術後夜間肺高血圧に陽圧呼吸療法が奏効した睡眠時無呼吸合併心房中隔欠損症の1例

Successful Nocturnal Continuous Positive Airway Pressure Treatment on a Patient of Obstructive Sleep Apnea Syndrome with Post Operative Pulmonary Hypertension in ASD: A case report

要旨　患者は74歳，女性．2007年4月労作時呼吸困難増悪のため当科精査加療入院し，経胸壁心エコー，経食道心エコーにより心房中隔欠損(二次口欠損型)と右心負荷所見を認めた．心臓カテーテル検査にて平均肺動脈圧38mmHg，Qp/Qs4.0と高値を認めるも肺対体血管抵抗比は低く，手術適応ありと判断し，心膜パッチ閉窓術を施行した．術直後収縮期肺動脈圧は30～40mmHgに低下したが，抜管後の夜間睡眠中，間歇的に収縮期肺動脈圧70mmHg台の上昇がみられた．睡眠時無呼吸症候群の関連を疑い，夜間のみ非侵襲的陽圧呼吸を併用，その後肺動脈圧は低下し順調に改善した．後日施行した終夜ポリソノグラフでは重症閉塞型睡眠時無呼吸を認めた．心房中隔欠損症と閉塞型睡眠時無呼吸症候群が併存し，肺高血圧に対する治療戦略を考えるうえでも興味深い症例を経験したので報告する．

　In April, 2007, a 74-year-old woman who complained of dyspnea on effort was admitted to our department. Both transthoracic and transesophageal echocardiography revealed atrial septal defect and right cardiac overload. Although it was hard to control cardiac heart failure caused by pulmonary hypertension, cardiac catheterization showed a rather low pulmonary-systemic resistance ratio 0.07, regardless of the high mean pulmonary artery pressure 38mmHg. The results encouraged us to perform surgical patch closure on the patient. Immediately after the operation, pulmonary artery pressure improved to 30-40mmHg. After extubation, however, sudden and transient elevation of pulmonary artery pressure was repeatedly observed during sleep time. Since sleep apnea syndrome had something to do with this event, we applied nocturnal non-invasive positive pressure therapy(BilevelPAP),resulting favorably in improvement of pulmonary artery pressure. A full polysomnograph performed later on, showed severe obstructive sleep apnea(OSAS). Thus, this case suggests a way to devise a treatment strategy for pulmonary hypertension.