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

Study Overview
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Brief Summary
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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).

Official Title
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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

Conditions
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Silicosis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: • Volunteers with silicosis for Patients Group; Volunteers without any respiratory disease for the control group. Exclusion Criteria: Smokers

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Control group<br>Group of nonsmokers individuals without respiratory disease. | |
| normal exam<br>subjects with silicosis , but with normal spirometric data | |
| mild obstruction<br>subjects with silicosis with mild obstruction in spirometric data | |
| moderate to severe obstruction<br>subjects with silicosis with moderate to severe obstruction in spirometric data | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| spirometric | 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). | 1 day | 
| Forced Oscillation technique | 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). | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Silicosis, forced oscillations, respiratory mechanics