膿胸に合併した敗血症・ARDSに好中球エラスターゼ阻害剤が奏効した低心機能の1例

Effectiveness of Neutrophil Elastase Inhibitor in a Patient with Low Cardiac Function for Sepsis and ARDS Complicated with Empyema

要旨　敗血症は全身性炎症性反応症候群(SIRS)に伴う急性肺障害(ALI/ARDS)の最も一般的な原因である．死亡率も高く発症早期から積極的な治療が重要と考えられる．今回，膿胸に合併した敗血症・ARDSに好中球エラスターゼ阻害剤が奏効した症例を経験したので報告する．患者は70歳，男性．陳旧性心筋梗塞(左室駆出率は33%)などにて近医通院中，膿胸を発症し当院紹介となった．トロッカーを挿入した直後に心室細動となったためACLSを開始した．電気的除細動を計8回施行した．敗血性ショックによるARDSが原因と考えられ，全身状態管理をするとともに好中球エラスターゼ阻害剤であるシベレスタットナトリウム投与を開始した．同剤投与後から肺機能の改善(PaO₂/FIO₂：54.3→138)を認めた．途中低心機能と低アルブミン血症のため輸液の慎重な管理を要したが，1カ月後には人工呼吸器から離脱した．2カ月半の入院の後，独歩にて自宅へ退院した．早期からの全身管理と好中球エラスターゼ阻害剤の使用が有用であったと思われる．

　A 70-year-old man developed left anterior chest pain, and was admitted to our hospital. His cardiac function was reduced(ejection fraction was 33%) because of old myocardial infarction. Chest X-ray, computed tomography(CT), and laboratory data revealed that he suffered from empyema and sepsis, and culture of blood and pleural fluid was positive for anaerobic bacteria. In spite of the therapy with intravenous antibiotics, his respiration status was deteriorated, and a drainage tube was inserted into his thoracic cavity. Soon after the operation, ventricular fibrillation occurred, and defibrillation, intubation and mechanical ventilation were required. Findings of Chest X-ray and CT were consistent with acute lung injury/acute respiratory distress syndrome(ALI/ARDS). The administration of sivelestat sodium hydrate(Elaspol), a neutrophil elastase inhibitor, along with antibiotics remarkably improved clinical condition(PaO₂/FIO₂：54.3→138) and became asepticaemic, although mechanical ventilation remained necessary because of the continued pulmonary congestion due to cardiac failure. During a month after treatment with sivelestat, respiratory and heart failure gradually improved and he was extubated. Indeed, he felt no dyspnea and could be discharged from hospital. Sepsis and systemic inflammatory response syndrome are known to cause life-threatening ALI/ARDS. Our case suggests that strategies for preventing and treating ALI/ARDS should include the administration of neutrophil elastase inhibitor at the early stage of the disease before irreversible alveolar damage may become predominant.