Oxygen transport during incremental exercise load as a predictor of operative risk in lung cancer patients.

To evaluate functional parameters related to the morbidity and mortality after thoracotomy, exercise loading was applied in 31 lung cancer patients under right heart catheterization. The routine pulmonary function and predicted postoperative pulmonary function (ppo) parameters were also evaluated. Patients were grouped according to postoperative complications: no complications (group 1, n = 17), nonfatal complications (group 2, n = 10), and fatal complications (group 3, n = 4). In all the patients %VCppo was above 40 percent and in patients undergoing pneumonectomy, pulmonary artery mean pressure during the unilateral pulmonary artery occlusion test was below 25 mm Hg. FEV1 percent and MVV/BSA were statistically significant between groups 1 and 2 but were not between groups 1 and 3 or groups 2 and 3. The %FEV1 ppo was statistically significant between groups 1 and 2 and groups 1 and 3 but was not between groups 2 and 3. Thus, the routine pulmonary function and predicted postoperative lung function tests, although they are mandatory for screening patients who are at risk, did not definitely discriminate between patients experiencing nonfatal and fatal complications after thoracotomy. VO2/BSALa20, CILa20, O2D/BSALa20, and TPVRILa20 were statistically significant between groups 1 and 3 and groups 2 and 3: in all the group 3 patients, as well as three patients of group 1 and one of group 2, VO2/BSALa20 was below 350 ml/min/m2. On the other hand, O2D/BSALa20 was below 500 ml/min/m2 in all the group 3 patients, while it was above 560 ml/min/m2 in all patients in groups 1 and 2. O2D/BSALa20 was the only parameter that definitely discriminated between experiencing nonfatal and fatal complications. We conclude that in addition to the generally accepted functional guidelines, VO2/BSALa20 should be above 400 ml/min/m2 and O2D/BSALa20 should be above 500 ml/min/m2 in patients who will undergo thoracotomy.