EXAM 3 LRTI Flashcards
Host defense mechanisms
nasopharynx: prevents moving down tract
trachea/bronchi: cough
oropharynx: saliva
alveoli/terminal: lining fluid and decreases binding, immune cells
What happens when the body does not do its job?
Pathogen-mediated(most significant): surface adhesions, pili
defense gone wrong:
host interventions: smoking, alcohol, most out of RT and causes damage
Host disease states: immunosuppression, DM
CAP definition
pneumonia that developed outside of the hospital or within the first 48 hrs of hospital admission
Pathogenesis CAP
Aspiration: most common, getting passed host defenses (good immune system prevents this)
Aerosolization: direct inhalation of pathogen, primarily viruses
Bloodborne: translocate to pulmonary site
Which microorganism is most common pathogenic organism for CAP?
Virus
What are most common bacterial pathogens for CAP?
Strep pneumoniae (most common)
Haemophilus influenzae
Staph aureus
atypical pathogens
- Mycoplasma pneumoniae
- legionella pneumophila
- chlamydia pneumoniae
streptococcus pneumoniae
increased pressence: DM, immunocompromised, HIV
Risk factors:
Age <6 or >65, prior ABX, co-morbidity, close quarters(daycare, dorm,ect)
mycoplasma pneumoniae
atypical
spread by person-person contact
imaging more pronounced –> patchy interstitial infiltrates
legionella pneumonophila
atypical
spread by aerosolization
risks: older males, chornic bronchitis, smokers
staph aureus
low prevalence in CAP
important to get MRSA nasal PCR
CAP clinical presentation
fever, chills, chest pain, SOB, productive cough
elderly patients symptoms may be absent
vitals: febrile, tachycardia >90, hypotension <90, tachycapnea RR>20-30
CAP CXR
recommended for all pts
dense lobar –> bacterial origin
patchy infiltrates –> atypical or viral pathogens
severe CAP major criteria
need 1
septic shock requiring vasopressors
respiratory failure requiring mechanical ventilation
Severe CAP minor criteria
need >3
RR 30 bpm
PaO2/FlO2 < 250
multilobar infiltrates
confusion
urema (BUN >20)
leukopenia (WBC < 4,000 cells)
Thrombrocytopenia (Plt < 100,000 uL)
Hypothermia (temp <36 C)
Hypotension requiring fluids
other CAP tools
Procalcitonin - usually elevated in pressence of bacterial infection, do not use to determine need for CAP
PSI - not used as often, >90 is higher mortality
CURB-65:
Confusion
Uremia (BUN > 19)
RR >30bpm
Hypotension (SBP<90, DBP < 60)
Age > 65
supportive measures CAP
O2
bronchodilators
fluids
chestphsyiotherapy
CAP treatment outpatient w/o comorbidities
amoxicillin q8h
doxycycline BID
macrolide resistance <25% –> azithromycin
CAP treatment outpatient w/ comordbidities
respiratory fluoroquinolones (levofloxacin or moxifloxacin)
combination therapy (b-lactam + macrolide/doxy):
Amoxicillin/clavulanate
cefpodoxime
cefuroxime
+
macrolides or doxycycline
CAP treatment inpatient non-severe (no MRSA/pseudomonas)
respiratory fluoroquinolones (levo or moxi)
combination therapy(b-lactam + macrolide):
ampicillin/sulbactam
ceftriaxone
+
macrolides
CAP treatment inpatient severe (no MRSA/pseudomonas)
combination therapy:
respiratory fluoroquinolone + b-lactam
combination therapy (preferred):
b-lactam + macrolide
ampicillin/sulbactam
ceftriaxone
CAP treatment MRSA
risk factors:
previous MRSA or IV antibiotics within last 90 day
coverage:
Vanc
linezolid
CAP treatment pseudomonas
risk factors:
previous pseudomonas or IV antibiotics
coverage:
zosyn
cefepime
meropenem
CAP treatment corticosteroids
Not recommended in non severe/severe CAP, influenza pneumonia
Only recommended when patient has CAP and septic shock
CAP clinical stability
temperature < 38
HR <100 bpm
RR < 24 bpm
SBP > 90mmHg
O2 sat > 90% or pO2 >60mmHg on room air
baseline mental status
continue antibiotics for 5 days
Aspiration pneumonia
recommend against anaerobic coverage unless lung abscess or empyema present
hospital acquired pneumonia
pneumonia occurring >48 hrs after hospital admission
ventilator acquired pneumonia
pneumonia occuring > 48 hrs after endotracheal
HAP/VAP pathogenesis
micro-aspiration of oropharyngeal secretions colonized with bacteria
Aspiration of esophageal/gastric contents
Hematogenous spread from another source
Diretc inoculation into airways via intubation
Mechanical ventilation –> bypasses host defenses and decreases LRT defenses
Risk factors HAP/VAP
Age, severity comorbidities, duration, endotracheal intubation, nasogastric tube, altered mental status, surgery, previous
diagnosis of HAP/VAP
no gold standard
timing: important for HAP and impacts choice of antibiotic
typical presentation: new lung infiltrate + clinical signs and symptoms
common pathogens of HAP/VAP
aerobic gram(-) bacilli: gram (-) rods
pseudomonas
enteric gram (-)
staph aureus: MRSA greater concern in the population
risk factors for MDR
prior IV abx use within 90 days
HAP treatment MRSA
vancomycin
linezolid
risk factors: ICUs where >10-20% MRSA isolates
HAP treatment pseudomonas
Piperacillin/tazobactam
cefepime
imipenem
meropenem
levofloxacin
HAP treatment not high risk mortality (no vent/septic shock)
Goal: MSSA + pseudomonas
piperacillin/tazobactam
cefepime
imipenem
meropenem
levofloxacin
HAP treatment not high risk mortality (no vent/septic shock)
+ MRSA
Goal: MRSA + pseudomonas
piperacillin/tazobactam
cefepime
imipenem
meropenem
levofloxacin
+ vancomycin or linezolid
HAP treatment high risk mortality and MRSA
Goal: MRSA + pseudomonas
piperacillin/tazobactam
cefepime
imipenem
meropenem
levofloxacin
tobra/amikacin
+ vancomycin or linezolid
VAP treatment
goal: MRSA + pseudomonas
piperacillin/tazobactam
cefepime
imipenem
meropenem
levofloxacin
tobra/amikacin
+ vancomycin or linezolid
duration for HAP/VAP
recommend 7-day duration
