A 23-year-old African American man with sickle cell disease (Hb SS disease) comes to the clinic for follow-up. He was admitted to the hospital 2 weeks ago due to headaches, slurred speech, and right-sided arm weakness. Imaging studies of the brain revealed no evidence of hemorrhage. The patient received an exchange transfusion, and his symptoms markedly improved. He was discharged home after 5 days of supportive care. Current medications include folate, acetaminophen, oxycodone, and a multivitamin.
Blood pressure is 123/77 mm Hg and pulse is 82/min. Oxygen saturation is 99% on room air. The lungs are clear to auscultation. A 2/6 systolic murmur is heard at the left upper sternal border. Muscle strength is 4/5 in the right arm and 5/5 in the left arm. The rest of the neurological examination, including speech and coordination, is within normal limits.
Laboratory results are as follows:
Baseline hemoglobin is approximately 6.9 g/dL. Chest x-ray is clear.
Which of the following is the best strategy to prevent further similar events in this patient?

Question

A 23-year-old African American man with sickle cell disease (Hb SS disease) comes to the clinic for follow-up.  He was admitted to the hospital 2 weeks ago due to headaches, slurred speech, and right-sided arm weakness.  Imaging studies of the brain revealed no evidence of hemorrhage.  The patient received an exchange transfusion, and his symptoms markedly improved.  He was discharged home after 5 days of supportive care.  Current medications include folate, acetaminophen, oxycodone, and a multivitamin.
Blood pressure is 123/77 mm Hg and pulse is 82/min.  Oxygen saturation is 99% on room air.  The lungs are clear to auscultation.  A 2/6 systolic murmur is heard at the left upper sternal border.  Muscle strength is 4/5 in the right arm and 5/5 in the left arm.  The rest of the neurological examination, including speech and coordination, is within normal limits.
Laboratory results are as follows:
 Baseline hemoglobin is approximately 6.9 g/dL.  Chest x-ray is clear.
Which of the following is the best strategy to prevent further similar events in this patient?

Quizplus · Accepted Answer

Sickle cell disease (SCD) is commonly associated with cerebrovascular complications, including ischemia and hemorrhagic infarction. Approximately 1 in 10 patients will have a stroke before age 20, and nearly 1 in 4 will have a stroke by age 45. Strokes in SCD are primarily caused by vascular clogging due to high concentrations of hemoglobin S (Hb S). Therefore, acute strokes are typically managed with urgent exchange transfusion to rapidly reduce Hb S levels. Secondary prophylaxis against recurrent stroke must then be provided using chronic simple transfusion therapy every 4-6 weeks with goal Hb S levels of <30% and total Hb levels of 9-12.5 mg/dL. This strategy reduces the risk of stroke recurrence from 65% to <20% and is superior to medical management with hydroxyurea. Patients receiving chronic transfusions must be monitored for iron overload; periodic chelation therapy is often required to prevent iron-related morbidity (eg, hepatic fibrosis, cirrhosis). (Choice A) Although aspirin is commonly prescribed to patients with SCD who have had a stroke, there is no evidence that it is an effective monotherapy for stroke prevention in SCD as it does not reduce Hb S levels. (Choice C) Exchange transfusion is primarily used for patients with SCD who have acute ischemic stroke. Exchange transfusion is expensive and time consuming, requires a catheter, and involves more blood than simple transfusion. As a result, it is not typically used for chronic therapy. (Choice D) Nimodipine is a calcium channel blocker that can reduce vasospasm in patients with subarachnoid hemorrhage, which is also a complication of SCD. However, nimodipine is not used for stroke prevention. (Choice E) Rivaroxaban is a factor Xa inhibitor used primarily to treat deep venous thrombus/pulmonary embolus or to prevent stroke in those with atrial fibrillation. Because strokes in SCD are primarily mediated by high concentrations of Hb S, factor Xa inhibitors are not effective for secondary prophylaxis. Educational objective: Patients with sickle cell disease are at high risk for ischemic or hemorrhagic stroke. Exchange transfusion is recommended for acute stroke; scheduled simple transfusions are recommended to prevent recurrent strokes. __________ References: Secondary prevention of overt strokes in sickle cell disease: therapeutic strategies and efficacy. (http://www.ncbi.nlm.nih.gov/pubmed/22160069) Stroke recurrence in children with sickle cell disease treated with hydroxyurea following first clinical stroke. (http://www.ncbi.nlm.nih.gov/pubmed/21898530)

A 23-Year-Old African American Man with Sickle Cell Disease (Hb