A. Complete blood count (CBC)
B. Activated partial thromboplastin time (aPTT)
C. Prothrombin time (PT)
D. Blood urea nitrogen (BUN)
Heparin dosing is based on aPTT results. The PT is reflective of warfarin’s anticoagulant effect.
A. vitamin E
B. vitamin K
C. protamine sulfate
D. calcium gluconate
Vitamin K is the antagonist for warfarin.
A. The patient is not receiving enough warfarin for a therapeutic effect.
B. The patient’s warfarin dose is therapeutic.
C. The patient is not receiving enough subcutaneous heparin for a therapeutic effect.
D. The patient is receiving a dangerously high amount of heparin.
INR determination is a routine test to evaluate coagulation while patients are taking warfarin, not heparin. A therapeutic INR is 2 to 3.
A. “I will avoid contact sports.”
B. “I will take my medication in the early evening each day.”
C. “I will increase the dark green leafy vegetables in my diet.”
D. “I will contact my physician if I develop excessive bruising.”
Dark green leafy vegetables are rich in vitamin K, which would antagonize the effects of warfarin. Therefore, it is important to maintain a consistent daily intake of vitamin K and avoid eating large amounts of these foods.
Clopidogrel (Plavix) is an antiplatelet drug indicated for thrombus prevention associated with strokes and myocardial infarction. Enoxaparin and heparin are anticoagulants. Alteplase is a thrombolytic drug.
A. tirofiban (Aggrastat)
B. protamine sulfate
C. warfarin (Coumadin)
D. aminocaproic acid (Amicar)
Tirofiban is a glycoprotein IIb/IIIa inhibitor that blocks the enzyme essential for platelet aggregation. This is given to prevent the formation of further clots and is faster acting than warfarin. Protamine sulfate is the antagonist for heparin, not an anticoagulant. Aminocaproic acid is an antifibrinolytic, the opposite of what is needed in this situation.
A. Low-molecular-weight heparin
B. Oral anticoagulant
C. Glycoprotein IIb/IIIa inhibitor
D. Thrombolytic drug
Enoxaparin is a low-molecular-weight heparin.
A. “There is really no difference, but dalteparin is preferred because it is less expensive.”
B. “Dalteparin is a low-molecular-weight heparin that has a more predictable anticoagulant effect.”
C. “I’m not really sure why some physicians choose dalteparin and some heparin, so you should ask your doctor.”
D. “The only difference is that heparin dosing is based on the patient’s weight.”
A low-molecular-weight heparin is more predictable in its effect than regular heparin. Dalteparin is more expensive than heparin and is dosed based upon the patient’s weight.
A. vitamin K
B. vitamin E
D. protamine sulfate
Protamine sulfate binds with heparin in the bloodstream to inactivate it and thus reverse its effect.
A. Administer 650 mg of acetylsalicylic acid (ASA), and reassess pain in 30 minutes.
B. Take advantage of a teachable moment to inform the patient of potential drug interactions with anticoagulants.
C. Explain to the patient that ASA is contraindicated, and administer ibuprofen as ordered.
D. Explain that the headache is an expected side effect and will subside shortly.
Patients taking an anticoagulant should not use medications that would further increase the risk of bleeding.
A. “Your concern is valid in that you are at an increased risk for bleeding, so I will call the doctor to discontinue the heparin.”
B. “It usually takes 4 to 5 days to achieve a full therapeutic effect for warfarin, so the heparin is continued to help prevent blood clots until the warfarin is working up to speed.”
C. “Because of your valve replacement, it is especially important for you to be fully anticoagulated, and the heparin and warfarin together are more effective than one alone.”
D. “Because you are now up and walking, you have a higher risk of blood clots and therefore need to be on both medications.”
Warfarin works by decreasing the production of clotting factors. However, it takes 4 to 5 days for the body to use up present clotting factors and thus achieve a full therapeutic anticoagulant effect. Because of this, heparin is continued until this is achieved.
A. “I will double my dose if I forget to take it the day before.”
B. “I should keep taking ibuprofen for my arthritis.”
C. “I should decrease the dose if I start bruising easily.”
D. “I should use a soft toothbrush for dental hygiene.”
The patient should reduce the risk of bleeding, such as using a soft toothbrush. The other choices are inaccurate.
A. Does not aspirate prior to injecting the medication
B. Massages the site after administration of the medication
C. Administers the medication greater than 2 inches away from the umbilicus
D. Injects the medication and then waits 10 seconds before withdrawing the needle
It is not recommended to massage the area of injection of anticoagulants due to the increased risk of hematoma formation.
C. Dong quai
E. St. John’s wort
C. Dong quai
E. St. John’s wort
Garlic, ginkgo, dong quai, and St. John’s wort alter blood coagulation and may increase the risk of bleeding when given concurrently with oral anticoagulants. Glucosamine does not affect coagulation.
A. Record vital signs and report changes.
B. Observe for signs and symptoms of bleeding.
C. Monitor liver enzymes.
D. Assess for cardiac dysrhythmias.
E. Administer injections intramuscularly to prevent bleeding.
B. Observe for signs and symptoms of bleeding
D. Assess for cardiac dysrhythmias
Alteplase can cause bleeding as well as cardiac dysrhythmias. Vital sign changes can alert the nurse to these complications. Alteplase does not directly affect liver enzymes. Injections should not be administered intramuscularly because of the increased risk of bleeding.