Coagulation Disorders

Question 1

Three major steps in the process of hemostasis

Answer 1

Prothrombinase converts prothrombin to thrombin
Thrombin converts fibrinogen to fibrin
Fibrin strands trap RBCs forming clot

Question 2

Role of platlets

Answer 2

Platelets adhere to and aggregate at site of injury in vessel

Question 3

Role of Platelets

Answer 3

Platelet activation leads to formation of fibrin network that trap RBCs forming clot

Question 4

Role of Cofactors in Hemostasis

Answer 4

Ca+2 and Vitamin K are critical for synthesis of clotting factors which stop wounds from bleeding

Question 5

Deep venous thrombosis (DVT)

Answer 5

Venous clots often develop in the legs as a DVT, but can migrate to lungs creating a pulmonary embolism

Question 6

Fibrinolysis

Answer 6

Plasmin breaks down fibrin network

Question 7

Clots migrating from left atrium can cause

Answer 7

strokes

Question 8

Clots migrating from the right atria can cause a

Answer 8

pulmonary embolism

Question 9

Coronary artery clots cause

Answer 9

MIs

Question 10

Heparin (Know this)

Answer 10

Enhances antithrombin activity
Decreases thrombin activity
Decreases prothrombinase activity

Question 11

Low molecular wt Heparin

Answer 11

Similar activity
Fewer adverse effects than heparin
Less risk of thrombocytopenia compared to heparin

Question 12

When do we use heparin

Answer 12

DVT, post stroke, post MI, prevent PE

Question 13

Mech of action for Heparin

Answer 13

Activates antithrombin III, which inhibits thrombin and factor Xa (prothrombinase).

Remember prothrombin istransformed into thrombin by a clotting factor known as factor X or prothrombinase and then thrombin acts to transform fibrinogen, also present in plasma, into fibrin, which, in combination with platelets from the blood, forms a clot
-DONT NEED TO KNOW

Prevents clot formation; does not break down existing clots

Question 14

Antidote for heparin

Answer 14

Protamine Sulfate

Question 15

Adverse effects of heparin

Answer 15

Osteoperosis
Bleeding
Skin lesions

Heparin Induced thrombocytopenia

Question 16

Warfarin used for

Answer 16

Prophlaxis of eventls like DVT and PE

prevention of CVA /MI

Does not treat

Question 16

Low molecular wt heparin advantages

Answer 16

Possess the same degree of anticoagulant activity as heparin but have several advantages which are;
Less likely to cause thrombocytopenia
Duration of action is 2 to 4 times longer.
Produce a more stable response.
Fewer follow up labs are needed.
Client can be trained to give S/C injections at home.
Often the drug of choice now .

Question 17

Heparin half life

Answer 17

Very brief

Question 18

Mech of action - Warfarin

Answer 18

Warfarin inhibits/blocks two enzymes that use Vitamin K to produce clotting factors

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Question 19

Adverse effects of Warfarin

Answer 19

Purple toe syndrom
Microembolism, osteperosis
Bone fractures
Abnormal bleeding

Question 20

Antidote for warfarin

Answer 20

Vit K

Question 21

Dietary reccomendations for Warfarin

Answer 21

Avoid Vit K high foods

Question 22

Nursing considerations for pts recieving anticoagulant therapy

Answer 22

Obtain a complete health history including allergies and drug history

Obtain baseline vital signs, especially heart rate and blood pressure, and clotting times

Question 23

What to be careful of for someone on anticoag therapy

Answer 23

Any accidental bumps
Aggressive teeth brushing

Question 24

What to monitor for pts on Heparin

Answer 24

CBC, INR, PT

Question 25

What pts should be more closely moniored if opn anticoag therapy

Answer 25

Also monitor patients with kidney or liver disease, GI, diabetes with extra care. At increased risk for bleeding/low platelets (liver) DM increases risk of blood clotting

Question 26

PT Test

Answer 26

PT stands for prothrombin time. It is a measure of how quickly blood clots. The traditional method for performing a PT test is to blood drawn and sent to a lab. At the lab, a substance called a reagent is added to the blood. The reagent causes the blood to begin clotting. The PT result is the time in seconds that is required for the blood to clot.

Question 27

INR Test

Answer 27

INR stands for International Normalized Ratio. As its name suggests, one INR result can be compared to another INR result regardless of how or where the result was obtained. So, the INR is just the standard unit used to report the result of a PT test. Range: Varies for person to person Most common is bw 2 and 4 Normal pt would have 1

Question 28

Higher INR means

Answer 28

Longer time for blood clotting

Question 29

Lower INR means increased risk for

Answer 29

Clotting

Question 30

Typical APTT

Answer 30

25-30 seconds

Question 31

Direct Thrombin and Factor Xa inhibitors

Answer 31

Newer drugs in the prevention and TX of venous thromboembolism and pulmonary emboli. Originally derived from chemicals found in leeches. Directly inhibit thrombin preventing the formation of fibrin used for the same types of indications as heparin or LMWH>

Question 32

Why would someone get an apixiban over warfarin

Answer 32

Apixiban requires NO monitoring

Question 33

Direct Thrombin and Factor Xa inhibitors use

Answer 33

Shorter half life, work faster

Question 34

Antiplatlet drugs include

Answer 34

Aspirin Reduces formation of thromboxanes (promotes activation of platelets) ADP receptor antagonists Prevent aggregation by blocking receptor Prevent activation of platelets

Question 35

Mech of action of antiplatlet drugs

Answer 35

Blocks ADP receptors on platelets, inhibiting platelet activation and aggregation, thereby extending clotting times

Question 35

Adverse effects of antiplatlet drugs

Answer 35

Headache, dizziness Flu-like syndrome Diarrhea Bruising Upper respiratory tract infections Rash, pruritis Serious bleeding

Question 36

Direct Xa inhibitors

Answer 36

Direct Oral Anticoagulants DOAC Only given PO Result in prolonged clotting time Reduce risk of stroke and systemic embolism in clients with nonvalvular a fib. TX of DVT and Pulmonary embolism Prophylaxis of DVT in client who have undergone knee or hip surgery. Apixaban and rivaroxaban. Adverse effect bleeding and there is no antidote. Abrupt discontinuation increases risk for thromboembolism. Increased risk of spinal and epidural hematomas in uncoagulated patients

Question 37

Thrombolysis

Answer 37

Anticoagulants prevent new clot formation Thrombolytics break down existing clots Fibrinolysis breakdown of fibrin fibers leading to disruption of clot

Question 38

Antiplatlet meds are NOT clot buster > T or F

Answer 38

True

Question 39

Therapeutic effects and uses

Answer 39

Thrombotic CVA Off-label use to restore IV catheter patency Mechanism of action Converts plasminogen to plasmin which breaks down fibrin in clot Lowers circulating fibrinogen and plasminogen

Question 40

Adverse effects of alteplase

Answer 40

Bleeding Angioedema (Also ace inhibs) Intercranial bleeding

Question 41

What to monitor when administering a thrombolytic?

Answer 41

BP, Pulse Q15 min for and H, then Q30 min INR, CBC, Monitor for internal bleeding

Question 42

Antifibrinolytics

Answer 42

Used to prevent and treat excessive bleeding post-surgery Formation of abnormal clots, possibly pulmonary clots Inactivates plasminogen precursor for plasmin that digests the fibrin clot. Very rare

Question 43

Acute uses of fibrinolytics

Answer 43

Acute hemorrhages Prevention of post-operative bleeding

Question 44

aptt used to monitor effectiveness of

Answer 44

Used to monitor the effectiveness of heparin

Question 45

PT used to monitor effectivness of

Answer 45

Warfarin