Measurement of pulmonary diffusion capacity Measurement of diffusion capacity by single-breath determination of carbon monoxide (CO) uptake in the lung (DL, CO) assesses the uptake of carbon monoxide (CO) from the lung over a breath-holding period [ 265].
As the distance away from the head-on section increased, the control capacity of dust diffusion firstly weakened and then strengthened.
The capacity of transversal diffusion to even out the wave velocities of adjacent areas is not infinite.
For our study population, RV/TLC (ratio of residual volume to total lung capacity) was available in 121 subjects, and Kco (ratio of diffusion capacity over alveolar volume) in 103 subjects.
Impaired diffusion in conjunction with restriction or obstruction was observed in 16 of those latter subjects, while the remaining 15 patients (9.6%) had isolated impaired diffusion (median diffusion capacity of the lung for carbon monoxide = 69% of predicted, range 59 to 75%).
We also compared the diffusing capacity for carbon monoxide (DLCO) between the two groups, as isolated depression of diffusion capacity is associated with PAH in SSc [28].
DLCO-SB, predicted diffusion capacity of a single breath; dSSc, diffuse systemic sclerosis; FVC, forced vital capacity; lSSc, limited systemic sclerosis; mRSS, modified Rodnan skin score; PAH, pulmonary arterial hypertension; RP, Raynaud phenomenon; SScSS, systemic sclerosis sine scleroderma; UCTD, undifferentiated connective tissue disease.
This is measured by means of single breath test of diffusion capacity for carbon monoxide adjusted for haemoglobin concentration in the blood.
Lung function tests showed a mild restrictive ventilatory impairment (CVF 74.23 ± 13.5) and mild decrease of diffusion capacity (DLCO 53.1 ± 17.05).
They found that if untreated, diffuse parenchymal disease on PET/CT, as opposed to parenchymal disease on CT without metabolic activity, predicted future deterioration of diffusion capacity measured by pulmonary function test.
