Respiratory constraints during activities in daily life and the impact on health status in patients with early-stage COPD: a cross-sectional study.

In patients with chronic obstructive pulmonary disease (COPD), exercise capacity is reduced, resulting over time in physical inactivity and worsened health status. It is unknown whether ventilatory constraints occur during activities of daily life (ADL) in early stages of COPD. The aim of this study was to assess respiratory mechanics during ADL and to study its consequences on dyspnoea, physical activity and health status in early-stage COPD compared with healthy controls. In this cross-sectional study, 39 early-stage COPD patients (mean FEV1 88±s.d. 12% predicted) and 20 controls performed 3 ADL: climbing stairs, vacuum cleaning and displacing groceries in a cupboard. Respiratory mechanics were measured during ADL. Physical activity was measured with accelerometry. Health status was assessed by the Nijmegen Clinical Screening Instrument. Compared with controls, COPD patients had greater ventilatory inefficiency and higher ventilatory requirements during ADL (P<0.05). Dyspnoea scores were increased in COPD compared with controls (P<0.001). During ADL, >50% of the patients developed dynamic hyperinflation in contrast to 10-35% of the controls. Higher dyspnoea was scored by patients with dynamic hyperinflation. Physical activity was low but comparable between both groups. From the patients, 55-84% experienced mild-to-severe problems in health status compared with 5-25% of the controls. Significant ventilatory constraints already occur in early-stage COPD patients during common ADL and result in increased dyspnoea. Physical activity level is not yet reduced, but many patients already experience limitations in health status. These findings reinforce the importance of early diagnosis of COPD and assessment of more than just spirometry.

[Medicinal intervention for COPD; even in patients with mild or moderate COPD?]. / Medicamenteuze interventie bij COPD, ook bij patiënten met lichte en matige COPD?

The classification of COPD based only on the presence of airway obstruction fails to provide insight into the burden of the disease, quality of life and prognosis. The severity of symptoms, degree of exercise intolerance and presence of comorbidity are also determinants for classifying the severity of the disease. COPD starts with abnormalities in the bronchiolar compartment which cause obstruction in the airways. This results in incomplete expiration; first during exercise and later, also at rest. This is called dynamic hyperinflation or air trapping. Such changes in the mechanics of breathing occur early in course of the disease, even in mild COPD (the GOLD I stage), and contribute to physical inactivity and deconditioning. Maximal bronchodilation--more precisely: bronchiolodilation--reduces the mechanism of dynamic hyperinflation inasmuch as the condition allows. This has a positive effect on the symptoms of dyspnoea during exercise and thus on exercise capacity and trainability, even early on in the disease. Medicinal therapy has a positive effect on the progression of COPD, also in the early stages of disease.

Diagnostic accuracy of metronome-paced tachypnea to detect dynamic hyperinflation.

INTRODUCTION: This prospective study was carried out to investigate if metronome-paced tachypnea (MPT) can serve as an accurate diagnostic tool to identify patients with chronic obstructive pulmonary disease (COPD) who are susceptible to develop dynamic hyperinflation during exercise. Commonly, this is assessed by measuring change in inspiratory capacity (IC) during cardiopulmonary exercise testing (CPET), which, however, is complex and laborious. METHODS: Fifty-three patients with COPD (FEV(1) 58 ± 22%pred) and 20 age-matched healthy subjects were characterized by lung function testing and performed CPET (reference standard) and MPT. The repeatability coefficient of IC (10·2%) was used as cut-off to classify subjects as hyperinflators during CPET. Subsequently, dynamic hyperinflation was measured after MPT. With receiver operating characteristic analysis, the optimal cut-off for MPT-induced dynamic hyperinflation was determined and sensitivity and specificity of MPT to identify hyperinflators were evaluated. RESULTS: With 10·2% decrease in IC as cut-off for CPET-induced dynamic hyperinflation, the optimal cut-off for MPT was 11·1% decrease in IC. Using these cut-offs, MPT had a sensitivity of 85% and specificity of 85% to identify the subjects who hyperinflated during CPET. CONCLUSIONS: The MPT test shows good overall accuracy to identify subjects who are susceptible to develop dynamic hyperinflation during CPET. Before considering the use of MPT as a screening tool for dynamic hyperinflation in COPD, sensitivity and specificity need further evaluation.

COPD Anno 2011: emphasis on bronch(iol)odilation.

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of disability and death worldwide. Although COPD is considered to be a preventable and treatable disease, there are concerns that COPD remains substantially underdiagnosed and undertreated. Even in mild disease, patients suffer from significant impairments in health status, which places a considerable burden on patients as well as society. Symptomatic patients are likely to progress to more advanced disease. To avoid breathlessness, they adapt and gradually reduce their activities, which, inevitably, leads to further deconditioning. As a consequence, a progressive deterioration in physical activity with increasing severity of COPD can be observed. Because physical activity is closely related to exacerbation rate, hospitalization, and mortality in patients with COPD, it is important to recognize the role of pharmaceutical interventions in enabling patients to stay physically active. Bronch(iol)odilation not only has important direct effects (symptom relief), but also exerts indirect effects on exercise capacity, exacerbation rate, health status, and mortality. In patients with COPD, the latter effects may be even more important than the direct effects. In this review the current view on causes and consequences of activity limitation in COPD is summarized. From this perspective, the rationale behind bronch(iol)odilator therapy as the cornerstone of treatment for patients with COPD will be discussed.