PI 1 Flashcards
classification of PNA
causative pathogenic organism
anatomic/radiologic location
acquisition
setting occur
why do we classify PNA
direct Abx therapy and determine risk of exposure to MDR organisms
PNA epidemiology
2nd mMC cause of hospital acq. infection,
MC in winter months and colder climates
mc in elderly and high mortality rate in very old
PNA pathogenesis
inflammation of lung parenchyma causing filling of the air spaces with exudates, inflammatory cells and fibrin = CONSOLIDATION
host defense mechanisms are defective or overwhelmed
how to organisms enter the lower respiratory tract
inhalation
aspiration
hematogenous spread
classification mechanisms of bacterial mechanisms
community acquired PNA (CAP)
healthcare associated PNA (HCAP)
hospital and ventilator associated PNA (HAP/VAP)
aspiration PNA
CAP
develops outside the hospital or care facility OR
within 48 hrs of admission to hospital
CAP in pts just admitted who has NOT
been hospitalized >2 days in last 90 days
significant healthcare contact (including HD, wound care, chemo, or IV ABX)
has not resided in >14 days in an extended care facility (ECF, SNF)
HCAP
non hospitalized patient or develops before 48hrs of hospitalization in pt with extensive healthcare contact
(IV therapy, HD, wound care, chemo in 30 days, residence in nursing home or long term care facility >14 days, hospitalization 2+ days)
HAP
occurs 48 hours+ after admission and did not appear to be incubating at time of admission
noscicomial PNA
VAP
HAP that develops more than 48-72 hrs following endotracheal ventilation
who is at risk of MDR pathogens?
ABX in preceding 90 days
current hospitalizations (>5 days)
high freq. ABX in community or specific unit
immunsuppressed
presence of risk factors/ family members
CAP bacterial pathogens
typical
Streptococcal app
H. Flu
Moraxella catarrhalis
s. aureus
MAY be anaerobes and gram neg
cause the TYPICAL symptoms of CAP
atypical CAP pathogens
infectious agents that cause “walking PNA”
Mycoplasma pan, legionella, chlamydia pneumo, chlamydophilia psittaci
adult CAP microbiology
bacterial (70-80)
Atypical (10-20)
viral (10-20)
typical pathogens Gram +
strep pneumonia
staph aureus
strep pneumonia
MC bacterial cause of CAP
rates are decreasing due to vaccination
rust colored sputum
staph areus
mc in groups of pt (post-flu, abx tx, HD, IVDA, pulmonary dx_
MRSA CAN cause cavitation
typical pathogens Gram -
H. flu
moraxella catarrali
klebsiella pneumoniae
psuedomonas aeruginosa
gram 0 bacilli
h. flu
cause of PNA in elder and underlying lung dz
routine immunization decreased prevalence
moraxella catarrali
gram - diplococcus
more common in COPD, PCM, neutropenia, and malignancy
often a copathogen
klebsiella pneumoniae
common in COPD, DM, and chronic alcohol abuse
causes necrotizing PNA with jelly sputum
Pseudomonas aeruginosa
only in certain groups of pts :
underlying lung dz repeated courses of Abx DM prolonged glucocorticoids, immunodeficiency recent ventilation
gram negative bacilli
E. coli, enterobacter, serrate, proteus
uncommon
causes severe PNA and req. intensive care unit