Activated partial thromboplastin aPTT

The recommended weight-adjusted regimen for UFH is an initial bolus of 60 U/kg (maximum 4,000 U) and an initial infusion of 12 U/kg/hour (maximum 1,000 U/hour). Due to a marked variability in the anticoagulant response in different individuals, the activated partial thromboplastin (aPTT) time needs to be monitored with a goal of 1.5 to 2 times the control value. Two consecutive therapeutic aPTT values need to be obtained in order to achieve a stable maintenance dose with subsequent daily aPTT to confirm the dose. UFH has been associated with a slight increase in major bleeding in most trials and serial blood counts should be obtained to monitor hemoglobin levels. In addition,... 

Activated partial thromboplastin time (aPTT) is a coagulation assay, which measures the time for plasma to clot upon activation by a particulate substance (e.g., kaolin) in the presence of negatively charged phospholipids. 

Before administering the first dose of heparin, the nurse obtains the patients vital signs. The most commonly used test to monitor heparin is activated partial thromboplastin time (APTT). Blood is drawn for laboratory studies before giving the first dose of heparin to obtain baseline data (See the discussion on preadministration assessment for the oral anticoagulants.)... 

A number of laboratory tests are available to measure the phases of hemostasis described above. The tests include platelet count, bleeding time, activated partial thromboplastin time (aPTT or PTT), prothrombin time (PT), thrombin time (TT), concentration of fibrinogen, fibrin clot stabifity, and measurement of fibrin degradation products. The platelet count quantitates the number of platelets, and the bleeding time is an overall test of platelet function. aPTT is a measure of the intrinsic pathway and PT of the extrinsic pathway. PT is used to measure the effectiveness of oral anticoagulants such as warfarin, and aPTT is used to monitor heparin therapy. The reader is referred to a textbook of hematology for a discussion of these tests. 

Patient is coagulopathic or has received heparin within past 48 h and has an elevated activated partial thromboplastin time (aPTT)... 

ACE, angiotensin-converting enzyme aPTT, activated partial thromboplastin time ARB, angiotensin receptor blocker BP, blood pressure CBC, complete blood count ECC, electrocardiogram HR, heart rate INR, International Normalized Ratio RR, respiratory rate SCr, serum creatinine, TTP, thrombotic thrombocytopenic purpura. 

II Umbilical cord, joint, and mucosal tract bleeding Prolonged prothrombin (PT) and activated partial thromboplastin time (aPTT) Specific assay for prothrombin... 

Activated partial thromboplastin time aPTT is performed by adding calcium phospholipids and kaolin to citrated blood and measures the time required for a fibrin clot to form. In this manner, aPTT measures the activity of intrinsic and common pathways. Prolongation of aPTT may be due to a deficiency or inhibitor for factors II, V, VIII, IX, X, XI, and XII. It also may be due to heparin, direct thrombin inhibitors, vitamin K deficiency, liver disease, or lupus anticoagulant. 

Abd Abdomen aPTT Activated partial thromboplastin time... 

The dose is titrated to maintain the activated partial thromboplastin time (aPTT) between 50 and 70 seconds. The first aPTT should be measured at... 

The activated partial thromboplastin time (aPTT) should be measured prior to initiation of therapy then no sooner than 6 hours after beginning the infusion or after a dose change. The traditional therapeutic range is 1.5 to 2.5... 

Pharmacology Enoxaparin, tinzaparin, and dalteparin are LMWHs. These agents enhance the inhibition of Factor Xa and thrombin by binding to and accelerating antithrombin activity. They preferentially potentiate the inhibition of Factor Xa, while only slightly affecting thrombin and clotting time (activated partial thromboplastin time [APTT] or PT). 

Determine patient baseline activated partial thromboplastin time (aPTT) prior to initiation of therapy with lepirudin, because lepirudin should not be started in patients presenting with a baseline aPTT ratio of 2.5 or more in order to avoid initial overdosing. 

Initial dosage in HIT or heparin-induced thrombocytopenia and thrombosis syndrome (HITTS) Before administering argatroban, discontinue heparin therapy and obtain a baseline activated partial thromboplastin time (aPTT). The recommended initial dose of argatroban for adults without hepatic impairment is 2 mcg/kg/min administered as a continuous infusion (see table). 

AMS acute myocardial syndrome ANC absolute neutrophil count ANS autonomic nervous system APACHE Acute Physiologic and Chronic Health Evaluation ICU illness severity scoring system APAP acetaminophen [N-acetyl-p-aminof enol] aPTT activated partial thromboplastin time ARB angiotensin 11 receptor blocker ARDS adult respiratory distress syndrome... 

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