pubmed-article:1022980 | pubmed:abstractText | Ventilatory function was studied by the authors in 43 subjects affected with obstructive respiratory disease. The research was performed both at rest and during two exercise tests -- 60 and 100 watts, respectively. The subjects were divided into three groups on the basis of tidal volume (at 30 1 ventilation) / vital capacity ratio. It was found that during muscular effort subjects with major impairment of spirometric indexes hypoventilated, whereas the opposite occurred in patients with lesser impairment. Moreover, subjects hyperventilating during muscular work were found to have brandypnea, whereas the opposite occurred in hyperventilating patients. It is suggested that progressing and worsening of obstructive emphysema lead to a relative hypoventilation during muscular work, which is due to an "inability" to increase the frequency of breathing. | lld:pubmed |