Assessing the prognosis of patients with chronic obstructive pulmonary disease

摘要

Historically, Chronic Obstructive Pulmonary Disease (COPD) has been viewed as an irreversible disease process for which little can be done; thus the prognosis was felt to be dismal and this led to a nihilistic approach to diagnosis and management. There is now optimism surrounding the disease process of COPD as the newest definitions affirm that although it is slowly progressive, it is also a 'partially' reversible disease process. Accordingly, these concepts set the stage not only for establishing which currently available parameters best predict prognosis (morbidity and mortality) in COPD, but also for developing additional validated instruments to establish the prognosis of COPD and to monitor the benefits of interventional therapies: both pharmacologic and non-pharmacologic. This paper will concentrate on the current recommendations of certain COPD guidelines (those of the American Thoracic Society/European Respiratory Society and the Global Initiative for Chronic Obstructive Lung Diseases) with regard to the use and utility of prognostic parameters in COPD. There will be a discussion of the prognostic instruments currently available for COPD: lung function measurements (forced expiratory volume in 1 s; ratio of inspiratory capacity:total lung capacity); imaging (chest X-ray); measures of dyspnea and exercise capacity (Medical Research Council scale, 6-min walk); and nutrition (body mass index). Complications and comorbidities of COPD (hypoxemia, hypercapnia, PAH + pulmonary arterial hypertension, congestive heart failure, coronary artery disease, other organ system failures) will also be discussed, as well as indices [BMI, obstructed airflow, dyspnea, and exercise (BODE) index] that combine some of the above parameters to better predict mortality compared to the predictive value established by any of the above parameters alone. An approach that is practical in the office setting will also be discussed.