Anatomical studies suggest that normal lungs grow by rapid alveolar addition until about 2 yrs of age followed by a gradual increase in alveolar dimensions. The aim of this study was to examine the hypothesis that normal lung growth can be monitored by computed tomography (CT). Therefore, the gas volume per gram of lung tissue was estimated from measurements of lung density obtained from CT sca...

The multibreath helium equilibration method is the technique recommended for routine measurement of static lung volumes in normal subjects. However, pregnancy could be an exception to this general rule, due to airway closure during the second half of gestation. The aim of this study was to compare the measurements of lung volumes by plethysmography and helium dilution during pregnancy. Twenty t...

D lco and the D lco VA ratio change with lung volume as would be expected with changes in surface area for diffusion. Percent predicted for D lco adjusted for lung volume (D aco ) and D lco VA ratio adjusted for lung volume (K aco ) also should be reported, using the following equations: D aco predicted 5 D lco predicted 3 (0.58 1 0.42 3 VA VAtlc) and K aco predicted 5 K co predicted 3 (0.42 1 ...

STUDY OBJECTIVES To clarify the significance of a functional lung pattern characterized by a decreased vital capacity (VC) and an increased residual volume (RV), but with a normal FEV1/VC ratio. SETTING A university teaching hospital. SUBJECTS Patients with bronchial asthma, pulmonary emphysema, and small airways disease, and older subjects. MEASUREMENTS Measurements of static and dynamic...

Measurements of ventilatory function, distribution of ventilation, diffusing capacity, and lung mechanics were made on healthy middle-aged smokers and nonsmokers drawn from a randomly selected population in order to assess the effects of cigarette smoking and the interrelationships of the several indices of lung function. Although very few subjects had abnormal function, there were significant ...

Chronic heart failure (CHF) disturbs the alveolar-capillary interface and increases the resistance to gas transfer. Alveolar-capillary membrane conductance (D(M)) and capillary blood volume (V(c)) are subcomponents of the lung diffusion capacity. Elevation of the capillary pressure causes alveolar-capillary membrane stress failure (i.e. increase in capillary permeability to water and ions, and ...

RATIONALE Previous investigations have identified several potential predictors of outcomes from lung volume reduction surgery (LVRS). A concern regarding these studies has been their small sample size, which may limit generalizability. We therefore sought to examine radiographic and physiologic predictors of surgical outcomes in a large, multicenter clinical investigation, the National Emphysem...

Pulmonary emphysema, as the term is generally used clinically, refers to an overinfiation or distention of the lungs (localized or diffuse), characterized by a relative increase in the amount of air which cannot be blown out with a forced expiration. The residual air capacity plus the vital capacity equals total observed lung capacity (TLC) for the individual, and in pulmonary emphysema the TLC...

Lapp, N. L., Amandus, H. E, Hall, R., and Morgan, W. K. C. (1974). Thorax, 29, 185-188. Lung volumes and flow rates in black and white subjects. It has been known for some time that the vital capacity and forced expiratory volume in one second of black subjects are about 12% lower than those of whites of the same age and height. In the present study, total lung capacity and residual volume were...