembolism in critically ill surgical patients undergoing major surgery. This was a randomized prospective study in which critically ill patients scheduled to undergo major elective surgery were allocated to receive subcutaneously either LMWH once daily and a placebo injection containing sterile 0.9% normal saline or 5000 IU UFH twice daily subcutaneously. Each patient was evaluated postoperatively clinically and confirmed by Doppler study for development of deep vein thrombosis (DVT). ⋯ However, minor hemorrhagic complications such as wound hematoma and surgical site bleeding were significantly more in the heparin group as compared with the LMWH group. Both UFH 5000 units subcutaneously twice daily and LMWH 40 mg once daily provide highly effective and well tolerated prophylaxis for critically ill surgical patients. Considering the advantage of once-daily dosing, a wider adoption of prophylaxis with LMWH may be justified on the basis of patient acceptability and saving of nursing time.
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Blood Coagul. Fibrinolysis · Jan 2010
Comparative StudyCarbon monoxide releasing molecule-2 increases the velocity of thrombus growth and strength in hemophilia A, hemophilia B and factor VII-deficient plasmas.
Carbon monoxide derived from carbon monoxide releasing molecules (CORMs) has been demonstrated to enhance normal plasma thrombus speed of growth and strength in vitro. We tested the hypothesis that tricarbonyldichlororuthenium (II) dimer (CORM-2) improves the velocity of formation and strength of hemophiliac plasma thrombi as determined by thrombelastography. Plasma deficient (<1% normal activity) in factor VIII (FVIII; n = 11 individuals), factor IX (FIX; n = 5 individuals) or factor VII (FVII; n = 4 individuals) was exposed to 0 or 100 micromol CORM-2, with coagulation initiated with tissue factor. ⋯ Lastly, CORM-2 exposure increased FVII-deficient plasma velocity of formation (45%) and strength (63%). CORM-2 markedly enhanced the velocity of clot growth and strength in hemophiliac plasma. These findings serve as the rationale to determine whether CORMs could be utilized as hemostatic agents.