Search PubMed⌕ Search

Biomedical subjects

D V Bates

Publications and source records attributed to D V Bates.

At least 73 records · Page 4Linked to original sources

The other lung.

Explore the source record for details and available documents.

Adult↗

Regional distribution of pulmonary ventilation and perfusion in elderly subjects.

Using radioactive xenon, we measured the regional distribution of pulmonary ventilation and blood flow in six normal men, whose ages ranged between 65 and 75 yr. The measurements were made in the standing position. The static volume-pressure relation of the lungs was also measured in five of the subjects. The results indicate that by comparison with normal young men: (a) Blood flow to the upper lung zones was increased, although it still remained predominant in the lower zones. (b) Ventilation distribution during a vital capacity inspiration was similar to that seen in young subjects. (c) In five of the six elderly subjects, however, the distribution of ventilation in the resting tidal volume range was not preferential to the lower zones as it was in young men. This was probably caused by airway closure in the lower lung zones. The elderly subjects thus exhibit during normal tidal volume breathing a ventilation distribution pattern similar to that observed in young subjects when breathing at low lung volumes, i.e., near residual volume. This difference is probably due to the combined effect of the loss in elastic recoil of the lungs observed in the elderly subjects and of a decreased resistance to collapse of the aged airways. These findings suggest that in the elderly subjects there is a significant regional ventilation-perfusion impairment during quiet breathing, which may explain in part the reported increase in alveolar-arterial oxygen difference with advancing age.

Journal Article↗

Regional lung function in patients with bronchial asthma.

The regional distribution of pulmonary ventilation and perfusion and regional alveolar ventilation/perfusion ratios were measured with radioactive xenon ((133)xenon) in 10 patients with asthma in remission. Four subjects had normal ventilation distribution, four had hypoventilation in some regions and normal ventilation in others, and two patients had abnormal ventilation in almost all lung regions. The lung bases were involved most frequently and the middle zones least frequently. Correlation was good between the degree of over-all ventilatory impairment calculated from (133)xenon values and measurement of the maximal midexpiratory flow rate the same day. Regions which were hypoventilated had low ventilation/perfusion ratios and also tended to be hypoperfused. In the eight subjects who had been studied similarly 5 yr previously, changes in regional function correlated in general with changes in over-all function.

Adult↗

Regional distribution of pulmonary ventilation and perfusion in obesity.

Five women and three men, all obese and weighing 95 to 140 kg, were studied by routine pulmonary function tests and by a radioactive xenon technique, while seated upright at rest, to measure the regional ventilation and perfusion distribution in the lung. In four subjects in whom the expiratory reserve volume averaged 49% of predicted normal, the ventilation distribution as measured with (133)xenon was normal. In the remaining four subjects, in whom the expiratory reserve volume was reduced to less than 0.4 L and averaged only 21% of predicted values, the distribution of a normal tidal breath was predominantly to the upper zones. In all subjects the perfusion distribution was predominantly to the lower lung zones but was slightly more uniform than in normal nonobese subjects. During tidal-volume breathing, therefore, in four subjects the ventilation and perfusion distribution was substantially normal, whereas in the remaining four perfusion was maximal in the lower zones, to which ventilation was significantly reduced. These findings show that there may be significant ventilation/perfusion abnormality on a regional basis in obese subjects, this abnormality bearing a close relationship to the reduction in expiratory reserve volume, a finding predictable from recently published data on normal nonobese subjects (1). The abnormalities of ventilation/perfusion relationships that were demonstrated in four of the eight obese subjects could cause a reduction in arterial oxygen tension during resting tidal ventilation.

Adult↗