Respiratory Infections Flashcards
most common cause of community acquired pneumonia (CAP) and most at risk
1= S. pneumoniae
#2= M. pneumoniae
Others: H. influenzae and the atypical pathogens, Legionella species, MSSA, Moraxella catarrhalis and C. pneumoniae
Increased risk: splenic dysfunction, diabetes mellitus, chronic cardiopulmonary, liver/pulmonary/renal disease, or HIV infection
most common cause hospital acquired pneumonia (HAP) and most at risk
S. pneumoniae, MSSA, E. coli, Klebsiella pneumoniae
consider MDR pathogens: MRSA. P. aeruginosa, extended spectrum beta lactamase producining gram neg bacilli, carbapenemase-producing gram neg bacilli
critically ill patients and is usually caused by bacteria.
Risk= high severity of illness, longer duration of hospitalization, supine positioning, witnessed aspiration, coma, acute respiratory distress syndrome, patient transport, and prior antibiotic exposure .
***The strongest predisposing factor, however, is mechanical ventilation (intubation)
aspiration pneumonia compared to CAP or HAP and those at risk for
Treated as a separate entity from CAP or HAP.
It was predominantly caused by anaerobic bacteria that commonly colonize the oropharynx. The epidemiologic evidence suggests a decreasing importance of anaerobic bacteria in aspiration pneumonia.
Aspiration pneumonia has a bacteriology similar to CAP or HAP, and anaerobic pathogens are less common and typically seen in patients with specific risk factors such as severe periodontal disease or those with specific clinical findings such as necrotizing pneumonia or lung abscess
Most common URI to be treated with ABX
sinusitis
duration of viral URI vs bacterial
URIs of less than 7 to 10 days’ duration are usually viral, whereas more prolonged or severe symptoms are often caused by bacteria
most common bacterial cause of sinusitis
S. pneumoniae and H. influenzae
most common bacterial cause of pharyngitis
streptococcal (strep throat)
most common pathogens ventilator pneumonia
MDR pathogens: MRSA, P. aeruginosa, extended spectrum beta lactamase producining gram neg bacilli, carbapenemase-producing gram neg bacilli, Acinetobacter spp.
how big do particles have to be for upper respiratory tract mechanisms to remove them
> 10 mu m
what size particles reach/cause infection in lower respiratory tract
0.5-1
best scale at predicting mortality r/t pneumonia
PSI
s/s CAP or aspiration pneumonia
respiratory and/or non-respiratory
cough (productive/non product.), SOB, difficulty breathing
fever, fatigue, sweats, HA, mylagias, mental status change
increased temp/RR, O2 sat >90, decreased breath sounds, rale or rhonchi, accessory muscles
CXR= infiltrates
labs= maybe elevated WBC/decreased in elderly, elevated neutrophils if bacterial, lymphocytes if viral
SEVERE CAP s/s
cough (productive/non product.), SOB, difficulty breathing
fever, fatigue, sweats, HA, mylagias, mental status change
RR > 30, SBP <90, DBP <60, u/o < 20mL/hr or < 80mL x4 hours
confusion, rales, rhonchi, diminished breath sounds
***Blood cultures on all pt admitted to ICU for pneumonia
first line abx for CAP healthy adult no risk factors MDR
amox, doxy, macrolide (erythromycin, clindamycin), azalide (azithromycin)
abx for CAP healthy adult, resistant organism suspected
fluoroquinolone active against s. pneumoniae
outpatient adult w/ pneumonia AND comorbidities tx
fluoroquinolone w/ or w/o combo amox-clav or cephalosporin plus macrolide/azalide or doxy
adult inpatient NOT in ICU tx
without risk of MRSA or P aeruginosa:
fluoroquoinolone alone or with
IV beta lactam (cefotamxmine, ceftriaxone, ampicillin-sulbactam) plus macrolide/azalide (clarithromycin/azithromyycin) OR doxy
most common bacteria if severe pneumonia (needs ICU)
S. pneumoniae or H. influenzae; increasingly L. pneumophila
is empirical coverage recommended for aspiration in IP setting?
not recommended unless there’s lung abscess or empyema
agents against influenza virus
oseltamivir and zanamivir
amantadine and rimantadine used to be effective against type A but resistance > 90%
most common pathogens in pediatric CAP
viruses
tx CAP in pediatric in area lacking PCN-resistance
first-line= high dose amoxicillin
second-line if atypical organism likely= macrolide (azithromycin, clarithromycin)
tx HAP/VAP
empirical= broad spectrum then de-escalate when get cultures
consider risk of mortality, risk of MRSA (hospital unit rate > 20%) and IV abx within 90 day
low risk mortality/MRSA= cefepime, piperacillin/tazobactam, or levofloxacin
high risk mortality or recent abx= double coverage for gram neg bacilli
MRSA suspected= vancomycin or linezolid
what does dose aminoglycosides (gentamicin, tobramycin) depend on
renal function
