Posttraumatic Hemothorax and Pneumothorax in a Patient on Oral Anticoagulant

SummaryTreatment with streptokinase (‘Kabikinase’) was given to 26 patients with venographically confirmed deep vein thrombosis extending into the popliteal vein or above. Treatment was continued for 4 days and the patients were allocated randomly to oral anticoagulant therapy or a course of treatment with ancrod (‘Arvin’) for 6 days followed by oral anticoagulant therapy. The degree of thrombolysis as judged by further venographic examination at 10 days was not significantly different between the 2 groups. The majority of patients showed clinical improvement but there was no appreciable difference between the groups at 3 and 6 months. Haemorrhagic complications were a more serious problem during the period of treatment with ancrod than during the equivalent period in the control group.

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A Novel Functional Assay of Protein C in Human Plasma and fts Comparison with Amidolytic and Anticoagulant Assays

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648377 ◽

1992 ◽

Vol 67 (01) ◽

pp. 046-049 ◽

Cited By ~ 10

Author(s):

H A Guglielmone ◽

M A Vides

Keyword(s):

Oral Anticoagulant ◽

Protein C ◽

Activated Protein C ◽

Protein S ◽

Normal Subjects ◽

Test Sample ◽

Functional Assay ◽

Fast Method ◽

Factor Va ◽

Protein C Activity

SummaryA simple and fast method for the quantitative determination of protein C activity in plasma is here described. The first step consists in the conversion of protein C in the test sample into activated protein C by means of an activator isolated from Southern Copperhead venom. Subsequently, the degradation of factor Va, in presence of protein C-deficient plasma, is measured by the prolongation of the prothrombin time which is proportional to the amount of protein C in the sample. The dose-response curve showed a linear relationship from 6 to 150% protein C activity and the inter- and intra-assay reproducibility was 3.5% and 5.6% respectively. In normal subjects, a mean of protein C level of 98 ± 15% of normal pooled plasma was found. Comparison with the anticoagulant assay in samples of patients with oral anticoagulant, liver cirrhosis, disseminated intravascular coagulation and severe preeclampsia revealed an excellent correlation (r = 0.94, p <0.001). Also, a similar correlation (r = 0.93, p <0.001) existed between amidolytic assay and the method here proposed for all the samples studied without including the oral anticoagulant group. These results allowed us to infer that this method evaluates the ability of protein C to interact with protein S, phospholipids, calcium ions and factor Va.

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A Comparison of a Moderate with Moderate-high Intensity Oral Anticoagulant Treatment in Patients with Mechanical Heart Valve Prostheses

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656064 ◽

1997 ◽

Vol 77 (05) ◽

pp. 0839-0844 ◽

Cited By ~ 34

Author(s):

Vittorio Pengo ◽

Fabio Barbero ◽

Alberto Banzato ◽

Elisabetta Garelli ◽

Franco Noventa ◽

...

Keyword(s):

Heart Valve ◽

High Intensity ◽

Oral Anticoagulant ◽

Oral Anticoagulants ◽

Mechanical Heart Valve ◽

Moderate Intensity ◽

Minor Bleeding ◽

Anticoagulant Treatment ◽

Oral Anticoagulant Treatment ◽

Valve Prostheses

SummaryBackground. The long-term administration of oral anticoagulants to patients with mechanical heart valve prostheses is generally accepted. However, the appropriate intensity of oral anticoagulant treatment in these patients is still controversial.Methods and Results. From March 1991 to March 1994, patients referred to the Padova Thrombosis Center who had undergone mechanical heart valve substitution at least 6 months earlier were randomly assigned to receive oral anticoagulants at moderate intensity (target INR = 3) or moderate-high intensity (target INR = 4). Principal end points were major bleeding, thromboembolism and vascular death. Minor bleeding was a secondary end-point.A total of 104 patients were assigned to the target 3 group and 101 to the target 4 group; they were followed for from 1.5 years to up 4.5 years (mean, 3 years). Principal end-points occurred in 13 patients in the target 3 group (4 per 100 patient-years) and in 20 patients in the target 4 group (6.9 per 100 patient-years). Major hemorrhagic events occurred in 15 patients, 4 in the target 3 group (1.2 per 100 patient-years) and 11 in the target 4 group (3.8 per 100 patient-years) (p = 0.019). The 12 recorded episodes of thromboembolism, 4 of which consisted of a visual deficit, were all transient ischemic attacks, 6 in the target 3 group (1.8 per 100 patient-years) and 6 in the target 4 group (2.1 per 100 patient- years). There were 3 vascular deaths in each group (0.9 and 1 per 100 patient-years for target 3 and target 4 groups, respectively). Minor bleeding episodes occurred 85 times (26 per 100 patient-years) in the target 3 group and 123 times (43 per 100 patient-years) in the target 4 group (p = 0.001).Conclusions. Mechanical heart valve patients on anticoagulant treatment who had been operated on at least 6 months earlier experienced fewer bleeding complications when maintained on a moderate intensity regimen (target INR = 3) than those on a moderate-high intensity regimen (target INR = 4). The number of thromboembolic events and vascular deaths did not differ between the two groups.

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Relationship Between Total Prothrombin, Native Prothrombin and the International Normalized Ratio (INR)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656342 ◽

1992 ◽

Vol 68 (02) ◽

pp. 160-164 ◽

Cited By ~ 3

Author(s):

P J Braun ◽

K M Szewczyk

Keyword(s):

Anticoagulant Therapy ◽

Oral Anticoagulant ◽

Inverse Relationship ◽

Low Dose ◽

Oral Anticoagulant Therapy ◽

International Normalized Ratio ◽

Antigen Assay ◽

Dose Oral ◽

Anticoagulated Patients ◽

Sensitive Method

SummaryPlasma levels of total prothrombin and fully-carboxylated (native) prothrombin were compared with results of prothrombin time (PT) assays for patients undergoing oral anticoagulant therapy. Mean concentrations of total and native prothrombin in non-anticoagulated patients were 119 ± 13 µg/ml and 118 ± 22 µg/ml, respectively. In anticoagulated patients, INR values ranged as high as 9, and levels of total prothrombin and native prothrombin decreased with increasing INR to minimum values of 40 µg/ml and 5 µg/ml, respectively. Des-carboxy-prothrombin increased with INR, to a maximum of 60 µg/ml. The strongest correlation was observed between native prothrombin and the reciprocal of the INR (1/INR) (r = 0.89, slope = 122 µg/ml, n = 200). These results indicated that native prothrombin varied over a wider range and was more closely related to INR values than either total or des-carboxy-prothrombin. Levels of native prothrombin were decreased 2-fold from normal levels at INR = 2, indicating that the native prothrombin antigen assay may be a sensitive method for monitoring low-dose oral anticoagulant therapy. The inverse relationship between concentration of native prothrombin and INR may help in identification of appropriate therapeutic ranges for oral anticoagulant therapy.

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Inhibition rather than Enhancement of Hemostatic System Activation during Initiation of Oral Anticoagulant Treatment

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656034 ◽

1997 ◽

Vol 77 (04) ◽

pp. 685-689 ◽

Cited By ~ 11

Author(s):

Paul A Kyrle ◽

Johannes Brockmeier ◽

Ansgar Weltermann ◽

Sabine Eichinger ◽

Wolfgang Speiser ◽

...

Keyword(s):

High Intensity ◽

Oral Anticoagulant ◽

Protein C ◽

Venous Blood ◽

Rapid Decline ◽

Oral Anticoagulant Treatment ◽

Shed Blood ◽

Low Intensity ◽

Hemostatic System ◽

System Activation

SummaryCoumarin-induced skin necrosis is believed to be due to a transient hypercoagulable state resulting from a more rapid decline of the protein C activity relative to that of coagulation factors (F) II, IX and X during initiation of oral anticoagulant therapy. We studied hemostatic system activation during early oral anticoagulant treatment with a technique that investigates coagulation activation in the microcirculation.We determined in 10 healthy volunteers the concentrations of prothrombin fragment F1+2 (f1.2) and thrombin-antithrombin complex (TAT) in blood emerging from an injury of the microvasculature (bleeding time incision) before and after initiation of both high-inten- sity and low-intensity coumarin therapy. In addition, f1.2, TAT, activated F VII (F Vila) and the activities of FII, F VII, F X and protein C were measured in venous blood.A rapid decline of F VII and protein C was observed in venous blood with activities at 24 h of 7 ± 1% and 43 ± 2%, respectively, during the high-intensity regimen. A 20 to 30% reduction of f1.2 and TAT was seen in venous blood at 72 h with no major difference between the high- and the low-intensity regimen. F Vila levels were substantially affected by anticoagulation with a >90% reduction at 48 h during the high-intensity regimen. Following high-intensity coumarin, a >50% decrease in the fl.2 and TAT levels was found in shed blood at 48 h suggesting substantial inhibition of thrombin generation during early oral anticoagulation. An increase in the f1.2 and TAT levels was seen neither in shed blood nor in venous blood.Our data do not support the concept of a transient imbalance between generation and inhibition of thrombin as the underlying pathomechanism of coumarin-induced skin nekrosis.

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Determination of the International Sensitivity Index of a New Near-Patient Testing Device to Monitor Oral Anticoagulant Therapy

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657641 ◽

1997 ◽

Vol 78 (02) ◽

pp. 855-858 ◽

Cited By ~ 25

Author(s):

Armando Tripodi ◽

Veena Chantarangkul ◽

Marigrazia Clerici ◽

Barbara Negri ◽

Pier Mannuccio Mannucci

Keyword(s):

Linear Relationship ◽

Whole Blood ◽

Oral Anticoagulant ◽

Oral Anticoagulant Therapy ◽

Oral Anticoagulants ◽

Calibration Model ◽

Testing Device ◽

Data Points ◽

Near Patient Testing

SummaryA key issue for the reliable use of new devices for the laboratory control of oral anticoagulant therapy with the INR is their conformity to the calibration model. In the past, their adequacy has mostly been assessed empirically without reference to the calibration model and the use of International Reference Preparations (IRP) for thromboplastin. In this study we reviewed the requirements to be fulfilled and applied them to the calibration of a new near-patient testing device (TAS, Cardiovascular Diagnostics) which uses thromboplastin-containing test cards for determination of the INR. On each of 10 working days citrat- ed whole blood and plasma samples were obtained from 2 healthy subjects and 6 patients on oral anticoagulants. PT testing on whole blood and plasma was done with the TAS and parallel testing for plasma by the manual technique with the IRP CRM 149S. Conformity to the calibration model was judged satisfactory if the following requirements were met: (i) there was a linear relationship between paired log-PTs (TAS vs CRM 149S); (ii) the regression line drawn through patients data points, passed through those of normals; (iii) the precision of the calibration expressed as the CV of the slope was <3%. A good linear relationship was observed for calibration plots for plasma and whole blood (r = 0.98). Regression lines drawn through patients data points, passed through those of normals. The CVs of the slope were in both cases 2.2% and the ISIs were 0.965 and 1.000 for whole blood and plasma. In conclusion, our study shows that near-patient testing devices can be considered reliable tools to measure INR in patients on oral anticoagulants and provides guidelines for their evaluation.

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DIRECE ORAL ANTICOAGULANT REDUCES STROKE SEVERITY IN PATIENTS WITH ACUTE ISCHEMIC STROKE AND NON-VALVULAR ATRIAL FIBRILLATION

10.26226/morressier.58e389b0d462b80292384f5f ◽

2017 ◽

Author(s):

Yuki Sakamoto

Keyword(s):

Atrial Fibrillation ◽

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Oral Anticoagulant ◽

Stroke Severity

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