Chest
Clinical InvestigationsDetermination of Bronchodilation in the Clinical Pulmonary Function Laboratory: Role of Changes in Static Lung Volumes
Section snippets
MATERIALS AND METHODS
The results of the pulmonary function studies of all patients referred to the Pulmonary Physiology Laboratory of the La Jolla Veterans Administration Hospital for evaluation of bronchodilator response to inhaled isoproterenol over a one-year period were analyzed retrospectively. All patients were evaluated clinically prior to testing on the basis of an interview and the response to a standard questionnaire modified after the British Medical Research Council Pulmonary Questionnaire. Standard
Patterns of Response
Two hundred forty-one patients underwent bronchodilator testing during a 12-month period. One hundred twenty-nine of the patients (54 percent) had no improvement in either static lung volumes or dynamic flow rates after administration’ of isoproterenol (Table 1). Of the 112 patients (46 percent of those studied) who did respond, 46 (41 percent of all responders and 19 percent of all patients tested) showed an increase in VC and fall in FRCB without a change in flow rates (isolated volume
DISCUSSION
These data indicate that patients with reversible obstructive airways disease can be identified in the clinical pulmonary function laboratory by selective improvement in static lung volumes after administration of isoproterenol. On the basis of changes in static lung volume parameters (VC and FRCB) and dynamic lung function parameters (FEV1/FVC% or FEF25–75%,), the patients studied could be separated into three patterns of response: isolated volume (increased VC and decreased FRCB following
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Manuscript received January 12; revision accepted March 20.