PMID: 970732Sep 1, 1976

The response of asthmatic subjects to isoproterenol inhaled at differing lung volumes

The American Review of Respiratory Disease
D J RileyN H Edelman

Abstract

Asthmatics are usually instructed to use pressurized bronchodilator aerosols by delivering a bolus of drug at the beginning of a full inspiration. Because airways are better dilated near total lung capacity, the delivery of the drug near the end of a full breath might allow better penetration of particles into the lung and greater bronchodilatation. To test this hypothesis, 13 asthmatic subjects inhaled 400 mug of isoproterenol at 20 per cent (low) and at 80 per cent (high) vital capacity. The studies were done on 2 separate days when the severity of asthma was the same. Forced vital capacity, 1-sec forced expiratory volume, specific airway conductance and maximal flow at 50 per cent of viral capacity were measured at frequent intervals after drug administration. Ten min after drug delivery, there was a significantly greater (P less than 0.05) improvement in 1-sec forced expiratory volume after the drug was inhaled at the high lung volume compared to the response after delivery at the low lung volume. The differences in forced vital capacity, specific conductance, and maximal flow at 50 per cent of vital capacity were not significant. We concluded that inhaling a bronchodilator drug at the end of a full inspiration causes relat...Continue Reading

Related Concepts

Respiratory Therapy
Lung
Breath
Vital Capacity Test
Bronchodilator Agents
Asthma
Novodrin
Lung Diseases
Forced Expiratory Volume Procedure
Lung Capacities

Related Feeds

Asthma

This feed focuses in Asthma in which your airways narrow and swell. This can make breathing difficult and trigger coughing, wheezing and shortness of breath.

Allergy and Asthma

Allergy and asthma are inflammatory disorders that are triggered by the activation of an allergen-specific regulatory t cell. These t cells become activated when allergens are recognized by allergen-presenting cells. Here is the latest research on allergy and asthma.