A client is receiving rivaroxaban (Xarelto) and asks the nurse to explain how it works. What response by the nurse is best?

Correct Answer: A

Rationale: The correct answer is A: It inhibits thrombin. Rivaroxaban is a direct factor Xa inhibitor, which works by specifically inhibiting the activity of factor Xa, a key enzyme in the coagulation cascade. By inhibiting factor Xa, rivaroxaban prevents the formation of thrombin, a crucial enzyme in the blood clotting process. Thrombin is responsible for converting fibrinogen to fibrin, which forms the meshwork of a blood clot. Therefore, by inhibiting thrombin formation, rivaroxaban effectively prevents blood clots from forming. Choice B is incorrect because rivaroxaban does not directly inhibit fibrinogen; it acts upstream by inhibiting factor Xa. Choice C is incorrect because rivaroxaban does not actually "thin" the blood like warfarin or heparin; it specifically targets factor Xa. Choice D is incorrect because rivaroxaban does not work against vitamin K like warfarin

Correct Answer: A

Rationale: The correct answer is A: Time to marrow relapse since initial diagnosis. This is because the time to marrow relapse indicates the aggressiveness of the leukemia and how quickly it has returned post-treatment. Quicker relapse indicates more aggressive disease, impacting survival. Choice B, sex, is not a significant factor in survival post-relapse. Choice C, central nervous system involvement, affects treatment but is not the primary factor for survival. Choice D, response to induction therapy, is crucial for initial treatment success but not the most important factor post-relapse survival. Therefore, choice A is the most critical factor for survival after relapse of acute lymphoblastic leukemia.

Correct Answer: D

Rationale: The correct answer is D: Send a skin fibroblast culture for Fanconi anemia testing. This is the most important next step because the patient has a family history suggestive of Fanconi anemia, which is an inherited bone marrow failure syndrome. Aplastic anemia in a child with a family history of bone marrow failure syndromes raises suspicion for inherited causes like Fanconi anemia. Testing for Fanconi anemia involves assessing chromosomal breakage in response to DNA cross-linking agents like diepoxybutane or mitomycin C, which is best done using skin fibroblast culture. This specific test can confirm or rule out Fanconi anemia as the underlying cause of aplastic anemia in this patient. The other choices are incorrect because administering ATG and cyclosporine (Choice A) may not be effective if the underlying cause is Fanconi anemia. Searching for a donor for matched unrelated transplant (Choice B) is premature without confirming the diagnosis.

Correct Answer: E

Rationale: Step 1: Hb Indianapolis is a rare unstable hemoglobin variant causing severe hemolytic anemia. Step 2: The clinical presentation includes jaundice, bony deformity, hepatosplenomegaly due to extramedullary hematopoiesis. Step 3: None of the choices directly address the specific characteristics of Hb Indianapolis. Step 4: Therefore, the correct answer must provide insight into the unique features of this condition. Step 5: Choice E is correct as it highlights that the clinical presentation of Hb Indianapolis is distinct from other beta-hemoglobinopathies. Step 6: Summary: Choices A, B, C, and D are incorrect as they do not address the specific features of Hb Indianapolis, unlike choice E.

Correct Answer: C

Rationale: The correct answer is C: Stage III. According to the St. Jude (Murphy) staging system for non-Hodgkin lymphoma, Stage III is defined as disease that extends beyond a single region (e.g., thorax) on one side of the diaphragm. In this case, the large mediastinal mass greater than 33% of thoracic diameter indicates involvement beyond a single region. The absence of disease in other sites based on the metastatic work-up rules out Stages IV. Since there is no information provided to suggest involvement on both sides of the diaphragm, Stage III is the most appropriate stage for this patient. Choice A (Stage I) is incorrect as the disease extends beyond a single region. Choice B (Stage II) is incorrect as it implies involvement on both sides of the diaphragm, which is not indicated. Choice D (Stage IV) is incorrect as there is no evidence of distant metastasis in the given scenario.