Oscillation Mechanics of the Respiratory System in Never-smoking Patients With Silicosis

Silicosis is a chronic and incurable occupational disease that can progress independent of the end of exposure. Recent works suggest that the Forced Oscillation Technique (FOT) may help to improve our understanding of the changes in lung mechanics, as well as in the detection of these changes.

Objectives: Analyze the effects of airway obstruction in silicosis on the respiratory impedance and evaluated the diagnostic use of the FOT in these patients. For this, the investigators used spirometry to classify airway obstruction, which resulted in four categories: control, patients with normal exam, mild obstruction, and moderate-to-severe obstruction. Resistive data were interpreted using the zero-intercept resistance (R0), the resistance at 4 Hz (Rrs4) and the mean resistance (Rm). The investigators also analyzed the mean reactance (Xm) and the dynamic compliance (Crs,dyn). The total mechanical load was evaluated using the absolute value of the respiratory impedance (Z4Hz). The diagnostic potential was evaluated by investigating the area under the receiver operating characteristic curve (AUC).

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Key information

Conditions

Silicosis Lung Diseases Lung Diseases, Interstitial Lung Injury Occupational Diseases Pneumoconiosis Respiratory Tract Diseases

Age range

18 year–90 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Laboratório de Instrumentação Biomédica

Rio de Janeiro, 21550-013, Brazil

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

• Volunteers with silicosis for Patients Group;

Volunteers without any respiratory disease for the control group.

Exclusion criteria

Smokers

Treatment and study plan

Primary outcomes

spirometric

Time frame: 1 day

Spirometry was used to classify airway obstruction, which resulted in four categories: control (n=21), patients with normal exam (n=12), mild obstruction (n=22), and moderate-to-severe obstruction (n=12).
Forced Oscillation technique

Time frame: 1 day

In the analysis of the forced oscillation technique was used the following data: Resistive data were interpreted using the zero-intercept resistance (R0), the resistance at 4 Hz (Rrs4) and the mean resistance (Rm). The researchers also analyzed the mean reactance (Xm) and the dynamic compliance (Crs,dyn). The total mechanical load was evaluated using the absolute value of the respiratory impedance (Z4Hz).

Sponsors and collaborators

Lead sponsor

Rio de Janeiro State University

Other

Registry information

Official study title

The Use of Forced Oscillation Technique in the Analysis of Respiratory System in Never-smoking Patients With Silicosis:Pathophysiological Study and Evaluation of Diagnostic Accuracy

Important dates

Study start: 2010
Primary completion: 2012
Study completion: 2013
First posted: Nov 14, 2012
Registry last updated: Oct 23, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed