Prediction of hypoxemia and mechanical ventilation after lung resection for cancer

Background. Hypoxemia usually occurs after thoracotomy, and respiratory fai lure represents a major complication. Methods. To define predictive factors of postoperative hypoxemia and mechan ical ventilation (MV), we prospectively studied 48 patients who had undergo ne lung resection. Preoperative data included, age, lung volume, force expi ratory volume in one second (FEV1), predictive postoperative FEV1 (FEV1ppo) , blood gases, diffusing capacity, and number of resected subsegments. Results. On postoperative day 1 or 2, hypoxemia was assessed by measurement of PaO2 and alveolar-arterial oxygen tension difference (A-aDO2) in 35 non ventilated patients breathing room air. The other patients (5 lobectomies, 9 pneumonectomies) required MV for pulmonary or nonpulmonary complications. Using simple and multiple regression analysis, the best predictors of post operative hypoxemia were FEV1ppo (r = 0.74, p < 0.001) in lobectomy and tid al volume (r = 0.67, p < 0.01) in pneumonectomy. Using discriminant analysi s, FEV1ppo in lobectomy and tidal volume in pneumonectomy were also conside red as the best predictive factors of MV for pulmonary complications. Conclusions. These results suggest that the degree of chronic obstructive p ulmonary disease in lobectomy and impairment of preoperative breathing patt ern in pneumonectomy are the main factors of respiratory failure after lung resection. (Ann Thorac Surg 1999;67:1460-5) (C) 1999 by The Society of Tho racic Surgeons.