每日一题_2022.2.20

A 35-year-old man with a seven-day history of confusion（混乱）, fever, chills（寒战）, and cough is admitted to the hospital for evaluation. His blood pressure is 140/82 mm Hg, heart rate 108 beats/min, respiratory rate 28 breaths/min, temperature 37.9°C (100.2°F), and oxygen saturation 95% on room air. On clinical examination, he is in distress（痛苦） and can move the right upper and lower extremities but is hemiparetic(轻偏瘫) on the left. The right pupil（瞳孔） is dilated at 4 mm but reactive, and the left pupil is 2 mm and reactive. CT is shown below. He is intubated and started on IV ceftriaxone and vancomycin. His head is placed at 45 degrees, and a bolus of mannitol is administered.

Which of the following is the most appropriate next step in this patient’s treatment.

A. Add IV ampicillin to the antibiotic regimen.

B. Perform lumbar puncture to obtain cerebrospinal fluid for chemical analysis and culture.

C. Institute hypothermia with a core temperature goal of 33°C (91.4 ̊F).

D. Administer IV dexamethasone.

答案解析：

这是一例继发于右侧基底神经节肿块的进行性神经功能恶化的年轻患者。他的临床表现表明即将发生疝。CT提示血管源性脑水肿，瞳孔不对称的临床检查提示腰椎穿刺可能风险太大，因为它将促进进一步向下的小脑幕切迹疝。类固醇的主要适应症是与脑肿瘤相关的血管源性水肿或伴随的脑照射和手术操作。尽管类固醇在这种模式中有益作用的确切机制尚不清楚，但类固醇降低了紧密连接通透性，进而稳定了被破坏的血脑屏障。有证据表明，治疗性低温可被认为是管理卒中和心脏骤停颅内高压的替代方法，但其用于感染性脑炎可能是有害的。可以考虑添加氨苄西林；但是，其不会对随后的小脑幕切迹疝产生任何影响。单核细胞增生李斯特菌虽然是普通人群中不常见的致病原因，但在孕妇、新生儿、老年人和免疫功能低下人群中是一种重要的病原体。

正确答案：D