[Prediction of postoperative lung function in patients with lung cancer and chronic obstructive pulmonary disease].

We studied the relations between preoperative and postoperative lung function in 62 patients with lung cancer who were admitted to our hospital from January 1985 to December 1994. Postoperative pulmonary function, especially vital capacity (VC) and forced expiratory volume in one second (FEV1), could be predicted from the number of unobstructed subsegmental bronchi, and correlations between predicted and measured values of VC and EFV1 were computed. In patients whose pulmonary function was measured more than 4 weeks postoperatively. The predicted and measured VC and FEV1 were found to be strongly correlated (r = 0.892 for VC, and 0.852 for FEV1). Similar correlations were found in patients without obstructive pulmonary dysfunction (FEV1% > or = 70%, r = 0.897 for VC, and 0.884 for FEV1). In one patient who had obstructive lung dysfunction due to pulmonary emphysema (EFV1% < 70%), an error of more than 30% was noted between the predicted and measured FEV1 values. Therefore, patients with lung cancer who have pulmonary emphysema may have postoperative FEV1 valves that are higher than their predicted values. This might be an effect of volume reduction.