Changes in Microcirculation and Functional Status During Exacerbation of COPD

Changes in Microcirculation and Functional Status During Exacerbation of COPD

This study investigates the influence of acute exacerbation of chronic obstructive pulmonary disease (COPD) on retinal microcirculation, on functional status and also investigates the prognostic value of retinal vessel caliber assessment in terms of hospitalization and mortality during 2 years of follow-up.

Recent findings suggest that patients with chronic obstructive pulmonary disease (COPD) are at increased risk for myocardial infarction and stroke during periods of acute exacerbation. These findings might be related to acute endothelial changes associated to increased systemic inflammation. Changes in the microcirculation can be explored noninvasively by studying retinal blood vessels that are visualized in fundus images. The retinal blood vessels have anatomical and physiological features that are comparable with the coronary circulation.

Patients with COPD experience quadriceps muscle weakness, which worsens during hospitalization by ~1% per day. This is the result of physical inactivity, in combination with increased oxidative stress and systemic inflammation. Physical inactivity is induced by the hospital environment, but is also related to symptoms of dyspnea caused by increased work of breathing and oxygen desaturation.

Muscle weakness and physical inactivity are associated to poor functional status and recurrent hospital admissions, independent of pulmonary impairment, which makes those patients with frequent exacerbations prone to enter a vicious cycle.

Simple functional screening tests during hospital stay might enable us to quantify the impact of a hospitalization on functional status and to identify patients at risk for repeated exacerbations.

Inclusion Criteria:

• Stable COPD (post-bronchodilator forced expiratory volume / forced vital capacity < 0.7), no exacerbations in the previous weeks. COPD patients with diagnosis of acute exacerbation, based on the GOLD criteria.

Exclusion Criteria:

• Inability to walk without support from others