Lower Respiratory Tract Infections Flashcards
(27 cards)
normal lower respiratory tract:
Lined by — , — epithelium
with —-producing goblet cells
* Normally, the — clears pathogens
-If pathogens reach the
alveoli, they are phagocytosed by—
ciliated columnar
mucous ?
mucociliary escalator
alveolar macrophages
pneumonia:
an — lower respiratory tract infection involving the —
CLASSIFICATION OF PNEUMONIA
1. —-acquired (CAP)
2. —-acquired (HAP)
3. — -associated (VAP)
4. —
Important to distinguish as different causative organisms,
& thus different — approaches
- risk factors for pneumonia:
* —
* Chronic — disease e.g., —
* —
* —
* —
* Season ( —)
acute
lung parenchyma
community
hospital
ventialtor
aspiration
empiric antibiotic
age
lung
COPD
smoking
alcoholism
co - morbitides
winter
1- how do patient present:
* Systemic signs: fever, rigors, malaise, myalgia, anorexia
* Cough (often — of — sputum)
* Dyspnoea
* Tachypnoea
* — (occasionally)
* — chest pain
2-diagnosis :
1. Clinical — & —
2. Laboratory investigations:
Microbiology
– Blood for culture
– Respiratory specimen:
* Sputum: — & —
* BAL ( —-patients): Gram stain & culture, —
– — antigen for legionella / pneumococcus
– Nose / throat swab for SARS-CoV-2, influenza PCR, RSV
(seasonal)
Other investigations
– WCC / Inflammatory markers, e.g. CRP, ESR /Blood gases
3. Radiology – Chest x-ray (CXR)
productive
purulent
haemotysis
pleuritic
history and examination
gram stain + culture
hospital
PCT
urinary antigen
Community acquired pneumonia (CAP)
Pneumonia acquired in the community (i.e., at home, in a nursing home)
Hospital-acquired pneumonia
* Pneumonia that occurs:
– — days after admission
– — days in hospital with known recent (past — weeks) IV — exposure e.g. during recent inpatient stay
Why is it different to CAP?
- Additional patient risk factors
- Different pathogen involved => different antimicrobials
required
“Healthcare-associated” pneumonia previously thought
to be similar but recent research has shown infections in this category are more like — than —
> 5
<5
six weeks
iv antimicrobial
CAP
HAP
- risk factors for hospital acquired pneumonia:
- General —
- Surgery
- Opiate —
- Immunosuppression
- Decreased level of —
- Mechanical ventilation, i.e. ventilator- associated pneumonia or VAP
- ventilator associated pneumonia VAP:
- Type of HAP that develops
more than — after — intubation - Can occur in 10-20% of
patients ventilated for –
– Mortality 25-50% - main cause of cap is —-
anaesthesisa
analgesia
consiosuness
48 hours
endotracheal
>48 hrs
streptococcus oenmonia 60% and 10-20% mycoplasma penumina
causes of HAP and VAP:
1. Gram — : including —- ones
* E. coli
* Klebsiella spp.
* Enterobacter spp.
* Pseudomonas spp.
2. Staphylococcus aureus: including —
3. Legionella pneumophila (most cases are —-acquired)
4. Viruses – SARS-CoV-2, influenza, RSV etc.
-ve bacili
multi-drug resistant
MRSA
community
( in cap:
1- Coxiella burnetii
Chlamydia pneumoniae
Chlamydia psittaci
(Gram negatives)
2-Staphylococcus aureus
3-Legionella pneumophila
4-Haemophilus influenzae
5-Mycoplasma pneumoniae (10-20%)
Streptococcus pneumoniae 60%
streptococcus pneumonia - penumoccous:
* Commonest cause of — acquired pneumonia
Remember: S. pneumoniae also causes:
- — & —
- — & — infection (—)
* Presentation
– — onset of illness followed by sustained —
– — sputum
– — chest pain
– Associated with — infection if severe
– — in 25%, less commonly —
* 10-20% mortality
community
sinusitis and otitis media
meningitis and bloodstream BSI
abeupt
fever
purulent
peluritic
bloodstream
Para-pneumonic effusions
empyema
1- s.penumiea diagnostic tests:
— culture , — culture , —-
2- diagnosis:
- are gram — , — in — or —-
- are — haemolytic
- catalyse —
- susceptible to — aka growth is inhibited by it
3- treatment are targeted for – results:
* — IV (if susceptible)—-
for oral switch (not oral penicillin due to bioavailability)
* —- IV, if penicillin-resistant
4- PREVENTION
Pneumococcal —
suputm , blood, urinary
gram -ve
cocci in chains or diplococci
alpha
-ve
optochin
culture
Benzylpenicillin IV.
Amoxicillin
Ceftriaxone
vaccines
haemphilus infuleznae:
Diagnosis: — culture
– Gram- — , —
– — : – CO2
* Require either – factor ( — ) & – factor ( – )
* Both of these found in — agar
Treatment:
20% produce — so are resistant to penicillin & amoxicillin (but covered by — )
H. influenzae is NOT the cause of influenza
(“the flu”)
* H. influenzae = bacteria which can cause —
* Influenza (“the flu”) is caused by the —
sputum
-ve coccobacili
fastidous
X factor ( haemin ) and V factor (NAD)
chocolate
β-lactamase
co-amoxiclav
pnemonia
influenza virus
atypical pneumonia:
* Term previously used to define infections caused by:
– — pneumoniae
– – pneumophila
– — pneumoniae
– Chlamydia psittaci
– — burnetii
* ‘Atypical pathogens’ more appropriate term than ‘atypical
pneumonia’
* These ‘atypical pathogens’ are characterised by being:
– Difficult to — early & not susceptible to — agents, hence treat with
e.g. — , — or —
macroplasma
legionella
chlamydia
coxiella
diagnosis
b lactam
macrolides, tetracyclines or fluoroquinolones
mycoplasma pneumonia:
* — and. — (common in this
group) – “ — pneumonia”
* SPREAD: Respiratory — , —-
INFECTION:
* Cough, — , —- , — pain
* Pneumonia (10%)
* Extra-pulmonary manifestations:
– —- (rarely clinically significant),
– — including Stevens-Johnson syndrome,
– —
– — (more common in — )
* DIAGNOSIS: Serology / nucleic acid amplification
testing (NAAT) on NPAs or respiratory samples
* TREATMENT: Has — - — e.g.
clarithromycin or tetracyclines e.g. doxycycline
school age children and young adults
walking
droplets and person to person
pharyngitis rihinora , ear pain
haemolysis
skin rash
carditis
encephalitis
children
no cell wall
macroldds
legionella penumophila :
* Acquisition: — of — from —
* Risks: Smoking, elderly, immunocompromised
* Clinical Presentation: — fever or Legionnaire’s disease
* Diagnosis: Urinary antigen/respiratory culture (doesn’t grow
on standard media – inform lab is suspected!)
* Treatment: — (e.g. clarithromycin) or —
(e.g. levofloxacin)
inhalation
aerosols
contaminated water
pontiac
macrolide , fluroquiolones
chalmydia species :
1- C. pneumoniae
* SPREAD: Respiratory — , — spread – —
* INFECTION:
– 3-4 week
incubation
– Pneumonia
– Pharyngitis
– — manifestations
2- C. psittaci
SPREAD: — :
Inhalation – droppings,
secretions of —
(—-)
INFECTION:
* Incubation: 1-3 weeks
* — , — symptoms especially
fever
– Pneumonia
– Complications rare but —
droplets
person to person
inhalation
etxtra pulmonary
airborne
infected birds
zoonosis
acute influenza like
severe
c.psittaci and c.pneumoiea diagnosis and treatment:
DIAGNOSIS
* Nucleic acid
amplification testing
e.g. —
* Serology to detect
specific –
– — fold rise in titre
TREATMENT
* No — in
cell wall – pencilin
no use!
* — or —
* Mortality up to 20%
if untreated
PCR
IgG
4 folds
peptidoglycan
tetracycline or macrolide
coxiella burnitii - Q fever:
* A worldwide—-
* — infectious at very — doses
SPREAD:
* — : Humans = incidental hosts.
Inhalation of contaminated —
arising from the placenta or parturient fluids of infected livestock
* Ingestion of — produced by
infected animals (rare)
Farmers, abattoir workers, vets i.e., occupational exposure
infection:
1. Acute infection
* Asymptomatic (50%)
* Influenza-like illness
* Pneumonia
* Hepatitis
* Pregnancy
complications
2. Chronic infection
* 1-5% infected people
* Culture negative
endocarditis
* Osteomyelitis,
vascular graft
infection
* More likely if
– pregnant,
immunocompromi
sed, underlying
valvular or
vascular disease
DIAGNOSIS:
– Serology
– Nucleic acid amplification testing (NAAT) (not
commonly available)
– Culture – very rarely done: biosafety level —
containment due to extreme infectivity
TREATMENT
* Acute: —
* Chronic: Combination therapy (e.g. — + —- ) for a prolonged period
zoonosis
highly
very low
airborne
aerosols
raw milk
level 3
deoxyclin
doxyclinc + rifampicin
other causes of CAP :
1- Staphylococcus aureus
– Mostly patients — infection
– S. aureus producing the — can cause severe – pneumonia in previously healthy young people
* Clinical Features
– — pneumonia, — formation
2- Klebsiella pneumoniae (a Gram- — , — )
– Alcoholics, elderly, aspiration, malignancy, diabetes
* Clinical Features
– — pneumonia, — formation
– Friedlander’s pneumonia (red-currant —- like sputum)
Both associated with severe CAP, & patients may
require intensive care
post influenza
PVL toxin
necrotising
multifocal
abscess
gram -ve bacillus
cavitating , abcess formation
jelly like
viral cause of CAP:
Respiratory viruses
* —
* Influenza A&B, sometimes with — pneumonia with e.g. S. pneumoniae
* RSV: — & —
As part of systemic infection:
* Varicella-zoster (chickenpox)- especially during
— , —
* Measles: — children
* CMV: —
SARS-CoV-2
secondary bacterial
young children and immunocompromised
preggo , immunispression
unvaccinated children
immunosuppressed
dont forget tb:
—- Cough
Haemoptysis
Fever / Night sweats
Anorexia
Weight loss
Haemoptysis
LRTI unresponsive to —
Less — presentation, symptoms over —/ —
If TB suspected – isolate, — precautions &
inform infection prevention and control team
productive
antibiotic
acute
weeks/moths
airborne
- start smart and choose empiric antibiotic ( clinical , acquisition aka community or hospital acquired , previous antibiotic , previous microbiology , allergy )
- CAP treatment ( beamunot guildlines) :
0-1: Mild Oral — or — or —
2: Moderate — + oral —
3-5: Severe IV co- amoxiclav + oral clarithromycin
May need to alter if: - Patient is admitted to ICU
- Risk factors for — infection
- Risk factors for antibiotic resistant organisms
1- Oral amoxicillin or clarithromycin or doxycycline
2- IV amoxicillin + oral clarithromycin
3- Pseudomonas aeruginosa i
HAP:
* Always check
– Previous positive microbiology or history of antibiotic resistant organisms (e.g. MRSA, ESBL etc.)
– Recent antimicrobials
* Check your hospital guidelines – different antibiotics to community acquired pneumonia!
– e.g. piperacillin-tazobactam for — but not —
prevention of CAP:
Modify risk factors
– Smoking
– Alcohol intake
– Management of chronic pulmonary conditions
Vaccination
* Covid vaccine
– — vaccines recommended for those at higher risk, e.g.
age > 80 years, immunocompromise, or living in long-term care facility
* Influenza vaccine (annual)
– chronic illness requiring regular medical follow-up / Immunosuppression
/ 65 years + / pregnant women etc.
* Pneumococcal vaccine
- Childhood vaccination programme / 65 years + / Clinical risk groups e.g.
splenectomy
prevention of HAP / VAP:
* Standard precautions
– Hand hygiene, environmental cleaning
* Avoid excessive sedation
* Mobilizing patients, Oral hygiene
* Legionella spp./ Pseudomonas spp. control strategies
* Annual influenza staff vaccination
If ventilated:
VAP care bundle- may include measures such as
* — secretions
* Ensure appropriate cuff size of —
* — head of bed
* Review need for ventilation daily
VAP
CAP
seasonal booster
suction
endotracheal tube
elevate
aspiration pneumonia:
(May be — or —- acquired)
1- Loss of —
* Post-anaesthesia
* Stroke or other neurological disorder
* Head injury
2- Organisms = — microflora usually:
* —
* — spp.
* — aureus
* — & other Gram —
community or hospital
gag reflex
oral
* Anaerobes
* Streptococcus spp.
* Staphylococcus aureus
* Escherichia coli & other Gram-negative bacilli
pneumonia in immunocompromised:
What patient groups are we talking about?
– Disease-induced immunosuppresion: cancer / asplenism /
HIV/ renal failure / hepatic failure
– Medications: chemotherapy, steroids, other
immunosuppressive medications
Two groups of organisms
1. Common causes of – / pneumonia e.g. —
2. — pathogens as:
Fungi
* Pneumocystis jiroveci (“PCP”)
* Aspergillus fumigatus
* Cryptococcus neoformans
Viruses
* Herpes simplex (HSV)
* Cytomegalovirus (CMV)
Mycobacteria
* Non-tuberculous mycobacteria (NTM) & M.
tuberculosis
LRTI / pneumococcus
opportunistic
lung abscess :
— infection involving — of — to produce —
Risk factors:
- — - altered — / —
Periodontal disease
Bronchiectasis
Bronchial carcinoma
Bacteraemia
Persons who – drugs
pulmonary
desctuction
parenchyma
cavaition
aspiration
consiousness
dysphagia
inject
bacterial causes:
Usually — – reflect the — microflora e.g —
Some pathogens can form — abscesses:
* S. aureus
* K. pneumoniae
* Streptococcus pyogenes
* Burkholderia pseudomallei – only in specific
geographical areas e.g. South-East Asia
polymicorbial
oral
Peptostreptococcus
mono microbial
