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PubMed1996

Significance of D-dimer concentrations during and after cardiopulmonary bypass.

OBJECTIVE: To determine whether D-dimer fragments predictably increase during cardiopulmonary bypass (CPB), and if so, whether increases correlate with postoperative blood loss or predict postoperative coagulopathy. DESIGN: Prospective observational study of 65 consecutive patients undergoing first-time coronary artery bypass graft (CABG) or first-time valve replacement. SETTING: Single center University teaching hospital. PARTICIPANTS: Male and female patients between the ages of 30 and 90 years undergoing first-time CABG or valve replacement surgery using CPB. Patients were excluded from study for prolonged preoperative bleeding time, preoperative warfarin therapy, perioperative intra-aortic balloon pump support, thrombolytic therapy in the week preceding operation, reoperation, and emergency operation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Blood sampling for platelet count, prothrombin time, partial thromboplastin time, thrombin time, fibrinogen, activated coagulation time (ACT) and D-dimer concentrations was obtained at four times during each case; (1) preoperatively, after insertion of the internal jugular introducer, before insertion of pulmonary artery catheter; (2) during CPB at 28 degrees C, immediately before rewarming; (3) after heparin neutralization (20 minutes after initial protamine dose); (4) 12 to 24 hours postoperatively. Blood loss in the intensive care unit was calculated by measuring total mediastinal drainage output at 1 and 4 hours after arrival from the operating room. An initial decrease in fibrinogen was noted during bypass, but no increase in D-dimer was identified. A few patients developed a modest increase in D-dimer after heparin neutralization, but none greater than 2.0 ug/mL. Postoperatively, fibrinogen concentration increased toward baseline levels. However, this is when six patients developed significant (> 2.0 ug/mL) D-dimer formation. Results suggest appropriate physiologic response-normalization of fibrinogen with new synthesis and remodeling of clot in the operative site causing D-dimer formation. Patients with highest D-dimer levels at 12 to 24 hours postoperatively had the highest blood loss at 4 hours postoperatively, suggesting that early postoperative excess bleeding predisposed to increased clot formation and subsequent clot remodeling causing elevated D-dimer concentrations. CONCLUSIONS: D-dimer concentration is not usually elevated in patients undergoing CPB when adequately anticoagulated as monitored using the ACT. When mild elevation of D-dimer occurs, it is most often after heparin neutralization and/or in the postoperative period and is not predictive of increased postoperative blood loss. Elevations of D-dimer concentrations in the postoperative period without corresponding decreases in fibrinogen concentrations may occur and do not signify coagulopathy.

Adult↗
PubMed1989

Flavone acetic acid induces a coagulopathy in mice.

The effects of flavone acetic acid (FAA) on the coagulation properties of plasma from tumour-bearing and non-tumour-bearing mice have been investigated. The study was carried out primarily on CBA mice and the CaNT tumour, although substantiating data are included for two other tumours grown in the WH strain. FAA was injected at a range of single doses up to a maximum of 300 mg kg-1, and clotting properties of the plasma were measured in vitro at various times after FAA administration. Platelet numbers and the concentration of fibrin degradation products (FDP) in the plasma were also determined. Following a dose of 300 mg kg-1, the clotting times were significantly reduced at 15-30 min in both tumour-bearing and non-tumour-bearing mice of both strains. Detailed studies on coagulation in the CBA strain (+/- CaNT tumour) indicate that in tumour-bearing animals the initial decrease in clotting time is followed 4-6 h later by an increase in clotting time, thrombin time and FDP levels. Platelet counts of tumour-bearing mice also decreased significantly over this period. Similar experiments in non-tumour-bearing mice did not show these late effects. All the data from the coagulation tests on mice with CaNT tumours are consistent with the hypothesis that intravascular coagulation occurs following treatment with FAA, and that vascular occlusion in tumours, as a results of FAA-induced coagulopathy, may contribute to tumour regression.

Animals↗
PubMedDate not supplied

Coagulation abnormalities in 22 cats with naturally occurring liver disease.

Twenty-two cats with liver disease were evaluated for coagulation abnormalities including alterations in prothrombin time, activated partial thromboplastin time, thrombin time, factor VII activity, and platelet count. The purpose of the study was to determine the prevalence of coagulation abnormalities in this population of cats, classify abnormalities according to underlying pathogenesis, and determine if serum biochemical parameters typically used as indicators of liver disease showed any correlation with the coagulation abnormalities present. Study results indicated that at least 1 coagulation abnormality was present in 82% of the cats. Prolongation of prothrombin time was most common (16/22 cats) and factor VII activity was below reference range (< 60%) in 15 cats. When classified according to underlying pathogenesis, vitamin K deficiency was the most common abnormality found (11/22). Other abnormalities were less common and included hepatic synthetic failure (3/22), indeterminate (3/22), and disseminated intravascular coagulation (1/22). Increase in alkaline phosphatase (ALP) activity was the only biochemical abnormality that showed statistically significant correlation with coagulation abnormalities (P = .023). Cats with marked increases in ALP activity were more likely to have coagulation abnormalities than those with only mild increases in ALP activity.

Animals↗
PubMedDate not supplied

Pharmacodynamic characteristics of low-molecular-weight dermatan sulphate after subcutaneous administration in acute myocardial infarction.

Sixteen patients (5 female and 11 male, mean age 59.1 years) who had had an acute myocardial infarction within the previous 7 days, were enrolled in an open pharmacodynamic study. Patients were randomly allocated to two treatment groups and given a single subcutaneous dose of 100 or 200 mg of a new low-molecular-weight dermatan sulphate. The drug pharmacodynamic profile was determined 1, 2, 4, 6, 8, 12 and 24 h after administration. The following coagulation and fibrinolysis tests were performed: activated partial thromboplastin time, thrombin time, activated factor X inhibition, Heptest (global clotting time), heparin cofactor II affinity, functional and antigenic plasminogen activator inhibitor and fibrin plate assay. Both Heptest and heparin cofactor II affinity were significantly increased (P < 0.001) in a dose-dependent manner. The XaI was enhanced, though to a lesser extent. None of the other coagulation or fibrinolysis tests showed significant changes at either dose. Systemic and local tolerance were always very good.

Adult↗
PubMed1981

The Australasian Reference Thromboplastin: I. A study in bleeding patients.

The prothrombin time, activated partial thromboplastin time, thrombin time, and skin bleeding time, with assays of factors II, VII, IX, and X, platelet count, and liver function tests were performed on a group of patients receiving long term warfarin therapy. There were 17 bleeding patients and 13 non-bleeding patients. A study was made, using the Australasian Reference Thromboplastin and 2 other thromboplastic reagents in common use. The Australasian Reference Thromboplastin was shown to be more sensitive to the coumarin induced coagulation defect than rabbit brain thromboplastin, and hence of more value in preventing haemorrhagic complications. The level of factor II assayed by the one stage method was a useful independent indicator of the intensity of oral anticoagulation, and correlated well with the development of bleeding.

Bleeding Time↗
PubMed2000

Coagulation and bleeding disorders: review and update.

Hemostasis is initiated by injury to the vascular wall, leading to the deposition of platelets adhering to components of the subendothelium. Platelet adhesion requires the presence of von Willebrand factor and platelet receptors (IIb/IIIa and Ib/IX). Additional platelets are recruited to the site of injury by release of platelet granular contents, including ADP. The "platelet plug" is stabilized by interaction with fibrinogen. In this review, I consider laboratory tests used to evaluate coagulation, including prothrombin time, activated partial thromboplastin time, thrombin time, and platelet count. I discuss hereditary disorders of platelets and/or coagulation proteins that lead to clinical bleeding as well as acquired disorders, including disseminated intravascular coagulation and acquired circulating anticoagulants.

Blood Coagulation Disorders↗
PubMed1991

Clinical relevance of monocyte procoagulant activity in horses with colic.

Endotoxin-activated monocytes express a thromboplastin-like procoagulant activity on the cell surface that may serve as a focal point for formation of microvascular thrombi. Because coagulopathy is a common sequela to endotoxemia in the equine species, we investigated the ability of monocytes, isolated from horses with colic, to express procoagulant activity. On the day of admission, and on the third and fifth day of hospitalization, monocytes were isolated from 30 adult horses with colic. A coagulation profile, including prothrombin time, activated partial thromboplastin time, thrombin time, and plasma fibrinogen and serum fibrin degradation products concentrations, was determined at each sample collection. The concentration of endotoxin in the plasma was quantitated at the time of admission. Ten clinically normal adult horses served as controls. The procoagulant activity of monocytes isolated from horses with colic was significantly (P less than 0.05) greater than that of the monocytes isolated from clinically normal horses. On the first and third day of hospitalization, the mean prothrombin time was significantly (P less than 0.05) longer in horses with colic, compared with clinically normal horses, and was the most common abnormality in the coagulation profile on the day of admission (25/30; 83%). Mean fibrin degradation products concentration was significantly (P less than 0.05) greater in horses with colic on the day of admission and was the second most common abnormality in the coagulation profile on day 1 (23/30; 77%). In horses with colic, the mean prothrombin and activated partial thromboplastin times were significantly (P less than 0.05) longer in horses that did not survive, compared with horses that survived.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

[Drug monitoring for valproic acid with HPLC or EMIT and concomitant measurements of clinical-chemical parameters (author's transl)].

Drug monitoring for valproic acid (Convulex) was performed in 200 children with a newly developed HPLC procedure and in part with an enzyme immunoassay (EMIT). In addition the activities of the transaminases and the lipase were determined as well as platelet count, prothrombin time, thrombin time, partial thromboplastin time, fibrinogen concentration and in some cases the coagulation factors II, V and X. There is not a higher frequency for pathological laboratory findings with higher serum levels. 81 children exhibited pathological findings, however only in one case therapy had to be stopped. Recommendations when to stop therapy are given.

Adolescent↗
PubMed1994

[Prevention of thromboembolism with low molecular weight heparin (Fragmin) in obstetrics].

A total of 130 obstetrical patients were treated with either low molecular weight (LMW) or unfractionated (UFH) heparin as part of prospective study comparing their efficacy in the prevention of thromboembolism. A single daily dose of 2500-5000 anti-Xa-units LMW heparin (Fragmin) or two to three daily doses of 5000 IU UFH (Liquemin) were given to two groups of 15 patients with therapeutic tocolysis and 50 patients with cesarean section. Patients with cesarean section were given 500 ml Dextran 60 i.v. during surgery followed by subcutaneous injection of heparin eight to ten hours after surgery. Heparin therapy was continued for ten days after surgery. None of the patients exhibited clinical signs of thrombosis. The majority of patients showed symptoms of local irritation at the site of heparin injection (69% of patients with LMW heparin; 80% of patients with UFH). Hematomas at the site of injection were significantly smaller when LMW heparin was used instead of UFH. A number of patients experienced headache after heparin application (10% of patients with LMW heparin; 13% of patients with UFH). There were no cases of post surgical haemorrhage. Comparison of daily profiles revealed a significantly higher anti-Xa-activity of LMW heparin compared to UFH. In contrast, other coagulation parameters were not different in the two experimental groups (antithrombin III, partial thrombin time, thrombin time). Hematologic parameters and liver enzymes were in the physiological range in both experimental groups and none of the patients exhibited signs of heparin induced thrombocytopenia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Fibrin polymerization defect in HIV-infected patients--evidence for a critical role of albumin in the prolongation of thrombin and reptilase clotting times.

Thrombin clotting time (TCT) and reptilase clotting time (RCT) were found significantly prolonged in a series of 72 HIV-infected patients drawn for routine coagulation testing. Both TCT and RCT were highly significantly correlated with albumin (r = -0.64, and r = -0.73 respectively, p < 0.0001). TCT and RCT were significantly higher (p < 0.0001) in a series of 30 other HIV-infected patients selected on their albumin level below 30.0 g/l (group 1) than in 30 HIV-infected patients with albumin level above 40.0 g/l or in 30 HIV-negative controls; the two latter groups were not different. In vitro supplementation of plasma from group 1 patients with purified human albumin up to 45.0 g/l (final concentration) lead to a dramatic shortening effect on both TCT and RCT, which reached normal values. The TCT and RCT of the purified fibrinogen solutions (2.0 g/l final concentration) were not different in the three groups, and normal polymerization curves were obtained in all cases. This further ruled out the presence of any dysfibrinogenemia in the plasma from group 1 patients. Using purified proteins, highly significant correlations were demonstrated between the albumin concentration and the prolongations of both TCT and RCT, which were of the same magnitude order than those found in the patients plasma. These results suggest that hypoalbuminemia is responsible for the acquired fibrin polymerization defect reported in HIV-infected patients. The pathophysiological defect reported in HIV-infected patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1998

The systemic fibrinolytic activity of intrapleural streptokinase.

Intrapleural fibrinolytics probably improve the drainage of loculated pleural effusions and empyemas. Studies of crude indices of systemic coagulation suggest this effect is accompanied by little systemic fibrinolysis, but few studies have assessed this in detail. This study examines the systemic fibrinolytic activity of two intrapleural streptokinase (IPSK) regimes in detail. Eight patients received a single dose of 250,000 IU IPSK, and a further eight received serial doses of 250,000 IU IPSK every 12 h for 3 d (total dose: 1.5 million IU). Each dose was retained in the pleural cavity for 2 h. Venous blood for prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, and D-dimers due to fibrin degradation were measured before any IPSK. These end points were then remeasured 24 h after IPSK in the single-dose group and after 24, 48, and 72 h in the group receiving serial doses. There were no physiologic or statistical differences in any of the indices after administration of IPSK. IPSK administered up to a dose of 1.5 million IU does not cause significant activation systemic fibrinolysis in humans.

Adult↗
PubMed1999

Hemostatic changes in patients with liver cirrhosis.

BACKGROUND: Hemostatic changes in liver disease are complicated. An overall evaluation of the main hemostatic parameters in patients with different degrees of cirrhosis of the liver has not been reported in Taiwan. METHODS: A series of hemostatic tests and parameters including activated partial thromboplastin time, prothrombin time, thrombin time, bleeding time, factor VIII assay, antithrombin activity, fibrinogen, plasminogen, protamine sulfate test, fibrin(ogen) degradation products, D-dimer, thrombin-antithrombin complex (measured by modified antithrombin), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1, euglobulin lysis test and venous occlusion test were performed in 51 patients with cirrhosis of the liver and 33 healthy controls. Among the cirrhotics, 18 were classified as Child-Pugh group A, 16 were B and 17 were C. RESULTS: Plasminogen, antithrombin and platelet count decreased progressively, starting with group A, then B and then C, relative to the controls. Factor VIII, activated partial thromboplastin time, prothrombin time, bleeding time, D-dimer and fibrin(ogen) degradation products increased progressively starting with group A, to B and then C, relative to controls. Severity of cirrhosis correlated with hemostatic changes. No significant change in the fibrinolytic response after challenge with the venous occlusion test was found in either Child-Pugh groups A, B, C or the controls, though progressive increases in tPA were found starting with group A, to B and then C, relative to controls. CONCLUSIONS: Our study proved a close relationship between the severity of cirrhosis and hemostatic changes. Activated partial thromboplastin time was better than bleeding time or thrombin time to demonstrate the severity of liver damage and hemostatic change in cirrhosis. Because the deterioration of coagulation function and increased fibrinolytic activity paralleled the severity of liver cirrhosis, adequate treatment for cirrhotic bleeding should not only correct the coagulation defects, but should also lower the increasing fibrinolytic activity.

Adult↗
PubMed2001

Early activation of inflammation and clotting in the preterm lamb with neonatal RDS: comparison of conventional ventilation and high frequency oscillatory ventilation.

In neonatal respiratory distress syndrome activation of inflammation and clotting is demonstrated. High frequency oscillatory ventilation (HFOV) is considered to be less damaging to the human preterm lung, resulting in less activation of inflammation and clotting compared with conventional ventilation (CV). To assess the sequence of events of activation of inflammation and clotting and to compare the impact of HFOV to CV, we ventilated preterm lambs delivered by cesarean section at 132 d gestational age (term 145 d) for 8 h by CV (n = 10) or HFOV (n = 11). Fifteen minutes after birth and at 2-h intervals thereafter blood samples, from umbilical catheters, were analyzed for AP50 (complement activation), number of polymorphonuclear leukocytes, beta-glucuronidase, platelet function, activated partial thromboplastin time, thrombin time and thrombin inhibition, and bronchoalveolar lavage fluid was analyzed for elastase, thrombin and protein. We found complement activation, low number of polymorphonuclear leukocytes and high levels of beta-glucuronidase already at 15 min after birth. Within 2 to 4 h after birth platelet function deteriorated, activated partial thromboplastin time prolonged, and thrombin inhibition decreased. Activation of inflammation and clotting in the lungs was demonstrated by increased levels of elastase and thrombin in bronchoalveolar lavage fluid. In the HFOV group, AP50 remained significantly higher than in the CV group, reflecting less complement activation, and platelet function analysis remained significantly lower, reflecting better platelet function. We conclude that systemic activation of inflammation can be found in the ventilated preterm lamb with respiratory distress syndrome within 15 min after birth. Afterward, or due to activation of inflammation, clotting is activated. HFOV possibly attenuates activation of inflammation.

Animals↗
PubMed1985

The effects of low-dose oral contraceptives on coagulation and fibrinolysis in two high-risk populations: young female smokers and older premenopausal women.

A study was undertaken to determine the effect of a low-dose oral contraceptive on the coagulation and inhibitory system of coagulation in 22 young healthy women who smoke and in 15 nonsmoking healthy women between the ages of 34 and 41. Smokers showed statistically significant oral contraceptive-related procoagulant alterations in prothrombin time, thrombin time, and fibrinogen antigen. Antithrombin III antigen and activity were significantly reduced, whereas plasminogen antigen and activity were increased. Inhibitor and fibrinolytic activity was either unaffected or enhanced by oral contraceptives in women over the age of 34: antithrombin III activity was unchanged, plasminogen antigen and activity increased (p less than 0.0007), and alpha 2-antiplasmin was significantly reduced (p less than 0.07). Whereas usage of oral contraceptives in young smokers may initiate biochemical changes in favor of thrombogenesis, their usage in nonsmoking older women enhanced fibrinolysis and had a neutral effect on inhibition and a minimal procoagulant effect.

Adult↗
PubMed2006

A novel fibrinogen Bbeta chain frameshift mutation in a patient with severe congenital hypofibrinogenaemia.

Congenital afibrinogenemia and severe hypofibrinogenemia are severe bleeding disorders characterized by either undetectable or very low levels of fibrinogen in patients' plasma and platelets. A majority of the reported cases are caused by mutations in the fibrinogen Aalpha chain. In this study, we identified a genetic defect in the fibrinogen Bbeta-chain (FGB) underlying severe hypofibrinogenemia. The propositus frequently displayed bleeding episodes with a prolonged blood-clotting time (thrombin time > 180 s, activated partial thromboplastin time > 300 s, prothrombin time > 120 s) and had a very low level of plasma fibrinogen (1.7-1.8 mg/dl). His parents had a consanguineous marriage, and their functional and immunological fibrinogen was approximately half of the normal level. The platelet fibrinogen level of the propositus could not be detected by western blotting, and his platelet aggregation was severely impaired. DNA screening of the whole fibrinogen gene revealed a homozygous GGGG-->GGG mutation at nucleotide 7,969-7,972 in his FGB gene. The propositus' parents are both heterozygous for this mutation. This mutation contributes to Gly419-->Val, and the 419-434 codons are frame shifted, and a stop codon is formed at codon 435. The predicted truncated Bbeta-chain is 27 amino acids shorter than the normal Bbeta-chain and a central beta-strand in the globular betaC domain is absent, which may lead to destabilization of the entire beta-domain. To the best of our knowledge, this is the first report of such a mutation which is associated with severe hypofibrinogenemia.

Adult↗
PubMed1984

[Heparin level and coagulation potential after subcutaneous injection of 7500 international units of heparin calcium].

A dosage of 7500 IU heparin calcium (Calciparin) was administered subcutaneously twice daily in 15 probands. Prior to and after the 1st and 7th injection heparin levels were determined in plasma and coagulation studies were done. The highest heparin levels were found around 4 hours after the injection. They were significantly higher after the 7th injection than after the 1st. Values decreased markedly after 8 hours. After 10-12 hours they approached the initial values, however remained significantly increased. The appropriate changes were seen in activated partial thromboplastin time, thrombin time and reaction- and clotting time in the thrombelastogram. Activity and concentration of antithrombin III decreased by about 10%. Fibrinogen and platelets remained largely unaffected. The results show that twice daily subcutaneous injections of 7500 IU heparin calcium are able to close the anticoagulation gap in plasma which occurs with administration of twice 5000 IU between two injections.

Adult↗
PubMed2005

Combinations of low doses of unfractionated heparin and of low-molecular-weight heparin prevent experimental venous thrombosis.

Synergism between low-molecular-weight heparin and low doses of unfractionated heparin (UH) enhancing anti-factor Xa activity and the release of tissue factor pathway inhibitor was observed. The aim of this study was to verify whether this association is effective in preventing experimental venous thrombosis. Seventy rats were allocated into 7 groups: the control group treated with distilled water, the H(350) group treated with UH 350 IU/kg, the E(2) group treated with enoxaparin 2 mg/kg, the H(175) group treated with UH 175 IU/kg, the E(1) group treated with enoxaparin 1 mg/kg, the H(175) + E(1) group treated with UH 175 IU/kg plus enoxaparin 1 mg/kg, and the H(100) + E(0.5) group treated with UH 100 IU/kg plus enoxaparin 0.5 mg/kg. Forty minutes after subcutaneous injection, thrombosis was induced in vena cava. Three hours later, if present, thrombi were withdrawn and weighed. Bleeding time, activated partial thromboplastin time, thrombin time (TT), and anti-factor Xa were measured at the beginning and end of the experiment. Forty-eight other animals were treated, but without inducing thrombus, and tests were performed 40 min after injection. Thrombus developed in 90.9% of control animals, 20% of the H(350) group, 22.2% of the E(2) group, 10% of the H(175) + E(1) group, and 30% of the H(100) + E(0.5) group; there was a difference between group C and the other groups. Only in the H(350) and H(175) + E(1) groups were TT and activated partial thromboplastin time prolonged in relation to control at the end of the experiment. Forty minutes after injection, TT was prolonged in the H(350) and H(175) + E(1) groups. In conclusion, combinations of low doses of low-molecular-weight heparin and low doses of UH were as effective as high doses of each one used alone in preventing thrombus development in rat vena cava.

Animals↗
PubMed1995

Ethnic variations in the haemostatic system: comparison between Arabs, Westerners (Europeans and Americans), Asians and Africans.

A wide variety of haemostatic variables were measured in healthy male subjects predominantly blood donors residing in Riyadh, the capital city of Saudi Arabia. Subjects were divided according to ethnic origin: Saudi Arabs n = 487, Westerners (Europeans and Americans) n = 300, South East Asians (Koreans and Filipinos) n = 360, and West Africans n = 82. There were no significant differences in prothrombin time, partial thromboplastin time, thrombin time, reptilase time, plasma fibrinogen, antithrombin, plasminogen and platelet count between Saudis, Westerners and Asians. Africans exhibited significantly lower plasma levels of fibrinogen, platelet count and plasminogen than other ethnic groups. Arabs and Africans had higher levels of FVIII:C and vWF:ristocetin cofactor than Westerners. On the other hand, FX was significantly higher in Westerners than in other ethnic groups. Smokers had higher fibrinogen levels than non-smokers. These variations, which could not be related to blood group distribution, physical parameters of height and weight, may be due to genetic and/or dietary habits. In conclusion, this study established the existence of racially determined variations in haemostatic variables, with Black Africans showing changes consistent with a lesser tendency towards atherosclerosis and cardiovascular disease than other ethnic groups. These variations should be taken into account when investigating the haemostatic system in patients.

Adolescent↗