Pneumonia Flashcards Preview

Term 5 - PathoPhysio > Pneumonia > Flashcards

Flashcards in Pneumonia Deck (12):

  • Cough
  • Acute: 
  • Subacute: 
  • Chronic: 

  • Acute: < 3 weeks
  • Subacute: 3-8 weeks
  • Chronic: > 8 weeks


  • virulence factors
  • Strept. Pneumoniae

  • Pneumolysin from Strept. Pneumoniae is cytotoxic to respiratory epithelium & directly inhibits immune and inflammatory cells and activates complement


  • virulence factors
  • Pseudo. aeruginosa

  • Pili of Pseudo. aeruginosa play important role in the attachment to host cells


Pathophysiology of Pneumonia

  • Host inflammatory response occurs when the capacity of alveolar macrophages to kill microorganisms exceeds the microbial load/virulence → Release of inflammatory mediators (IL-8 and granulocyte colony-stimulating factor) that stimulate the release of neutrophils and their attraction to the lung →  Inflammatory mediators released by macrophages and the newly recruited neutrophils create an alveolar capillary leak

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  • Atypical Pneumonia: Legionella
  • Diversity of presentations:

  • Cough, fever, headaches, Myalgias, hyponatremia, Obtundation, Hemoptysis, Nausea, diarrhea


  • L.Pneumophilia is the most common aerobic, waterborne, gram-negative, unencapsulated, nonmotile, catalase-positive, and weakly oxidase +ve bacillus


Gram stain – no organisms

  • Sputum direct fluorescent Ab (2-4 hours)
  • Cutlure on charcoal yeast extract (3-5 days)
  • Legionella urinary Ag (1-3 days)
  • Serology for Ab titer (>3 weeks into course)


  • Hospital-acquired (or Nosocomial) Pneumonia
  • Major pathogens

  •  P. aeruginosa,
  • Kl. pneumoniae,
  • E. Coli & Serratia marcescens (Gram -ve rods);
  • Staph. aureus (mainly Methicillin-resistant Staph aureus) 
  • Acinetobacter.


  • Aspiration Pneumonia
  • Major pathogens:

  • Aerobic Gram +/- bacteria (Pneumococci, Staph. auerus, H. influenzae, pseudomonas and enterobacteria) 
  • Oral anaerobes (hard to treat)


  • Anaerobic Pathogens
  • Major pathogens

  • Major pathogens: Peptostreptococcus, Bacteroides, Fusobacterium, Prevotella and microaerophilic streptococci.
  • Frequently found in aspiration pneumonia, empyema, lung abscesses
  • Characterized by foul smelling (putrid) and bad tasting sputum.
  • Produce cavitation or numerous small abscesses that spread to involve several pulmonary segments (necrotizing pneumonia).


Complication of Pneumonia


  • Parapneumonic effusion
  • Lung abscess
  • Empyema
  • Respiratory failure


  • Bronchiectasis


  • Complication of Pneumonia: Lung abscess
  • Most common pathogens:

  • Def: Necrosis of pulmonary tissue and formation of cavity containing necrotic debris by infection.
  • Multiple small (<2cm) abscesses is called necrotizing pneumonia.
  • Most common pathogens: Streptococci, anaerobes, Klebsiella, Pseudomonas and Staph aureus
  • May take 1-2 weeks in case if anaerobes and early in others
  • PE: Amphoric or cavernous breath sounds with or without concomitant consolidation findings and finger clubbing
  • Chest X-ray shows cavity with a air-fluid level



  • Def: Pus in pleural space.
  • Pathophysiology: Parapneumonic effusion gets infected and neutrophils buildup.
  • Risk factors: Patients who have pneumonia due to immunosuppression, aspiration, poor dental hygiene and chronic lung disease.
  • PE: Egophony, Tubular breath sounds, Reduced breath sounds and Dullness to percussion.
  • Chest X-ray: Extension of the air-fluid level to the chest wall, extension of the air-fluid level across fissure lines, and a tapering border of the air-fluid collection (loculated empyema).

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