急性呼吸促迫症候群を発症したが救命することのできた粟粒結核の1例 A RARE CASE OF MILIARY TUBERCULOSIS DEVELOPING TO ACUTE RESPIRATORY DISTRESS SYNDROME IN WHICH THE PATIENTS LIFE WAS SAVED

症例は84歳男性．他院にて高血圧症に対する管理を受けていたが，1か月ほど続く全身倦怠感と食欲不振に加えて咳嗽，高熱も出現したため，当科を受診し精査加療目的で入院した．入院時，SpO2 92%（room air）と呼吸状態悪く，非定型感染を疑う血液検査所見を認め，胸部X線検査と胸部CT検査で，両肺野にスリガラス状陰影とびまん性粒状影を認めたことから粟粒結核を含む肺感染症を念頭に，抗結核薬と塩酸シプロフロキサシン（CPFX）の投与を開始した．後日，喀痰・胃液および尿より結核菌検出の報告があり，粟粒結核の診断が確定した．入院第3病日には，低酸素血症が進行し，急性呼吸促迫症候群（Acute Respiratory Distress Syndrome；ARDS）を発症し，直ちに人工呼吸器を装着するとともに副腎皮質ステロイド薬の投与を開始した．治療は奏功し，挿管後6日で抜管し得た．その後の経過も順調であった．粟粒結核の播種性血管内凝固症候群（DIC）やARDS発症例では死亡率70〜80%と極めて予後不良とする報告が多いが，本症例では早期治療（治療的診断）により救命することが出来た．高齢者が原因不明の高熱を来した場合には，粟粒結核を念頭に置いた鑑別診断が必要で時機を逸せず抗結核薬療法を行うことが肝要である．

The patient was an 84-year-old male who was treated for hypertension in another hospital. In addition to general malaise and anorexia lasting for about a month, the patient had a high fever, which prompted the referral to our department. Chest x-ray and chest CT scan upon admission revealed ground glass appearance and diffuse granular infiltration in both lung fields. We suspected a pulmonary infection, such as miliary tuberculosis, and an anti-TB regimen and ciprofloxacin CPFX were administered. Mycobacterium tuberculosis in the sputum, gastric juices, and urine were detected several days later by bacteriological tests, confirmed the diagnosis of miliary tuberculosis. On the third day of hospitalization, hypoxemia worsened and developed into acute respiratory distress syndrome ARDS; the patient was immediately placed on a ventilator and corticosteroids were administered. The patient responded well to these treatments, and was successfully extubated 6 days later. The patient had slow but steady, uneventful recovery after extubation, and he was discharged home on hospital day 83. Review of literature indicates an extremely poor prognosis of miliary tuberculosis developing to ARDS, with mortality of 70-80. We believe that this patient survived due the to early introduction of anti-TB drug therapy, even before the diagnosis was confirmed. When an elderly individual develops a high fever of unknown origin with pulmonary infiltrate, a differential diagnosis must be made with miliary tuberculosis in mind and anti-TB drug therapy should be initiated even before the diagnosis is confirmed.