A 20-month-old otherwise healthy male presents late for his 18-month well child check. During his first year of life, he took iron-fortified formula and had a point-of-care hemoglobin (Hgb) of 12 g/dL at his 1-year well child check. His mother reports that he is a picky eater but loves milk and has recently become obsessive about chewing the corners of his cardboard books. Physical examination is normal except for a flow murmur. Which combination of laboratory test results listed below would most likely characterize this patient?

Correct Answer: A

Rationale: The correct answer is A because it indicates iron deficiency anemia. The low Hgb of 8.7 g/dL is below normal range for his age. The MCV of 60 fL is low, indicating microcytic anemia which is characteristic of iron deficiency. The serum ferritin level of 2 ng/mL is very low, supporting the diagnosis. Choice B is incorrect as the Hgb and MCV are within normal range, and the ferritin level is not indicative of iron deficiency. Choice C has a low Hgb but normal MCV and ferritin level. Choice D has a normal Hgb and low ferritin, but the MCV is high, inconsistent with iron deficiency anemia.

Correct Answer: C

Rationale: The correct answer is C: Check the pressure dressing frequently for signs of excessive or active bleeding. After a bone marrow aspiration and biopsy, the priority is to monitor for bleeding, as these procedures can cause bleeding complications. Checking the pressure dressing helps to detect any signs of excessive bleeding early, allowing for prompt intervention. This is crucial to prevent complications such as hematoma or hemorrhage. Incorrect choices: A: Teaching the client to avoid activity is important but not the priority immediately post-procedure. B: Administering NSAIDs may not be appropriate as they can increase the risk of bleeding. D: Reporting laboratory results is important but not the priority in this immediate post-procedure scenario.

Correct Answer: b

Rationale: The correct answer is B: Decreased red blood cell count. Anemia is characterized by a decrease in the number of red blood cells, leading to a lower than normal red blood cell count. In anemia, the body cannot transport enough oxygen to tissues, leading to symptoms such as fatigue and shortness of breath. Increased hematocrit (A) and decreased hemoglobin (D) are related to anemia but not specific enough to be conclusive. Decreased serum iron (C) may be seen in iron-deficiency anemia but is not always present in all types of anemia.

Correct Answer: C

Rationale: The correct answer is C: Aplastic anemia. Aplastic anemia is characterized by a low reticulocyte production index due to bone marrow failure, leading to decreased red blood cell production and subsequently causing anemia. Thalassemia (choice A) is a genetic disorder resulting in abnormal hemoglobin production, not bone marrow failure. Vitamin B12 deficiency (choice B) can lead to macrocytic anemia, not a low reticulocyte production index. Sideroblastic anemia (choice D) is characterized by abnormal iron metabolism in the bone marrow, not bone marrow failure.

Correct Answer: D

Rationale: The correct answer is D: Vitamin K deficiency. Prolonged prothrombin time and activated partial thromboplastin time indicate impaired blood clotting, which is characteristic of vitamin K deficiency. Vitamin K is essential for synthesizing clotting factors II, VII, IX, and X. Hemophilia A (choice A) is a genetic disorder resulting in deficiency of clotting factor VIII, not vitamin K-dependent factors. Thrombocytopenia (choice B) is a condition characterized by low platelet count, not affecting clotting factor synthesis. Von Willebrand factor disease (choice C) involves a deficiency or dysfunction of von Willebrand factor, not related to vitamin K deficiency.