Complexity of the Airflow in COPD

June 27, 2013 updated by: Karla Dames, Rio de Janeiro State University

Complexity of the Airflow at Different Levels of Bronchial Obstruction of COPD.

Recently, there has been a growing interest in the study of nonlinear dynamics as a methodology for complementary analysis to characterize the respiratory pattern. These methods are well established in studies of heart rate. The analyzes evaluate complex signals, including large-scale fractal correlations and distributions in time series, and can provide relevant clinical information.

Measures such as approximate entropy and sample entropy have shown great potential in the evaluation of the complexity of the respiratory system, providing information relevant to the understanding of physiological and pathophysiological processes. These measures are based on the concept of non-linearity in the presence of a high number of interconnections, resulting in the complex behavior exhibited by physiological systems.

The approximate entropy (ApEn) is related to the amount of clutter, complexity or unpredictability of a data series over time. In a complementary way, the sample entropy (SampEn), is a far more elaborate than the ApEn, to reduce possible biased estimates due to self-similarity.

A study conducted by our group in asthma patients with different levels of bronchial obstruction demonstrated a significant reduction in airflow approximate entropy (ApEnV´) in asthmatic subjects. Investigators believe that in COPD, similar to that which occurs in asthma disorders that are associated with complex changes in the pathophysiology triggering breath control, possibly resulting in changes in air flow (V´).

Considering the development "silent" changes of mechanical ventilation in COPD patients and its clinical relevance, as well as the difficulty of identifying such changes through conventional methods, we observed the need to obtain more detailed information, including the complexity of the system breathing for better understanding of factors that contribute to the illness.

In this context, the objectives of this study were: (1) analyze the influence of airway obstruction in the complexity of the patterns of airflow in patients with COPD, (2) evaluate the diagnostic power of the test in identifying the changes caused by COPD.

Study Overview

Status

Unknown

Conditions

Study Type

Observational

Enrollment (Anticipated)

90

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Brazil
      • Rio de Janeiro, Brazil, 21550-013
        • Recruiting
        • Laboratório de Instrumentação Biomédica
        • Contact:
          • Karla Dames, Principal Investigator
          • Phone Number: : (5521)97456496
          • Email: kkdames@gmail.com
        • Principal Investigator:
          • Karla Dames, MSc.
        • Principal Investigator:
          • Pedro L de Melo, DSc.
        • Principal Investigator:
          • Agnaldo J Lopes, Dr.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

40 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

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 of patients with COPD will be comprised of individuals treated at the Department of Pneumology (Hospital Universitário Pedro Ernesto), at different levels of airflow obstruction.

Description

Inclusion Criteria:

  • volunteers with COPD for Patients Group;
  • volunteers without any respiratory disease for the control group.

Exclusion Criteria:

  • individuals with history of tuberculosis or other lung disease,
  • heart disease in general and
  • disability in the exams.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Time Perspectives: Cross-Sectional

Cohorts and Interventions

Group / Cohort
Control group
Group of nonsmokers individuals without respiratory disease.
NE
Smokers wiht normal spirometry.
LV
Patients with COPD level I, mild.
MOD
Patients with COPD level II, moderate.
GV
Patients with COPD level III, severe.
MGV
Patients with COPD level IV, very severe.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Respiratory Impedance in Different Phases of the Cycle Ventilation in Patients with Chronic Obstructive Pulmonary Disease
Time Frame: up to 3 years
The aim of the study was to analyze the changes in the respiratory system impedance (Zrs) in the different phases of the respiratory cycle of patients with Chronic Obstructive Pulmonary Disease (COPD). This research was conducted using a monofrequency version of the forced oscillation technique (mFOT) and consisted of a controlled observational study where 31 individuals were analyzed, 8 controls and 23 individuals with COPD. The patients presented different degrees of airway obstruction.
up to 3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Rio de Janeiro State University

Collaborators

Conselho Nacional de Desenvolvimento Científico e Tecnológico
Rio de Janeiro State Research Supporting Foundation (FAPERJ)

Investigators

  • Study Director: Pedro L de Melo, DSc., State University of Rio de Janeiro

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

March 1, 2010

Primary Completion (Anticipated)

July 1, 2013

Study Completion (Anticipated)

December 1, 2013

Study Registration Dates

First Submitted

June 21, 2013

First Submitted That Met QC Criteria

June 27, 2013

First Posted (Estimate)

June 28, 2013

Study Record Updates

Last Update Posted (Estimate)

June 28, 2013

Last Update Submitted That Met QC Criteria

June 27, 2013

Last Verified

June 1, 2013

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • UERJ-DPOC-01

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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