9 & 11.2 LRTIs & Imaging Flashcards
how are alveolar microbiota part of the defences for respiratory tract?
compete with other organisms to prevent establishment of infection
virulence factor of
-chlamydia pneumoniae
-mycoplasma
-influenza
-strep pneumonia/neisseria
-ciliostatic
-shear off cilia
-reduced mucous velocity
-split IgA
virulence factor of
-pneumococcus
-mycobacterium/legionella
-capsule inhibits phagocytosis
-resists phagocytosis
why is CXR normal in acute bronchitis?
doesn’t affect lung parenchyma, no fluid filling alveoli
lobar vs broncho pneumonia on CXR
lobar is complete lobe opacity
broncho is catchy consolidations
atypical organisms causing CAP
-mycoplasma (holiday, dry cough, rash)
-legionella
-coxiella burnetti
how to decide need to admit for pneumonia?
CURB-65 + observations
length of ABx treatment for CAP
5-7 days if mild
7-10 days if severe
why are clarithromycin/doxycycline needed for CAP treatment?
start them anyway in case CAP caused by atypical organisms, then stop if not
why are second line antipseudomonal beta lactase needed for HAP?
treat pseudomonas risk
how many anterior ribs should be visible on PA xray?
8-10
compare L and R main bronchus, and the implication
R is shorter, wider, straighter so more likely foreign bodies, especially in children
why could hilum appear convex?
filled by masses/lymph nodes
lingular lobe
projection of L upper lobe, corresponds to R middle lobe
why might R para tracheal stripe be thicker?
lymph nodes, masses
aorta pulmonary window is a common site for lymph node enlargement. try or false?
true
pneumonia on CXR
-air bronchograms
-fissures thicken
lung cancer on CXR
-rounded opacity
-+/- effusion
-+/- lymphadenopathy
pulmonary oedema on CXR
-bats wing peihilar shadwoing
-peripheral lines
-pleural effusions
COVID on CXR/CT
-multiple peripheral opacities
CF on CXR
-bronchiectasis
-thickened bronchial walls: tram track
-airway plugging
-+/- venous catheter
PE on CXR
-normal
-peripheral opacity if infarction
-IV septum straighter if R heart strain
pneumomediastinum on CXR
-streaky linear lucencies
-gas in neck and axillae
-oesophageal tear
pleural plaques on CXR
-calcified
mesothelioma on CXR
-lung enacted by ‘rind’ of tissue
cough reflex
-irritation of cough receptos
-VCs adduct
-external intercostals and diaphragm contract, air enters lungs
-VCs and epiglottis close, traps air
-intrathoracic pressure increased
-rapid relaxation of internal intercostals and abdominal muscles, VCs abduct sharply for rapid expulsion
