Advantage of impulse oscillometry over spirometry to diagnose chronic obstructive pulmonary disease and monitor pulmonary responses to bronchodilators: An observational study.

OBJECTIVES: This retrospective study was a comparative analysis of sensitivity of impulse oscillometry and spirometry techniques for use in a mixed chronic obstructive pulmonary disease group for assessing disease severity and inhalation therapy. METHODS: A total of 30 patients with mild-to-moderate chronic obstructive pulmonary disease were monitored by impulse oscillometry, followed by spirometry. Lung function was measured at baseline after bronchodilation and at follow-up (3-18 months). The impulse oscillometry parameters were resistance in the small and large airways at 5 Hz (R5), resistance in the large airways at 15 Hz (R15), and lung reactance (area under the curve X; AX). RESULTS: After the bronchodilator therapy, forced expiratory volume in 1 second (FEV1) readings evaluated by spirometry were unaffected at baseline and at follow-up, while impulse oscillometry detected an immediate improvement in lung function, in terms of AX (p = 0.043). All impulse oscillometry parameters significantly improved at follow-up, with a decrease in AX by 37% (p = 0.0008), R5 by 20% (p = 0.0011), and R15 by 12% (p = 0.0097). DISCUSSION: Impulse oscillometry parameters demonstrated greater sensitivity compared with spirometry for monitoring reversibility of airway obstruction and the effect of maintenance therapy. Impulse oscillometry may facilitate early treatment dose optimization and personalized medicine for chronic obstructive pulmonary disease patients.

Retrospective observations on the ability to diagnose and manage patients with asthma through the use of impulse oscillometry: comparison with spirometry and overview of the literature.

OBJECTIVE: Impulse oscillometry (IOS) is an evolving technology for the diagnosis and followup of patients with asthma. Our objective is to review the findings on patients who underwent both spirometry and IOS during clinical evaluations of their asthma. The goal was to retrospectively evaluate IOS during the initial diagnosis and followup of patients with asthma in comparison with spirometry. METHODS: We routinely perform IOS and spirometry evaluation in patients with suspected asthma during baseline visits and at followup. We reviewed the data on 39 patients over the age of 13 with asthma at baseline and following treatment with inhaled corticosteroids. IOS and spirometry were both done at baseline, following short acting bronchodilator administration, and at followup after at least three months of inhaled corticosteroid treatment. RESULTS: IOS showed improvement in airway function both initially, following short acting bronchodilator introduction, and later after initiation of long term inhaled corticosteroid treatment, even when the spirometry did not reveal improvement. We noted the IOS improvement in the reactance or AX as well as the resistance in smaller airways or R5. CONCLUSION: IOS may provide a useful measure towards identifying an asthma diagnosis and followup without inducing the extra respiratory effort spirometry requires.