ABSTRACT
Until the 1940s ventilatory capacity was assessed by using a spirometer to measure maximum voluntary ventilation. This test reflected both inspiratory and expiratory flows and was reduced by obstructive and restrictive lung disorders, respiratory muscle disorders, and poor motivation. When this test was displaced by the single breath forced expiratory spirogram, expiratory airflow obstruction was swiftly adopted as the dominant functional abnormality in breathless patients with chronic bronchitis and emphysema-and indeed with asthma. The recognition of airflow obstruction led to attempts, staring productively at the Ciba symposium in 1958 (1), to incorporate this concept with the older terminology of chronic bronchitis and emphysema. There was a brief flurry of largely synonymous terms being proposed, but insidiously chronic obstructive pulmonary disease (COPD) became the preferred English-language term and has been used in guidelines worldwide with definitions that differ slightly in detail (as will be discussed through this chapter), but not in concept (Table 1) (2-6). So far the term has not been widely adopted by affected patients or the lay public (7).
