Pneumonia, Community-Acquired

Incidence of CAP requiring hospitalization is 24.8:10,000 individuals.

Incidence is 9 times higher among those 65 y of age or older (compared with age group 18–49).

Incidence is 25 times higher among those 80 y of age or older (compared with age group 18–49).

Intraop decrease in FRC could worsen the severity of hypoxemia.

Prolonged mechanical ventilation.

Irritable airway at increased risk for laryngospasm

Hypoxemia

CAP is defined as involving no history of hospitalization within 90 d of onset of symptoms.

The responsible pathogen is identified in approximately 40% of cases.

Viral pathogens:

• Human rhinovirus

• Influenza (A or B)

• HMPV

• RSV

• Parainfluenza virus

Bacterial pathogens:

• Streptococcus pneumoniae (gram-positive cocci in chains)

• Mycoplasma pneumoniae (small bacterium, Mollicutes, no peptidoglycan cell wall [no stain])

• Legionella pneumophila (gram-negative, aerobic, non-spore-forming)

• Chlamydia pneumonia (gram-negative, small)

• Staphylococcus aureus (gram-positive cocci in clusters)

• Enterobacteriaceae (gram-negative, enteric)

Viruses (23%):

• Human rhinovirus most common (9%)

• Influenza (6%)

• HMPV, RSV, and parainfluenza viruses; coronaviruses and adenovirus

Bacteria (11%):

• S. pneumoniae most common (5%)

• M. pneumoniae , L. pneumophila, and C. pneumoniae second most common (4%)

• Staphylococcus aureus (1%)

• Enterobacteriaceae (1%)

Bacteria plus virus (2%)

Fungus or mycobacteria (1%)