Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.6 (thromboplastin)
 13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Significant postoperative bleeding following open-heart surgery is often ascribed to the so-called heparin 'rebound' phenomenon and as such is treated with additional empiric doses of protamine sulphate. However, inappropriate protamine administration has been reported to be associated with acute pulmonary hypertension. The efficacy of heparin reversal was investigated in 42 patients undergoing open-heart surgery. The standard heparin bolus of 3 mg/kg body weight (4.1 IU/ml blood) administered before cardiopulmonary bypass was countered at the end of bypass using an empirical equivalent (3 mg/kg) of protamine. This regimen resulted in complete heparin neutralization (measured by the Hepcon HMS [Hemotec Inc., Englewood, CO, USA]) 15 min after protamine administration in all 42 patients, but heparin levels (0.4 IU/ml) were transiently detectable (duration less than 1 h) in six (14%) of the 42 cases 2 h later. Twenty-four hour postoperative bleeding in these patients did not differ significantly from that seen in patients who did not exhibit heparin rebound. Similarly, the thrombelastographic profiles (at 15 min and 2 h post-operation) and coagulation screen (prothrombin time, activated partial thromboplastin time, activated clotting time and platelets) did not differ significantly from those of non-rebound patients. The significance, if any, of the phenomenon of heparin rebound following cardiac surgery remains to be elucidated, and, until such time, conservative administration of protamine in response to 'rebound' is recommended.
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PMID:Heparin rebound phenomenon--much ado about nothing? 160 90

There is limited published data on the agreement between techniques for monitoring heparin levels. The aim of this study was to validate the Hepcon/HMS, with particular focus on the agreement with laboratory anti-Xa assay. The performances of two ACT instruments--Hemochron and HemoTec--were also evaluated, including an assessment for interchangeability. Blood samples from 42 adult cardiopulmonary bypass (CPB) patients were analysed for activated clotting time (ACT), whole-blood heparin concentration (Hepcon/HMS) and anti-factor Xa (anti-Xa) plasma heparin concentration. Agreement between measures was determined using the method of Bland and Altman. Simple analysis of agreement between the Hepcon and anti-Xa heparin revealed the Hepcon has a mean bias of -0.46 U/mL, with the limits of agreement +/- 1.12 U/mL. The comparison between ACT instruments indicated a mean difference of -96 seconds for the HemoTec, with limits of +/- 265 seconds. The Hepcon/ HMS instrument displayed satisfactory agreement with anti-Xa plasma heparin concentration, as the expected variation would not be expected to cause problems in the clinical setting. Agreement between the two measurements of ACT may be satisfactory, provided each is assigned a different target value.
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PMID:Heparin monitoring during cardiac surgery. Part 1: Validation of whole-blood heparin concentration and activated clotting time. 1460 42

Systemic lupus erythematosis (SLE) is an autoimmune disease frequently accompanied by the presence of an antiphospholipid antibody (APA). Early referred to as the lupus anticoagulant (LAC), this APA consists of immunoglobulins that are known to interfere with coagulation tests that are phospholipid dependent. Such tests include the partial thromboplastin time (PTT), the activated clotting time (ACT) and may affect the thrombin time (TT). This challenges the cardiac surgical team and the perfusionist responsible for monitoring anticoagulation while performing cardiopulmonary bypass (CPB). A 46-year-old female with a history of SLE, severe mitral insufficiency, an anterior wall myocardial infarction, and the presence of a LAC was admitted for mitral valve surgery. Replacement of the mitral valve was accomplished successfully, utilizing CPB. Anticoagulation was managed using the Hepcon HMS PLUS, a device that calculates an individual's heparin dose response and permits assessment of the heparin concentration throughout the procedure. The patient recovered and was sent home 16 days after surgery.
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PMID:A case report of mitral valve replacement in a patient with lupus antibody syndrome. 1471 75