共查询到20条相似文献,搜索用时 15 毫秒
1.
The activated partial thromboplastin time (APTT) and prothrombin time (PT) have three principal uses. In screening for coagulation disorders (or increased risk of postoperative hemorrhage), the tests add no information to the preoperative care of patients without clinical findings indicative of increased bleeding risk. Furthermore, the prevalence of asymptomatic congenital coagulopathies is so low that false-positive test results greatly outnumber true-positive results. Thus, clinicians may use clinical assessment to screen and should reserve coagulation tests to investigate patients with abnormal findings. In evaluating abnormal bleeding, these tests are sufficiently sensitive that if both are negative, further investigation of the coagulation system is obviated. If one or both tests are positive, the pattern of results directs further attention to limited segments of the coagulation sequence. In monitoring anticoagulation therapy, the APTT and PT tests appear to contribute to the safety and effectiveness of heparin and warfarin therapies, respectively. 相似文献
2.
3.
Human plasma fibrinogen measurement derived from activated partial thromboplastin time clot formation. 总被引:2,自引:0,他引:2
F Sobas M Hanss P Ffrench M C Trzeciak M Dechavanne C Négrier 《Blood coagulation & fibrinolysis》2002,13(1):61-68
Prothrombin time-derived measurement of fibrinogen (PTd) has already been described. Activated partial thromboplastin time-derived measurement of fibrinogen (aPTTd) has not yet been clearly defined. Using an MDA II coagulometer (Organon Teknika, Durham, North Carolina, USA), we have therefore compared fibrinogen levels determined with Clauss, PTd, and aPTTd assays and an enzyme immunoassay (EIA) in 172 samples. Of these, 47 were from pre-operative controls, 18 from patients with liver disease, 28 from patients with hyperfibrinogenaemia, 33 from patients treated with vitamin K antagonists, 22 from patients treated with unfractionated heparin and 24 from haemophilic patients. Within the normal range, interassay and intra-assay variations were comparable. For control samples, PTd, aPTTd and Clauss assays were well correlated, without any systematic error. EIA was also correlated but values were slightly higher (mean of difference = 0.24). Pathological samples showed an overestimation of fibrinogen when using PTd measurements in patients treated with vitamin K antagonists, as well as when using aPTTd measurements in patients presenting with factor VIII and factor IX deficiencies. These results indicate that, despite expected financial savings, aPTTd fibrinogen measurements should not be used without restriction. PTd and aPTTd fibrinogen determinations are provided without any additional cost. Their comparison with Clauss fibrinogen results may constitute a validation tool or have additional diagnostic utility (e.g. identifying polymerization abnormalities in case of dissimilar results). 相似文献
4.
G Lutze H J Presser H Urbahn 《Zeitschrift für die gesamte innere Medizin und ihre Grenzgebiete》1989,44(8):235-240
For the laboratory control of a heparin therapy thrombin time, partial thromboplastin time and activated recalcification time are used. On account of distinct differences in the heparin sensitivity of these reactions an indication-related application is necessary. The ability of evidence and the possibility of establishing test-specific therapeutic regions are restricted by differences caused by reagents, individual variability and influence by accompanying haemostasiological changes. The own approach, taking into consideration the so-called heparin resistance, it presented. 相似文献
5.
The effect of the normal variations of fibrinogen concentration (180 mg. per centto 650 mg. per cent) on the diluted (12.5 per cent) plasma prothrombin time inman, as observed in this study, is not significant. 相似文献
6.
Michael P. Ero Nathaniel R. Harvey Jack L. Harbert James W. Janc Kay H. Chin Steven L. Barriere 《Journal of thrombosis and thrombolysis》2014,38(2):235-240
Telavancin is approved in the United States, Canada, and Europe (At the time of submission, the telavancin European marketing authorization for nosocomial pneumonia was suspended until Theravance provides evidence of a new European Medicines Agency approved supplier) as an antibiotic to treat certain Gram-positive bacterial skin infections. Telavancin has been shown to prolong plasmatic prothrombin (PT) and activated partial thromboplastin (aPTT) clotting times in clinical diagnostic lab-based assays. In this study, we evaluated the potential for telavancin to prolong whole blood PT/International Normalized Ratio (INR) and aPTT tests on point-of-care (POC) instruments. Whole blood collected from 8 healthy subjects was supplemented with telavancin to final concentrations of 0, 10, 20, and 100 μg/ml. Final concentrations were selected to match trough, twice trough, and peak plasma levels following the approved 10 mg/kg dose. Four widely employed POC coagulation instruments were chosen to be representative of the POC platforms currently in use.. These systems were the Roche Coaguchek XS, the Abbott iSTAT, the ITC Hemochron SIG+, and the Alere INRatio2 POC devices. The PT/INR measured by the Coaguchek XS showed the greatest sensitivity to the presence of telavancin. The PT/INR measured by the Hemochron SIG+ and iSTAT were sensitive to telavancin but to a lesser extent. The INRatio2 was the least sensitive to the presence of telavancin when testing the whole blood PT/INR. Only the Hemochron SIG+ device was capable of measuring aPTT and showed a concentration-dependent increase in aPTT. This study supports the current recommendation that PT and aPTT monitoring be conducted immediately to the next dose of telavancin when coagulation parameters are tested using POC instrumentation. 相似文献
7.
8.
9.
10.
R B Francis 《Annals of internal medicine》1986,105(4):626-627
11.
Underestimation of plasma level of factor V coagulant activity and fibrinogen concentration together with prolonged prothrombin time,activated partial thromboplastin time and thrombin time can result from pre‐analytical very low calcium level in citrated sample tube
下载免费PDF全文
![点击此处可从《International journal of laboratory hematology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
C. d'Audigier C. Delassasseigne A. Robert V. Eschwège 《International journal of laboratory hematology》2016,38(1):50-53
12.
A Cobas Bio centrifugal analyzer was used in a clinical laboratory for the performance of chromogenic clotting assays. Three commercially available photometric clotting tests--prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen--were compared with the traditional clotting assays during 3 months. No great discrepancies were found between the traditional assays and the new photometric assays. The chromogenic PT could replace the traditional thrombotest, PT and Normotest, because it was sensitive and accurate over a broad range of clotting factor activity. Furthermore the chromogenic PT could be used to discriminate between a decreased clotting activity due to vitamin K deficiency or to a decreased protein synthesis by the liver. A decreased protein synthesis was confirmed by measuring a decrease in the serum cholinesterase activity. The chromogenic aPTT could be used for the assay of heparin concentrations in the therapeutic range and turned out to be more sensitive for deficiencies of factor VIII and factor IX than a traditional clotting aPTT. We conclude that the accuracy and practicability of clotting assays are improved by the new assays without diminishing the clinical value of the results. 相似文献
13.
Tivadar Fenyvesi Ingrid J?rg Christel Weiss Job Harenberg 《Blood coagulation & fibrinolysis》2004,15(7):605-611
The activated partial thromboplastin time (aPTT) is currently the most common test used to measure the anticoagulation intensity of heparins and direct thrombin inhibitors (DTIs). Vitamin K antagonists variably affect aPTT reagents. Interactions between heparin and DTIs occur during concurrent therapy. Three DTIs (lepirudin, argatroban, melagatran) and one unfractionated heparin (liquemin) were added to normal plasma (NP) samples (n = 23) and to vitamin K antagonist plasma (VKAP) samples (n = 23) of patients treated with phenprocoumon. Lepirudin and argatroban were added at concentrations from 300 to 3000 ng/ml, melagatran from 30 to 1000 ng/ml, and unfractionated heparin from 0.016 to 0.48 IU/ml. Wave parameters of clotting time and aPTT ratio curves were evaluated by multivariate analysis for inhibitors, aPTT reagents and NP and VKAP samples. Normal ranges resulting from NP samples were 34.5 +/- 1.0 s with Pathromtin SL and 33.9 +/- 0.8 s with Platelin LS. Normal ranges using VKAP were 52.8 +/- 2.6 s (Pathromtin SL) and 44.2 +/- 1.1 s (Platelin LS) (P < 0.0001). Variance analysis showed that inhibitors, plasmas (NP versus VKAP) and reagents influenced the wave characteristics of aPTT (s) (P < 0.0001) and aPTT ratios (P < 0.0001). Distinct statistical differences between aPTT reagents on one hand and normal versus vitamin K antagonist plasma on the other hand make a comparison of reported aPTT results difficult, especially during overlapping therapy with vitamin K antagonists. 相似文献
14.
15.
Giuseppe Lippi Gian Cesare Guidi Massimo Franchini Emmanuel J. Favaloro 《Diabetes research and clinical practice》2009,83(2):e33-e34
We performed a meta-analysis of five randomized, placebo-controlled trials to characterize the impact of plant sterols/stanols on plasma lipids in patients with type 2 diabetes. Upon meta-analysis, plant sterols/stanols significantly reduced total and LDL cholesterol, with a trend towards improvement in HDL. No beneficial effect on triglycerides was apparent. 相似文献
16.
M.A. DELORME M.J. INWOOD B. O'KEEFE 《International journal of laboratory hematology》1990,12(4):433-436
Summary. The thrombin clotting time (TCT) has been used at our institution, along with the activated partial thromboplastin time (aPTT), for monitoring heparin therapy. We have observed that, in some patients, a discrepancy develops between the heparin levels predicted by the TCT and the aPTT with the TCT consistently predicting a lower heparin level than the aPTT. An inverse relationship was noted between the functional antithrombin III (AT-III) level and the magnitude of this discrepancy. 相似文献
17.
18.
Martin Koestenberger Siegfried Gallistl Leschnik Bettina Christina Cimenti Joerg Kutschera Gerhard Cvirn 《Blood coagulation & fibrinolysis》2006,17(8):677-680
Melagatran is the active form of the oral direct thrombin inhibitor ximelagatran. Melagatran does not require antithrombin as a cofactor. Its administration is therefore of special interest in neonatal patients, whose plasma is relatively deficient in antithrombin. We investigated the effects of increasing amounts of melagatran (0.05-1 micromol/l) on the activated partial thromboplastin time (APTT) and ecarin clotting time (ECT) in cord versus adult plasma. Both the APTT and ECT were dose-dependently prolonged in the presence of increasing amounts of melagatran. Furthermore, the ECT revealed a higher susceptibility of cord plasma to addition of melagatran than adult plasma. Whereas similar amounts of melagatran were required in cord and adult plasma samples to double the APTT (IC(50), 0.47 vs 0.46 micromol/l), significantly less melagatran was required in cord versus adult plasma to double the ECT (IC(50), 0.26 vs 0.56 micromol/l). Based on APTT measurements, similar plasma levels of melagatran might be required in neonates and in adults to treat thromboembolic complications. The APTT, however, is relatively insensitive to plasma melagatran concentrations. When the sensitive indicator ECT is used, results suggest that lower amounts of melagatran might be required in neonates than in adults. This has to be scrutinized in future clinical studies. 相似文献
19.
Martin Koestenberger Gerhard Cvirn Siegfried Gallistl Wolfgang Muntean 《Blood coagulation & fibrinolysis》2004,15(8):693-697
Recombinant human activated protein C (rhAPC) has recently been demonstrated to be a promising candidate to improve the outcome for patients with severe sepsis. Plasma-derived activated protein C and unfractionated heparin (UH) exert anticoagulant synergy due to mechanisms that simultaneously decrease thrombin generation. Melagatran, a new direct thrombin inhibitor, does not bind to plasma proteins or requires antithrombin as a cofactor. The latter is often consumed in patients with severe sepsis. We investigated the anticoagulant efficiency in combined administration of rhAPC and UH or melagatran in terms of prolongation of the standard clotting assays activated partial thromboplastin time (aPTT) and prothrombin time (PT) in pooled plasma samples in vitro. RhAPC dose-dependently prolonged the aPTT but not the PT. The ability of UH and melagatran to prolong the aPTT was significantly enhanced in combination with rhAPC. The combined administration of rhAPC and melagatran, but not UH, resulted in additive prolongation of the PT. In control measurements the capability of rhAPC to suppress prothrombin fragment 1.2 generation dose-dependently increased in combination with heparin and melagatran. Our study demonstrates the respective effects of rhAPC, UH, melagatran and further different additive effects in combined administration of rhAPC and UH or melagatran on the prolongation of the aPTT and PT clotting assays usually used to monitor anticoagulant treatment. 相似文献