Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Thrombin Time”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

[Coagulation tests from capillary blood. Determination of thromboplastin time, thrombin time, fibrinogen, factor II (prothrombin), factor V (accelerin) and factor X (Stuart-Prower factor) from capillary blood].

Methods are described for the determination of the thromboplastin time, the thrombin time, for fibrinogen and factor II, V and X from capillary blood. These methods are easy to perform and comparison of the results from venous and capillary blood showed a very good correlation. The described methods seem suitable for routine coagulation tests in pediatrics.

Automation↗

[The determination of activated partial thromboplastin time, coagulate time and thrombin time in patients with epistaxis of indeterminate cause].

OBJECTIVE: To explore the coagulation mechanism of indeterminate epistaxis. METHOD: 36 cases with epistaxis of indeterminate cause were studies by mean of detecting activated partial thromboplastin time (APTT), coagulate time (CT) and thrombin time. The results of first APTT, APTT after 8 min and CT were observed. RESULT: 1. The first APTT in epistaxis and normal group didn't show statistical difference (P > 0.05). But the APTT after 8 min in epistaxis were significantly different compared with the first APTT and that in normal group (P < 0.01). 2. The CT prolonged in 33.3% patients with epistaxis, which was higher significantly than that in the normal group (P < 0.01). (3) The epistaxis thrombin time (TT) was longer than that in normal group. CONCLUSION: The result suggest that during blood coagulation in indeterminate epistaxis, the activated factors in internal coagulating system may decompose more quickly than that in normal group. Antiagglutinating factors increase in blood.

Adolescent↗

Effects of haemolysis, lipaemia and bilirubinaemia on prothrombin time, activated partial thromboplastin time and thrombin time in plasma samples from healthy dogs.

Interferences caused by haemolysis, lipaemia and bilirubinaemia on prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT in normal canine plasma samples were studied using commercially available reagents and a steel ball coagulometer. Haemolysis significantly interfered with APTT (P = 0.0076) and TT (P = 0.0292). Regression analysis showed that TT was significantly shortened as haemoglobin concentrations increased. Lipaemia increased as demonstrated by regression analysis. Bilirubin significantly interfered with PT (P=0.0003) and APTT (P=0.002). Although statistically significant, none of the differences found were of clinical relevance.

Animals↗

[Unexpectedly prolonged thrombin time].

The thrombin time assay is able to detect abnormalities of the terminal phase of plasmatic coagulation. The differential diagnosis of thrombin time prolongation includes (1) inhibition of the added thrombin by exogenous heparin or endogenous heparin-like anticoagulant, seldom by acquired antibovine thrombin antibodies, (2) qualitative fibrinogen disorders (congenital and acquired dysfibrinogemia, (3) quantitative fibrinogen disorders (hypo- and afibrinogenemia), and (4) delayed fibrin polymerization due to fibrin/fibrinogen degradation products, paraproteins or seldom acquired antibodies against fibrinogen.

Adult↗

In vitro effect of hemodilution on activated clotting time and high-dose thrombin time during cardiopulmonary bypass.

BACKGROUND: Extreme dilution of clotting factors, as may occur during pediatric or neonatal cardiopulmonary bypass, often leads to inadequate monitoring of anticoagulation with activated clotting time (ACT). In this study we postulate that the high-dose thrombin time (HiTT) is less influenced by extreme dilution of clotting factors because it stimulates clotting through the common pathway. METHODS: Heparinized prebypass blood was obtained from 30 adult cardiac surgical patients and was diluted in a laboratory setting with saline solution to mimic the clinical clear prime solution (group I; n = 10), with saline solution containing similar heparin as in the prebypass blood (group II; n = 10), and with fresh frozen plasma to substitute clotting factors in the diluted blood (group III; n = 10). Blood was diluted to four different degrees: a control without dilution, 25%, 50%, and 75% dilution. The ACT and HiTT were measured and compared. RESULTS: In group I, significant prolongation of ACT was observed in blood diluted to 75% as compared with the nondiluted blood (p < 0.01). In contrast, HiTT was not prolonged at any degree of dilution but reduced proportionally to dilution up to 75%, reflecting the concomitant reduction of heparin. In group II, ACT increased at 25% dilution (p < 0.01) whereas HiTT increased at 50% dilution (p < 0.01). In group III, no prolongation of ACT or HiTT was found in any degree of dilution. Furthermore, adding fibrinogen to the diluted blood (n = 4) did not cause ACT to recover at 75% dilution, suggesting that dilution of other factors in the early clotting cascade rather than fibrinogen alone increases ACT. CONCLUSIONS: These results imply that when blood is extremely diluted during cardiopulmonary bypass with a clear prime without substituted clotting factors, HiTT is a better test than ACT for anticoagulation monitoring.

Adult↗

[Monitoring heparin therapy by thrombin time and activated partial thromboplastin time--a comparison].

In 106 plasma samples obtained from patients on heparin therapy, monitoring by 2 methods (activated partial thromboplastin time and thrombin clotting time--APTT and TT) was compared. All patients in whom APTT indicated markedly higher plasma heparin concentrations than the TT were critically ill (group B): their main diagnoses included severe infectious disease, severe liver disease and extensive myocardial infarction. Patients with lesser discrepancies between the results of APTT and TT did not suffer from such severe conditions (group A). Cardiac surgery without major postoperative problems, limited myocardial infarction and uncomplicated thromboembolism were the main diagnoses in this group. In group B, non-heparin related prolongation of APTT was thought to be the main factor responsible for the overestimation of plasma heparin concentrations by this test. We conclude that in patients with severe infectious disease, liver disease or extensive tissue necroses (i.e. myocardial infarction), APTT cannot be recommended for laboratory monitoring of heparin therapy.

Blood Coagulation Tests↗

Elevated fibrinogen in an acute phase reaction prolongs the reptilase time but typically not the thrombin time.

The effects of elevated fibrinogen on thrombin and reptilase times have not been well documented. High fibrinogen levels are common (38% of specimens submitted to our coagulation laboratory). Among 102 patients in the present study, an endogenously elevated fibrinogen level was significantly associated, as follows, with prolonged reptilase times: 1 (4%) of 28 with normal fibrinogen levels, 6 (20%) of 30 with levels in the 400 to 700 mg/dL (4.0-7.0 g/L) range, 10 (34%) of 29 with levels in the 700 to 1,000 mg/dL (7.0-10.0 g/L) range, and 7 (47%) of 15 with fibrinogen levels greater than 1,000 mg/dL (10.0 g/L). This association was independent of patient age and fibrin degradation product titer. In contrast, thrombin time was not altered notably by elevated fibrinogen levels. In 4 patients studied further, the prolonged clotting times could be corrected or nearly corrected by adding calcium chloride or albumin, whereas no such corrections were demonstrable in samples from several hereditary dysfibrinogenemia control subjects. An elevated fibrinogen level is common and is associated with reptilase time prolongations. For patients with prolonged reptilase times, a fibrinogen assay is suggested before establishing a diagnosis of dysfibrinogenemia.

Acute-Phase Reaction↗

The seial thrombin time in the diagnosis of consumptive coagulopathy.

Acute consumptive coagulopathy may be initiated by diverse events. It is frequently necessary to establish the diagnosis with urgency. Rational therapy can only be approached with knowledge of the relative impact the primary consumption exerts upon hemostasis as well as the effects of secondary fibrinolysis. A constellation of interlocking tests within the capability of the small laboratory is presented. This includes the prothrombin time, the activated partial thromboplastin time, the serial thrombin time, the heat precipitation fibrinogen level, the platelet count, red cell morphology, the levels of fibrin (fibrinogen) degradation products and selected factor assays. This series can be completed within 45 minutes. Interpretation, with particular emphasis upon the stage in the natural history of the process when evaluation is instituted, and underlying diseases which modify typical patterns are discussed. The discriminant function of the serial thrombin time is stressed.

Adult↗

Iatrogenic immunization with bovine thrombin: a mechanism for prolonged thrombin times after surgery.

Unexplained very-prolonged thrombin times (greater than 300 s) were found in plasma from four patients. Other coagulation variables were normal, and there was no history of coagulopathy. Mixing studies suggested the presence of thrombin inhibitors in patient plasma. Substitution of human thrombin for bovine thrombin in performing the thrombin time test resulted in normal clotting times, indicating that the inhibitory activity was directed primarily against bovine thrombin. Each patient had been treated with topical bovine thrombin during previous surgery. In the one patient with a preoperative thrombin time, the initial value was normal and prolongation began 16 days after surgery. An enzyme-linked immunoassay showed elevated levels of IgM or IgG antibodies to bovine thrombin in each patient tested. Affinity-purified antibodies to bovine thrombin from patient serum prolonged the thrombin time of normal plasma. These results suggest that iatrogenic immunization by intraoperative exposure to bovine thrombin is responsible for antibodies to bovine thrombin, which accounts for the prolonged thrombin times found in some patients after surgery.

Adolescent↗

[Polybrene thrombin time--a simple new method for monitoring a fibrinolytic therapy].

The thrombin time is essential to control the fibrinolytic therapy with streptokinase. But it is not efficient to use the thrombin time to estimate the fibrinolytic activity if heparin is applied simultaneously. After addition of heparin antidote polybrene the results are comparable with the reptilase time (so-called polybrene thrombin time). In the case of a fibrinolytic therapy it is recommended to use the thrombin time according to AB-D.L. (heparin-sensitive method) and the polybrene thrombin time (heparin-insensitive method).

Blood Coagulation Tests↗

Influence of fibrinogen degradation products on thrombin time, activated partial thromboplastin time and prothrombin time of canine plasma.

To investigate how thrombin time, activated partial thromboplastin time (APTT) and prothrombin time are influenced by fibrinogen degradation products (FDP), different concentrations (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8 and 1.0 mg/ml) of the purified FDP X, Y, D and E were added to the plasma of healthy dogs. If fragment Y was added to the plasma a considerable inhibitory effect could be demonstrated for all three test systems. A significant prolongation (p < 0.05) was found for concentrations of > or =0.1 mg/ml (thrombin time, APTT) and > or =0.2 mg/ml (prothrombin time). With FDP Y concentrations from >0.185 mg/ml (prothrombin time) to >0.24 mg/ml (APTT) coagulation time was prolonged beyond the respective reference range. As regards the other fragments, a comparable inhibitory effect could only be shown for fragment X added to the thrombin time test system. This effect can most probably be explained by the competition of the FDP X and fibrinogen for the fibrinogen binding sites of thrombin, rather than by a fibrin polymerization disorder. The results demonstrate that for plasma with normal fibrinogen concentration the group tests are only prolonged beyond the reference range at FDP concentrations very rarely found in spontaneous hyperfibrinolysis.

Animals↗