Modification of the effect of fiberoptic bronchoscopy on pulmonary mechanics.

Thirty-three patients who were to undergo diagnostic fiberoptic bronchoscopy were studied. Pulmonary function tests were performed before the procedure, after topical lidocaine anesthesia, and immediately and four hours after bronchoscopy. Nine patients received aerosolized isoproterenol (Isuprel) before the topical anesthesia, and nine received aerosolized atropine. Pulmonary function tests were also performed after this intervention. In those patients receiving no premedication, all the indices of expiratory flow were reduced significantly immediately after bronchoscopy, and after the topical anesthesia, the FEV1 and FVC were significantly reduced. In the atropine groups, the FVC and FEV1 increased significantly after atropine, and increased still further following topical lidocaine anesthesia. By four hours after bronchoscopy, however, the midmaximal expiratory flow ws significantly reduced. In the isoproterenol group, only the FEV1 was significantly improved by the drug, and this improvement persisted even after the lidocaine. It decreased transiently immediately after bronchoscopy, but by four hours, was significantly above baseline again. The FVC diminished significantly immediately after bronchoscopy. It is concluded that fiberoptic bronchoscopy deleteriously affects pulmonary function and that inhaled isoproterenol or atropine largely protects against these deleterious effects.