Pneumonia and primary
lung abscesses may result from aspiration of infectious material from the oropharyngeal cavity and the upper respiratory tract. Most subjects suffer from an impaired mechanical or immunologic defense, for example
alcoholism or
dysphagia following
stroke. The early course of the disease is uncharacteristic.
Necrotizing pneumonia,
pulmonary abscesses and the characteristic, foul-smelling, putrid discharge only occur 8-14 days after the initial aspiration event. Although common respiratory pathogens are frequently isolated from the lower airways of these patients, anaerobic bacteria play a pivotal role in cavitary
lung disease following aspiration. Anaerobic coverage is therefore a requirement for an adequate
antibiotic regimen, and antibacterial activity against common respiratory pathogens appears reasonable in most cases. Aminopenicillins/
beta-lactamase inhibitors, newer
fluoroquinolones with anaerobic activity (
moxifloxacin) and
clindamycin have demonstrated equal clinical efficacy in the treatment of
aspiration pneumonia and primary
lung abscess. Prolonged
antibiotic therapy is required in cases with extensive damage of lung tissue. Since
antibiotics can provide cure in 80-90% of cases,
surgical procedures are limited to severe complications, such as
pleural empyema. Cavitary
lung disease has a broad differential diagnosis, including aspiration of sterile gastric content (
Mendelson syndrome),
staphylococcal pneumonia,
tuberculosis, primary
carcinoma of the lung,
metastases and
vasculitis.