Typical Pneumonia Flashcards
Pneumonia
Inflammation of lung parenchyma (alveoli)
S/S - cough , fever, dyspnea and radiographic infiltrates
Why are elderly predisposed?
Cumulative effect of conditions such as smoking related COPD, heart failure, demetia, seizures, diabetes, alcoholism.
CAP Common MO
Strep Pneumonia Mycoplasma Pneumonia Hemophilus influenza Clamydophila pneumonia Viruses (Inf A and B, adenovirus, RSV and parainfluenza)
Typical Pneumonia CAP
Purulent! productive cough
Strep, hemophilus, moraxella
Tends to be severe
Atypical Pneumonia CAP
Dry non productive cough
MO - mycoplasma, chlamydophila, legionella
Defenses in alveolar lining fluid
Alveolar macrophages
Fibronectin - adhesin involved in cell-cell adhesion, by attaching to both bacteria and PMNs - promotes phagocytic function
Surfactant - act as opsonins to enhance phagocytosis by macrophages and PMNS
Diagnostic Test for CAP
Sputum gram stain and culture
Blood culture
PCR not routinely done
differential test for strep species
add a P disk (optochin) to the blood culture. Inhibits Strep pneumonia growth
Streptococcus pneumonia - VF
Capsular polysaccharide - inhibits phagocytosis
Surface adhesin A
Surface protein C binds complement factor H - inhibiting C3 convertase
Pneumolysin - cytotoxic, activates complement
Pathogenesis of Strep Pneumonia
- colonization
- reach trachea and bronchi - if clearance is impaired due to allergies, smoking, URI
- MO escape phagocytosis by having capsule
- in alveoli bacteria proliferate, activate complement , generate cytokines, and attract PMSs and exudate into alveolar spades.
NO Inflammation of intersititium, no necrosis no abscess formation
Can spread to pleura, cause pleural effusion and emphysema
Pathogenesis of Strep Pneumonia
- colonization
- reach trachea and bronchi - if clearance is impaired due to allergies, smoking, URI
- MO escape phagocytosis by having capsule
fatalities by Strep - 2 pathway
Respiratory failure - hypoxemia, cyanosis, labored breathing, need for mechanical ventilation
Sepsis with spread sometimes to meninges. Sepsis can lead to shock with poor perfusion of multiple organs including kidney and brain
Hemophilus Influenzae
Gram - rod. Non encapsulated strains are normal URT flora
Encapsulated cause pneumonia
Grow on chocolate agar - need protoporhyrin (X) and NAD (V)
Prevention of pneumonia
Polysaccharide - for adults >65 years
Conjugate - Kids
or u could just not smoke