Lung disease with chronic obstruction in opium smokers in Singapore. Clinical, electrocardiographic, radiological, functional and pathological features.

Fifty-four opium smokers with chronic obstructive lung disease were studied for two-and-a-half years. Forty-eight patients had a cough for at least two years before the onset of inappropriate exertional dyspnoea. Fine, bubbling adventitious sounds suggesting small airway disease were heard on auscultation over the middle and lower lobes in 38 patients. The prevalence of inflammatory lung disease and chronic respiratory failure in this series is suggested as the main cause for the frequent finding of right ventricular hypertrophy and congestive heart failure. Physiological studies revealed moderate to severe airways obstruction with gross over-inflation and, in 32 patients, an additional restrictive defect probably due to peribronchiolar fibrosis. Radiological evidence of chronic bronchitis and bronchiolitis was observed in 45 patients, pure' chronic bronchiolitis in six patients, and widespread' emphysema in 25 patients respectively. Necropsy examinations in nine patients, however, showed destructive emphysema of variable severity in all. Chronic bronchiolitis often associated with striking bronchiolectasis was present in six cases. More severe bronchiolar rather than bronchial inflammation was noted. The heavy opium smokers had characteristic nodular shadows on chest radiography, sometimes associated with a striking reticular pattern not seen in `pure' cigarette smokers. This was due to gross pigmented dust (presumably carbon) deposition in relation to blood vessels, lymphatics, and bronchioles, and also within the alveoli. It is speculated that the initial lesion is an acquired bronchiolitis. Opium smoking induces an irritative bronchopathy favouring repeated attacks of acute bronchiolitis and eventually resulting in obliterative bronchiolitis, peribronchiolar fibrosis, chronic bronchitis, and destructive emphysema.