Pathology of pulmonary infection Flashcards
what happened to the guy who had ravioli in his alveoli?
he pasta way
what is a primary pathogenic microorganism?
very pathogenic and infects everyone regardless of health
what is a opportunistic pathogenic microorganism?
uses immunosuppression to infect host (the organism is not normally capable of producing disease in patents with intact lung defences) (ex: low grade bacterial pathogens, CMV, pneumocystis jirovecii, other fungi and yeasts)
is the respiratory tract sterile?
the upper one is not, the lower one is
what is acute epiglottitis?
inflammation of the epiglottis, obstructing the respirator tract, is an upper respiratory tract infection
what is a facultative microorganism?
may result to parasitic activity but does not rely on it’s host for the completion of its life cycle
what does the capacity of a patient to resist an infection depend on?
state of host defence mechanisms, age of patients
name 6 upper respiratory tract infections
- coryza (common cold)
- sore throat syndrome
- acute laryngotracheobronchitis
- laryngitis
- sinusitis
- acute epiglottis
what bacteria can cause acute epiglottis?
groupe A beta-haemolytic streptococci haemophilus influenza (type b- Hib)
what virus can rarely cause acute epiglottis?
parainfluenza virus type 4, but not necessarily
name 3 lower respiratory tract infections
bronchitis, bronchiolitis, pneumonia
what is the respiratory tract defence mechanism composed of?
macrophage-mucocilliary escalator system, general immune system (humeral and cellular immunity), respiratory tract secretion
how does the upper respiratory tract protect the lower one?
upper respiratory tract as a ‘filter’
TRUE/FALSE patients will only get respiratory tract infection of all of the defence mechanisms fail
FALSE failure of any of these systems increases the risk of respiratory tract infection
what are the components of the macrophage-mucocilliary escalator system?
it includes:
- alveolar macrophages
- mucociliary escalator
- cough reflex
how does this system work in the ciliated airways?
clearance of particles via the muco-ciliary escalator (cilia push mucous-trapped particles up the airways)
how does this system work in the smaller airways?
alveolar macrophages clear the particles by phagocytosis when these deposit on the terminal bronchioles/ proximal alveoli, then take the interstitial pathway via lymph to the lymph nodes
what in the airways is lost with influenza?
bronchial epithelium lost
what 3 ways are there of classifying pneumonia?
- anatomical (via radiology)
- aetiological (via circumstances, most useful)
- microbiological (most appropriate for treatment)
what 6 different aetiological pneumonia are there?
- community acquired pneumonia
- hospital acquired (nocosomial) pneumonia
- pneumonia in the immunocompromised
- atypical pneumonia
- aspiration pneumonia
- recurrent pneumonia
what is bronchopneumonia?
pneumonia in the middle? ‘often bilateral basal patch opacification relating to the focal nature of the consolidation’
what is lobar pneumonia?
consolidation on one side only (one lung affected)
what are the complications of pneumonia?
- pleurisy, pleural effusion, empyema
- lung abscess
- bronchiectasis
- mass lesion, constructive bronchiolitis, COP (cryptogenic organising pneumonia), all due to aspiration (inhaling food, liquids, or vomiting in lungs)
- death
what happens to most pneumonias?
they just resolve
what is a lung abscess?
obstructed bronchus because of tumour, aspiration of an object, particular organism (staph aureus, some pneumococci, Klebsiella), necrotic lung
when can lung abscesses be metastatic?
in pyaemia (blood poisoning caused by the spread of pus-forming bacteria)
what is bronchiectasis?
pathological dilatation of bronchi
what causes bronchiectasis?
severe infective episode, recurrent infections, proximal bronchial obstruction, lung parenchymal destruction
TRUE/FALSE most bronchiectasis start during adulthood
WRONG 75% start in childhood
what are the symptoms of bronchiectasis?
cough, abundant purulent foul sputum, haemoptysis (coughing blood), signs of chronic infection, coarse crackles, clubbing
how do you treat bronchiectasis?
thin section CT (previously bronchography), postural drainage, antibiotics, surgery
what are the main causes of a local bronchial obstruction?
tumour, foreign body
what are the main reasons for local pulmonary damage?
bronchiectasis
what are the main reasons for a generalised lung disease?
cystic fibrosis, COPD
what non-respiratory disease could eventually affect the respiratory tract?
anything which compromises the immune system (HIV…)
what is aspiration pneumonia?
a lung infection developed after you aspirate food, liquid or vomit into your lungs
how do you get aspiration pneumonia?
vomiting, oesophageal lesion, obstetric anaesthesia, neuromuscular disorders, sedation (basically anything that compromises the system that separates food from airways)
is the airflow in airways laminar or turbulent?
depends on pressure difference, could be both
where does diffusion in the airways happen?
beyond terminal bronchiole, in alveoli
what is the minimum value of FIO2 to have 98% saturated Hb leave the capillary bed?
0,21
why does CO2 rapidly equilibrate between blood and air?
because it is very soluble
