一位72歲男性以反覆心跳停止合併呼吸性酸中毒為表現之小細胞肺癌罕病經驗

A Rare Case of Small Cell Lung Cancer Presenting as Recurrent Cardiac Arrest with Respiratory Acidosis in a 72-Year-Old Man

心跳停止是一種嚴重且危急生命的問題，除了常見的高級心臟救命術（Advanced Cardiac Life Support, ACLS）所提及的5H5T之外，有些背後仍隱含複雜的問題，若未即時處理將會造成不可逆之傷害。本個案為72歲男性，因兩度心跳停止後合併呼吸性酸中毒轉入，隨後又因相同原因反覆進出加護病房，經評估後發現個案呼吸驅動力降低，產生中樞性睡眠呼吸中止症。進行腦脊髓液、腦部核磁共振檢查結果為疑似自體免疫性腦炎，且腫瘤伴生神經症候群Anti-Hu抗體呈現陽性，而Anti-Hu抗體常與腫瘤具有高度相關性，且當同時引發腦炎時，將有可能造成腦幹損傷，此時對於二氧化碳分壓上升的敏感度降低，進而造成二氧化碳堆積，造成嚴重呼吸性酸中毒，進而造成心跳停止；進一步追蹤胸部電腦斷層顯示縱膈腔淋巴結腫大，經由胸腔內視鏡手術切片後確診為小細胞肺癌。最終透過使用化學治療、手術、類固醇及血漿置換術來預防腫瘤伴生神經症候群的惡化，症狀逐漸獲得改善並出院。腫瘤伴生神經症候群為罕見疾病，其神經學症狀常於癌症診斷前發生，故審視評估與及時處置，將能有效降低患者疾病嚴重度、避免不可逆之傷害。

 

Cardiac arrest is a life-threatening circumstance. While the etiologies 5H5T outlined in Advanced Cardiac Life Support (ACLS) protocols are widely recognized, the definite pathophysiology may be obscured at the first time. Promptly identifying the key factors can prevent irreversible damage. This case report presents a 72-year-old male patient who was hospitalized due to two episodes of cardiac arrest, accompanied with respiratory acidosis. Subsequently, the patient was admitted to the intensive care unit repeatedly for the same situation. During the investigation for hypercapnia, the patient was found to have reduced respiratory drive, leading to central sleep apnea. The results of cerebrospinal fluid (CSF) analysis and brain magnetic resonance imaging (MRI) both suggested autoimmune en-cephalitis. Testing for paraneoplastic neurological syndromes (PNS) revealed the presence of anti-Hu antibodies in both CSF and serum. Subsequent chest computed tomography (CT) revealed mediastinal lymphadenopathy, and a biopsy performed via video-assisted thoracic surgery (VATS) confirmed the final diagnosis of small cell lung cancer. The patient was treated with a combination of chemotherapy, surgery, corticosteroids, and plasma exchange to prevent the progression of the paraneoplastic neu-rological syndrome. Paraneoplastic neurological syndromes are rare disorders. Anti-Hu antibody is highly associated with malignancy, contributing to brainstem injury and impaired sensitivity to partial pressure of carbon dioxide. Consequently, carbon dioxide accumulation results in severe respiratory acidosis, which may ultimately precipitate cardiac arrest. Moreover, neurological symptoms often pre-cede the diagnosis of cancer. Therefore, thorough evaluation and timely intervention for paraneoplastic neurological syndromes are crucial to mitigating disease severity and preventing irreversible damage.