Mi - LRTI Flashcards
contrast URTI and LRTI
URTI = sinusitis / tonsilitis
LRTI = bronchitis / pneumonia / empyema / bronchiectasis / lung abscess
list 5 ways the airway can be compromised
poor swallow
abnormal ciliary function
dilated airways
HIV
immunosuppression
18F PC: fever, cough, malaise
Presented at A&E with:
sats 87
temp 38
RR 24
WCC high - neuts high
CRP high
CXR shows consolidation R lower lobe
CT shows collapsed R lower lobe
Dx & most likely organism?
R lower lobe pneumonia
streptococcus pneumoniae
what does strep pneumoniae look like
diplococci
purple (gram stain +)
why can strep pneumonia look green on the agar plate
alpha haemolysis as its sensitive to optochin
what % of CAP is caused by strep pneumoniae
30-50%
what is strep pneumoniae sensitive to almost always
penecillin
what is pneumonia
inflammation of the lung alveoli (LRTI)
what is the mortality % of pneumonia
5-10%
what % of people with pneumonia are admitted
20-40%
how can you tell where in the lung the pneumonia is
localising Sx
abnormal CXR
PC of pneumonia
fever
pleuritic chest pain
cough
SoB
malaise
N&V
what is HAP associated with
ventilators
RFs for developing pneumonia
lung disease
immunocompromise
geography / seasonal / epidemics
travel
exposure
bacterial causes of CAP
strep pneumoniae
Hameophilus influenzae
Moraxella catarrhalis
Staph aureus
klebsiella pneumoniae
what 2 bugs cause the most CAP and what % of CAP do they cause
strep pneumoniae
haemophilus influenzae
85%
bacterial causes of HAP
legionella mycoplasma
coxiella burnetti
chlymidia psitticae
what is coxiella burnetti also known as
Q fever
who gets chlymidia psitticae
people with birds
what do people with chlymidia psitticae get (physical sign)
splenomegaly
what pneumonia pathogens affect neonates (0 to 1 month)
E coli
group B strep (GBS)
Listeria
what pneumonia pathogens affect 1-6 month olds
Chlymidia trachomatia
RSV
Staph aureus
what pneumonia pathogens affect 6 months - 5 year olds
Mycoplasma
Influenza
what pneumonia pathogens affect 5+ year olds
strep pneumoniae
Ix for pneumonia
FBC, U&Es, CRP
blood cultures
sputum MC&S
ABGs
CXR
why are ABGs done in pneumonia
detect hypoxia
what score is used to determine who should be admitted with pneumonia
CURB65
components & cut offs of CURB65
confusion
urea >7
RR >30
BP <90S or<60D
>65 years old
2+ admit
2-5 severe
what is bronchitis
inflammation of medium sized airways
who gets bronchitis
smokers
kids with RSV
Sx of bronchitis
cough
fever
increased sputum
SoB
what does the CXR of bronchitis show
nothing its normal
what causes bronchitis
viruses - RSV, COVID, influenza
CAP bacteria
Mx of bronchitis
bronchodilators
physiotherapy
what stain is used to detect haem influenzae
chocolate agar
what does H influenzae look like
coccibacilli
gram - (pink)
what % of CAP is caused by H influenzae
18-35%
who gets H influenzae CAP
people with lung disease
what caution must be taken with treating H Influenzae
be careful with beta lactams as it may produce beta lactamase
62M SoB & recent confusion
smoker
Bloods: low Na
CXR: bilateral interstitial changes
Dx?
Legionella
Sx of legionella
confusion
abdo pain
low sodium
low lymphocytes
how do you get legionella
inhalation of infected water droplets
from aerosols / air con
how do you diagnose legionella
Ag in urine
what do you culture legionella on
buffered charcoal yeast extract
what is legionella sensitive to
macrolides
what do the atypical CAP organisms have in common
no cell wall
name the CAP atypicals
mycoplasma
legionella
chlymidia
Coxiella
what ABx work with atypicals
clari
doxycycline
what extrapulmonary features can be present with atypicals
hepatitis
low Na
what % of CAP are atypicals
20%
what is clinical course of atypicals
flu like prodrome
fever
pneumonia
who gets coxiella burnetti
people with pets / farm animals
how is coxiella burnetti spread
aerosol / infected milk
how do you diagnose coxiella burnetti
serology
what is coxiella burnetti sensitive to
macrolides
who gets chlymidia psittaci
people with birds
how is chlymidia psittaci spread
inhalation of infected droplets
how is chlymidia psittaci diagnosed
serology
what is chlymidia psittaci sensitive to
macrolides
74F SoB, fever, R pleuritic chest pain
O/E reduced percussion, reduced air entry at R base
CXR - consolidation R base
Admitted, given beta lactams, atypical cover but continued to spike fevers and have raised CRP
Dx?
Empyema with collapsed lung
what causes are behind why resp patients fail to improve when on a Tx
Empyema / abscess
tumour
resistance eg TB
not absorbing the ABx
immunosuppression
what clues in the history suggest TB
ethnicity
prolonged prodrome
fever
weight loss
haemoptysis
CXR of TB
upper lobe cavitation but high variability
when can HAP be diagnosed
> 48 hours in hospital
who gets HAP
previous ABx
ventilator users
what type of bacteria usually cause HAP
gram -
bacterial causes of HAP
staph aureus
enterpbacteria
pseudomonas
candida
% of HAP caused by staph aureus
19%
% of HAP caused by enterobacteria
31%
% of HAP caused by pseudomonas
17%
% of HAP caused by candida
7%
who gets candida HAP
immunosuppressed
64M in hopsital for months, treated for lymph node TB, has SoB.
CXR shows bilateral patchy ground glass shadowing. Dx?
PCP - pneumocystis jirovecii
what is pneumocystis jirovecii
protazoa
ubiquitous in environment
Sx of pneumocystis jirovecii
INSIDIOUS
dry cough
weight loss
SoB
malaise
what does the CXR of pneumocystis jirovecii show
bats wing sign
ground glass shadowing
how is pneumocystis jirovecii clinically diagnosed
walking test - their O2 sats will drastically fall after walking
how is pneumocystis jirovecii properly diagnosed
immunoflurescence on BAL or PCR
Tx of pneumocystis jirovecii
septrin (co-trimoxazole)
how can you prevent someone from getting pneumocystis jirovecii & who would you give this to
prophylactic septrin if immunosuppressed
who typically gets pneumocystis jirovecii
HIV pts
cancer pts
immunosuppressed pts
22M chemo for leukaemia.
Prolonged neutropenia, fevers, raised CRP despite ABx.
CT thorax: infiltration, interstitial change
Dx and pathogen?
Aspergillosus
aspergillus fumigatus
what is aspergillosus
allergic bronchopulmonary disease due to aspergillus
what does the agar plate look like for aspergillus
flowering spores of aspergillus
what LRTI is associated with HIV
PCP
TB
atypical mycobacteria
what LRTI pathogen is associated with neutropenia
fungi eg aspergillus
what LRTI virus is associated with BM transplant
CMV
what LRTI is associated with splenectomy
encapsulated bacteria eg strep pneumoniae, H.influenzae
possible Ix for LRTI
sputum
blood culture
BAL / pleural fluid
Ag or AB test
immunoflurescnce
PCR
what is BAL and when is it used
broncheoalveolar lavage
ITU
which pathogens are diagnosed by Ag test
strep pneumoniae
legionella
what is important to remember when taking BCs for Dx of LRTI
do it before ABx
