Pneumonia Basics:
What is pneumonia?
Infection of the lung parenchyma
-Occurs when the normal defenses are impaired
Pneumonia Basics:
What are the normal defenses that must be bypassed by something causing pneumonia?
-Cough
-Cilia
-Mucous
Cough Reflex
-If impaired, can't cough up particles/debris
Mucociliary elevator
-If impaired, can't clear the mucous that traps debris and bacteria
Mucous Plugging
-If excessive mucous develops and blocks a tube, an infection can develop behind the block more helpful hints
Clinical Features of Typical Pneumonia:
What are the typical features of an infection?
Fever and chills
Clinical Features of Typical Pneumonia:
What does an infection in the lung cause?
Productive cough
-Trying to cough out the offending agent
Clinical Features of Typical Pneumonia:
What are the possible different colors of sputum? What do they indicate?
Yellow/green - pus
Rusty - blood
Currant Jelly - Klebsiella
Clinical Features of Typical Pneumonia:
Why can patients develop pleuritic chest pain?
If the infection spreads to infect the pleura
Clinical Features of Typical Pneumonia:
Patients can develop pleuritic chest pain. What substances transmit the pain signals?
Bradykinin
PGE2
Clinical Features of Typical Pneumonia:
There is consolidation of the lungs. What signs are seen?
-Percussion
-Tactile Fremitus
-Breath Sounds
-Egophony?
-Dullness to percussion (not as resonant)
-Increased tactile fremitus
-Decreased breath sounds
-E to A changes
Diagnosis of Pneumonia:
What is the best test to diagnose?
CXR
Diagnosis of Pneumonia:
What are the three patterns of pneumonia?
Lobar pneumonia
Bronchopneumonia
Interstitial (atypical) pneumonia
Diagnosis of Pneumonia:
How is gram stain and culture used?
Used to identify the causative organism
Diagnosis of Pneumonia:
How are blood cultures used?
Used to identify the causative organism
Diagnosis of Pneumonia:
What changes are seen in WBC counts?
Increase in WBC
-Mainly neutrophils
Lobar Pneumonia:
What is this?
Consolidation of one lobe of the lung
Lobar Pneumonia:
What is the most common agent? What ages are affected?
Strep pneumoniae (95%)
-Adults/elderly affected
Mnemonic: MOPS
Lobar Pneumonia:
What is the second most common agent?
Klebsiella pneumoniae (5%)
-the 4 A's
Lobar Pneumonia:
Klebsiella involves the 4 A's. What are they?
Aspiration pneumonia
Abscess formation
Alcoholics
diAbetics
Also in elderly people in nursing homes
Lobar Pneumonia:
For Klebsiella, what does the sputum look like and why?
Red currant jelly sputum
-Due to the mucinous capsule of Klebsiella
Lobar Pneumonia:
What can complicate Klebsiella pneumoniae?
Often complicated by an abscess
Lobar Pneumonia:
What are the four gross phases of lobar pneumonia?
1- congestion
2- red hepatization
3- gray hepatization
4- resolution
Lobar Pneumonia:
What happens in the congestion phase?
Congestions of the vessels and edema
Lobar Pneumonia:
What happens in the red hepatization phase?
There is an exudate into the alveoli
-Neutrophils and RBC fill the alveolar spaces
-Normally spongy lung feels solid (like the liver)
Lobar Pneumonia:
What happens in the gray hepatization phase?
There is still an exudate, but the RBC are degraded
-Loses the red color
-Still feels solid
Lobar Pneumonia:
What happens in the resolution phase?
Type II pneumocytes cause the regeneration of damaged tissue
Bronchopneumonia:
How does this appear on CXR?
Scattered patchy infiltrates around the bronchioles
-Multifocal and bilateral
Bronchopneumonia:
Staph aureus causes bronchopneumonia. Why is this significant?
MCC of secondary pneumonia
MCC of nosocomial pneumonia
Bronchopneumonia:
What often complicates S. aureus pneumonia?
Very pyogenic
-Often complicated by abscess or empyema
Bronchopneumonia:
Haemophilus influenzae causes bronchopneumonia. Why is this significant?
2nd MCC of secondary infection (after Staph aureus)
MCC of pneumonia in patients with COPD
-Exacerbates COPD
Bronchopneumonia:
Pseudomonas aeruginosa causes bronchopneumonia. Why is this significant?
MCC of pneumonia in cystic fibrosis patients
Bronchopneumonia:
Moraxella catarrhalis causes bronchopneumonia. Why is this significant?
2nd MCC of pneumonia in patients with COPD
-After H. influenzae
-Exacerbates COPD
Interstitial (Atypical) Pneumonia:
How does it appear on CXR?
Patchy interstitial infiltrate
-Doesn't invade alveoli (atypical)
Interstitial (Atypical) Pneumonia:
What are the clinical findings?
Low fever - normally high
Non-productive cough - normally productive
No consolidation - doesn't invade alveoli
Interstitial (Atypical) Pneumonia:
Mycoplasma pneumoniae causes atypical pneumonia. Why is this significant?
-What people get this?
-Appearance on CXR?
-Complications?
-Gram stain?
MCC of atypical pneumonia
-People living in close quarters (army, prison, dorms)
-CXR appears worse than the pt
-Cold agglutination IgM antibodies -> anemia
-Immune complexes can form-> erythema multiforme
-Gram stain doesn't work (no cell wall)
Interstitial (Atypical) Pneumonia:
Chlamydia pneumonia can cause atypical pneumonia. Why is this significant?
2nd MCC of atypical pneumonia
-Seen in young adults
Interstitial (Atypical) Pneumonia:
Chlamydia psittaci can cause atypical pneumonia. Why is this significant?
Cause of atypical pneumonia from bird droppings
Interstitial (Atypical) Pneumonia:
RSV can cause atypical pneumonia. Why is this significant?
MCC of atypical pneumonia in infants
Interstitial (Atypical) Pneumonia:
CMV can cause atypical pneumonia. Why is this significant?
MCC of atypical pneumonia in transplant patients
-Immunocompromised
Interstitial (Atypical) Pneumonia:
Influenza can cause atypical pneumonia. Why is this significant?
Can progress to pneumonia if immune system is weak
-Elder, immunocompromised, COPD
Predisposes to secondary pneumonias
Interstitial (Atypical) Pneumonia:
Coxiella burnetti can cause atypical pneumonia. Why is this significant?
Causes atypical pneumonia in farmers and vets
-Found in livestock and their placentas
This is an abnormal Rickettsia
-Spores instead of arthropod
-No rash
-Causes pneumonia with high fever (Q fever)
Aspiration Pneumonia:
What patients are at risk for this?
Anyone at risk for aspiration
-Alcoholics
-Comatose pts
-Etc
Aspiration Pneumonia:
What are the causative agents?
Pneumonia From Belly
Peptococcus
Fusobacterium
Bacteroides
Aspiration Pneumonia:
How does it appear on CXR?
Pneumonia in Right Lower Lobe
-This is where aspirated material goes
Pneumonia Basics:
What is pneumonia?
Infection of the lung parenchyma
-Occurs when the normal defenses are impaired
Pneumonia Basics:
What are the normal defenses that must be bypassed by something causing pneumonia?
-Cough
-Cilia
-Mucous
Cough Reflex
-If impaired, can't cough up particles/debris
Mucociliary elevator
-If impaired, can't clear the mucous that traps debris and bacteria
Mucous Plugging
-If excessive mucous develops and blocks a tube, an infection can develop behind the block more helpful hints
Clinical Features of Typical Pneumonia:
What are the typical features of an infection?
Fever and chills
Clinical Features of Typical Pneumonia:
What does an infection in the lung cause?
Productive cough
-Trying to cough out the offending agent