Hiperinsuflação dinâmica no esforço: ainda muito a ser esclarecido

Abstract

Dyspnea on exertion is a very common complaint in patients with COPD. Results of pulmonary function testing at rest are often limited in explaining patient complaints and do not always reflect the pathophysiological mechanisms related to exertion. In this context, cardiopulmonary exercise testing can be performed with the prospect of not only confirming and measuring the reduced exercise tolerance but also of characterizing the multiple factors that can potentially contribute to exercise limitation. In COPD, although various mechanisms can act on exercise intolerance, mechanisms such as decreased peripheral strength and cardiovascular dysfunction, airflow limitation with dynamic air trapping has unique significance.(1-4)

Airway disease: similarities and differences between asthma, COPD and bronchiectasis

“…Furthermore, the prevalence of these diseases is underestimated according to epidemiological surveys, which further increases the complexity of managing these diseases. In Brazil, acute asthma exacerbations and chronic obstructive pulmonary disease (COPD) are major causes of hospitalization (1),(2). Despite the presentation of similar symptoms, such as dyspnea, coughing, wheezing and expectoration, airway diseases have different underlying pathophysiological processes and must be distinguished to enable the administration of appropriate treatment.…”

“…Surveys on the prevalence of asthma suggest a prevalence of approximately 9% in the British population. In Brazil, an epidemiological study of the population in São Paulo revealed a COPD prevalence of 15.8% (4), whereas the prevalence of asthma was estimated to be approximately 10% of the general population (1). Several studies have suggested a similar prevalence of asthma among children and adult populations; however, extensive variability has been found depending on multiple factors that include geographic differences and socioeconomic status (5).…”

“…Drug costs are the main expenses that are associated with the treatment of asthma, whereas COPD and bronchiectasis have a greater economic impact due to high hospitalization rates (12). The main findings from these epidemiological studies are as follows: (1) the prevalence of chronic obstructive pulmonary disease, which is closely correlated with the definition that is used, is an important social and economic problem; (2) the overlap between asthma, COPD and bronchiectasis is associated with an increase in clinical severity and mortality; and (3) approximately half of patients with obstructive findings on spirometry are not properly diagnosed; therefore, screening programs that include a pulmonary function evaluation (with an assessment of both spirometry and peak flow) should be adopted to decrease the proportion of patients without adequate monitoring (13),(14). …”

“…However, many patients may present with a reversal after the use of a bronchodilator without exhibiting normalization in pulmonary function tests, thus indicating signs of bronchial remodeling. In addition, clinically stable patients may present with normal spirometry but a positive bronchial provocation test (1). Other functional variables can be used for the diagnosis of obstructive lung disease, such as the forced expiratory flow at 50% of the FVC FEF50%/0.5FVC (80) ratio.…”

“…In more severe cases of patients with bronchiectasis, the dilation of large airways can be visualized as a thickening of the peribronchovascular interstitium using this method. A universal radiographic finding in obstructive diseases is lung hyperinflation, which is characterized as follows: (1) an increase in the lung volume, (2) an increase in the intercostal spaces, (3) a rectification of the diaphragmatic domes, (4) an accentuation of the retrosternal space and (5) the presence of air below the inferior border of the heart (82). …”