pneumonia
DESCRIPTION
Pneumonia pathophysiologyTRANSCRIPT
Aspiration from the oropharynx Pathogens inhaled as contaminated droplets Hematogenous spread, or by
contiguous extension from
an infected pleural or
mediastinal space
Etiologic Agent
When barriers are overcome or when the microorganisms are small
enough to be inhaled to the alveolar level
When the capacity of the alveolar macrophages to
ingest or kill the microorganisms is exceeded
Alveolar macrophages initiate the inflammatory
response to bolster lower respiratory tract defenses
Release of inflammatory
mediators: interleukin (IL)-1
and tumor necrosis factor
(TNF)
Fever
Chemokines: IL-8, GCSF Release of Neutrophils
Peripheral
leukocytosis and
increased purulent
secretions
Inflammatory mediators released by macrophages + neutrophils Alveolar
capillary leak
(initially
localized) Radiographic infiltrate
Hemoptysis
Hypoxemia
Rales
Alveolar Filling
+ Some bacterial pathogens
Severe Hypoxemia
Increased respiratory drive
in SIRS Respiratory Alkalosis
Dyspnea
If severe enough, the changes in lung
mechanics secondary to reductions in
lung volume and compliance and the
intrapulmonary shunting of blood may
cause the patient's death.