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CompletedNCT01725971Updated Oct 23, 2014

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

An observational study in Silicosis, sponsored by Rio de Janeiro State University. Completed at 1 site in Brazil. Open to participants aged 18 Years to 90 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2014-10-23.

Sponsored by Rio de Janeiro State University · Observational

Study type
Observational
Time perspective
Cross-sectional
Enrollment
67
Ages
18 Years to 90 Years
Sex
All
01

Study 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).

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Conditions studied

  • Silicosis

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Keywords

  • Silicosis
  • forced oscillations
  • respiratory mechanics
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Who can participate

Ages eligible
18 Years to 90 Years
Sexes eligible
All
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.

Inclusion criteria

    • Volunteers with silicosis for Patients Group;

      • Volunteers without any respiratory disease for the control group.

Exclusion criteria

Exclusion Criteria:

  • Smokers
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Study design

Time perspective
Cross-sectional
Enrollment
67 participants (actual)

Groups and 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

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What researchers measure

Primary outcomes

  1. 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).

    Time frame: 1 day

  2. 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).

    Time frame: 1 day

06

Study locations

1 site
  • Laboratório de Instrumentação Biomédica
    Rio de janeiro, 21550-013, Brazil
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References and documents

Publications

  • 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. PubMed 23778400 ↗
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Registry details

Key details

Study ID
NCT01725971
Lead sponsor
Rio de Janeiro State University
Responsible party
Paula Morisco de Sá (researcher, Rio de Janeiro State University) — Principal investigator
First posted
Nov 14, 2012
Start date
Jul 2010
Primary completion
Dec 2012
Completion
Jun 2013
Last update
Oct 23, 2014

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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