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The effects of inhaled bronchodilators at rest and during exercise were studied in 15 subjects with chronic obstructive pulmonary disease. In a crossover study against placebo, albuterol caused a significant increase in expiratory flow and reduced lung hyperinflation and dyspnea at rest, but this was not associated with differences in symptoms with exercise or any relevant parameter of physical performance. Dynamic hyperinflation occurred during exercise similarly after placebo or albuterol and was associated with a reduction of forced expiratory flows. This, in turn, was correlated with the bronchoconstrictor effect of deep inhalation determined at rest. In a parallel group study, expiratory flow was increased by 3-wk treatment with salmeterol (n= 9) but not with placebo (n= 6). However, in neither group was the response to exercise different from baseline. These results suggest that in chronic obstructive pulmonary disease effective pharmacological bronchodilation at rest may not be predictive of benefits of exercise tolerance. This may be related to the occurrence of airway narrowing during exercise, particularly when a deep inhalation at rest is followed by a decrease in expiratory flow.

To assess (1) the possibility ofpredicting long-term postoperative lung function, and (2) theusefulness of maximal oxygen consumption( V˙o2max) as a criterion for operabilityand as a predictor of long-term disability.

We hypothesized that an altered effect of lung inflation on airway caliber may in part explain the isolated volume response to bronchodilators, i.e., an increase of forced vital capacity (FVC) without change in 1-s forced expiratory volume (FEV1). Small-airway caliber was measured by high-resolution computed tomography at functional residual capacity and total lung capacity in five chronic obstructive pulmonary disease patients with an isolated increase of FVC (FVC responders) and five with an increase of both FVC and FEV1(FVC-FEV1responders) after inhalation of salbutamol. In FVC-FEV1responders, the airway diameter increased with the cube root of increase in lung volume but was unchanged or even decreased in four of five FVC responders. FVC responders had more severe emphysema, as inferred from lung function and imaging studies, than FVC-FEV1responders. We speculate that longitudinal traction or space competition (Verbeken EK, Cauberghs M, and Van de Woestijne KP, J Appl Physiol81: 2468–2480, 1996) are possible underlying mechanisms. We conclude that the isolated volume response to bronchodilators is associated with severe emphysema and likely results from an altered effect of lung inflation on airway caliber.

To evaluate lung function in patients cured from childhood acute lymphoblastic leukemia (ALL) with chemotherapy alone or plus bone marrow transplantation (BMT). Pulmonary toxicity is a well-recognized side effect of many ALL treatments.