Flashcards in 42. Respiratory Tract Infections Deck (35):
upper vs lower respiratory tract?
upper has bacteria lower is normally sterile
the respiratory system actively clears infectious particles...give role of each:
- epiglottic reflex
- mucus secreting and ciliated cells
- alveolar macrophages
- nonspecific and specific immune response
- nares: filtration
- epiglottic reflex: prevents aspiration
- cough: particle expulsion
- mucus secreting and ciliated cells: entrap and expel particles
- alveolar macrophages: ingest and kill bacteria
- nonspecific and specific immune response: antibodies, opsonins, complement
- lymph: drainage
otitis media pathogenesis?
1. eustacian tube obstruction
2. air absorbed into middle ear (low pressure)
3. fluid collects
4. bacteria proliferate
5. release of inflammatory mediators
acute otitis media epidemiology?
common in young kids
peak during URI season
RFs: fam hx, prematurity, anatomic abn, immune defic, group daycare, secondhand smoke
AOM signs and sxs?
- irritability, headache, anorexia, vomiting, diarrhea
- hearing loss
AOM vs OME?
- tx w/Abx
- more inflammatory
OME: (otitis media w/effusion)
- present 1-3 months after AOM
- no Abx
Rx for AOM?
Amoxicillin (high dose for S.pneumo altered PBP) maybe w/clavulanate if suspect H.flu (eg conjunctivitis)
complication of AOM
- middle ear cavity and mastoid ear spaces are continuous
- purulent material accumulates in the mastoid cavities
- boggy, swollen mastoid
- ear displaced
sinusitis vs common cold
- getting better in a week
- bacterial infection of paranasal sinuses
- localizing signs to sinus area
- severe headache or focal pain
- ill and highly febrile for a long time
- sinusitis has a longer duration
sinusitis risk factors?
- URI, allergy, foreign body
impeded ciliary function
- URI, immotile cilia syndrome
Abn mucous production
- URI, CF, decongestant use
breach of sinuses (cleft palate, dental infections, swimming)
sinusitis pathogens in kids?
chronic sinusitis bugs?
dx of sinusitis?
radiograph or CT (fro recurrent episodes, suspected complications, unclear diagnosis)
tx of acute sinusitis?
spontaneous resolution 4-60%
kids: amoxicillin +/- clavulanate
adults: amox/clav or cephalosporin or quinolone (coverage of S. aureus more impt in adults)
expect improvement in 2-3 days (otherwise re-eval)
IV abx for severe disease
complications of sinusitis?
viral infection is 90% (self-limiting and no tx necessary)
common pathogen in bacterial: S. pyogenes
pharyngitis caused by S. pyogenes primarily effects ppl 5-10 y/o
GAS pharyngitis clinical manifestations?
headache, abdominal sxs
tender cervical lymphadenopathy
scarlet fever rash
ABSENT cough, coryza, conjunctivitis
rapid strep test
if ^^ negative, do cx
judicious use of Abx in pharyngitis?
clinical suspicion AND lab testing
don't treat presumptively
PCN = drug of choice
strep pharyngitis complications?
suppurative: peritonsillar abscess, retropharyngeal abscess
nonsuppurative: acute rheumatic fever (preventable), glomerulonephritis
extremes of age most susceptible
6th leading cause of death in the US
2-3 million adults affected annualy
pna: inflammation and consolidation of the lung (alveolar unless otherwise specified)
- lobar or bronchial
pneumonitis: inflammation of the lung
empyema: exudate or pus (WBC, fibrin, serum)
signs and sxs of pneumonia?
- tachypnea (infant w/RR = 60)
- cough and sputum production
- dyspnea and work on breathing: flaring, grunting, retractions
- tubular (decreased) breath sounds
- dullness to percussion
- increased (or decreased) vocal fremitus (toy truck)
- GI complains
risk factors for bacterial PNA?
- tracheo-esophageal fistula
- sequestration of lung
- comatose state
alterations in mucous clearance
bacterial pna characteristics?
low or high WBC (15K)
neutrophil predominance w/bands
higher risk for empyema
bacterial pna pathogens?
bacterial pneumonia dx by culture?
- blood culture positive in bacterial pneumonia
atypical pneumonia characteristics?
normal or high WBC w/LYMPHOCYTE PREDOMINANCE
CXR w/ diffuse and/or interstitial involvement
atypical pna pathogens?
common cause of atypical pneumonia
- cold agglutinins (50-70%)
dx w/serologies of cold agglutinins
treat w/ MACROLIDES
fear the severe presentation!
- progressive even when on abx
- prevelant pna in the ICU
aerosolized water droplets
SPUTUM PURULENT w/NO ORGANISMS
urine legionella Ag test
severe pna characteristics?
ANTECEDENT INFLUENZA INFECTION (S.aureus)
effusion, empyema, pneumothorax
pneumatoceles (usu develop later)
severe pneumonia causes?
S. pneumo is the most common cause of bacterial pneumonia, incl severe pna, but in a hospitalized pt, worry about S.aureus and CA-MRSA
atypical pathogens, esp legionella, can also cause severe pna, so in the ill pt, empiric tx should cover both typicals and atypicals