26 terms

Bacterial Pneumonia

Silverblatt - 4/20/11
What is the route that most pathogens reach the lungs?
Aspiration (breathing in)
What precedes infection in pneumonia?
Colonization of the oropharynx
*What are the host defenses to pneumonia? and what makes lower respiratory infection more likely?
epiglottal reflex, cough & mucociliary elevator, normal oral flora, PMNs (neutrophils), cellular and humoral immune sx

when these mechanisms are impaired: by disease, environmental conditions or self-inflicted abuse
What is "normal" tx for pneumonia?
usually empiric based on knowledge of likely pathogens for clinical setting
What is the most common cause of death due to infectious disease?
What fxn do normal flora in the mouth have as a defense?
Block sites of attachment for potential pathogen
What is the first line of defense in the Lower Respiratory Tract (LRT)?
Alveolar Macrophages: kill intracellular organisms, present antigens to T cells, secrete cytokines
How is Streptococcus pneumoneae spread? Mycobacterium tuberculosis? Staphylococcus aureus?
1. Aspiration of Oropharyngeal Secretions (Streptococcus pneumoneae)
2. Inhalation of Aerosolized Droplets (Mycobacteria tuberculosis)
3. Hematogenous Spread (Staphylococcus aureus )
Why is hypoventilation (recent surg., COPD) a risk factor for pneumonia?
unable to exhale pathogens, allow to seed
There are 10+ organisms that can cause pneumonia, what are they and what is the prototype?
Streptococcus pneumoniea *prototype
Haemophilus influenzae
Gram-negative rods
Staphylococcus aureus
Legionella pneumophila
Mycoplasma pneumoniae
Chlamydia species
Mycobacteria tuberculosis
Unusual organisms
Does S. pnuemoniae leave a destructive lesion after resolution?
What are the characteristics of Haemophilus influenza?
gram -, tiny, pleiomorphic (rods and cocci), no necrotic process
** Which organisms cause a necrotic process? which do not?
Gram (-) rods
S. aureus

S. pnuemoniae
Haemophilus influenza

Atypicals: (generally less intense disease)
Legionella pneumophila
Mycoplasma pneumoniae
Chlamydaphilia species
Do anaerobes cause necrotic disease? where are they commonly found?
Yes. dental and GI
* What are the clinical features?
1. Infection
Fever, chills, Malaise
Leukocytosis with left shift
2. Respiratory tract irritation
Cough of Purulent sputum
3. Parenchymal Inflamation
Respiratory distress
Pleuritic chest pain
Rales (expansion of collapsed small airways)
Evidence of consolidation
What is observed on physical exam of alveolar infiltrate? interstitial pneumonia?
consolidation, ground glass appearance on X-ray

rales (no consolidation), reticular-nodular pattern on X-ray
* What types of pneumonia are typically lobar?
S. pneumoniae, H. influenzae
(consolidation, no rales)
* What types are typically bronchopneumonia?
most types: rales w/out consolidation
General: what type of pneumonia show thickened alveolar walls, lymphocytes and mononuclear cells, but not polys?
viral pneumonia
Is a sputum or blood culture more reliable for dx?
What is key in antibiotics given for pneumonia?
give early: preferably within 4 hours of presentation
high dose
What is the common tx for community acquired with no comorbidities?
Macrolide (ribosome) or Respiratory FQ
What is the common tx for community aquired - hospitalized pneumonia?
Respiratory FQ (fluoroquinilone - DNA) or Macrolide
What is the common tx for hospital acquired: ICU?
Imipenem (b-lactam - cell wall)
Is there a pneumonia vaccine? what does is target? who should get i?
Streptococcal pneumoniae (Pneumovax)

age >65
at risk adults
children over 2 with chronic disease
Vaccination against what other disease can help prevent pneumonia?