PNEUMONIA is a topic covered in the Harrison's Manual of Medicine.

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Harrison’s Manual of Medicine

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Pneumonia, an infection of the lung parenchyma, is classified as community-acquired (CAP), hospital-acquired (HAP), ventilator-associated (VAP), or health care–associated (HCAP). Although the HCAP category initially referred to CAP caused by a multidrug-resistant (MDR) pathogen, it now describes pts with at least two or three risk factors for infection with MDR pathogens (Table 134-1).

TABLE 134-1: Risk Factors for Pathogens Resistant to Usual Therapy for Community-Acquired Pneumoniaa

Hospitalization ≥2 days in previous 90 days

Use of antibiotics in previous 90 days


Nonambulatory status

Tube feedings

Gastric acid suppression

Severe COPD or bronchiectasisb

Hospitalization ≥2 days in previous 90 days

Use of antibiotics in previous 90 days

Chronic hemodialysis in previous 30 days

Documented prior MRSA colonization

Congestive heart failure

Gastric acid suppression

Cavitary infiltrate or necrosis

Gross hemoptysis


Erythematous rash

Concurrent influenza

Young, previously healthy status

Summer-month onset

aCephalosporin/macrolide or respiratory fluoroquinolone.
bRisk for Pseudomonas aeruginosa infection.
Abbreviations: COPD, chronic obstructive pulmonary disease; MRSA, methicillin-resistant Staphylococcus aureus.

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