[Control of breathing in patients with mechanical disorders of the lung]

22 normal volunteers, 57 patients with obstructive changes and 34 with restrictive type changes were studied. The following parameters were analyzed: maximal inspiratory and expiratory pressures, occlusion pressure and components of the breathing pattern. The patients were divided according to the degree of airway resistance and fall of vital capacity. All patients compared with the healthy volunteers demonstrated higher minute ventilation, and a higher neuro-muscular respiratory drive as shown by the VT/Ti index and occlusion pressure. The breathing pattern did not correlate significantly with the different abnormalities of respiratory function in the studied groups. In the patients with obstructive changes a weak correlation was found between the occlusion pressure and airway resistance. In patients with restrictive type changes a weak correlation between occlusion pressure, static and specific compliance was found. The occlusion pressure was a more specific parameter characterizing respiratory drive compared with the VT/Ti index. Disturbances of pulmonary mechanics have a small but significant effect on respiratory control.