A 4-year-old boy is pale with intermittent jaundice and splenomegaly. Laboratory results are as follows: RBC 4.85 M/mcL (N); Hgb 8.6 g/dL (L); Hct 25.8% (L); MCV 81.6 (N); MCHC 38% (H); RDW 20% (H); Retic 7% (H). What are the two best tests to distinguish autoimmune hemolytic anemia from hereditary spherocytosis?
- A. Free erythrocyte protoporphyrin and IgG levels
- B. Hemoglobin electrophoresis and direct antiglobulin test (DAT)
- C. Lactate dehydrogenase (LDH) and modified Russell viper venom test
- D. Red cell distribution width (RDW) and mean corpuscular hemoglobin concentration (MCHC)
Correct Answer: E
Rationale: As the correct answer is not provided, I'll provide a step-by-step rationale for each choice:
A: Free erythrocyte protoporphyrin and IgG levels are not specific tests for distinguishing between autoimmune hemolytic anemia and hereditary spherocytosis.
B: Hemoglobin electrophoresis and direct antiglobulin test (DAT) can help differentiate between these two conditions as autoimmune hemolytic anemia is associated with a positive DAT, while hereditary spherocytosis typically has a negative DAT.
C: Lactate dehydrogenase (LDH) and modified Russell viper venom test are not specific tests for distinguishing between autoimmune hemolytic anemia and hereditary spherocytosis.
D: Red cell distribution width (RDW) and mean corpuscular hemoglobin concentration (MCHC) are not typically used to distinguish between autoimmune hemolytic anemia and hereditary spherocytosis.
Therefore, the best tests
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An 18-year old male patient with acute lymphoblastic leukemia recently started maintenance therapy and is complaining of increased hip pain. The pain increases during weight-bearing activity; however, it occasionally hurts at night as well. His CBCd is normal. Which of the following risk factors is most commonly associated with this process?
- A. Younger age at diagnosis
- B. Non-White race
- C. Low body-mass index
- D. Dexamethasone exposure
Correct Answer: D
Rationale: The correct answer is D: Dexamethasone exposure. Dexamethasone is a corticosteroid commonly used in the treatment of acute lymphoblastic leukemia. It can lead to avascular necrosis of the hip, causing hip pain during weight-bearing activities. This is due to its negative impact on bone health and blood supply to the hip joint. Other choices are incorrect because younger age at diagnosis is not a risk factor for avascular necrosis, non-White race and low body-mass index are not directly associated with this process.
Plat. Transfusion is not indicated in:
- A. aplastic an.
- B. uraemia with bleeding
- C. DIC
- D. immunogenic thrombocytopenia
Correct Answer: D
Rationale: The correct answer is D: immunogenic thrombocytopenia. Platelet transfusion is not indicated in immunogenic thrombocytopenia because it involves antibodies attacking platelets, which would render transfused platelets ineffective. Platelet transfusion is indicated in aplastic anemia (A) to increase platelet count, in uremia with bleeding (B) to replace dysfunctional platelets, and in DIC (C) to help manage severe bleeding. In summary, platelet transfusion is contraindicated in immunogenic thrombocytopenia due to ineffective platelet response.
A 16-year-old female patient with severe factor XI deficiency presents with acute appendicitis and requires urgent surgery. You are called by the surgeon, who wants to know what, if any, blood products or treatments are required to reduce the risk of perioperative bleeding. The patient weighs 62 kg. What should you tell him to administer?
- A. Cryoprecipitate (five units), which will likely raise her factor XI level to 20%
- B. Factor XI concentrate (20 units/kg), which will raise her factor XI level to 20%
- C. Fresh frozen plasma (20 mL/kg), which will raise her factor XI level to 20%
- D. Prothrombin complex concentrate (40 units/kg), which will raise her factor XI level to 20%
Correct Answer: C
Rationale: The correct answer is C: Fresh frozen plasma (20 mL/kg), which will raise her factor XI level to 20%. Fresh frozen plasma contains various clotting factors, including factor XI. In patients with severe factor XI deficiency, like this 16-year-old female, fresh frozen plasma can provide factor XI replacement and improve hemostasis. The dose of 20 mL/kg is appropriate to achieve a factor XI level of around 20%, which is sufficient for hemostasis during surgery.
Now, let's analyze the other choices:
A: Cryoprecipitate (five units), which will likely raise her factor XI level to 20% - Cryoprecipitate contains factor VIII and fibrinogen, but the amount of factor XI in cryoprecipitate is minimal and may not significantly raise factor XI levels to the required 20%.
B: Factor XI concentrate (20 units/kg), which will raise her factor XI level to 20% - While factor XI concentrate is
A nurse is caring for a client who has chronic stable angina. The nurse should identify that which of the following drugs inhibits the action of adenosine diphosphate receptors (ADP) on platelets and can be prescribed to reduce the client's risk for myocardial infarction?
- A. Clopidogrel
- B. Heparin
- C. Warfarin
- D. Alteplase
Correct Answer: A
Rationale: 1. Clopidogrel inhibits ADP receptors on platelets, reducing platelet aggregation and clot formation.
2. By reducing platelet aggregation, clopidogrel decreases the risk of myocardial infarction in patients with chronic stable angina.
3. Heparin acts by inhibiting thrombin and factor Xa, not ADP receptors.
4. Warfarin inhibits vitamin K-dependent clotting factors, not ADP receptors.
5. Alteplase is a thrombolytic agent that dissolves blood clots, not an ADP receptor inhibitor.
A 2-month-old girl is found to have a small, hard mass on her scalp. The mass increases in size over the next 4 weeks. A biopsy is performed that confirms a diagnosis of embryonal rhabdomyosarcoma. You initiate chemotherapy with vincristine, dactinomycin, and cyclophosphamide. The child presents to clinic for day 1 of cycle 3 of chemotherapy, and the mass on her scalp is smaller. She is afebrile, absolute neutrophil count is 1,405 cells/mcL, platelet count is 154,000/mcL, and total bilirubin is 0.8 mg/dL. Her mother reports she looks very tired because her eyelids have been 'very droopy,' and she thinks she has a sore throat because her cry is hoarse. Her last bowel movement was 2 days ago. What is the most appropriate chemotherapy plan?
- A. Continue vincristine, dactinomycin, and cyclophosphamide at full dosage.
- B. Do not administer any chemotherapy; rhabdomyosarcoma is progressing and she needs different therapy.
- C. Administer dactinomycin and cyclophosphamide but hold the vincristine and reevaluate weekly. If the ptosis and hoarse cry resolve, vincristine can be resumed with a dose reduction and, if tolerated, re-escalated to the full dose in the future.
- D. Administer dactinomycin and cyclophosphamide but discontinue vincristine permanently.
Correct Answer: C
Rationale: The correct answer is C because the child is showing signs of vincristine-induced neurotoxicity, which can manifest as droopy eyelids (ptosis) and hoarse cry. Holding vincristine and reevaluating weekly allows for monitoring of symptoms. If resolved, vincristine can be resumed with a dose reduction to prevent further neurotoxicity. Dactinomycin and cyclophosphamide are continued to maintain treatment efficacy. Continuing full-dose vincristine (choice A) can worsen neurotoxicity. With rhabdomyosarcoma responding to the current regimen, stopping all chemotherapy (choice B) is not appropriate. Discontinuing vincristine permanently (choice D) may compromise the treatment plan.