Coagulation and Lab Evaluation

Question 1

Primary hemostasis

Answer 1

Vessel/platelets/vWF interactions

Question 2

Secondary hemostasis

Answer 2

Coagulation and anticoagulant factors, cross links the platelet plug to strengthen it

Question 3

Fibrinolysis

Answer 3

Plasmin activation and fibrin and dissolution

Question 4

Coagulation cascade enzymatic reactions 3

and 2 requirements

Answer 4

1) formation of thrombin
2) conversion of fibrinogen into fibrin
3) clot stabilization/formation

Phospholipid surface (platelets) and Ca2+

Question 5

Production center of coagulation factors

Answer 5

Liver

Question 6

Liver function/dz

Answer 6

removes activated coagulation factors.

If diseased can result in the hypocoagulation

Question 7

Vitamin K dependent factors Canada

Answer 7

II, VII, IX, X 1972

Question 8

3 likes that merge for coagulation cascade

Answer 8

Intrinsic, extrinsic, common

occur simultaneously

Question 9

coagulation is primarily activated through…

Answer 9

extrinsic

Question 10

Intrinsic components

Answer 10

not 12…. but 11.98

Question 11

extrinsic components

Answer 11

III (TF)

Question 12

PT

Answer 12

Extrinsic system - Play Tennis (outside - Extrinsic)

Question 13

PTT

Answer 13

Intrinsic system - Play Table Tennis (inside - intrinsic)

Question 14

Common pathway factors

Answer 14

10,5,2,1

Question 15

Intrinsic pathway initiation

Answer 15

factor 12 in contact with a negatively charged surface

Question 16

Factor XII deficiency

Answer 16

Common in Cats.

prolonged clotting time even though not clinically bleeding

Question 17

Factor VIII and IX deficiency

Answer 17

sex-linked
Hemophilia A: VIII
Hemophilia B: IX

Question 18

Extrinsic pathway initiation

Answer 18

Factor III  (tissue factor) exposure at site of tissue injury activates X and IX (crosses over to intrinsic)
can be activated during traumatic venipuncture (clotted sample)

Question 19

Factor VII

Answer 19

Produced in liver, vit. K dependent
shortest half life of Vit. K dependent factors
first factor to deplete in early rodenticide toxicity
USE TEST PT for vit K antagonist

Question 20

Common Pathway initiation

Answer 20

Thrombin responsible for amplification of hemostasis (PT/PTT tests used in combo to test this)
Promote platelet aggregation and activation

Question 21

Antithrombin

Answer 21

inhibitor of coagulation
lost in protein-losing nephropathies/enteropathies
Consumed in DIC
Directly inhibits thrombin and indirectly inhibits thrombin formation

Question 22

anticoagulant Proteins other from Liver

Answer 22

Proteins C and S

Fibrin(ogen) degradation products

Question 23

Fibrinolytic proteins (break down clots)

Answer 23

Plasmin degrades fibrinogen, fibrin monomers/polymers, and cross-linked Fibrin
leads to FDPs and D-Dimers

Question 24

FDP vs. D-Dimers

Answer 24

formed from degradation of fibrinogen, fibrin and cross-linked fibrin (ANY PART OF THE MESH WORK)
D-dimers are formed only from degradation of cross-linked fibrin SPECIFICALLY FOR CROSS LINKED

Question 25

Activated Clotting Time (ACT)

Answer 25

Intrinsic and common pathway. Severe thrombocytopenia (,10,000/uL) may prolong clot time requires significant depletion of a factor to be abnormal

Question 26

Samples collected for coagulation

Answer 26

``` trisodium citrate (Blue Top) for PTT, PT, TT avoid traumatic venipuncture ```

Question 27

PTT

Answer 27

``` Partial Thromboplastin Time intrinsic and common Prolonged when at least one factor of these pathways are decreased to 30% of normal NOT affected by thrombocytopenia NOT an indicator of hypercoaguloability ```

Question 28

PT

Answer 28

``` Prothrombin Time Extrinsic and common pathways Prolonged when at least one factor is decreased by 30% NOT affected by thrombocytopenia NOT indicator of hypercoagulability ```

Question 29

Fibrinogen concentration 2

Answer 29

Heat precipitation - (point of care) only detects large differences. Better at determining INCREASED concentrations with inflammatory disease low concentration is indicative of decreased production or increased consumption (DIC) Clauss method - (laboratory use) assess thrombin conversion to fibrinogen and fibrin, time to clot is measured Prolonged suggests low or absent FIBRINOGEN

Question 30

FDP

Answer 30

``` detect increased fibrin(ogen)olysis increased concentration seen with: Thrombosis/thromboembolism DIC Internal hemorrhage Surgery Liver Dz (lack antithrombin 3) Kidney Dz (same as liver) ```

Question 31

D- Dimers

Answer 31

increase in only fibrinolysis | thromboembolic dz or DIC (detects an antigen when fibrin is cross-linked)

Question 32

Antithrombin III

Answer 32

reported as a percent of normal Lower than 70% increased risk for thrombosis decrease: decreased production (increased consumption or loss): Liver dz (production Protein losing enteropathy/colic (loss) Protein losing neuropathy (loss) DIC (consumption)

Question 33

Evaluate the bleeding pattern of bleeding patient (3)

Answer 33

Primary hemostatic defect Secondary hemostatic defect Mixed

Question 34

Primary Hemostatic defect

Answer 34

``` defects in platelets or vessels: Petechia Ecchymoses spontaneous bleeding from MM Prolonged bleeding from injections site ```

Question 35

Primary Hemostatic defect evaluation

Answer 35

Platelet count | Buccal Mucosal Bleeding Time (BMBT)

Question 36

Secondary Hemostatic defects

Answer 36

acquired disorders or congenital cause leading to: Hematomas bleeding into joints, m., body cavity Injection site initially clots and bleeding reoccurs later (clot not stable)

Question 37

Secondary Hemostasis defect evaluation

Answer 37

ACT, PTT, PT, TT

Question 38

congenital causes

Answer 38

RARE: factor XII deficiency Hemophilia A and B (Factors VII and IX)

Question 39

Acquired causes

Answer 39

More COMMON: Vit. K antagonism/malabsorption Markedly impaired liver function

Question 40

Vitamin K Antagonism

Answer 40

Rodenticides: inhibit recycling of Vitamin K1 Moldy sweet clover ACT, PTT, PT prolonged IF EARLY ONLY INCREASE IN PT Deficiency (not able to absorb Vit. K): biliary obstruction or severe enteric dz

Question 41

Coagulopathy associated with liver dz

Answer 41

Decreased production of coagulation factors! Decreased clearance! ACT, PTT, PT prolonged increase FDPs can progress to DIC

Question 42

Mixed hemostatic defect

Answer 42

Clinical and laboratory tests that indicate a defect in both primary and secondary DIC IS THE BIG ONE! disseminated intravascular coagulopathy (Death Is Coming) really the only one widespread thrombus formation and hemorrhage ALWAYS secondary to another process

Question 43

Common Causes of DIC

Answer 43

Sepsis, neoplasia, severe trauma, heat stroke

Question 44

Evaluation for DIC

Answer 44

platelet numbers are classically mild to moderate 1) thrombocytopenia combined with prolongations of the PT and/or PTT 2) decrease in ATIII or fibrinogen due to consumption 3) Increased FDPs or D-dimers 4) Fragmented erythrocytes (small animal)