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

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

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01725971

Enrollment

Registered

2012-11-14

Start date

2010-07-31

Completion date

2013-06-30

Last updated

2014-10-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Silicosis

Keywords

Silicosis, forced oscillations, respiratory mechanics

Brief summary

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).

Interventions

None listed

Study design

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Age

18 Years to 90 Years

Healthy volunteers

Yes

Inclusion criteria

* • Volunteers with silicosis for Patients Group; * Volunteers without any respiratory disease for the control group.

Exclusion criteria

* Smokers

Design outcomes

Primary

Measure	Time frame	Description
spirometric	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	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).

Countries

Brazil

Outcome results