Evaluation of expiratory volume, diffusion capacity, and exercise tolerance following major lung resection - A prospective follow-up analysis

Background: Lung resections determine a variable functional reduction depending on the extent of the resection and the time elapsed from the operation. The objectives of this study were to prospectively investigate the postoperative changes in FEN',, carbon monoxide lung diffusion capacity (D-LCO), and exercise tolerance after major lung resection at repeated evaluation times. Methods: FEV1, DLCO, and peak oxygen consumption (Vo(2)peak) calculated using the stair climbing test were measured in 200 patients preoperatively, at discharge, and 1 month and 3 months after lobectomy or pneumonectomy. Preoperative and repeated postoperative measures were compared, and a time-series, cross-sectional regression analysis was performed to identify factors associated with postoperative Vo(2)peak. Results: One month after lobectomy, FEV1, DLCO, and Vo(2)Peak values were 79.5%, 81.5%, and 96% of preoperative values and recovered up to 84%, 88.5%, and 97% after 3 months, respectively. One month after pnemuonectomy, FEV1 percentage of predicted, DLCO percentage of predieted, and Vo(2)peak values were 65%, 75%, and 87% of preoperative values, and were 66%, 80%, and 89% after 3 months, respectively. Three months after lobectomy, 27% of patients with COPD had improved FEV1, 34% had improved DLCO, and 43% had improved Vo(2)peak compared to preoperative values. The time-series, cross-sectional regression analysis showed that postoperative Vo(2)peak values were directly associated with preoperative values of Vo(2)Peak, and postoperative values of FEV1 and DLCO, and were inversely associated with age and body mass index. Conclusions: Our findings may be used during preoperative counseling and for deciding eligibility for operation along with other more traditional measures of outcome.