This is seen in elderly debilitated persons who are bed-ridden. It is a form of aspiration pneumonia. Inadequate cough reflex, excessive respiratory secretions and pulmonary congestion favor the development of hypostatic pneumonia. Microbial flora is derived from the upper respiratory secretions. The lesion is a bronchopneumonia. Hypostatic Pneumonia acts as a pre-terminal event in many elderly debilitated individuals. Avoidance of prolonged recumbency, frequent change of posture (Once in 2 hours) in comatose and debilitated subjects and regular breathing exercises help in preventing this condition.
Bronchopneumonia (Acute lobular Pneumonia)
Inflammation of the bronchial wall and the pulmonary parenchyma is the essential lesion in bronchopneumonia. This leads to patchy consolidation of the lung. The disease is more common during infancy and old age.
Bronchopneumonia may occur as a complication of several diseases such as whooping cough, measles and other viral infections in children. Chronic bronchitis, emphysema and viral infections of the respiratory tract may be complicated by bronchopneumonia. Rarely bronchopneumonia may occur as the primary lesion.
The common organisms are staphylococci, streptococci, pneumococci and H. influenzae. Rarely rickettsiae, viruses and fungi may cause bronchopneumonia. The inflammatory lesions are widespread and patchy over both lungs, more in the lower lobes. The terminal bronchioles are affected initially and the alveoli are involved secondarily. There is collapse and consolidation in the affected lobule. Confluence of lesions may give rise to larger areas of consolidation. The exudates show neutrophils and fibrin. Interstitial edema develops. There is compensatory emphysema around the collapsed alveoli.
The extent of pulmonary involvement and the virulence of the infective agent determine the clinical picture. Generally the onset is insidious. In the majority of cases bronchopneumonia follows the primary illness after a period of apparent improvement. The temperature goes up and tachypnea and cough may develop. The child may be cyanosed. Unlike as in lobar pneumonia, pleural involvement and herpes labialis are rare. Physical examination of the chest reveals widespread rales. Signs of extensive consolidation are rare. X-ray shows bilateral irregular and patchy shadows, more in the lower zones.
Rarely bronchopneumonia may lead to bronchiectasis, pulmonary fibrosis, lung abscess or emphysema. Morality is higher in patients with chronic respiratory or cardiovascular disease.
Prompt use of the appropriate antibiotic brings down the fever and helps in resolution of the lesions. In children suffering from measles and other viral infections, occurrence of bronchopneumonia should be anticipated and early therapy started.