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Objective: In patients with chronic obstructive pulmonary disease (COPD), patient age and initial value of forced expiratory volume in 1 second (FEV1) have been considered the most accurate predictors of mortality among the parameters obtained from pulmonary exercise tests. However, few studies have examined the predictive variables of prognosis among exercise parameters in COPD. We therefore attempted to identify the best index for predicting long-term survival in patients with COPD among the cardiopulmonary variables obtained during exercise testing., Patients and Methods: Fifty-eight patients with COPD (50 men and 8 women) without hypoxemia at rest or other serious complications performed resting pulmonary function tests followed by a symptom-limited ramp exercise test on a cycle ergometer with breath-by-breath gas analysis and arterial blood gas sampling., Results: After 3,570+/-1,373 days follow-up (mean+/-SD), 21 died because of deaths by respiratory failure. The overall survival rates calculated by the Kaplan-Meier method were 92.9% and 75.8% at 5 years and 10 years, respectively. In univariate Cox hazards analysis, age, FEV1, VC, RV/TLC, VEmax, VO2max, VCO2max, PaO2max, PacO2max, and PaO2 at rest were found to be significant prognostic indices of survival. However, multivariate analysis revealed only FEV1, PaO2max, and age as independent predictors of mortality. In severe COPD patients (FEV1 <50% predicted, n=35), PaO2max and age also correlated with prognosis, whereas FEV1 did not., Conclusion: Pulmonary exercise testing is useful in predicting prognosis in patients with COPD.

A ramp exercise test was thought to be adequate especially for evaluation of patients with respiratory system diseases. First, we told about the significances, the methods and apparatus, the arrangements for workload and the matters that demand special attentions of this exercise test. Next, various indices which were obtained during ramp exercise and the estimations of them were explained. Furthermore, we referred to the exercise-limiting factors for patients with COPD and pulmonary fibrosis as symmetrical respiratory system diseases.

To assess the clinical utility of a ramp exercise test in patients with pulmonary diseases, the gas exchange variables from normal volunteers and patients with pulmonary diseases during ramp exercise were compared to those during steady-state exercise. Measurements during ramp exercise could titrate the extent of the patients' maximal exercise as well as the adequate performance of parameters in gas exchange coupling. There were no significant differences in the four variables achieved between the two exercises. These gas exchange variables during ramp exercise made it possible to predict the exercise-limiting factors for patients with COPD and pulmonary fibrosis. Furthermore, a ramp exercise test could be performed safely even in patients with severe lung diseases and required a shorter period than a steady state exercise test. Thus, a ramp exercise test is thought to be useful in the evaluation of patients with pulmonary diseases.