Am. J. Respir. Crit. Care Med., Vol 149, No. 6, Jun 1994, 1648-1653.
The bacteriology of obstructive pneumonitis. A prospective study using ultrasound-guided transthoracic needle aspiration
YS Liaw, PC Yang, ZG Wu, CJ Yu, DB Chang, LN Lee, SH Kuo and KT Luh
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Republic of China.
Obstructive pneumonitis, the opacity that develops distal to an obstructing
endobronchial lesion or external compression, is actually a combination of
atelectasis, bronchiectasis with mucus plugging, and true parenchymal
inflammation. In the majority of cases, it is usually not possible to
determine whether infection is present or not from the radiographic
findings alone. The aim of this study was to evaluate the bacteriology of
obstructive pneumonitis and the influence of this result on the treatment
of patients. From March 1992 to February 1993, 26 consecutive patients (20
men and six women) with obstructive pneumonitis were investigated. The
obstructive pneumonitis had been caused by malignant tumors in 24 and
benign lesions in two. Chest ultrasound (US) and US-guided percutaneous
transthoracic aspirations were undergone to obtain specimens for
microbiologic examination. Microorganisms were isolated from seven of nine
febrile patients and two of 17 nonfebrile patients. A total of 16 bacterial
strains are detected in obstructive pneumonitis (Pseudomonas aeruginosa,
Klebsiella pneumoniae, viridant streptococci, Bacteroides fragilis, two
Peptostreptococcus species, Mycobacterium tuberculosis, Pseudomonas
maltophilia, Streptococcus sanguis, Staphylococcus aureus, Bacteroides
thetaiotamomicrons, Bacteroides intermedius, Bacteroides species,
Veillonella species, aerobic gram-positive bacilli, and Escherichia coli).
In five cases the isolates were monobacteriae, and in the remaining four
cases, cultures yielded more than one bacteria. The results of aspirate
cultures led to changes in the initial antibiotic trial in seven of nine
patients, and fever subsided thereafter. Pneumothorax occurred in one cases
as the sole complication. The pathogen causing obstructive pneumonitis is
very heterogeneous, and polymicrobial infection is common.(ABSTRACT
TRUNCATED AT 250 WORDS)
