Lung disease in reformed drug addicts: diagnostic and physiologic correlations

Pulmonary morphologic alterations secondary alterations secondary to intravenous drug abuse have been previously identified by histopathologic study of autopsy and biopsy material. Recent investigative efforts have been directed toward defining functional abnormalities that would allow for early clinical diagnosis. For this reason, 12 asymptomatic addicts were studied with roentgenography, spirometry, single breath diffusing capacity (DLco), 99Tc perfusion and 133 Xe ventilation scanning. Nine of the twelve were heavy cigarette smokers. None reported historical evidence of chronic bronchitis or right-sided endocarditis. The DLco was the only significant routine pulmonary function abnormality (p less than .001) observed in these patients. The DLco was significantly reduced even after correction for smoking habits (p less than .001). The decrease in DLco correlated with the number of perfusion defects detected by 99Tc scanning (r = -.560). There was no correlation between DLco and the number of defects on the 133Xe ventilation scan, age, pack-years smoked, or other routine pulmonary function tests. Further, there was no correlation between the number of perfusion and the number of ventilation defects. The data suggest that the decrease in DLco found in these addicts is the result of reduction of the pulmonary capillary bed secondary to vascular or interstitial granulomatosis.