Anticoagulants And Antiplatelets

Question 0

Coagulation cascade

Answer 0

Intrinsic or extrinsic pathways lead to formation of fibrin clot

Question 1

Steps of coagulation cascade

Answer 1

◦Injured cells release prothrombin activator
◦Prothrombin activator changes prothrombin to thrombin.
◦Thrombin changes fibrinogen to fibrin
◦Fibrin forms insoluble web over injured area to stop blood flow

Question 2

Fibrinolysis

Answer 2

•Clot removal
•Initiated by release of tissue plasminogen activator (tPA)
◦tPA converts plaminogen to plasmin
◦Plasmin digests fibrin strands – thus, circulation is restored
◦Regulated so unwanted clots are removed and fibrin is left in wounds

Question 3

Antiplatelet medications

Answer 3

•Interferes with platelet aggregation, prolonging bleeding time
•Platelet aggregation occurs after vasoconstriction
•Platelets give off enzymes that cause increased platelet activity
◦ADP, Thromboxane A2 (TXA2)
•Antiplatelet medication affects ADP and TXA2

Question 4

Common antiplatelet medications

Answer 4

◦aspirin (ASA)
◦ticlopidine (Ticlid)
◦clopidogrel (Plavix)

Question 5

Antiplatelet contraindications

Answer 5

•Underlying bleeding disorders
•Severe liver impairment    
•Any active bleeding
•Pregnancy
•Aspirin = “allergic triad”  
           caution with renal or otic disease
           gout

Question 6

Antiplatelet adverse effects

Answer 6

•Bruising and petechiae
•GI include:  N/V/D and pain
•Headache dizziness weakness
•Aspirin=hearing changes
•Watch for anaphylactic reactions
•Watch for platelet number
◦thrombocytopenia

Question 7

Antiplatelet nursing implications

Answer 7

• Important history and physical before giving medications
• Monitor intake and output (dehydration)
• Watch for bleeding
• Discontinue medications 7 – 10 days prior to surgery, dental work
• Watch for hearing loss, dizziness, LOC changes

Question 8

Antiplatelet patient teaching

Answer 8

• Teach patients to avoid any activity that would increase bleeding
• GI bleeding symptoms as well as any other bleeding
• Teach patient to take ASA with food to decrease stomach upset

Question 9

Antiplatelet therapeutic use

Answer 9

Prevent clot formation

Question 10

Anticoagulation medications

Answer 10

• Prolongs bleeding by interfering with the clotting cascade

* Given when patient has a high risk of developing thrombosis

Question 11

Warfarin action

Answer 11

•warfarin:

Interferes with the vitamin K dependent factors by reducing synthesis of vitamin K

Question 12

Heparin action

Answer 12

•heparin:

prevents conversion of prothrombin to thrombin and the conversion of fibrinogen to fibrin

Question 13

Coumadin specific points

Answer 13

◦Atrial fib, CHF, valvular disease, pulmonary embolus, deep vein thrombosis
◦Takes 3 to 5 days for therapeutic dose
◦Long term treatment ORAL

Question 14

Heparin specific points

Answer 14

•Heparin
◦Quick onset, used with emergencies with the above, also with procedures pregnancy
◦DIC
◦Intravenous and subcutaneous, short half life

Question 15

Enoxaparin specific points

Answer 15

•Enoxaparin
◦Same as heparin except half life longer
◦Lower molecular weight, so doesn’t bind with proteins

Question 16

Anticoagulation contraindications

Answer 16

• Active bleeding
• Head injury
• Recent surgery
• Bleeding disorder
• Advanced liver and renal disease
• Postpartum
• Pregnancy with warfarin

Question 17

Anticoagulation drug interactions

Answer 17

• Any antiplatelet or antithrombotic medication
• Spinal-epidural anesthesia
• Foods with high vitamin K content
• Some herbs
• Many drug interactions with warfarin
• Alcohol

Question 18

Anticoagulation adverse reactions

Answer 18

• Bleeding
• Hypersensitivity reactions, some life threatening
• GI effects including N/V/D pain
• Heparin can cause “HITT” heparin induced thrombocytopenia and thrombosis
• Subcutaneous injection site reactions

Question 19

Anticoagulation patient teaching

Answer 19

•Teach patient to watch for any signs of bleeding
•Teach patient to use soft toothbrushes, electric razors and be careful of injury
•Liver enzymes may elevate, showing cell damage
Warn patient of the effects of alcohol, especially with warfarin and blood tests

Question 20

Anticoagulation lab values

Answer 20

•Monitor lab values to include:
–prothrombin time (PT)
–international normalized ratio (INR)
–thrombin time, activated partial thromboplasin time (aPTT) complete blood count (CBC)

Question 21

Thrombolytics

Answer 21

• Used to break down existing clots, not just prevent them
• Dissolves all clots it comes in contact with
• Converts plasminogen to plastin, which breaks down fibrin
• Used in very serious, life threatening situations
• “Window of opportunity” for best results
• First one available was streptokinase, now others are developed

Question 22

Thrombolytic therapeutic uses

Answer 22

• Acute MI
• Massive PE
• Thrombotic strokes (R/O hemorrhagic)
• Deep vein thrombosis

Question 23

Thrombolytic contraindications

Answer 23

• Active bleed or recent bleed
• Recent CVA
• Severe hypertension
• Recent surgery
• Any increase risk of bleeding
• Postpartum/pregnancy
• End stage renal or liver disease
• Streptokinase used only once

Question 24

Thrombolytic adverse reactions

Answer 24

• Hemorrhage
• Anemia
• Hypersensitivity esp with Streptokinase

Question 25

Thrombolytic nursing implications

Answer 25

•Given only IV
•Monitor for anaphylactic reactions
•Watch for bleeding from all portals
◦Monitor vital signs frequently
◦Prevent injury, assess neurovascular and cardiovascular status frequently
◦Monitor lab values