Assessing the correlations of anticoagulant effects between Thromboelastography [TEG] and anti-Xa activity in patients on therapeutic dose of low-molecular-weight heparin (LMWH)?

1."The thromboelastography is used to define the viscoelastic properties of blood to potentially predict the degree of anticoagulation from LMWH. All patients admitted to the critical care unit (CCU) with acute coronary syndromes (ACS) are started on LMWH. A blood sample will be taken once 4 hours after the therapeutic dose of enoxaparin is given on day 3. A TEG will be performed on these samples along with the anti-Xa levels and other coagulation parameters. Thromboelastograph Protocol for Sodium Citrated samples Specimen 1. Blood is drawn via venipuncture from the patient into Greiner Vacuette(Registered) #9NC (sodium citrate) Coagulation tubes. The samples must be filled to the mark and inverted 3 times to adequately mix the sample. 2. The exact collection time MUST be written onto the specimen. 3. The specimen will then be sent immediately to pathology for processing. 4. Samples are "rested" (undisturbed) for a minimum of 15 mins prior to analysis. Protocol 1. Routine daily maintenance and QC will be undertaken as per lab protocol. 2. Disposable cups and pins are placed into the TEG cup and allowed to warm to 370C. 3. Patient data is entered into the computer as required. 4. 20µl of 0.2M Calcium Chloride (CaCl2) is added to the TEG test cup. 5. The citrated sample is well mixed by gentle inversion, and 1 ml transferred to a vial of Kaolin activator. 6. This sample is mixed 5 times by inversion and 340µl pipetted into the TEG cup. 7. The carrier is raised until flush with the instrument, the lever placed in the "test" position and the test started in the usual manner. 8. The second channel can by activated by following steps from 2 above for additional testing if required." 2. 3.Pts do not receive LMWH prior to admission 4.Normal patients receive enoxaparin 1mg/kg twice daily subcutaneously 5.Patients with eGFR < 30 ml/min receive 1mg/kg daily 6.Obese patients (BMI > 35kg/m2) receive 1 mb/kg based on lean body mass (note. the length of time patients are on enoxaparin once TEG has been performed is irrelevant to the study.)