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Pneumonia - Higher Yield

 

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