Aspiration Pneumonia

¹ Instructor in Clinical Medicine, State University of New York College of Medicine.
² Professor of Medicine, State University of New York, Downstate Medical Center; Director of Pulmonary Disease Division II, Kings County Hospital Center.

1. Aspiration pneumonia is a pulmonary problem that may present a great deal of diagnostic difficulty and is frequently neglected in the differential diagnosis of pulmonary lesions.

2. Aspiration pneumonia may result from (a) aspiration of oils-lipoid, (b) food and gastric secretions, (c) foreign bodies, and (d) infected materials.

3. Illustrated cases of each type are presented.

4. Aspiration pneumonias have a tendency for localization in the most dependent portions of the lungs at the time of aspiration.

5. Lipoid pneumonia should be considered in all basal pneumonic processes of undetermined etiology. Chief differentiation is when the lesion (paraffinoma) resembles neoplasm. Clinical, radiologic, and cytologic approach is necessary for establishing a diagnosis.

6. Aspiration of gastric contents produces pulmonary edema early and may cause acute bronchial obstruction. Later foreign body reaction occurs and leads to chronic bronchial obstruction and pulmonary fibrosis.

7. Pathologic changes in the lung after aspiration of a foreign body depend on site of lodgements, chemical and physical characteristics of the substance, and length of time that elapses before its removal.

8. There is a whole range of aspiration pneumonias due to inhalation of infected material from the mouth and throat varying in severity from solitary lung abscess and a predominant pneumonic process, to less severe forms of respiratory tract infections.

9. Aspiration of infected material from the mouth and throat occurs in patients with poor dental hygiene, with poor or absent gag reflexes due to states of unconsciousness, most commonly seen in alcoholics.