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 FEV1, carbon monoxide lung diffusion capacity (Dlco), and exercise tolerance after major lung resection at repeated evaluation times.
Methods: FEV1, Dlco, and peak oxygen consumption (V̇o2peak) 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 V̇o2peak.
Results: One month after lobectomy, FEV1, Dlco, and V̇o2peak 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 pneumonectomy, FEV1 percentage of predicted, Dlco percentage of predicted, and V̇o2peak 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 V̇o2peak compared to preoperative values. The time-series, cross-sectional regression analysis showed that postoperative V̇o2peak values were directly associated with preoperative values of V̇o2peak, 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.