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).
|Study Design:||Time Perspective: Cross-Sectional|
|Official 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|
- spirometric [ Time Frame: 1 day ] [ Designated as safety issue: No ]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 ] [ Designated as safety issue: No ]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).
|Study Start Date:||July 2010|
|Estimated Study Completion Date:||June 2013|
|Estimated Primary Completion Date:||December 2012 (Final data collection date for primary outcome measure)|
Group of nonsmokers individuals without respiratory disease.
subjects with silicosis , but with normal spirometric data
subjects with silicosis with mild obstruction in spirometric data
moderate to severe obstruction
subjects with silicosis with moderate to severe obstruction in spirometric data
|Contact: Paula M Sá||(5521)2334-0705||paulamorisco@hotmail..com|
|Laboratório de Instrumentação Biomédica||Recruiting|
|Rio de janeiro, Brazil, 21550-013|
|Contact: Paula M Sá (5521)2334-0705 firstname.lastname@example.org|
|Principal Investigator: Paula M Sá|
|Principal Investigator: Agnaldo José Lopes|
|Principal Investigator: José Manoel Jansen|
|Principal Investigator: Pedro L de Melo|