Flashcards in Community-Acquired Pneumonia Deck (21):
Which is true about PNA?
a. It's incidence has declined since ABx.
b. ID'ing the causative organism is key to diagnosis.
c. It can occur in a healthy person w/o other risk factors.
d. The clinical picture (history, physical exam) for community-acquired PNA is very sensitive and specific.`
c. It can indeed occur in healthy people without risk factors.
Which is more useful in determining how to treat PNA?
a. A procedure that will reliably ID the organism.
b. A thorough history, physical exam, and plain CXR.
Really you only need to do a procedure like bronchoscopy/lavage if the patient is very very sick.
(This is not to say that culture and sensitivity testing aren't important, but the ABx that you would start based on the clinical picture usually tend to work well.)
Lungs are usually sterile.
But mouths are not. Which is pretty remarkable.
If you know the kind of deficit in someone's defense mechanism, it suggests potential organism that could be causing the infection.
Yes. For example neutropenia predisposes to invasive aspergillosis.
Interestingly, Strep. pneumo doesn't have many virulence factors. What is its superpower?
Its capsule, which enables it to avoid phagocytosis.
Interestingly... it promotes complement fixation, so there's lots of inflammation and damage, but not much clearance of the bug.
Definition of community acquired PNA (CAP)?
It's not... hospital-acquired, healthcare-associated, or chronic.
Common clinical presentation of PNA?
Fever, cough, dyspnea, pleuritic chest pain, with a sudden onset.
(though elderly can present with fever and altered mental status alone)
Does sputum production give you a clue about the location of the inflammation?
Clear or non-productive: Interstitial.
Productive: lobar or bronchopneumonia.
(within the latter category, sputum color really doesn't tell you that much)
Physical exam findings typical of PNA?
Dullness to percussion.
Splinting (trying not to move side of ribcage with PNA)
If the clinical picture looks like PNA, but the CXR doesn't show infiltrates, what do you call it? (usually)
(sometimes, though, the infiltrates don't show up if the patient is dehydrated)
Should bronchitis be treated with ABx?
Exceptions = pertussis, to reduce transmission. COPD? Influenza.
What's the yield of ID'ing a specific organism in PNA?
Low - 20-50% from sputum culture, 10-20% from blood culture.
What characteristic of a sputum sample makes you think it's from the lungs, and not the nose/mouth?
If from lungs, will have many PMNs and few epithelial cells.
8 common organisms causative of acute CAP?
Chlamydia pneumoniae (not trachomatis, fyi)
Drug resistant S. pneumo
Severity gives you a big clue about the etiology of the CAP. What are 3 categories of severity?
Most common organism causing CAP in an ambulatory setting?
Mycoplasma (and viruses)
(and just never determined)
Most common organism causing CAP in a hospitalized, non-ICU setting?
What organism becomes much more prevalent when you look at in CAP patients in an ICU?
Legionella jumps up to 2nd most common (still behind S. pneumo)
What in particular should you ask about when taking the history of a patient with CAP (or really, any PNA)?
Exposures to unusual stuff.
Like spelunking or inhaling rabbit shit.
Does culturing a pathogen mean the patient has PNA?
Nope. Many pathogens colonize the mouth, oropharynx etc. without causing disease.