胸郭形成術後慢性呼吸不全の急性増悪例に体外式人工呼吸器が有用であった1例

A Case of Improvement in Acute Exacerbation of Chronic Respiratory Failure after Thoracoplasty by Extrathoracic Mechanical Ventilation(Biphasic Cuirass Ventilation)

要旨　患者は79歳，女性．23歳時，肺結核で右胸郭形成術を施行，9年前よりHOT導入されていた．2006年4月，心不全・呼吸不全が悪化し緊急入院した．気管切開や挿管加療は本人，家族ともに望まなかったため体外式人工呼吸(biphasic cuirass ventilation；BCV)を試みたところ，SpO₂は装着後直ちに88%から95%へ上昇した．当初は間歇的装着を予定し一旦中断したが，BCV非装着時にCO₂ナルコーシスを生じたためBCVで継続的な呼吸管理を行った．連続装着36時間後に意識が回復，48時間後の動脈血液ガスでpH7.393，PaCO₂75.2mmHgと改善し，72時間後には呼吸不全に伴う意識障害が改善した．BCVにより利尿効果も促進され心不全の改善も得られたことから，結核後遺症による慢性呼吸不全疾患などに今後積極的に検討すべき治療法ではないかと考えた．

　A 79-year-old woman was admitted to our hospital in April, 2006, due to cardiac failure and exacerbation of chronic respiratory failure. At the age of 23, the patient had undergone right-lung thoracoplasty because of lung tuberculosis and had suffered chronic restrictive respiratory failure, while, nine years before the present incident, home oxygen therapy had been required. As invasive treatment, such as tracheotomy, intubation and artificial respiration, was refused, we tried extrathoracic ventilation in the form of Biphasic Cuirass Ventilation(BCV). This was immediately effective, producing a rise in the SpO₂ level from 88% to 95%, and we therefore scheduled several hours a day of assisted ventilation via BCV. However, during non-assisted ventilation, the patient suffered CO₂ narcosis, so assisted respiratory ventilation via BCV was maintained continuously. After 36 hours, the patient regained consciousness, and after 48 hours blood gas data improved to a pH of 7.393, and a PCO₂ of 75.2mmHg. After 72 hours, the consciousness disorder due to respiratory failure had improved sufficiently. Increasing diuresis due to BCV, and improvement of cardiac failure was also brought about. BCV is thus an important and highly useful technique for chronic respiratory failure as a sequela of tuberculosis.