Pneumonia Flashcards
What is pneumonia?
- Acute lower respiratory infection of the lung parenchyma
- inflammatory consolidation from intra-alveolar exudate
What are the three types of pneumonia?
- Community acquired
- Hospital acquired
- Aspiration; bowel contents are inhaled into pulmonary tracts after vomiting
Ventilator associated and atypical also
What are pulmonary defences?
- Nasal hair
- Microflora of RT
- Cough
- Mucus
- Mucociliary escalator
- Alveolar macrophages
- IgA
What causes loss of pulmonary defences?
- Loss of cough reflex; Coma
- Injured mucociliary escalator; smoking
- Decrease in alveolar macrophages; smoking + alcohol
- Pulmonary congestion
- Obstruction
What are risk factors for pneumonia?
- > 65 years
- Smokers
- Malnourished
- Immunocompromised
- Reccurent RTI’s
- Medications
- Seasonal
- Organism virulence
environmental
What species is most common in community acquired pneumonia?
- Streptococcus pneumoniae (60%)
What species is most common in hospital pneumonia?
- Pseudomonas Aeruginosa
What species is most common in aspiration pneumonia?
- Gram-negative anaerobes
E.coli, Klebsiella pneumoniae, Haemophilus influenzae
How is pneumonia transmitted?
- Droplet spread
- water, air-conditioning, hospital ventilators
What happens after transmission?
of pneumonia
- Inhalation; colonises nasopharynx
- Infection; virulence factors cause inflammation of lung parenchyma
How does pathogenesis occur in the alveoli?
- Pathogen arrives in alveolar space
- Uncontrolled multiplication of pathogens
- Cytokines produced by alveolar macrophages
- Neutrophils recruited into alveolar space → systemic circulation
What are the cardinal symptoms of pneumonia?
- Cough; usually productive with purulent sputum
- SOB
- Pleuritic chest pain
What are some systemic symptoms of pneumonia?
- Fever/Chills
- Malaise
- Fatigue
- Anorexia
- Confusion
What are the cardinal signs of pneumonia?
Vitals:
- Tachypnoea
- Hypoxia
- Tachycardia
- Fever
What are chest examination findings of pneumonia?
signs
- Dull percussion (fluid)
- increased tactile fremitus
- inspiratory crackles
- reduced air entry at site of infection
What is parapneumonic pleural effusion?
- pleural effusion that forms adjacent to site of pneumonia
What causes cough, phlegm, SOB, hypoxia, dull percussion in pneumonia?
- accumulation of exudate in alveolar spaces
- impairs gas exchange
What causes systemic effects of pneumonia?
fever, chills, tachycardia
- endotoxins, exotoxins
- interleukin, TNF release
- sepsis; RAAS + baroreceptor activation, catecholamine, NO release
What is the anatomical classification of pneumonia?
- Lobar
- Bronchopneumonia: starts at bronchioles
What are the stages of lobar pneumonia?
- Congestion
- Red Hepatization
- Grey Hepatization
- Resolution or Scarring
95% cases due to Strep. pneumoniae, M>F 3:1, neglected people, alcoholic
What are some characteristics of bronchopneumonia?
- Patchy infiltrate
- affects old or very young
- abscess
- strep pneumoniae/haemophilus influenza
What is atypical pneumonia?
- Infiltrate OUTSIDE alveoli
- no consolidation
- milder symptoms
- non-productive cough, rales
“walking pneumonia”
What organisms are responsible for atypical pneumonia?
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Legionella pneumoniae
- Mycobacteria
- Viruses
What are some risk factors for aspiration pneumonia?
- impaired cough reflex
- pyloric stenosis
- oesophageal obstruction
- hiatus hernia
