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

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Paula Morisco de Sá, Rio de Janeiro State University
ClinicalTrials.gov Identifier:
NCT01725971
First received: October 30, 2012
Last updated: October 21, 2014
Last verified: October 2014
  Purpose

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).


Condition
Silicosis

Study Type: Observational
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

Resource links provided by NLM:


Further study details as provided by Rio de Janeiro State University:

Primary Outcome Measures:
  • 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).


Enrollment: 67
Study Start Date: July 2010
Study Completion Date: June 2013
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts
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

Ages Eligible for Study:   18 Years to 90 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
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.

Criteria

Inclusion Criteria:

  • • Volunteers with silicosis for Patients Group;

    • Volunteers without any respiratory disease for the control group.

Exclusion Criteria:

  • Smokers
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01725971

Locations
Brazil
Laboratório de Instrumentação Biomédica
Rio de janeiro, Brazil, 21550-013
Sponsors and Collaborators
Rio de Janeiro State University
  More Information

No publications provided

Responsible Party: Paula Morisco de Sá, researcher, Rio de Janeiro State University
ClinicalTrials.gov Identifier: NCT01725971     History of Changes
Other Study ID Numbers: Silicose2012, Silicose2012
Study First Received: October 30, 2012
Last Updated: October 21, 2014
Health Authority: Brazil: Ethics Committee
Brazil: National Committee of Ethics in Research

Keywords provided by Rio de Janeiro State University:
Silicosis
forced oscillations
respiratory mechanics

Additional relevant MeSH terms:
Silicosis
Lung Diseases
Lung Diseases, Interstitial
Lung Injury
Occupational Diseases
Pneumoconiosis
Respiratory Tract Diseases
Respiratory System Agents
Pharmacologic Actions
Therapeutic Uses

ClinicalTrials.gov processed this record on October 29, 2014