Análise em tempo real da impedância do sistema respiratório e da mobilidade toracoabdominal em portadores de DPOC com obstrução brônquica acentuada / Real-time analysis of respiratory system impedance and thoracoabdominal mobility of COPD patients with severe bronchial obstruction
AUTOR(ES)
Karla Kristine Dames da Silva
DATA DE PUBLICAÇÃO
2009
RESUMO
Introduction: COPD is carachterized by airflow limitation associated abnormal inflammatory response of the lung to noxious particles or gases. The mechanical alterations associated with COPD have been related with dysfunction of the diaphragm, observed since the initial phases of the disease. Several studies have confirmed the high potential of FOT in the assessment of the mechanics modifications related to COPD. However, such studies did not allow a real-time analysis of the changes in the respiratory system, and the thoracoabdominal mobility of these individuals. Thus, the goals of the present study were to analyze, in real-time, the impedance alterations of the respiratory system in different phases of the respiratory cycle of COPD patients. Methodology: This research consists of a controlled observational study where 48 individuals were analyzed, 23 controls and 25 individuals with COPD and severe airway obstruction. Firstly, they performed simultaneous analysis of impedance of the respiratory system and thoracoabdominal motion. In subsequent examinations, these subjects were submitted to spirometry. Results: The results demonstrated an increase of the respiratory system impedance in individuals with COPD compared with the control group in all of the studied parameters (Zt, Zi, Ze, Zii, Zie, ΔZrs e Zpp) (p<0.0001). Considering the different phases of the respiratory cycle, higher impedances were observed in the inspiratory phase (p<0.004). Only 10% of individuals with COPD showed thoracoabdominal asynchrony (φ≥ 45), and the mean values showed no statistical difference when compared to the control group. Discussions: The total impedance of the respiratory system increased in individuals with COPD, which describes the increase of the mechanic load of the respiratory system in these individuals. These alterations are coherent with the physiopathology of COPD, associated with airflow obstruction and lung parenchyma destruction. The increase of the impedance in the inspiratory phase suggests an increase of the resistive and elastic work. There were not signals of thoracoabdominal asynchrony in the major part of the studied individuals, suggesting that some adaptation mechanisms act to compensate respiratory muscle fatigue. Conclusion: The COPD results in the increase of the mechanic load of the respiratory system. These alterations were identified by the increase of the respiratory system impedance, which was more evidence in the inspiratory phase. The thoracoabdominal asynchrony was not usual in individuals with COPD. Those results are consistent with previously published data and physiopathological fundamentals, confirming the potential of monofrequency FOT in the assessment of the modifications related to COPD.
ASSUNTO(S)
chronic obstructive pulmonary disease volume expiratório forçado forced expiratory volume técnica de oscilações forçadas oscilometria thoracoabdominal mobility mecânica respiratória doença pulmonar obstrutiva crônica mobilidade toracoabdominal oscillometry respiratory function tests fisiologia da respiracao respiratory mechanics dpoc forced oscilation technique testes de função respiratória copd
