Day 1 Coag overview

What is in virchows triad

• changes in the vessel walls

• changes in blood flow

• changes in blood

platelets activation and aggregation involves

• collagen

• von willebrands factor

• GP receptors

Evaluation of primary homeostasis screening test is

plt count

Confirmatory tests evaluating primary homeostasis are

• Plt function screen

• Plt aggregation

• Possibly flow cytometry

Intrinsic pathway is what test

PTT

Extrinsic pathway is what test

PT

What factors are included in the intrinsic pathway of blood coagulation?

The intrinsic pathway includes factors XII, XI, IX, and VIII.

What factors are included in the extrinsic pathway of blood coagulation?

The extrinsic pathway includes factor VII and tissue factor (TF). This pathway is activated when tissue factor is exposed to blood.

What factors are included in the common pathway of blood coagulation?

The common pathway includes factors X, V, II (prothrombin), and I (fibrinogen). This pathway is activated by both the intrinsic and extrinsic pathways.

How long does a PTT take

25-30 sec

how long does a PT take

10-15 sec

Extrinsic pathway generates ______ amounts of fibrin and thrombin

smaller

Intrinsic pathway generates ______ amounts of fibrin and thrombin and ______ the response of the common pathway

larger; amplifies

What does thrombin do?

converts fibrinogen into fibrin

What does factor XIII do

stabilize the fibrin clot

Fibrinolysis uses tissue plasminogen activators to….

convert plasminogen to plasmin, which breaks down fibrin.

Primary homeostasis involves…

the formation of a plt plug

Secondary homeostasis involves…

stabilizing the plt plug with fibrin

Stop the clot formation by…

activation and control mechanisms w/ Protein C/S

Fibrinolysis is the system that…

dissolves and removes the clot

Defects in primary homeostasis involves…

bruises, nose bleeds, bleeding after dental work, and overall mucosal bleeding

in the body intrinsic and extrinsic are connected by…

VIIa being activated by F IX looping in F IXa

Zymogens

inactive precursors that circulate in plasma and act as procoagulants

F1

fibrinogen

F2

Prothrombin

F3

tissue factor (thromboplastin)

F4

Calcium

F5

liable factor, proaccelerin

F7

stable factor, proconvertin

F8

antihemophilic factor

F9

plasma thromboplastin component

F10

stuart-prower factor

F11

plasma thromboplastin antecedent

F12

hageman factor

F13

fibrin stabilizing factor

What factors are VitK dependent (Prothrombin group)

• FII

• FVII

• FIX

• FX

Fibrinogen group factors are …

• FV

• FVIII

• FXIII (this is the only one not consumed)

Contact group contains

• FXI

• FXII

• HMWK

• Prekallikren

What factors has the shortest half life

VII (6 hrs)

Coumadin acts as

an anticoagulant by inhibiting vitamin K dependent clotting factors.

Intact epithelium has a _______ ________ that protects from clots and repels plts

negative charge

What do endothelial cells release that controls plts

prostacyclin, ADPase, and nitric oxide

TFP inhibitor helps to inactivate factor…

VII

endothelial cells express heparan sulfate and antithrombin binds to it to neutralize…

thrombin and FXa

heparin acts as

an anticoagulant by enhancing the activity of antithrombin.

unfractionated heparin

can be used for treatment of all forms of thrombosis

• prevents thrombin generation

• Delays circulation of thrombin

Asparin acts on what part of the plt pathways

cyclooxygenase (COX) enzymes in the platelet pathways, inhibiting the formation of thromboxane A2, which is necessary for platelet aggregation.

what is the main active component of fibrinolytic system

plasmin

activators of the system include

• contact factors of the coag system

• tissue type plasminogen activator and urokinase type activator

• streptokinase

what are inhibitors of the fibrinolytic system

plasminogen activator inhibitors 1,2,3

alpha 2 antiplasmin

tissue activatable fibrinolysis inhibitor

What tube is used to collect coag samples

3.2% sodium citrate in silicon-coated glass tubes or plastic lined tubes

bad specimens for coag includes

• underfilled

• overfilled

• hemolyzed

• clotted

• in glass tube

PT stability

24 hrs

PTT stability

4hrs

T/F lipemia can interfere with OD clotting systems

T

Electromechanical

based on completion of an electrical circuit by a fibrin strand

electromagnetic

based on increase in plasma viscosity as fibrin forms

Prothrombin time uses what reagents

• thromboplastin

• Ca++

• Patient plasma

Thromboplastin has what sources

rabbit brain

human placenta

human brain

recombinant

glod standard reagents are a

ISI of 1

INR =

(PT/PTnorm)^ISI

INR range normal

2-3

INR range with mechanical heart valve

2.5-3.5PTT

PTT reagents

• activators and Partial thromboplastin reagent

What makes up the PTT reagent

phospholipids

What do the PTT activators contain

kaolin, celite, micronized celite, ellagic acid

When doing a PT and PTT test how much factor is needed to show no issues

40% or greater of all factors

Long PTT means do a

mixing study

If a patients mixing study does not correct then what does that mean

inhibitor is present (lupus-like anticoagulant or factor specific)