Chest
Clinical Investigations: COPDExercise Limitation in Obstructive Lung Disease
Section snippets
Subjects
We studied 25 patients (16 male) with OLD, of whom 19 had COPD and 6 had asthma. Their diagnosis was made according to the recommendations of the American Thoracic Society.7 The anthropometric characteristics are given in Table 1. At the time of the study, all patients were in stable clinical and functional state, and had no contraindications for exercise testing. Patients with evidence of cardiovascular disorders were excluded. To avoid any potential influence of medication on testing,
RESULTS
The resting pulmonary function variables and max (percent predicted) of the OLD patients are given in Table 2. The severity of OLD ranged from mild to very severe (33 FEV1, percent predicted). Table 3 lists the correlation and variation coefficients of the relationships between max and different anthropometric characteristics and respiratory variables in which the correlation of the simple linear regressions was significant. The highest correlation coefficient was found
DISCUSSION
The main findings of the present study are that in patients with OLD, there is a close correlation between max and resting IC.
According to the stepwise multiple regression analysis, in OLD the sole contributor to max was resting IC, which explained about 70% of the variance (r2 = 0.66). The residual variance is probably due to the fact that in OLD patients, (1) the max during exercise is not limited only by ventilation but also by skeletal muscle dysfunction,14 and (2) only
REFERENCES (18)
- et al.
Exercise tolerance in chronic airway obstruction
Am Rev Respir Dis
(1971) - et al.
The ventilatory capacity of patients with chronic airway obstruction
Clin Sci
(1969) - et al.
A simple method to detect expiratory flow limitation during spontaneous breathing
Eur Respir J
(1995) - et al.
Relationship between chronic dyspnea and expiratory flow-limitation in patients with chronic obstructive pulmonary disease
Am J Respir Crit Care Med
(1996) - et al.
Detection of expiratory flow limitation during exercise in COPD patients
J Appl Physiol
(1997) - et al.
Exertional breathlessness in patients with chronic airflow limitation: the role of lung hyperinflation
Am Rev Respir Dis
(1993) Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease (COPD) and asthma
Am Rev Respir Dis
(1987)Standardization of spirometry
Am J Respir Crit Care Med
(1995)- et al.
Reliability of inspiratory capacity for estimating end-expiratory lung volume changes during exercise in patients with chronic obstructive pulmonary disease
Am J Respir Crit Care Med
(1997)