Term
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Definition
| Process that leads to the cessation of bleeding from a blood vessel |
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Term
| Factors Influencing Hemostasis |
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Definition
1. Type and degree of vessel damage
2. Ability of vasoconstriction to occur
3. Availability of platelets and their functionality
4. Availability of clotting factors and their functionality
5. Absence of inhibitors and anticoagulants |
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Term
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Definition
1. Vascular Damage
2. Exposed Subendothelium
3. Platelet Adhesion
4. Platelet Aggregation
5. Platelet Plug Formation
6. Fibrin Stabilization
Initialization #1 and #2
Primary Hemostasis #3,#4,and #5
Secondary Hemostasis #6 |
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Term
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Definition
Vasoconstriction
Rerouting of Blood Flow
Platelet Aggregation
Contact activation of coagulation system (startup of secondary hemostasis) |
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Term
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Definition
Develop Platelet Plug via binding collagen and basement membrane; this binding causes shape change in the plts; promotes plts to bind to one another (Plt aggregation)
Main Functions
1. Maintenance of Vascular integrity
2. Platelt plug formation
3. Stabilization of plt plug; fibrin strands weave around bound plts creates fibrin clot |
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Term
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Definition
1. Adhesion' adhere collegen take on spiny shape and vWF is absorbed by surface receptors on plt and exposed subendothelial tissue
2. Release; plts dump contents of granaules adid in aggregation process; act as chemical signal
3. Aggregation; plts bind eachother; chemical signal stimulation
4. Stabilization; Addition of interwoven fibrin strands which produce fibrin clot |
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Term
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Definition
1. Intrinsic Pathway
2. Extrinsic Pathway
3. Common Pathway |
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Term
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Definition
| Tissue Factor interaction with Factor VII (circulating factor) leads to activation of Factor VIIa which catalyzes the reaction of factor X to Xa |
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Term
| Control of the Extrinsic Pathway |
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Definition
| Controlled by Tissue Factor Pathway Inhibitor TFPI; binds and inhibits Factor X; Controls the initiation of the Common Pathway |
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Term
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Definition
| Collagen exposure leads to HMWK, Prekallikrien (Fletcher Factor), and Factor XII (Hageman Factor) forming a complex. This complex catalyzes a conversion of factor XII to its active form XIIa which triggers the intrinsic pathway. XIIa triggers conversion XI to XIa (in presence of HMWK). XIA converts Factor IX to IXa in presence of Ca2+. IXa, Ca2+, plt factor, and factor VIII activate Factor X which activates prothrombin to thrombin in the common pathway |
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Term
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Definition
| Activation of Factor X into Xa. Xa in the presence of factor V (cofactor), Ca2+, and plt factor convert prothrombin to its active form thrombin. Thrombin catalyzes the conversion of frinogen into fibrin monomer. Thrombin also causes conversion of factor XII into XIIa (stabilizing fibrin monomers) |
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Term
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Definition
Fibrinogen
Intrinsic, Extrinsic, Common |
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Term
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Definition
Prothrombin
Intrinsic, Extrinsic, Common
Vitamin K |
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Term
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Definition
Tissue Thromboplastin
Extrinsic |
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Term
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Definition
Proaccelerin
Intrinsic, Extrinsic, Common |
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Term
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Definition
Proconvertin
Extrinsic
Vitamin K |
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Term
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Definition
Antihemophiliac Factor
Intrinsic |
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Term
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Definition
Christmas Factor
Intrinsic
Vitamin K |
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Term
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Definition
Stuart-Prower Factor
Intrinsic, Extrinsic, Common
Vitamin K |
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Term
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Definition
Plasma Thromboplastin
Intrinsic |
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Term
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Definition
Hageman/Contact Factor
Intrinsic |
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Term
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Definition
Fibrin Stabilizing Factor
Intrinsic, Extrinsic, Common |
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Term
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Definition
Fletcher Factor
Intrinsic |
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Term
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Definition
Fitzgerald Factor
Intrinsic |
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Term
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Definition
| Fibrin is broken down and removed from the clot which leads to the complete dissolution of the clot |
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Term
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Definition
| Plasminogen->Plasmin->Fibrin Clot->D-Dimer |
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Term
| Blood Collection Tube Used in Coagulation Testing |
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Definition
Sodium Citrate; Light Blue Top; 9:1 blood to anticoagulant ratio
Waste Tube should be used |
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Term
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Definition
Extrinsic and Common Pathways
Factors I, II, V, VII, X
Coag disorder assessment and therapeutic monitoring of oral anticoagulant (such as Warfarin)
reported as number of seconds needed for a clot to form
Value is converted into International Normalized Ration (INR) |
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Term
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Definition
2.0-3.0 INR
INR= (PT of patient/PT of geometric mean of the normal population)^ISI
ISI=International Sensitivity Index (sensitivity of the manufacture reagent) |
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Term
| Activated Partial Thromboplastin Time (APTT) |
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Definition
Intrinsic and Common Pathway
Factors I, II, V, VIII, IX, X, XI, XII, Prekallikrein, and HMWK
Factor VII and XIII are not assayed in this test
Used to determine therapeutic effectiveness of heparin |
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Term
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Definition
Measures Factor I; Determines if there is enough fibrinogen present for normal clotting
Perform when there is a prolonged abnormal PT and/or APTT
Normal Range is 200-400 mg/dL
Levels <100mg/dL associated with free bleeding |
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Term
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Definition
Indicates fibrin has been formed and degraded (fibrinolysis)
Elevated when coagulation is activated
Confirms that thrombin and plasmin have been generated
Dx for DVT and PE |
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Term
| Fibrin/fibrinogen Degradation Products (FDP) Assay |
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Definition
| Detects degradation products of fibrinolysis less specific compared to the D-Dimer test similar to it. |
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Term
| Platelet Function Assay (PFA) |
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Definition
| Aspirin and other drugs falsely prolong platelet function |
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Term
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Definition
Performed after unexpected prolonged PT or APTT
If addition of pooled plasma corrects then that means the patient has a factor deficiency. If it is not corrected it means the patient has an inhibitor. |
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Term
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Definition
Tested on unexpected prolonged Pt or APTT
Performed after mixing studies
Confirmatory test for the mixing study screening test
Test for specific factor deficiencies |
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Term
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Definition
Deficiency of Factor VII
Inherited or auto-antibodies produced against VII
Sex-linked inheritance |
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Term
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Definition
Deficiency of factor IX.
Sex-linked recessive inheritance |
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Term
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Definition
Platelet Disorder; functional defect in vWF. Decrease function of Factor VIII. Impaired platelet adhesion and aggregation. VWD stabilizes factor VIII
Treated with DDAVP raises levels of vWF and factor VIII |
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Term
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Definition
| Loss of functionality of vitamin k dependent factors II, VII, IX, X (Known as the Prothrombin group) |
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Term
| Disseminated Intravascular Coagulation (DIC) |
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Definition
| Clotting factors are depleted in the blood due to them being used up. |
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Term
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Definition
Genetic platelet disorder characterized by abnormally larger platelets and a mod decrease in
platelet count. Bleeding |
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Term
| Liver Disease and Coagulation Disorders |
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Definition
Decrease in vit K dependent factors
Increase in Factor VIII
Prolonged PT
Lack of fibrinogen |
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Term
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Definition
IV or subcutaneously
Inhibits Thrombin |
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Term
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Definition
Orally given
Vitamin K antagonist |
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Term
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Definition
Most common
directed towards phospholipids
IgG Antibody
Causes Thrombosis and Abnormal clotting |
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Term
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Definition
most common= anti-factor VIII
acquired hemophilia a
2nd most common= anti-factor IX
acquired hemophilia b |
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Term
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Definition
Warfarin
Liver disease
DIC
Vit K deficiency
Cirrhosis
Hepatitis
Inadequate levels factor I, II, V, VII, X |
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Term
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Definition
Heparin
Liver disease
Vit K Defieciency
Hemophilias
DIC
von Willebrand Disease
Lupus anticoagulant
Inadequate levels factor I, II, V, VIII, IX, X, XI, XII |
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Term
| False Elevation of PT or aPTT |
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Definition
Blood collection error
Hct >55%
Clotted Specimen
Heparin contamination (aPTT prolonged) |
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Term
| When to perform a Mixing Study? |
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Definition
No hx of heparin or warfarin therapy
No hx of liver disease
Prolonged PT and/or aPTT |
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Term
| Mixing Studies Test Principles |
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Definition
Pt needs >405 of each factor to be detected
Pt with inadequate levels <40$ of any factor would be prolonged and then corrected with the addition of pooled normal plasma (collection of 20 donors which adds up to 1005 of each factor) |
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Term
| Mixing Study Mix of pt and pooled normal plasma |
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Definition
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Term
| Lupus Anticoagulant (LA) Testing |
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Definition
Dilute Russells Viper Venom Time (DRVVT; Help to ID the Abs dependence on phospholipids
Hexagonal Phospholipid Test (HPP) and Platelet neutralization assay; dependence on phospholipids for LA to take effect |
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Term
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Definition
Embolism; obstruction of an artery
DVT, PE |
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Term
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Definition
Protein C is vitamin K dependent also known as factor XIV; inactivates factor Va and VIIIa. Regulatory protein
Protein S is a cofactor of protein C
Mutated S and c means no off switch and excessive coagulation would occur. |
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Term
| APC Resistance nd Factor v Leiden Mutation Testing |
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Definition
FVL is a mutation that causes increased thromboembolisms
Russells viper venom time RVVT screenin test for FVL; venom activates factor V and X; pts clotting decreases because venom. |
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Term
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Definition
Type I: most common; loss in VWF expression mild
Type II: Protien is dysfunctional
Type III: Rare; autosomal recessive; no VWF or Factor VIII activity; spontaneous bleeding |
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Term
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Definition
PFAs if both EDP and ADP are prolonged thenits possible theres a plt defect, thrombocytopenia (Plt <100), or anemia (<28% hct)
VWF activity assays |
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Term
| New Oral Anticoagulants NOACs |
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Definition
Dabigatran (Pradaxa); Thrombin inhibitor; TT, dTT, ECA recommended
Apixaban; Factor Xa Inhibitor
Edoxaban; Factor Xa Inhibitor
Rivaroxaban; Factor Xa Inhibitor
Recommended testing for all drugs except Dabigatran= Anti-Xa |
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