Spirometry in the Lung Health Study. 1. Methods and quality control.

The Lung Health Study is a randomized clinical trial designed to determine whether a smoking intervention program and prescription of an inhaled bronchodilator can reduce the annual rate of decline of FEV1 (FEV1 slope) in cigarette smokers with mild to moderate airflow limitation. During the recruitment period, spirometry measurements were obtained during three screening visits from 5,887 cigarette smokers 35 to 60 yr of age. To improve the statistical power of the study to detect significant differences in the FEV1 slopes among study groups, the spirometry testing protocol carefully controls for multiple factors that are known to increase intraindividual variability of FEV1 and FVC results.

The Cardiovascular Health Study: design and rationale.

The Cardiovascular Health Study (CHS) is a population-based, longitudinal study of coronary heart disease and stroke in adults aged 65 years and older. The main objective of the study is to identify factors related to the onset and course of coronary heart disease and stroke. CHS is designed to determine the importance of conventional cardiovascular disease (CVD) risk factors in older adults, and to identify new risk factors in this age group, especially those that may be protective and modifiable.

Effect of inhaled methacholine on inspiratory flow.

One hundred consecutive outpatients with symptoms suggestive of asthma who came to the Pulmonary Function Laboratory for a methacholine challenge test were studied. In addition to the forced expiratory maneuvers, forced inspiratory maneuvers were performed before and after the maximal response to methacholine. In 24 patients, the methacholine challenge suggested that they had asthma (forced expiratory volume in 1 s [FEV1] decrease greater than or equal to 20 percent).

Carbon monoxide diffusing capacity of the lungs determined by single-breath and steady-state exercise methods.

We measured carbon monoxide diffusing capacity of the lungs (DL,CO) by both the resting single-breath (SB) and steady-state (SS) exercise methods in 95 patients referred for pulmonary function testing. A 10-second breath-holding method was used for the SB test. DL,CO (SS) was measured during the last minute of a 3-minute exercise test on a 9-inch step.

Effect of effort on measurement of forced expiratory volume in one second.

The American Thoracic Society recommends that the largest FEV1 be reported from a set of forced expiratory vital capacity maneuvers performed with maximal expiratory effort. However, increased expiratory effort can decrease the FEV1. When we evaluated the peak expiratory flow rate (PEFR) in 5 normal subjects, measured from flow-volume curves, as a noninvasive index of expiratory effort, it was positively correlated with indices of effort obtained by using an esophageal balloon.

Physician's guide to spirometers.

Three pulmonary specialists compare the manual volume spirometer with the latest high-tech models and answer key questions on choosing the one that's right for your office. Also included: a buyer's guide to available models.

Watch out for outreach.

Pulmonary function testing outreach services permit hospitals or physician offices without local expert technicians or pulmonary specialist physicians to use the services of such experts at another location via electronic transmission of data and via computerization. A potential subscriber to an outreach service should investigate the cost and timeliness of service provision and should estimate testing volume and cost effectiveness. A potential provider of outreach services should investigate the potential market volume, the reimbursement rates, the choice of instrumentation, and the expected income/expense picture.

Effect of lidocaine on the ventilatory and airway responses to exercise in asthmatics.

An aerosol of 4% lidocaine was delivered during the last third of inspiration to patients with bronchial asthma while they were quietly breathing. After this procedure, both cough reflex (inhalation of 10% citric acid) and gag reflex (mechanical irritation of the larynx) were absent in all patients for 15 to 20 min. This type of anesthesia was tolerated well by all patients, and did not significantly influence baseline pulmonary function tests.