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Upon completion of the chapter, the reader will be able to:

  1. List the common pathogens that cause community-acquired pneumonia (CAP), aspiration pneumonia, ventilator-associated pneumonia (VAP; early versus late onset), and health care–associated pneumonia.

  2. Explain the host defenses that protect against infection.

  3. Explain the pathophysiology of pneumonia.

  4. List the signs and symptoms associated with CAP and VAP.

  5. Identify patient and organism factors required to guide the selection of a specific antimicrobial regimen for an individual patient.

  6. Design an appropriate empirical antimicrobial regimen based on patient-specific data for an individual with CAP, aspiration pneumonia, and VAP or health care–associated pneumonia (early vs late onset).

  7. Design an appropriate antimicrobial regimen based on both patient- and organism-specific data.

  8. Develop a monitoring plan based on patient-specific information for a patient with CAP and health care–associated pneumonia or VAP.

  9. Formulate appropriate educational information to be provided to a patient with pneumonia.


Pneumonia is inflammation of the lung with consolidation. The cause of the inflammation is infection, which can be caused by a wide range of organisms. KEY CONCEPT There are five classifications of pneumonia: community-acquired, aspiration, hospital-acquired, ventilator-associated, and health care-associated. Patients who develop pneumonia in the outpatient setting and have not been in any health care facilities, which include wound care and hemodialysis clinics, have community-acquired pneumonia (CAP). Pneumonia can be caused by aspiration of either oropharyngeal or gastrointestinal contents. Hospital-acquired pneumonia (HAP) is defined as pneumonia that occurs 48 hours or more after admission.1,2 Ventilator-associated pneumonia (VAP) requires endotracheal intubation for at least 48 to 72 hours before the onset of pneumonia.2 Health care–associated pneumonia (HCAP), which is defined as pneumonia occurring in any patient hospitalized for at least 2 days within 90 days of the onset of the infection; residing in a nursing home or long-term care facility; received IV antibiotic therapy, wound care, or chemotherapy within the last 30 days prior to the onset of the infection; or having attended a hemodialysis clinic.2,3


Etiology and Mortality Rates

KEY CONCEPT The etiology of bacterial pneumonia varies in accordance with the type of pneumonia. Table 71–1 lists the more common pathogens associated with the various types or classifications of pneumonia. Streptococcus pneumoniae colonizes the nasopharyngeal flora in up to 50% of healthy adults and may colonize the lower airways in individuals with chronic bronchitis.4,5 It possesses many virulence factors, enhancing its ability to cause infection in the respiratory tract. KEY CONCEPT Therefore, it is not surprising that S. pneumoniae is the predominant bacterial pathogen associated with CAP. The second most common pathogen is one of the atypical organisms, Mycoplasma pneumoniae. Nontypeable Haemophilus influenzae intermittently colonizes about 80% of the population, and the incidence ...

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