L1 LRTI Flashcards
What are the main LRTI ?
- Pneumonia
- Lung abscess
- TB
- Bronchiectasis
What are the predisposing factors of bacterial ( typical ) pneumonia ?
- The systemic resistance of the host is lowered
- leukopenia
- immune suppressive drugs
- immunological deficiency
- wasting chronic diseases
- severe malnutrition
- diabetes - The local defenses of the lung is impaired
- pulmonary edema or congestion
- accumulation of secretions
- injury to mucociliary apparatus
- inhibition of cough reflex
- injury to the bactericidal effects of alveolar macrophages
What are the causes of Community-Acquired Bacterial Pneumonias ? And who they affect ? (7 groups )
- Streptococcus pneumoniae (pneumococcus): Most common cause of community acquired acute pneumonia.
- Hemophilus influenzae: Neonates and children
- Moraxella catarrhalis: Elderly
- Staphylococcus aureus: Sec. bacterial pneumonia in children and healthy adults following viral respiratory illness.
- Klebsiella pneumoniae: Debilitated and malnourished
- Mycoplasma pneumoniae: Children and young adults
- Others: Pseudomonas aeroginosa, Legionells pneumophilia
What are the Four stages of inflammation in lobar pneumonia ?
- Stage of congestion
- intra-alveolar fluid with a few neutrophils and numerous bacteria. - Stage of red hepatization
- Massive confluent exudation, as neutrophils, red cells and fibrin fill alveolar spaces - Stage of gray hepatization
- disintegration of red cells and the persistence of fibrinosuppurative exudate. - Stage of resolution
- exudate within alveolar spaces is broken down by enzymatic digestion to produce granular, semifluid debris
What will happen to exudate debris ?
- resorbed, ingested by macrophages
- expectorated
- organized by fibroblasts
What is specific about the consolidation in bronchopneumonia?
Foci of consolidation are uni- or multilobar. Frequently bilateral and basal
It is gray-red to yellow
A neutrophil-rich exudate fills the bronchi, bronchioles, and adjacent alveolar spaces.
What are the complications of bacterial ( typical pneumonia) ?
- Abscess formation
- Embyema
- spread of infection to the plural cavity and accumulation of exudate - Organization of exudate
- leading to lung consolidation - Dissemination of bacteria
- to brain / kidney / spleen / pericardium / meninges / heart
What are the main causes of lung abscess ?
- Aspiration of infective material ( most common )
- After bacterial pneumonia
- Septic embolism from thrombophlebitis or infective bacterial endocarditis
- Neoplasia obstructing bronchpulmonary segment
- Traumatic penetration of infection from neighboring organs
Why infections and lung abscesses are More common in right side ?
right main bronchus is more vertical
What are the trends of lung abscesses location ?
- Mostly they are only one
- In pneumonia and bronchiectasis, multiple in basal regions
- If caused by septic emboli, it can occur at any region
What are the complications of lung abscess?
- Embyema (Extension to pleural cavity)
- Hemorrhage
- Brain abscess and meningitis from ( septic emboli )
- Secondary amyloidosis (type AA).
What are the Viruses that cause pneumonia ?
- Influenza virus types A and B
- respiratory syncytial virus
- human adenovirus
- rhinoviruses
- rubeola (measles virus)
- varicella viruses.
Why viral pneumonia is always predisposing to bacterial superinfection ?
As the viruses enter and damage and kill the infected cells it will damage the mucociliary action, leading to secretion accumulation
When the viral pneumonia contain Pink hyaline membrane ?
If the interstitial pneumonia is complicated acute respiratory distress syndrome ( ARDS )
What is the main and predominant feature of viral interstitial pneumonia?
- it is widening of walls of alveoli due to interstitial inflammatory reaction (lymphocytes, macrophages and occasional plasma cells).
- Alveoli are ( free of exudate ) or ( may contain proteinaceous material and a cellular exudate )
