Related Experiment Video
Updated: Aug 30, 2026

Employing the Forced Oscillation Technique for the Assessment of Respiratory Mechanics in Adults
Published on: February 9, 2022
Relationship among pulmonary function, bronchial reactivity, and exhaled nitric oxide in a large group of asthmatic
Stephen J Langley1, Sophie Goldthorpe, Adnan Custovic
1Medicines Evaluation Unit, North West Lung Research Centre, Wythenshawe Hospital, Manchester, England. slangley@meu.org.uk
Background:
Bronchial reactivity and exhaled nitric oxide (eNO) are not often used to monitor control and severity of asthma in clinical practice.
Objective:
To evaluate the relationship among different physiologic measures (pulmonary function, nonspecific bronchial reactivity, and eNO) in asthmatic patients.
Methods:
Cross-sectional, hospital-based study conducted in patients with varied asthma severity.
Results:
A total of 392 patients participated in the study. There was no difference in eNO levels between patients taking inhaled corticosteroids (ICS group) and patients not receiving inhaled corticosteroids (NICS group). However, the percentage of predicted forced expiratory volume in 1 second (FEV1) and the provocative dose of methacholine causing a 20% decrease in FEV1 were significantly lower in the ICS group compared with the NICS group (mean, 83.2%; 95% confidence interval [CI], 80.4%-86.0%; vs mean, 94.1%; 95% CI, 91.1%-97.1%; P = .001; and geometric mean, 0.32 mg; 95% CI, 0.23-0.45 mg; vs geometric mean, 0.58 mg; 95% CI, 0.42-0.81 mg; P = .01; respectively). Patients with more severe bronchial hyperresponsiveness had a lower percentage of predicted FEV1 values (P < .001) and levels of eNO were significantly increased with increasing bronchial hyperresponsiveness (P < .001). There was no relationship between the percentage of predicted FEV1 and eNO. Atopic patients had significantly higher eNO levels than nonatopic patients (geometric mean, 11.21 ppb; 95% CI, 10.07-12.49 ppb; vs geometric mean, 7.76 ppb; 95% CI, 6.11-9.85 ppb; P = .006; respectively).
Conclusions:
eNO values are not related to the degree of airway obstruction but are related to airway reactivity and atopic status independent of inhaled corticosteroid use. Higher values of eNO are seen with increased airway reactivity.
Related Concept Videos
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
Pulmonary Function Tests
Pulmonary Function Tests are crucial diagnostic tools for assessing respiratory function, particularly in patients with chronic respiratory disorders. They comprehensively evaluate lung volumes, ventilatory function, breathing mechanics, diffusion, and gas exchange. These tests help diagnose pulmonary diseases and play a significant role in monitoring disease progression, evaluating disability, and assessing response to therapy.
PFTs involve using a spirometer, a...
Asthma I: Introduction
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
Asthma III: Clinical Manifestations
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
