Complexity of the Airflow in COPD
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|ClinicalTrials.gov Identifier: NCT01888705|
Recruitment Status : Unknown
Verified June 2013 by Karla Dames, Rio de Janeiro State University.
Recruitment status was: Recruiting
First Posted : June 28, 2013
Last Update Posted : June 28, 2013
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.
|Condition or disease|
|Study Type :||Observational [Patient Registry]|
|Estimated Enrollment :||90 participants|
|Target Follow-Up Duration:||1 Day|
|Official Title:||Complexity of the Airflow at Different Levels of Bronchial Obstruction of COPD.|
|Study Start Date :||March 2010|
|Estimated Primary Completion Date :||July 2013|
|Estimated Study Completion Date :||December 2013|
Group of nonsmokers individuals without respiratory disease.
Smokers wiht normal spirometry.
Patients with COPD level I, mild.
Patients with COPD level II, moderate.
Patients with COPD level III, severe.
Patients with COPD level IV, very severe.
- 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.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01888705
|Laboratório de Instrumentação Biomédica||Recruiting|
|Rio de Janeiro, Brazil, 21550-013|
|Contact: Karla Dames, Principal Investigator : (5521)97456496 email@example.com|
|Principal Investigator: Karla Dames, MSc.|
|Principal Investigator: Pedro L de Melo, DSc.|
|Principal Investigator: Agnaldo J Lopes, Dr.|
|Study Director:||Pedro L de Melo, DSc.||State University of Rio de Janeiro|