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

NCT01725971 | Completed

• 1 other identifier: Silicose2012
• Study Type: observational
• Target: 67
• Locations: 1 country
• Sites: 1

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).

Conditions

Silicosis

Keywords

Silicosis; forced oscillations; respiratory mechanics

Outcome Measures

Primary Outcomes (2)

• 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

Study Arms (4)

Control group

Group of nonsmokers individuals without respiratory disease.

normal exam

subjects with silicosis , but with normal spirometric data

mild obstruction

subjects with silicosis with mild obstruction in spirometric data

moderate to severe obstruction

subjects with silicosis with moderate to severe obstruction in spirometric data

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The control group will consist of healthy subjects, nonsmokers, who had no episode of respiratory infection thirty days before the examinations. The group with diagnosis of silicosis was established based on a history of substantial exposure to silica dusts and compatible radiological features, together with exclusion of other competing diagnoses.

You may qualify if:

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

You may not qualify if:

• Smokers

Sponsors & Collaborators

• Rio de Janeiro State University: lead

Study Sites (1)

Laboratório de Instrumentação Biomédica

Rio de Janeiro, Rio de Janeiro, 21550-013, Brazil

Location

Related Publications (1)

• Sa PM, Lopes AJ, Jansen JM, Melo PL. Oscillation mechanics of the respiratory system in never-smoking patients with silicosis: pathophysiological study and evaluation of diagnostic accuracy. Clinics (Sao Paulo). 2013 May;68(5):644-51. doi: 10.6061/clinics/2013(05)11.

  PMID: 23778400 DERIVED

MeSH Terms

Conditions

Silicosis

Condition Hierarchy (Ancestors)

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

Study Design

• Study Type: observational
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: researcher

Study Record Dates

• First Submitted: October 30, 2012
• First Posted: November 14, 2012
• Study Start: July 1, 2010
• Primary Completion: December 1, 2012
• Study Completion: June 1, 2013
• Last Updated: October 23, 2014

Record last verified: 2014-10

Locations

BR (1)