Increased sensitivity of regional measurements in early detection of narcotic lung disease.

Intravascular foreign body thromboembolism and interstitial or vascular granulomata in the lungs are common sequelae to intravenous drug abuse. Early detection of such complications is important, because of the youthful population often involved. Conventional pulmonary function tests, including forced expiratory volumes, diffusion capacity for CO (DLco), chest radiograph and arterial blood gas analysis were performed in 23 narcotic addicts, most of whom had no pulmonary symptoms. The results were compared with radionuclide pulmonary function studies obtained following inhalation of 133Xe gas and injection of 99-mTc albumin microparticles. Thirteen subjects who had normal nonnuclear pulmonary function tests, including DLco and chest radiograph, demonstrated significant abnormalities of regional lung perfusion by lung scan. Of the ten subjects with abnormal DLco all had abnormal perfusion scans and five were noted to have hypoxia at rest. In addition, six of the ten subjects with abnormal DLco revealed a history of concomitant "solid pill abuse" along with heroin abuse, whereas only 2 of 13 subjects with normal DLco admitted tooccasional solid pill abuse. The perfusion lung scan is therefore a sensitive means for detection of early lung disease in narcotic addicts.