pathology of pulmonary infection Flashcards
(36 cards)
what three factors affect the affect likelyhood of a lung infection?
- microorganism pathogenicity
- capacity to resist infection
- population risk
what is a primary microorganism?
a microogranism able to infect anyone
what is a fucultative microorganism?
a microorganism that needs a little ‘help’ when infecting a host eg. the host is less able to resist infection
what is an opportunistic microorgansim?
a microorganism that can’t infect a host unless the hosts capacity to resist infection is very compomised
what two factors affect a patient’s capacity to resist infection?
- state of defence mechanisms
- age of patient
name some URTI
- Coryza - common cold
- Sore throat syndrome
- Acute Laryngotracheobronchitis (Croup)
- Laryngitis
- Sinusitis
- Acute Epiglottitis
when is acute epiglottiitis a problem?
in children as their thrachea is smaller so an inflammation of the epiglottis may cause the airway to be obstructed
which microorganisms cause acute epiglottitis?
- haemophilus influenzae
- group A beta haemolytic streptococci
- rarely caused by parainfluenza virus 4
- some other viruses
name some LRTI
bronchitis
bronchiolitis
pneumonia
what are the respiratory tract defence machanisms?
- macrophage-mucociliary escalator system
- general immune system
- respiratory tract secretions
- upper respiratory tract as filter eg. nasal hairs
how are particles and microorganisms removed from the terminal bronchioles and proximal alveoli?
macrophages phagocytose particles and pathogens then transport to lymph nodes via lymph
where does the mucociliary escalator begin?
the respiratory bronchioles
how can the influenza virus cause bacterial lung infections ?
the influenza virus is cytopathic and destroys the cells of the mucociliary excalator. this means that the defence mechanism to bacteria is compromised and secondary infection is much more likely
how can pneumonia be classified according to aetiology?
Community Acquired Pneumonia Hospital Acquired (Nosocomial) Pneumonia Pneumonia in the Immunocompromised Atypical Pneumonia Aspiration Pneumonia Recurrent Pneumonia
what is nosocomial pneumonia?
hospital acquired pneumonia?
what is hypostatic pneumonia?
usually occurs in elderly people with cardiac failure, extra secretions in the lung, oedema in the lung or suppressed cough reflex. All these thing leads to accumulation of fluid in the lung which acts as a ‘petri dish’ for bacteria.
what is bronchopneumonia?
an acute infection causes acute inflammation in very local areas of the lung, these areas become filled with pus, this is called local consolidation.
what is local consolidation?
the building of pus in certain localise areas in the lung during a pneumonia infection
Is pleural effusion likely in bronchopneumonia?
no as the infection is isolated in specific areas and so won’t spread to the pleura
where is bronchopneumonia most likely to be found in the lungs?
the base
what does bronchopneumonia look like on an x-ray?
- often bilateral
- basal
- patchy opacification
what does lobar pneumonia look like on an xray?
complete opacification of one lobe only
what causes lobar pneumonia?
caused by a primary pathogen, infects a whole lobe as the body’s response to the pathogen is vigorous
do most pneumonias resolve?
yes
