Reliability of Laboratory Tests for the Control of Oral Anticoagulation

1975 ◽  
Vol 33 (02) ◽  
pp. 387-387
Author(s):  
L Poller
1977 ◽  
Author(s):  
W. Theiss ◽  
A. Wirtzfeld ◽  
E. Sauer ◽  
L. Lutilsky ◽  
A. Kriessmann

Under fibrinolytic therapy, the levels of fibrinogen and of fibrin(ogen)degradation products (FDP) grossly influence most of the laboratory tests usually performed for clinical control of fibrinolytic treatment. Although these interferences are basically known, there is a lack of more detailed analysis under true clinical conditions. Therefore, fibrinogen determination according to Clauss (1957), thrombin time, and thromboplastin time were used for routine monitoring of 29 patients undergoing therapy with streptokinase for up to 6 days, and the results of these tests were correlated with true clottable fibrinogen as determined according to Ratnoff and Menzie (1961) and with FDP as determined according to Merskey et al. (1966).Fibrinogen determination by the Clauss method yielded poor results; for immediate clinical control, however, they were sufficient, when values above 80 mg/dl were obtained (r=0.60 when compared to actual fibrinogen concentration). Values below 80 mg/dl were completely unreliable and more closely reflected FDP (r=0.63) than actual fibrinogen levels (r<0.20). The Clauss assay is entirely insufficient, when exact fibrinogen determinations are required as for rheological or pharmacological considerations. Quite in contrast, fibrinogen levels measured according to Ratnoff and Menzie were independent of FDP levels.After bilogarithmic transformation, the thrombin time closely correlated to the FDP level (r=0.86); it thus is a valuable test for quickly estimating FDP. Since FDP also greatly influence thromboplastin time determinations (r=0.79), they must duely be considered, when overlapping oral anticoagulation is planned towards the end of fibrinolytic therapy.


1999 ◽  
Vol 56 (9) ◽  
pp. 481-483
Author(s):  
Züger ◽  
Demarmels Biasiutti

Wir berichten über einen 76jährigen Patienten, welcher trotz gut eingestellter oraler Antikoagulation mit Phenprocoumon rezidivierende Thrombosen erlitt bei leichtgradiger chronischer disseminierter intravasaler Gerinnung. Die Abklärungen ergaben das Vorliegen eines Bronchus-Karzinoms (Non small cell cancer of the lung, NSCCL) mit hilären und mediastinalen Lymphknotenmetastasen. Aufgrund der Assoziation von rezidivierenden Thrombosen, aktivierter Gerinnung und Tumorleiden wurde die Diagnose eines Trousseau Syndroms gestellt. Basierend auf Fallberichten aus der Literatur wurde die Therapie auf intravenöses Heparin gewechselt, welches die thrombotische Koagulopathie stoppte. Aus praktischen Gründen erfolgte dann eine Umstellung der Therapie auf subcutanes niedermolekulares Heparin in therapeutischer Dosierung, welches während 6.5 Monaten ebenso effektiv war und eine Alternative zur etablierten Therapie mit unfraktioniertem Heparin bei Trousseau Syndrom darstellen dürfte.


VASA ◽  
2001 ◽  
Vol 30 (Supplement 58) ◽  
pp. 21-27
Author(s):  
Luther

In diabetic foot disease, critical limb ischaemia (CLI) cannot be precisely described using established definitions. For clinical use, the Fontaine classification complemented with any objective verification of a reduced arterial circulation is sufficient for decision making. For scientific purposes, objective measurement criteria should be reported. Assessment of CLI should rely on the physical examination of the limb arteries, complemented by laboratory tests like the shape of the PVR curve at ankle or toe levels, and arteriography. The prognosis of CLI in diabetic foot disease depends on the success of arterial reconstruction. The best prognosis for the patients is with a preserved limb. Reconstructive surgery is the best choice for the majority of patients.


2012 ◽  
Vol 17 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Rosalind Potts ◽  
Robin Law ◽  
John F. Golding ◽  
David Groome

Retrieval-induced forgetting (RIF) refers to the finding that the retrieval of an item from memory impairs the retrieval of related items. The extent to which this impairment is found in laboratory tests varies between individuals, and recent studies have reported an association between individual differences in the strength of the RIF effect and other cognitive and clinical factors. The present study investigated the reliability of these individual differences in the RIF effect. A RIF task was administered to the same individuals on two occasions (sessions T1 and T2), one week apart. For Experiments 1 and 2 the final retrieval test at each session made use of a category-cue procedure, whereas Experiment 3 employed category-plus-letter cues, and Experiment 4 used a recognition test. In Experiment 2 the same test items that were studied, practiced, and tested at T1 were also studied, practiced, and tested at T2, but for the remaining three experiments two different item sets were used at T1 and T2. A significant RIF effect was found in all four experiments. A significant correlation was found between RIF scores at T1 and T2 in Experiment 2, but for the other three experiments the correlations between RIF scores at T1 and T2 failed to reach significance. This study therefore failed to find clear evidence for reliable individual differences in RIF performance, except where the same test materials were used for both test sessions. These findings have important implications for studies involving individual differences in RIF performance.


1974 ◽  
Vol 32 (02/03) ◽  
pp. 483-491
Author(s):  
E. A Loeliger ◽  
M. J Boekhout-Mussert ◽  
L. P van Halem-Visser ◽  
J. D. E Habbema ◽  
H de Jonge

SummaryThe present study concerned the reproducibility of the so-called prothrombin time as assessed with a series of more commonly used modifications of the Quick’s onestage assay procedure, i.e. the British comparative reagent, homemade human brain thromboplastin, Simplastin, Simplastin A, and Thrombotest. All five procedures were tested manually on pooled lyophilized normal and patients’ plasmas. In addition, Simplastin A and Thrombotest were investigated semiautomatically on individual freshly prepared patients’ plasmas. From the results obtained, the following conclusions may be drawn :The reproducibility of results obtained with manual reading on lyophilized plasmas is satisfactory for all five test procedures. For Simplastin, the reproducibility of values in the range of insufficient anticoagulation is relatively low due to the low discrimination power of the test procedure in the near-normal range (so-called low sensitivity of rabbit brain thromboplastins). The reproducibility of Thrombotest excels as a consequence of its particularly easily discerned coagulation endpoint.The reproducibility of Thrombotest, when tested on freshly prepared plasmas using Schnitger’s semiautomatic coagulometer (a fibrinometer-liJce apparatus), is no longer superior to that of Simplastin A.The constant of proportionality between the coagulation times formed with Simplastin A and Thrombotest was estimated at 0.64.Reconstituted Thrombotest is stable for 24 hours when stored at 4° C, whereas reconstituted Simplastin A is not.The Simplastin A method and Thrombotest seem to be equally sensitive to “activation” of blood coagulation upon storage.


1994 ◽  
Vol 72 (05) ◽  
pp. 676-681 ◽  
Author(s):  
J van der Meer ◽  
H L Hillege ◽  
P H J M Dunselman ◽  
B J M Mulder ◽  
H R Michels ◽  
...  

SummaryTo assess the optimal level of oral anticoagulation to prevent occlusion of vein coronary bypass grafts, 318 patients from a graft patency trial were analysed retrospectively. Oral anticoagulant therapy was started one day before surgery and continued for one year, after which graft occlusion was assessed by angiography. The aimed level of anticoagulation was 2.8-1.8 International Normalized Ratio (INR). Clinical outcome was assessed by the incidence of myocardial infarction, thrombosis and major bleeding.The observed anticoagulation level was 2.8-4.8 INR for 54%, and 1.8-3.8 INR for 75% of time per patient. Occlusion rates in patients who spent <35, 35-70, and ≥70% of time within INR range 2.8-1.8 were 10.5%, 10.8% and 11.8%, respectively (differences not statistically significant). Patients who spent ≥70% of time within INR range 1.8-3.8 versus 2.8-4.8 showed comparable occlusion rates. The risk of graft occlusion was not related to quality of anticoagulation early (0-3 months) or late (3-12 months) after surgery. Myocardial infarction, thrombosis and major bleeding occurred in 1.3%, 2.0% and 2.9% of patients.To maintain vein graft patency in the first postoperative year by oral anticoagulation, a level within INR range 1.8-3.8 for ≥70% of time seems to be sufficient.


1964 ◽  
Vol 11 (02) ◽  
pp. 506-512 ◽  
Author(s):  
V. A Lovric ◽  
J Margolis

SummaryAn adaptation of “kaolin clotting time” and prothrombin time for use on haemolysed capillary blood provided simple and sensitive screening tests suitable for use in infants and children. A survey of three year’s experience shows that these are reliable routine laboratory tests for detection of latent coagulation disorders.


1981 ◽  
Vol 46 (04) ◽  
pp. 752-756 ◽  
Author(s):  
L Zuckerman ◽  
E Cohen ◽  
J P Vagher ◽  
E Woodward ◽  
J A Caprini

SummaryThrombelastography, although proven as a useful research tool has not been evaluated for its clinical utility against common coagulation laboratory tests. In this study we compare the thrombelastographic measurements with six common tests (the hematocrit, platelet count, fibrinogen, prothrombin time, activated thromboplastin time and fibrin split products). For such comparisons, two samples of subjects were selected, 141 normal volunteers and 121 patients with cancer. The data was subjected to various statistical techniques such as correlation, ANOVA, canonical and discriminant analysis to measure the extent of the correlations between the two sets of variables and their relative strength to detect blood clotting abnormalities. The results indicate that, although there is a strong relationship between the thrombelastographic variables and these common laboratory tests, the thrombelastographic variables contain additional information on the hemostatic process.


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