[Evolution of the early respiratory function after lung resection for cancer]. / Evolution de la fonction respiratoire postopératoire immédiate après résection pulmonaire pour cancer.

The assessment of the postoperative risk in lung resection is a major challenge for pneumologists and thoracic surgeons. Restrictive syndromes have been observed along with a disproportionate decrease of FEV1 in lobectomies. The purpose of the present study is to describe the early response of pulmonary function after thoracotomy and resection for lung cancer. In a prospective study, the authors included 31 patients (19 lobectomy patients: mean age 59+/-10 years and 12 pneumonectomy patients: mean age 56+/-9 years) without postoperative complications. Pulmonary function tests were performed before and after surgery on Days 1, 5 (D5), 10 and within the fourth month. The main aspect of the ventilation was an unexpected similarity in subgroups during the early perioperative period up to D5. When compared with the preoperative value, about a 50% decrease in the vital capacity and total lung capacity was observed. In both subgroups about a 40% decrease was noted in the inspiratory and expiratory reserve volume. In the lobectomy sub-group, the change in the forced expiratory volume in one second over forced vital capacity (FEV/FVC) ratio was found to be higher than predicted (52+/-16% at D5 versus 67+/-14% predicted). However, the FEV/FVC ratio did not change, attesting to major restrictive ventilation. Partial recovery of the FEV was dependant on the mobile volume and especially the inspiratory volume. These findings should have implications in patient management.

Prediction of hypoxemia and mechanical ventilation after lung resection for cancer.

BACKGROUND: Hypoxemia usually occurs after thoracotomy, and respiratory failure represents a major complication. METHODS: To define predictive factors of postoperative hypoxemia and mechanical ventilation (MV), we prospectively studied 48 patients who had undergone lung resection. Preoperative data included, age, lung volume, force expiratory 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 nonventilated 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 postoperative hypoxemia were FEV1ppo (r = 0.74, p < 0.001) in lobectomy and tidal volume (r = 0.67, p < 0.01) in pneumonectomy. Using discriminant analysis, FEV1ppo in lobectomy and tidal volume in pneumonectomy were also considered as the best predictive factors of MV for pulmonary complications. CONCLUSIONS: These results suggest that the degree of chronic obstructive pulmonary disease in lobectomy and impairment of preoperative breathing pattern in pneumonectomy are the main factors of respiratory failure after lung resection.