The Operability of Pulmonary Cancer Seen from the Standpoint of Cardiopulmonary Function Tests

¹ Professor of Surgery, Nihon University School of Medicine
² Instructors, Nihon University School of Medicine
³ Tokyo, Japan

1. As a negative correlation is present between the size of tumors localized in the lung field and the percentage vital capacity, the growth and extension of pulmonary cancer can be estimated by the grade of decrease of percentage vital capacity. The cardiopulmonary function is not so markedly disturbed in the lung-field type of carcinoma, but it is more or less markedly disturbed in the hilar type.

2. In the early stage of pulmonary cancer (80 per cent VC or more), a slight disturbance of ventilatory distribution, and perfusion is observed, but in the advanced stage (80-60 per cent VC) the ventilatory disturbance becomes more pronounced, due to the growth of the tumor accompanied by pneumonitis, atelectasis and pulmonary emphysema. As no compensatory reaction of pulmonary circulation is observed in cases of lung cancer having percentage vital capacity below 60 per cent, hypoxemia seems to be prevented by the increase of heart rate and respiratory rate.

3. Lobectomy is feasible for patients with lung cancer having 60 per cent or more vital capacity. In case of proposed pneumonectomy, it is desirable to have 80 per cent or more maximal breathing capacity and arterial O₂ saturation above 90 per cent.