MIDTERM: APTT (lab) Flashcards
(26 cards)
Detects coagulation factor deficiency in Intrinsic and Common pathway
Activated Partial Thromboplastin Time (APTT)
Normal value for APTT
25-35 seconds (lab manual) or 35-45 seconds (PPT ni sire)
It is the time required to generate thrombin and fibrin polymers in intrinsic pathway
Activated Partial Thromboplastin Time (APTT)
Specimen used for APTT
Citrated blood
Reagent used for APTT
Thromboplastin, Activator (Kaolin, Celite, Ellagic acid), Calcium chloride, Phospholipids
Used for detecting the presence of circulating anticoagulants (inhibitors) and for monitoring heparin therapy
Activated Partial Thromboplastin Time (APTT)
What are the factors present in the intrinsic coagulation mechanism that are not measured in APTT?
Platelets and Factor XIII
Is Factor VII measured in APTT?
No. Because it in the extrinsic system
This is bound by the sodium citrate anticoagulant to prevent coagulation
Calcium in the whole blood
The plasma after centrifugation contains all intrinsic coagulation factors except?
Platelets and calcium
In APPT, these are added to the plasma
Calcium and a phospholipids substitute
These are much more sensitive to coagulation factor deficiencies than the whole blood clotting time
PT and APTT
Abnormally prolonged PT and APTT are cause by?
- Deficiency in one of the coagulation factors involved in the intrinsic and common pathway
- Inhibitor of coagulation may be present
An abnormally shortened APTT may be caused by?
- Partial clotting of the blood as a result of a traumatic venipuncture
- High levels of Factor 3
- Disseminated intravascular coagulation (DIC)
- Presence of platelets in plasma
Measures the availability of functional fibrinogen
Thrombin Time
Determine the rate of thrombin-induced cleavage of fibrinogen to fibrin monomers
Thrombin Time
Reagent used in Thrombin Time
Thrombin reagent and Calcium chloride
In Thrombin Time test, how many mL of plasma do you add in a plastic tube or siliconized glassware?
0.2 mL plasma
Normal value in Thrombin Time
15-18 seconds
Thrombin time is prolonged in:
- Fibrinogen deficiency
- Presence of Fibrin degradation products
- Presence of Thrombolytic agent
- Presence of Heparin
- Presence of Streptokinase
Ducker’s Test (5M Urea Solubility Test) is used for?
Factor XIII deficiency
Reagent used in Ducker’s Test (5M Urea Solubility Test)
5M Urea (or 1% monochloroacetic acid, 2% acetic acid)
In Ducker’s Test (5M Urea Solubility Test), you add ___ mL of Calcium Chloride to ____ mL PPP.
0.2 mL on both
In Ducker’s Test (5M Urea Solubility Test), You incubate the tube at?
37C for 30 minutes
