Bacterial Pneumonia Flashcards
tyes of pneumonia
community-acquired pneumonia
nosocomial pneumonia - hospital-acquired, ventilator-associated, and healthcare-associated
typical symptoms of pneumonia
dry or productive cough
dyspnea
fever
diagnostic findings for pneumonia
dullness to percussion
bronchial breath sounds
E to A changes (egophony)
CXR shows pattern distinf for pneumonia
gram stains, blood cultures, or bronchoscopic smpling are other tests
hospital-acquired pneumonia (HAP)
> 48 hours after admission, not incubating at the time of admission
ventilator-associated pneumonia (VAP)
> 48-72 hours after endotracheal intubation
healthcare-associated pneumonia (HCAP)
hospitalized within 90 days
resident of a nursing home or long-term care facility
intravenous antibiotic therapy, chemotherapy, or wound care within 30 days
attended a hospital or hemodialysis clinic
pathogenesis of pneumonia
aspiration of upper flora
inhalation of aerosolized organisms
hematogenous spread
factors that increase risk of pneumonia
impaired level of consciousness
impaired cough reflex
alveolar macrophage dysfunction
How does pneumonia develop in an intubated patient?
Secretions will accumulate around the inflated cuff
Leaks around the cuff will allow secretions to pass down into the lungs
Increased risk for pneumonia because there is no way for the lungs to clear
inhaled pathogens
influenza
coxiella burnetii (Q fever)
anthrax
tuberculosis
aspergillosis
histoplasmosis
hematogenous pathogens
tricuspid valve: S. aureus endocarditis
retropharyngeal abscess/jugular venous thrombophlebitis: Fusobacterium spp. (Lemierre’s syndrome)
patterns of pneumonia
lobar pnuemonia
bronchopneumonia
interstitial pneumonia
lung abscess
most common pathogens that cause CAP
streptococcus pneumoniae
Haemophilus influenzae
Mycoplasma pneumoniae
Chlamydophila pneumoniae
Legionella pneumophila
oral anaerobes, influenza virus, respiratory syncytial virus
How does particle size affect deposition of inhaled particles?
large particles > 10 microns impact nose and upper airways
very small particles < 1-3 microns fail to settle out by gravity and remain suspended in the air
droplet nuclei particles 3-5 microns are deposited in the small airways and alveoli and may result in infection
What are common pneumonias are caused by aerosols
influenza
tuberculosis
llegionellosis
histoplasmosis
Q fever
anthrax
typical pneumonia
commonly caused by S. pneumoniae and H. influenzae
sudden onset of fever
cough productive of purulent sputum
pleuritic chest pain
signs of pulmonary consolidation
atypical pneumonia
commonly caused by M. pneumoniae and C. pneumoniae
gradual onset
low grade fever
dry cough
minimal evidence of pulmonary involvement on physical exam
clinical diagnosis of nosocomial pneumonia
new or progressive pulmonary infiltrates
purulent tracheobronchial secretions
fever
leukocytosis
differential diagnosis of nosocomial pneumonia
fluid overload
atelectasis
pulmonary hemorrhage
pulmonary embolism
malignancy
scoring systems to determine if a person with CAP can receive outpatient treatment
CURB-65 (confusion, uremia, respiratory rate, low blood pressure, age >/= 65 years)
Pneumonia Severity Index (PSI)
management of CAP
empiric antibiotic therapy - respiratory fluoroquinolone (moxifloxacin or levofloxacin)
beta-lactam plus a macrolide (ceftriaxone plus azithromycin)
management for nosocomial pneumonia
obtain appropriate samples
begin a combination of antibiotics to treat the most common pathogens based on local antibiograms, prior antibiotic exposure, early vs. late onset
de-escalate antibiotics based on results of clinical microbiology evaluation
antibiotic therapy for nocosomial pneumonia
early-onset and no risk factors for MDR pathogens - limited spectrum antibiotic therapy
late-onset (>/= 5 days) or risk factors for MDR pathogens - broad spectrum antibiotic therapy for MDR pathogens
risk factors for MDR pathogens
antimicrobial therapy within 90 days
current hospitalization of five days or more
hospitalization for more than two days within 90 days
high frequency of antibiotic resistance in the community or in the specific hostial unit
resitence in nursing home or extended care facility
home infusion therapy
chronic dialysis
home wound care
family member with multidrug-resistant pathogen or immunosuppressive disease and/or therapy
antibiotics for MDR pathogens
broad spectrum
ex. meropenem or linezolid plus azithromycin
prevention of community-acquired pneumonia
influenza vaccine
pneumococcal polysaccharide vaccine
pneumococcal conjugate polysaccharide vaccine
nosocomial pneumonia prevention
effective infection control
avoid intubation whenever possible
semi-recumbent positioning
continuous suctioning of subglottic secretions
treatment regimen for HAP
antibiotic therapy initially directed at anticipated pathogens and later tailored to organisms identified in cultures of respiratory secretions
blood or pleural fluid and supportive care
initial antimicrobial therapy for VAP
selected according to the presence or absence of risk factors for infection associated with health care
initial antimicrobial regimens for someone with risk factors should appropriately treat potentially resistant pathogens including MRSA and Pseudomonas aeruginosa
