This type of secondary pneumonia is invariably preceded by bronchial infection, which accounts for the widespread patchy distribution of the lesion.
It occurs most frequently at the extremes of life and may be described as 'hypostatic pneumonia' when it occurs in elderly or debilitated patients. In children, it is often a complication of measles or whooping cough, and in adults, of acute bronchitis or influenza. It is particularly common in patients with chronic bronchitis.
Pathology
There is acute inflammation of bronchi, especially the terminal bronchioles, which are filled with pus. Collapse and consolidation of the associated groups of alveoli follow. The lesions are distributed bilaterally in small patches which tend to become larger by confluence and are more often extensive in the lower lobes. There is interstitial oedema and compensatory emphysema around the collapsed alveoli.
Clinical features
After two or three days of acute bronchitis, as bronchopneumonia develops, the temperature rises to a higher level, the pulse and respiration rates increase, and breathlessness and central cyanosis appear. There is generally a severe cough with purulent sputum. Pleural pain is uncommon, in contrast to pneumococcal pneumonia.
During the early stages the physical signs are those of acute bronchitis but crepitations later becomes more numerous. Radiological examination shows mottled opacities in both lung fields, chiefly in the lower zones. A neutrophil leucocytosis is present.
Course and complications
The disease has a more insidious onset than pneumococcal pneumonia and tends to run a more protracted course up to ten days. In complete resolution may lead to bronchiectasis and replacement fibrosis. Mortality is higher at the extremes of life especially if the disease supervenes on chronic bronchitis and empysema or any debilitating illness.
Management
Ampicillin 250-500 mg 4 times daily by mouth or cotrimoxazole 960 mg every 12 hours are usually effective in acute bronchopneumonia. Control of pleural pain, oxygen and physiotherapy may be required.
It occurs most frequently at the extremes of life and may be described as 'hypostatic pneumonia' when it occurs in elderly or debilitated patients. In children, it is often a complication of measles or whooping cough, and in adults, of acute bronchitis or influenza. It is particularly common in patients with chronic bronchitis.
Pathology
There is acute inflammation of bronchi, especially the terminal bronchioles, which are filled with pus. Collapse and consolidation of the associated groups of alveoli follow. The lesions are distributed bilaterally in small patches which tend to become larger by confluence and are more often extensive in the lower lobes. There is interstitial oedema and compensatory emphysema around the collapsed alveoli.
Clinical features
After two or three days of acute bronchitis, as bronchopneumonia develops, the temperature rises to a higher level, the pulse and respiration rates increase, and breathlessness and central cyanosis appear. There is generally a severe cough with purulent sputum. Pleural pain is uncommon, in contrast to pneumococcal pneumonia.
During the early stages the physical signs are those of acute bronchitis but crepitations later becomes more numerous. Radiological examination shows mottled opacities in both lung fields, chiefly in the lower zones. A neutrophil leucocytosis is present.
Course and complications
The disease has a more insidious onset than pneumococcal pneumonia and tends to run a more protracted course up to ten days. In complete resolution may lead to bronchiectasis and replacement fibrosis. Mortality is higher at the extremes of life especially if the disease supervenes on chronic bronchitis and empysema or any debilitating illness.
Management
Ampicillin 250-500 mg 4 times daily by mouth or cotrimoxazole 960 mg every 12 hours are usually effective in acute bronchopneumonia. Control of pleural pain, oxygen and physiotherapy may be required.
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