Comment:

Pre‑bronchodilator FEV I is extremely severely reduced and there is no improvement with acute

bronchodilator administration. There is a mild reduction in forced vital capacity and a very severe reduction in the FEV I /FVC ratio. There is a profound reduction in gas transfer and lung volumes show an extremely severe elevation in RV and FRC consistent with gas trapping and hyperinflation. There is a moderate elevation in TLC as well. There is very poor single breath estimation of alveolar volume indicating extremely slow gas mixing. Arterial blood gases demonstrate mild hypoxaernia

and a mild increase in the A‑a gradient. Since 1996 there has been a moderate deterioration in FEV I and lung volumes. Oxygen saturation was measured at rest and on exercise. The resting oxygen saturation was 94% and dropped to 84% at 45% predicted maximum workload. There is evidence for very severe obstructive lung disease and emphysema with exercise capacity limited by pulmonary disease.