7. 低肺機能合併症例と周術期管理

Perioperative Management for Cardiovascular Surgery on the Patients with Pulmonary Dysfunction

心臓大血管外科においては，患者の高齢化や重症化に伴い，さまざまな合併症を有する患者の手術適応，周術期管理に難渋することが増えてきている．特に高齢者における低肺機能の問題は重大な問題で，開心術後の手術合併症（morbidity）と手術死亡（mortality）の主な要因となっている．術前呼吸機能の評価のあり方，リスクモデルからみた手術適応決定，呼吸不全症例の手術成績，対策，最近経験した低肺機能自験例について述べる．

The factors influencing the pulmonary function after cardiovascular surgery are decreased compliance of thorax due to sternotomy, phrenic nerve injury, wound pain and decreased blood flow after internal mammary artery harvest on coronary artery bypass grafting （CABG）. Another factor is systemic inflammatory response syndrome （SIRS） associated with cardio-pulmonary bypass. So, we should take care of pulmonary function after surgery not only on the patients with pulmonary dysfunction but also on the patients with normal pulmonary function. Because the results after cardiovascular surgery for the patients with pulmonary dysfunction depends on the severity of the pulmonary function, preoperative assessment of it is important. The predictor for adverse results are chronic obstructive lung disease （COPD） itself and FEV1.0％＜50％ and so on. Even of the patients has no history of pulmonary disease, preoperative evaluation is necessary. For the patients with pulmonary dysfunction, we should consider fast-track recovery after operation, meaning early extubation, choice of less invasive surgery procedure and change of surgical procedure. Prohibition of smoking for more than 4 weeks, pre- and post-operatively pulmonary rehabilitation are also important for improve the operative results.