INTRODUCTION: The clinical state of patients after pneumonectomy varies from normal to seriously impaired daily life. The objective of the study is to identify laboratory parameters which determine the clinical postpneumonectomy state.METHODS: Thirty-five patients who underwent pneumonectomy for lung carcinoma (mean age: 61.5 +/- 7.2 years, left sided: 23) were prospectively studied with preoperative and 6-month postoperative spirometry, Doppler echocardiography for calculation of right ventricular systolic pressure and arterial blood gas. The clinical postpneumonectomy state was defined as the class of dyspnea on exertion: I = on heavy exertion, II = on moderate exertion, III = on mild exertion, IV = on minimal exertion.RESULTS: Postoperative forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and percent of the predicted FVC were significantly lower in patients with class III and IV than in patients with class I and II dyspnea, while right ventricular systolic pressure and percent reduction of FVC and FEV1 were significantly higher in patients with class IV dyspnea. On multiple regression analysis, postoperative FEV1 and percent reduction of FVC were found to strongly affect the postpneumonectomy state. Right pneumonectomy, obstructive pattern at preoperative spirometry, bronchial obstruction limited to up to three bronchopulmonary segments at preoperative bronchoscopy and predicted FEV1 less than 1.4 liter by the ventilation/perfusion lung scanning were connected with seriously impaired postpneumonectomy state.CONCLUSIONS: The postpneumonectomy state is affected by low actual postpneumonectomy FEV1 values and serious percent reduction of FVC from preoperative values. Right pneumonectomy together with obstructive ventilatory pattern and minimal bronchial obstruction are preoperative factors that result in serious reduction of FEV1 and percent reduction of FVC.