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Figure 17.9 Lobar pneumonia, grey hepatisation stage. A, The sectioned surface of the lung shows grey-brown, firm area of consolidation
(liver-like) affecting a lobe (arrow). B, The cellular exudates in the alveolar lumina is lying separated from the septal walls by a clear space. The
infiltrate in the lumina is composed of neutrophils and macrophages.

are otitis media, mastoiditis, meningitis, brain abscess and consolidation affecting one or more lobes, frequently
purulent arthritis. found bilaterally and more often involving the lower zones CHAPTER 17
CLINICAL FEATURES. Classically, the onset of lobar of the lungs due to gravitation of the secretions. On cut
pneumonia is sudden. The major symptoms are: shaking surface, these patchy consolidated lesions are dry,
chills, fever, malaise with pleuritic chest pain, dyspnoea and granular, firm, red or grey in colour, 3 to 4 cm in diameter,
cough with expectoration which may be mucoid, purulent slightly elevated over the surface and are often centred
or even bloody. The common physical findings are fever, around a bronchiole (Fig. 17.10). These patchy areas are
tachycardia, and tachypnoea, and sometimes cyanosis if the best picked up by passing the fingertips on the cut surface.
patient is severely hypoxaemic. There is generally a marked Histologically, the following features are observed
neutrophilic leucocytosis. Blood cultures are positive in about (Fig. 17.11):
30% of cases. Chest radiograph may reveal consolidation. i) Acute bronchiolitis.
Culture of the organisms in the sputum and antibiotic ii) Suppurative exudate, consisting chiefly of neutrophils, The Respiratory System
sensitivity are most significant investigations for institution in the peribronchiolar alveoli.
of specific antibiotics. The response to antibiotics is usually iii) Thickening of the alveolar septa by congested
rapid with clinical improvement in 48 to 72 hours after the capillaries and leucocytic infiltration.
initiation of antibiotics. iv) Less involved alveoli contain oedema fluid.

Bronchopneumonia (Lobular Pneumonia) COMPLICATIONS. The complications of lobar pneumonia
may occur in bronchopneumonia as well. However, complete
Bronchopneumonia or lobular pneumonia is infection of the resolution of bronchopneumonia is uncommon. There is
terminal bronchioles that extends into the surrounding generally some degree of destruction of the bronchioles
alveoli resulting in patchy consolidation of the lung. The resulting in foci of bronchiolar fibrosis that may eventually
condition is particularly frequent at the extremes of life (i.e. cause bronchiectasis.
in infancy and old age), as a terminal event in chronic
debilitating diseases and as a secondary infection following CLINICAL FEATURES. The patients of bronchopneumonia
viral respiratory infections such as influenza, measles etc. are generally infants or elderly individuals. There may be
history of preceding bed-ridden illness, chronic debility,
ETIOLOGY. The common organisms responsible for aspiration of gastric contents or upper respiratory infection.
bronchopneumonia are staphylococci, streptococci, For initial 2 to 3 days, there are features of acute bronchitis
pneumococci, Klebsiella pneumoniae, Haemophilus influenzae, but subsequently signs and symptoms similar to those of
and gram-negative bacilli like Pseudomonas and coliform lobar pneumonia appear. Blood examination usually shows
bacteria. a neutrophilic leucocytosis. Chest radiograph shows mottled,
focal opacities in both the lungs, chiefly in the lower zones.
MORPHOLOGIC FEATURES. Grossly, bronchopneu- The salient features of the two main types of bacterial
monia is identified by patchy areas of red or grey
pneumonias are contrasted in Table 17.2.