Nokea
The clinical manifestations of sickle cell anemia (SCA) are primarily the result of which physiologic alteration?
- A. Decreased blood viscosity
- B. Deficiency in coagulation
- C. Increased red blood cell (RBC) destruction
- D. Greater affinity for oxygen
Correct Answer: C
Rationale: SCA causes increased RBC destruction due to sickled cells, leading to vasoocclusion and hemolysis. Sickled cells increase viscosity, not decrease it; coagulation is unaffected; and sickled hemoglobin has reduced oxygen affinity, transforming under low oxygen tension.
You may also like to solve these questions
An 8-year-old girl is receiving a blood transfusion when the nurse notes that she has developed precordial pain, dyspnea, distended neck veins, slight cyanosis, and a dry cough. These manifestations are most suggestive of what complication?
- A. Air embolism
- B. Allergic reaction
- C. Hemolytic reaction
- D. Circulatory overload
Correct Answer: D
Rationale: Circulatory overload presents with precordial pain, dyspnea, distended neck veins, cyanosis, and dry cough due to fluid volume excess. Air embolism causes sudden respiratory distress, allergic reactions involve urticaria and wheezing, and hemolytic reactions include fever and shock.
The regulation of red blood cell (RBC) production is thought to be controlled by which physiologic factor?
- A. Hemoglobin
- B. Tissue hypoxia
- C. Reticulocyte count
- D. Number of RBCs
Correct Answer: B
Rationale: Tissue hypoxia triggers the kidneys to release erythropoietin, stimulating bone marrow to produce RBCs. Hemoglobin levels indirectly influence this through oxygen delivery, reticulocyte count monitors production, and RBC numbers don?t directly control production.
A school-age child is admitted in vasoocclusive sickle cell crisis (pain episode). The childs care should include which therapeutic interventions?
- A. Hydration and pain management
- B. Oxygenation and factor VIII replacement
- C. Electrolyte replacement and administration of heparin
- D. Correction of alkalosis and reduction of energy expenditure
Correct Answer: A
Rationale: Vasoocclusive sickle cell crisis requires hydration to reduce blood viscosity and pain management to alleviate discomfort. Oxygen may prevent further sickling but doesn?t reverse it, factor VIII and heparin are irrelevant, and acidosis, not alkalosis, needs correction.
What physiologic defect is responsible for causing anemia?
- A. Increased blood viscosity
- B. Depressed hematopoietic system
- C. Presence of abnormal hemoglobin
- D. Decreased oxygen-carrying capacity of blood
Correct Answer: D
Rationale: Anemia is defined by reduced RBCs or hemoglobin, leading to decreased oxygen-carrying capacity. Increased viscosity occurs with too many cells, a depressed hematopoietic system or abnormal hemoglobin may contribute, but the core defect is reduced oxygen delivery.
For children who do not have a matched sibling bone marrow donor, the therapeutic management of aplastic anemia includes what intervention?
- A. Antibiotics
- B. Antiretroviral drugs
- C. Iron supplementation
- D. Immunosuppressive therapy
Correct Answer: D
Rationale: Immunosuppressive therapy (e.g., antilymphocyte globulin, cyclosporine) treats aplastic anemia, likely an autoimmune condition, improving prognosis. Antibiotics treat infections, not the condition; antiretrovirals and iron are irrelevant to aplastic anemia management.