Alterations in collagen and elastin and microangiopathy result in thickening of the alveolar epithelial basal lamina, leading to reduced pulmonary capacity for the diffusion of carbon monoxide (8, 10).
As tumours develop, their metabolic demand for oxygen and substrates exceeds the capacity of diffusion mechanisms to deliver these substances.
In addition, data regarding restrictive ventilatory defect (decreased forced vital capacity, or FVC) and diffusion impairment (decreased diffusion capacity for carbon monoxide, DLCO) and how the diagnosis of IPF/UIP (biopsy or CT scan) was made were obtained from chart abstraction on the patients with IPF/UIP.
This investigation reveals that the capacity for the gas-diffusion-electrode can be substantially increased, if the activated carbon is modified by attaching long-chain hydrophobic molecules onto the surface.
Pulmonary function test results were as follows: forced vital capacity (FVC), 3.46 L (91%); forced expiratory volume in 1 sec (FEV1), 2.31 L (74%); FEV1 FVC ratio, 67; total lung capacity, 5.27 L (95%); residual volume, 1.57 L (91%); diffusion capacity for carbon monoxide, 23.1 mL/mmHg/min (81%); and diffusion capacity for CO corrected for total lung capacity by single breath, 4.61 mL/mmHg/L (87%).
A restrictive pattern of pulmonary function abnormalities with reduction in forced vital capacity and diffusion capacity for carbon monoxide below 80% of predicted value (based on age, sex, height and ethnic origin) was used to assess interstitial lung involvement.
N.A., not available; CT, computed tomography; * according to Scadding [reference [ 14]; FVC, forced vital capacity; DLCO, diffusion capacity for carbon monoxide; ** predicted values according to European Community for Coal and Steel [reference [ 20, 21]; MSB, maxillary sinus bilateral; MSS, maxillary sinus singular; ES, ethmoidal sinus; FS, frontal sinus.
Considering the scaling factor of 5 and the fact that the diffusion capacity is inversely proportional to the square of the surface area, we have a diffusion capacity for a child for O2 and CO2 as 2.5 mL/min (mmHg)−1 and 19 mL/min (mmHg)−1, respectively.
Severity of COPD is clinically assessed by lung function tests and diffusion capacity for carbon monoxide.
This is measured by means of single breath test of diffusion capacity for carbon monoxide adjusted for haemoglobin concentration in the blood.
