A passenger sits without moving through a long overnight flight. This raises the risk of deep vein thrombosis mainly through which element of Virchow's triad?
Stasis of blood flow
✓
Endothelial injury
Hypercoagulability
Vasoconstriction
Correct Answer
Stasis of blood flow
Prolonged sitting slows venous return from the legs, and pooled, slow-moving blood clots more easily, which is the stasis element of the triad. Endothelial injury refers to vessel wall damage from surgery, trauma or catheters. Hypercoagulability refers to blood that clots too readily, as with estrogen use or inherited clotting disorders. Vasoconstriction is not one of the three elements of Virchow's triad.
Category: Clotting Physiology
Question 2
Vitamin K is required for the liver to synthesize which group of clotting factors?
I, V, VIII and XIII
II, VII, IX and X
✓
III, IV, XI and XII
V, VIII, XI and XII
Correct Answer
II, VII, IX and X
Factors II (prothrombin), VII, IX and X need vitamin K to become functional, which is why warfarin, a vitamin K antagonist, lowers all four. I, V, VIII and XIII do not depend on vitamin K. III, IV, XI and XII include tissue factor and calcium, which are not vitamin K dependent. V, VIII, XI and XII are also made without vitamin K.
Category: Clotting Physiology
Question 3
Which coagulation factor converts fibrinogen into fibrin to form a stable clot?
Factor VII
Factor X
Thrombin (factor II)
✓
Factor XII
Correct Answer
Thrombin (factor II)
Thrombin, the activated form of factor II, cuts fibrinogen into fibrin strands and also activates other factors that amplify and stabilize the clot. Factor VII works with tissue factor to start the extrinsic pathway. Factor X, once activated, converts prothrombin to thrombin rather than acting on fibrinogen. Factor XII starts the intrinsic pathway when it contacts exposed collagen.
Category: Clotting Physiology
Question 4
When giving enoxaparin from a prefilled syringe, which action is correct?
Inject into the deltoid muscle
Aspirate before injecting
Massage the site afterward
Leave the air bubble in the syringe
✓
Correct Answer
Leave the air bubble in the syringe
The air bubble in a prefilled enoxaparin syringe is left in place so the full dose is delivered and the drug is not left along the needle track; the injection goes into a pinched fold of abdominal skin. Inject into the deltoid muscle is wrong because the drug is given subcutaneously, not intramuscularly. Aspirate before injecting is not done with subcutaneous anticoagulants because it increases tissue trauma and bruising. Massage the site afterward increases bruising and is avoided.
Category: Heparin and LMWH
Question 5
Enoxaparin can accumulate and raise the risk of bleeding in a patient with which condition?
Severe kidney impairment
✓
Hypothyroidism
Controlled hypertension
Osteoarthritis
Correct Answer
Severe kidney impairment
Enoxaparin is cleared by the kidneys, so it builds up when renal function is poor and raises the risk of bleeding; the provider adjusts therapy or chooses a different anticoagulant. Hypothyroidism does not change enoxaparin clearance. Controlled hypertension does not affect how the drug is eliminated. Osteoarthritis has no effect on how the drug is eliminated.
Category: Heparin and LMWH
Question 6
Long-term heparin therapy can cause which adverse effect?
Gynecomastia
Osteoporosis
✓
Hypoglycemia
Ototoxicity
Correct Answer
Osteoporosis
Prolonged heparin use can weaken bone and lead to osteoporosis and fractures, in addition to its risks of bleeding, heparin-induced thrombocytopenia and hyperkalemia. Gynecomastia is linked to drugs such as spironolactone, not heparin. Hypoglycemia is not an effect of heparin. Ototoxicity is linked to loop diuretics and aminoglycosides.
Category: Heparin and LMWH
Question 7
Which instruction about taking dabigatran capsules is correct?
Open it and sprinkle the contents on food
Crush it and mix it with water
Swallow the capsule whole
✓
Chew the capsule before swallowing
Correct Answer
Swallow the capsule whole
Dabigatran capsules must be swallowed whole because opening, crushing or chewing them greatly increases absorption and the risk of bleeding; they are also kept in the original container to protect them from moisture. Open it and sprinkle the contents on food is not allowed for this drug. Crush it and mix it with water releases the drug too quickly. Chew the capsule before swallowing has the same problem.
Category: Direct Oral Anticoagulants
Question 8
A patient taking dabigatran has life-threatening bleeding. Which reversal agent binds dabigatran directly?
Protamine sulfate
Vitamin K
Andexanet alfa
Idarucizumab
✓
Correct Answer
Idarucizumab
Idarucizumab is a monoclonal antibody fragment that binds dabigatran and neutralizes its anticoagulant effect rapidly. Protamine sulfate reverses heparin. Vitamin K reverses warfarin by restoring clotting factor production. Andexanet alfa reverses the factor Xa inhibitors apixaban and rivaroxaban, not a direct thrombin inhibitor.
Category: Direct Oral Anticoagulants
Question 9
A patient whose warfarin dose has been stable begins taking St. John's wort. What effect on the warfarin should the nurse anticipate?
Decreased anticoagulant effect
✓
Increased anticoagulant effect
Faster onset of action
No change in effect
Correct Answer
Decreased anticoagulant effect
St. John's wort induces liver enzymes that break down warfarin, so warfarin levels fall, the INR drops and the risk of clotting rises. Increased anticoagulant effect would be expected from enzyme inhibitors such as amiodarone instead. Faster onset of action is not an effect of this herb. No change in effect is incorrect, which is why patients must report all supplements.
Category: Warfarin
Question 10
Why is warfarin avoided in most pregnant patients who need anticoagulation?
It loses its effect as blood volume rises
It crosses the placenta and can harm the fetus
✓
It causes gestational hypertension
It must be injected during pregnancy
Correct Answer
It crosses the placenta and can harm the fetus
Warfarin crosses the placenta and can cause birth defects and fetal bleeding, so a heparin product such as enoxaparin, which does not cross the placenta, is usually used instead; rare exceptions include some patients with mechanical heart valves. It loses its effect as blood volume rises is not the reason it is avoided. It causes gestational hypertension is not a known effect of warfarin. It must be injected during pregnancy is false, since warfarin is an oral drug in all patients.
Category: Warfarin
Question 11
A patient taking warfarin asks how to shave safely. Which device should the nurse recommend?
Straight razor
Disposable blade razor
Electric razor
✓
Safety razor
Correct Answer
Electric razor
An electric razor does not cut the skin, so it prevents the nicks that can bleed heavily in an anticoagulated patient; a soft toothbrush is recommended for the same reason. Straight razor use risks deep cuts. Disposable blade razor use can easily nick the skin. Safety razor still uses an exposed blade that can cause cuts.
Category: Bleeding Precautions
Question 12
A patient taking apixaban calls the clinic. Which reported finding should be reported to the provider right away?
A small bruise after bumping a table
Mild tiredness after exercise
Dry, itchy skin
Black, tarry stools
✓
Correct Answer
Black, tarry stools
Black, tarry stools suggest bleeding in the upper gastrointestinal tract, a serious complication of any anticoagulant that needs prompt evaluation. A small bruise after bumping a table is a minor, expected finding. Mild tiredness after exercise is not a sign of bleeding by itself. Dry, itchy skin is not related to apixaban's bleeding risk.
Category: Bleeding Precautions
Question 13
Clopidogrel may fail to prevent clots in a patient who is a poor metabolizer through which liver enzyme?
CYP2C19
✓
CYP3A4
CYP2D6
CYP1A2
Correct Answer
CYP2C19
Clopidogrel must be activated by CYP2C19, so people with reduced-function gene variants, or those taking strong CYP2C19 inhibitors, make little active drug; a boxed warning advises considering another P2Y12 inhibitor. CYP3A4 metabolizes many drugs but is not the key step for clopidogrel activation. CYP2D6 is important for drugs such as codeine. CYP1A2 is important for drugs such as theophylline.
Category: Antiplatelets
Question 14
Which adverse effect is particularly associated with ticagrelor and can limit daily activities?
Gynecomastia
Shortness of breath
✓
Dry cough
Ringing in the ears
Correct Answer
Shortness of breath
Ticagrelor commonly causes dyspnea, a sensation of shortness of breath that is usually mild but can bother patients enough to affect activity; it should be reported rather than handled by stopping the drug. Gynecomastia is not linked to ticagrelor. Dry cough is typical of ACE inhibitors. Ringing in the ears is associated with high-dose aspirin and loop diuretics.
Category: Antiplatelets
Question 15
Prasugrel is contraindicated in a patient with a history of which condition?
Hypertension
Type 2 diabetes
Transient ischemic attack
✓
Hyperlipidemia
Correct Answer
Transient ischemic attack
Prasugrel carries a boxed warning against use in patients with a prior stroke or transient ischemic attack because it raises the risk of intracranial and fatal bleeding in that group. Hypertension is not a contraindication. Type 2 diabetes is not a contraindication. Hyperlipidemia is common in patients with coronary disease and does not prevent its use.
Category: Antiplatelets
Question 16
During an eptifibatide infusion, which lab value is monitored closely because the drug can cause it to fall profoundly?
Serum potassium
Blood glucose
Serum sodium
Platelet count
✓
Correct Answer
Platelet count
Eptifibatide is a glycoprotein IIb/IIIa inhibitor that can cause profound thrombocytopenia, so platelet counts are checked and the drug is stopped if they drop significantly. Serum potassium is not lowered by this drug. Blood glucose is not affected by it. Serum sodium is not a specific concern with this drug.
Category: Antiplatelets
Question 17
A patient with a suspected MI is given a non-enteric-coated aspirin tablet. How should the patient take it?
Chew it before swallowing
✓
Swallow it whole with water
Take it with an antacid
Wait and take it with a meal
Correct Answer
Chew it before swallowing
Chewing aspirin speeds its absorption so it blocks platelet thromboxane production faster during an acute heart attack. Swallow it whole with water slows absorption compared with chewing. Take it with an antacid is not part of acute MI care and can alter absorption. Wait and take it with a meal delays a drug that is needed right away.
Category: Antiplatelets
Question 18
Which P2Y12 inhibitor is given intravenously during percutaneous coronary intervention?
Clopidogrel
Cangrelor
✓
Prasugrel
Ticagrelor
Correct Answer
Cangrelor
Cangrelor is the only intravenous P2Y12 inhibitor; it inhibits platelets almost immediately and platelet function recovers quickly after the infusion stops. Clopidogrel is an oral prodrug whose effect lasts for days. Prasugrel is an oral drug with long-lasting platelet inhibition. Ticagrelor is an oral drug that binds the receptor reversibly.
Category: Antiplatelets
Question 19
A patient is receiving an alteplase infusion. Which nursing action is correct?
Encourage early ambulation
Place a new subclavian line
Avoid intramuscular injections
✓
Apply heat to puncture sites
Correct Answer
Avoid intramuscular injections
Thrombolytics break down existing clots throughout the body, so needle sticks and invasive procedures are kept to a minimum and intramuscular injections are avoided to prevent bleeding into muscle. Encourage early ambulation is wrong because the patient stays on bedrest to reduce falls and bleeding. Place a new subclavian line is avoided because that site cannot be compressed. Apply heat to puncture sites would increase blood flow, while pressure is applied instead.
Category: Thrombolytics
Question 20
For a patient with ST-elevation MI, which thrombolytic is given as a single weight-based IV bolus?
Alteplase
Eptifibatide
Cangrelor
Tenecteplase
✓
Correct Answer
Tenecteplase
Tenecteplase is given as one IV push, so it is quicker to prepare and does not need a dedicated line or pump. Alteplase is a thrombolytic given as a bolus followed by an infusion through a dedicated line. Eptifibatide is a glycoprotein IIb/IIIa antiplatelet drug, not a thrombolytic. Cangrelor is an IV P2Y12 antiplatelet drug, not a thrombolytic.
Category: Thrombolytics