Diseases-2

• CXR characteristics of viral pneumonia


  • Interstitial infiltrates on CXR
• Definitions

  • VAP- Ventilator associated PNA
  • CAP- community acquired PNA
  • HAP- Hospital acquired PNA
• Bacteria shapes

  • Cocci
  • Bacilli
  • Spirilla
• How granulomas are formed

  Immune system encounters a substance it cannot remove, forms a granuloma to wall off and contain the substance, involves aggregation of immune cells like macrophages and T cells
• Sputum characteristics in bacterial pneumonias

  • Green sputum- Pneumococcal, Haemophilus, Pseudomonas
  • Red jelly like sputum- Klebsiella
  • Foul smelling sputum- Anaerobe bacteria
  • Rust colored sputum- Staphylococcus and streptococcus
• Gold standard for diagnosing pneumonia is infiltrates in CXR
• Differences in Viral pneumonia vs. bacterial pneumonia


  • Bacterial pneumonia often sudden onset with high fever, chills, productive cough, rapid breathing. Viral pneumonia more gradual with cough, fever, fatigue, difficulty breathing. Treatment differs, antibiotics for bacterial, antivirals and supportive care for viral.
• Antiviral medications for RSV

  • Ribavirin
  • Palivizumab
• Most common cause of PNA in US: bacteria
• Pneumonia associated with barking cough

  Viral pneumonia
• Common organisms associated with HAP

  • Enterobacter species
  • Acientobacter species
  • Escherichia coli
  • Klebsiella species
  • Pseudomonas aeruginosa
  • Serratia species
  • Staph aureus
• Characteristics on CXR for lobar pneumonia

  • Homogenous consolidation of edema in one or more lobes
• Palpation and percussion for pneumonia

  • Percussion dull over areas of consolidation, palpation for lymphadenopathy and tracheal deviation
• Bronchopneumonia


  AKA lobular/multifocal, caused by aspiration of secretions from colonized trachea, associated with HAP
• Characteristics of CXR with tuberculosis


  • Upper lobe infiltrates and cavitary lesions
• Population at high risk for TB is HIV
• How TB is spread

  Airborne, spreads from person to person by droplet nuclei (1 to 5 microns). People with TB tend to cough, sing, sneeze, shout, sputum induction or aerosol treatment tend to spread.
• How TB is diagnosed

  ID of M. tuberculosis in a culture, usually gathered by sputum, ways to get sputum are sputum induction, bronchoscopy/BAL, spontaneous sputum sample and gastric washing (for kids)
• Initial defense against TB


  • The mucociliary escalator system
• Differences between Latent TB (LTBI) and Active TB infection


  • Active TB: Symptoms, CXR abnormalities, positive sputum/blood tests
  • Latent TB: No symptoms, positive TST/IGRA, normal CXR
• 1. Spot TB Test


  Blood test that identifies infection by measuring immune response to TB proteins, cannot distinguish active vs latent
• TB symptoms


  • Cough, fever, night sweats, hemoptysis, dyspnea, anorexia, malaise, clubbing, pallor, pleuritic chest pain, mild anemia, leukocytosis, thrombocytosis, elevated CRP, hyponatremia
• Sputum characteristics of TB

  • Yellow or yellow-green sputum, rarely foul smelling, hemoptysis can develop
• First line anti TB medications

  • Isonazid (INH)
  • Rifampin (RIF)
  • Pyrazinamide (PZA)
  • Ethambutol (EMB)
  • Rifapentine (RPT)
• Treatment phases for TB

  1. Initial phase (2 months, kills most TB, prevents resistance, determines outcome)

  2. Continuation phase (4-7 months, kills remaining bacilli, high risk of disease returning if not continued)

  3. Treatment completion (6-9 months, duration depends on patient response, drugs used, drug susceptibility)