3National Heart, Lung, and Blood Institute. Morbidity and mortali- ty: 2002 chartbook on cardiovascular, lung and blood diseases [ M ]. Bethesda, MA : National Institutes of Health, 2002.
4Rankin JA, Snyder PE, Schachter EN, et al. Bronchoalveolar layage: its safety in subjects with mild asthma [ J]. Chest, 1984, (85) :723 -728.
5British Thoracic Society Bronchoscopy Guidelines Committee, a Subcommittee of Standards of Care Committee of British Thoracic Society. British Thoracic Society guidelines on diagnostic flexible bronchoscopy[ J]. Thorax,2001,56( Suppll ) : 1 - 21.
6Hattotuwa K, Gamble EA, O'Shaughnessy T, et al. Safety of bron- choscopy, biopsy, and BAL in research patients with COPD[ J]. Chest,2002, (122) : 1909 - 1912.
7Salisbury BG, Metzger LF, Altose MD, et al. Effect of fiberoptic bronchoscopy on respiratory performance in patients with chronic airways obstruction[ J ]. Thorax, 1975, (30) :441 - 446.