A patient with a severe chronic airway obstruction and preserved exercise capacity (a case report).

We report a patient with chronic obstructive pulmonary disease (COPD) in whom severe lung function disorders are combined with completely preserved exercise capacity. We assessed the exercise capacity of a 44-year-old man (height 155 cm, BMI 19.6 kg.m-2, FEV1%pred. = 30.9%, FRC%pred. = 158%, KCO%pred. = 46.2%, PaO2 = 64.0 mmHg, Medical Research Council Dyspnea scale = 1, Baseline Dyspnea Index = 10) by the 6-minute walking distance test (6MWD) and the symptom-limited cardiopulmonary exercise test (CPET) on a treadmill using the Bruce protocol. The patient was able to walk 667 meters in the test and achieved peak relative oxygen consumption (VO2/kg) of 21.9 mL.min-1.kg-1. We attribute the preserved exercise capacity of the patient to the combined beneficial effect of the following factors: 1. Efficient extraction of the hemoglobin-transported oxygen from the alveoli (P50 = 3.10 kPa). 2. Optimal right ventricle remodelling with mild hypertrophy, without dilatation and congestion. 3. Hypoxic normoxemia without polyglobulia, resulting in good rheologic properties of blood. 4. A preserved locomotory activity of the patient. Such a combination of severe lung function disorders with mildly pronounced dyspnea and preserved exercise capacity supports the concept that the function profile of COPD patients is multidimensional and therefore such patients should have a complete assessment of their disability condition.

A factor analysis of dyspnea indexes and lung function parameters in patients with chronic obstructive pulmonary disease.

The purpose of the present study was to investigate the correlation between dyspnea ratings and a large group of lung function parameters, and extract those factors that best reflect the functional profile of patients with COPD using factor analysis. Ninety nine patients with COPD in stable clinical condition (age 60 +/- 8 years, ATS score = 2.5 +/- 0.9, FEV1% pred. = 33 +/- 13%) were included in the study. The factor analysis of the results yielded 5 factors which accounted for 80.1% of the total variance of the changes. The highest coefficients found between the factors and the original group of variables after Varimax rotation are given in the following table: Factor 1: Oxygen-cost diagram: 0.92; ATS dyspnea score: -0.80; TL,CO/VA: 0.78; Factor 2: FEV1% pred.: 0.87; FEV1/VC%: 0.86; FEV1L: 0.79; Factor 3: MIF50% pred.: 0.85; FIV1% pred.: 0.76; PImax: 0.67; Factor 4: PaCO2: -0.81; SaO2: 0.77; Mean pulmonary arterial pressure: -0.67 Factor 5: Age: 0.88; Six minutes walk distance: -0.72 The factor analysis showed that the functional profile of COPD patients has several dimensions. Therefore, in order to have COPD comprehensively evaluated, assessment of dyspnea and the respective set of lung function parameters (exercise capacity, forced inspiration and pulmonary hemodynamics), should be included in the battery of tests, besides the conventional tests.