A nurse is caring for a client who is about to begin taking aspirin to reduce the risk of a cardiovascular event. The nurse should identify that the drug inhibits platelet aggregation by which of the following mechanisms?

Correct Answer: D

Rationale: The correct answer is D: Inhibiting cyclooxygenase action in platelets. Aspirin inhibits cyclooxygenase, specifically COX-1, in platelets, leading to the inhibition of thromboxane A2 production. Thromboxane A2 is a potent platelet aggregator. By inhibiting its production, aspirin reduces platelet aggregation, thus reducing the risk of cardiovascular events. A: Activating thromboxane A2 - This is incorrect because aspirin actually inhibits the production of thromboxane A2. B: Blocking adenosine diphosphate receptor agonists - This is incorrect because aspirin primarily works through the inhibition of cyclooxygenase, not adenosine diphosphate receptors. C: Suppressing specific clotting factors - This is incorrect because aspirin's primary mechanism of action is through platelet inhibition, not through suppressing clotting factors.

Correct Answer: D

Rationale: In microcytic hypochromic anemia, the correct answer is D because red cells are smaller (microcytic) and have a pale large central pallor (hypochromic). This is due to decreased hemoglobin content and iron deficiency. Choice A is incorrect as red cells are smaller, not larger. Choice B is incorrect as the red blood cell count is typically decreased in this type of anemia. Choice C is incorrect as both hematocrit and mean corpuscular hemoglobin are decreased in microcytic hypochromic anemia, not normal. Therefore, the correct answer is D based on the characteristic features of microcytic hypochromic anemia.

Correct Answer: B

Rationale: Platelets are responsible for clot formation in the body. When a wound occurs, platelets adhere to the site and release chemicals to initiate clotting. They then aggregate to form a plug, stopping bleeding. Plasma carries platelets but is not directly involved in clot formation. Red blood cells transport oxygen but do not participate in clotting. White blood cells are part of the immune system and do not play a role in clot formation. Therefore, platelets are the correct choice for clot formation in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Contains clotting factors. Plasma is the liquid component of blood that contains essential clotting factors necessary for blood coagulation. This infusion helps replenish clotting factors in patients with bleeding disorders, aiding in the formation of blood clots to stop bleeding. Choice B is incorrect as plasma does not carry oxygen; that is the role of red blood cells. Choice C is incorrect as plasma does not directly support cellular metabolism; that is the role of nutrients. Choice D is incorrect as plasma does not remove waste products; that is the role of the kidneys and liver.

Correct Answer: D

Rationale: The correct answer is D: Administer the daily Coumadin as ordered. A therapeutic INR range for patients on warfarin is typically between 2-3. A patient with an INR of 2.5 is within this range, indicating that their blood is adequately anticoagulated. Therefore, the next dose of Coumadin should be administered as prescribed to maintain the therapeutic effect. Holding the dose (B) may lead to subtherapeutic anticoagulation, and notifying the physician (A) is not necessary as the INR is within range. Administering vitamin K (C) is indicated for patients with a high INR and signs of bleeding, which is not the case here.