Pathoma Pulmonary Infections Flashcards
Pneumonia
Infection of the lung parenchyma
Normal cause of Pneumonia
Occurs when normal defenses are impaired
Clinical features of PNA
Fever and chills, cough with yellow green or rusty sputum, tachypnea with pleuritic chest pain, decreased breath sounds with dullness to percussion
Labs for PNA
Elevated WBC count
3 chest x ray patterns involving Penumonia
Lobar PNA - Whole lobe consolidated
Bronchopneumonia - Consolidation in patchy pattern on airways
Interstitial pneumonia - N oconsolidation, just inflammation in the interstitium. Increased in lung markings
CXR for bacterial PNA
Lobar and broncho PNA
CXR for viral PNA
Interstitial PNA
Most common causes of lobar PNA
Strep Pneumonia in 95%
Klebsiella pneumonia in 5% or less
Which PNA is associated with community-acquired?
Streptococcus Pneumoniae
Which PNA is associated with malnourished or debilitated individuals like in nursing homes?
Klebsiella Pneumoniae?
Regarding Klebsiella PNA, we typically see this PNA etiology and complication:
Thick mucoid capsule results in gelatinous sputum (currant) jelly.
Often complicated by abscess
4 phases of lobar pneumonia
- Congestion - congested vessels and edema
- Red Hepatization - Develop exudate in the lung with blood and neutrophils, making a thick, tougher lung over spongy normal one
- Grey Hepatization - RBCs break down
- Resolution - Resolve exudate and heal
Discuss lung healing and the most important cell involved
Type II pneumocyte which a stem cell of the lung that regenerates the lung.
How does bronchiopneumonia look?
Scattered, often bilateral. Centered around bronchioles
There are 5 bacteria associated with bronchopneumonia:
- Staph Aureus
- H Influenza
- Pseudomonas aeruginosa
- Moraxella Catarrhalis
- Legionella Pneumophila
This bacteria is seen in cystic fibrosis patients who have bronchopneumonia
Pseudomonas Aeruginosa
This bacteria is seen in community acquired pneumonia patients who have bronchopneumonia
H. Influenza
M. Catarrhalis
L. Pneumophila
This bacteria is seen superimposed on COPD patients patients who have bronchopneumonia
H. Influenza
M. Catarrhalis
L. Pneumophila
This bacteria is seen in patients who have bronchopneumonia and is often associated with an abscess and empyema, which is pus
S. Aureus
This bacteria is seen in patients who have bronchopneumonia and are immune compromised
L. Pneumophila
This bacteria is associated with bronchopneumonia and is superimposed on a viral upper respiratory infection
S. Aureus
This bacteria is best visualized on a silver stainm and is associated with bronchopneumonia
L. Pneumophila
This bacteria is associated with bronchopneumonia and is the most common cause of secondary pneumonia
S. Aureus
Presentation of interstitial pneumonia, also called atypical PNA
Diffuse infiltrates
Presents with relatively mild upper respiratory symptoms like minimal sputum, cough, and low fever
Most common cause of atypical PNA in infants
RSV - Respiratory Syncytial virus
This atypical pneumonia is associated with post transplant immunosuppressive therapy
Cytomegalovirus (CMV)
Most common cause of atypical PNA, usually in young adults
Mycoplasma pneumoniae
Complications of atypical pneumoniae caused by Mycoplasma pneumoniae
- Autoimmune hemolytic anemia (IgM against I antigen on RBCs causes cold hemolytic anemia)
- Erythema multiforme
Why can’t we visualize Mycoplasma pneumoniae on a gram stain?
No cell wall
Second msot common cause of atypical pneumonia
Chlamydia pneumoniae
This causes an atypical pneumonia of the elderly or immune compromised or those with preexisting lung disease
Influenza virus
Typically atypical pneumonia does not present with a high fever, but with this organism, it does:
Coxiella Burnetti
What is special about Coxiella Burnetti?
It is rickettsial, but it distinct because
- Causes pneumonia
- Does not require arthropod vector for transmission (survives as highly heat-resistant endospores)
- Does not produce a skin rash
This organism increases the risk for superimposed S. Aureus or H. Influenza bacterial pneumonia
Influenza virus
This organism puts farmers and vets at risk for developing atypical pneumonia
Coxiella burnetti
Who gets Aspiration Pneumonia?
Those at risk for aspiration…idiot
Like alcoholics and comatose patients, and Nick
What causes aspiration pneumonia? Give top 3 examples
Anaerobic bacteria in the oropharynx like:
- Bacteroides
- Fusobacterium
- Peptococcus
spiration Pneumonia classically results in what?
Right lower lobe abscess
What causes tuberculosis?
Inhalation of aerosolized Mycobacterium tuberculosis
What is primary TB?
Results from initial exposure of M. Tuberculosis
Symptoms of primary TB
Usually asymptomatic
Describe what is happening biologically with primary TB
Results in focal caseating necrosis in the lower lobe of the lung and hilar lymph nodes. The foci undergo fibrosis and calcification, forming a Ghon complex.
What is secondary TB and who gets it the most?
Its when you have a reactivation of your TB, usually seen in AIDS and sometimes with aging
Where does Secondary TB hit and what does it lead to
Occurs at the apex of the lung
Forms a cavitary foci of caseous necrosis, may also lead to miliary pulmonary TB or tuberculosis bronchopneumonia
Presentation of Secondary TB
- Fever and night sweats
- Cough with hemoptysis
- Weight loss
Biopsy/staining of secondary TB shows what?
Biopsy reveals caseating granulomas
AFB stain reveals red acid-fast bacilli
Secondary TB can spread to any tissue. What are the top three and what do they cause?
- Meninges leading to meningitis
- Kidney which can lead to sterile pyuria
- Lumbar vertebrae leading to Pott Disease
Can also go to cervical lymph nodes but everything does.
What is the most common organ affected by secondary TB?
Kidney
With Meningitis caused by Secondary TB, which ones are most affected and how do we know?
The base of the brain, you’ll see granulomas there
