Some Unresolved Problems in Chronic Respiratory Disease

Abstract

In this lecture the position concerning some of the present-day problems in the field of chronic respiratory disease have been reviewed. First among these —the differentiation of the 3 components chronic bronchitis, emphysema and asthma—is seen to have been only partly accomplished by accepted definitions. The place of emphysema as a major accompaniment of chronic bronchitis is particularly baffling during life. The controversy regarding the reversibility of airways obstruction is held to affect the definition of asthma and should be a stimulus to renewed efforts to clarify the situation. In both emphysema and asthma attention ought to be directed towards epidemiological studies in order to elucidate aetiological factors.

The second major problem—that of the earliest stages of chronic bronchitis— is important in the recognition of the role of causative factors known to be important at a later stage. Air pollution and infection thus occupy a tentative causative role even before cigarette smoking becomes effective in eliciting mucus production by the airways. The role of genetic factors has been highlighted with the advent of knowledge concerning the serum α 1-antitrypsin globulin. Detailed clinical and epidemiological studies are now required.

The third problem is a prognostic one. In such long-lasting complaints as those under consideration, diagnosis at an early stage might surely lead to attempts to prevent progression. Here the mystery of the variability of the natural history of different individuals is the problem and airways obstruction is seen to be a major determinant of ventilatory/perfusion relationships. These in turn are prognostically related not only to respiratory failure but to pulmonary hypertension and cor pulmonale.