Materials and Methods
Forty patients (31 male), with a mean age of 42.5 ±20.3 years, were studied. Seventeen were alcoholics, 14 were heavy smokers, and 8 patients had COPD. Other underlying diseases included three cases of diabetes mellitus, and one each of the following: chronic renal failure, asthma, breast cancer, rheumatoid arthritis, hepatic cirrhosis, and obstructive jaundice. The mean arterial oxygen partial pressure was 68.5 ± 18.2 mm Hg with a mean P(A-a)Ot of 41.4 ±17.2 mm Hg. The white blood cell count showed 15,165 ±6,471 cells per cubic millimeter, with 67.5 ± 18.0 percent mature neutrophils and 19.1 ± 18.5 percent band forms.
The chest radiographs classified according to Fraser et al showed the following patterns: lobar (29 cases), bronchopneumonic (6 cases), interstitial (1 case), and alveolointerstitial (4 cases).
Definitions and Entry Criteria
Patients were selected from among those admitted to the hospital between August 1989 and September 1990. All patients fulfilled the following criteria: presence of a new chest radiographic shadow associated with two of the following signs: (1) fever over 38°C; (2) white blood cell count over 10,000/mm; and (3) purulent sputum. Patients with contraindications to perform bronchoscopy, ipimuno-suppressed patients, and patients who had previously received antibiotics were excluded from the study. All patients were evaluated by one of the authors (PJ., F.S., M.M.) and a signed consent to perform bronchoscopy was obtained from all of them. Blood cultures were taken at the time of hospital admission, and, when possible, a sputum sample (or culture was secured before bronchoscopy.