pneumonia Flashcards
What mediates pain?
prostaglandin E2 and bradykinin
What are the CXR patterns for pneumonia? bacteria vs. viral
lobar pneumonia, bronchopneumonia (brochoproblems). and interstitial pneomonia (incr. on lung markings)
lobar and bronchopneumia are usually bacterial, while interstitial pneumonia is usually viral.
lobar pneumonia: definition, casues
consolidation of an entire lobe, usually bacterial: S. pneumo (95%), and klebsiella.
What should I know about klebsiella in terms of lobar pneumonia?
enteric flora that is aspirated: elder in NHs, alcoholics, diabetics. this bug has a THICK MUCOID CAPSULE, so patients present with currant jelly gelatinous sputum. It is often complicated by abscesses.
What are the phases of lobar pneumonia?
congestion, red hepatization (exudate with blood and neutrophils- lung looks solid), grey hepatization (red blood cells break down), resolution
What is bronchopneumonia?
scattered patchy consolidation centered around bronchioles. often multifocal and bilateral. it is PATCHY.
What are key casues of bronchopneumonia?
S. aureus, H flu, pseudomonas, moraxella, legionella
S. aureus and bronchopneumonia?
most common cause of secondary pneumonia (pneumonia superimposed on a viral URI), often complicated by abscess or empyema (pus in the pleural space)
H flu and bronchopneumonia
common cause of secondary pneumonia or pneumonia superimposed on COPD
What bugs commonly cause pneumonia superimposed on COPD?
H. flu, moraxella, legionella
What should I know about legionella?
often associated transmitted by water soucres. intracellular ogranism best visualized with a silver stain. causes community acquired bronchopulmonary pneumonia, esp. in COPD and immunocompromised pts.
What is interstitial pneumonia?
diffuse interstitial infiltrates. presents with mild URI symptoms- minimal sputum, cough, low fever. air sacs are pretty empty, but there is inflammation in the interstitial spaces.
What is the most common cause of interstitial pneumonia?
mycoplasma pneumonia. can make an autoimmune hemolytic anemia (IgM against antigen on RBCs causes cold hemolytic anemia). no visible on gram stain because no cell wall.
What is the most common casue of atypical pneumonia in infants? post transplant?
RSV in babies, CMV post transplant
How is influenza virus related to pneumonia?
the virus itself can cause atypical pneumonia. it is also the most common casue of superimposed S. aureus or H flu bacterial pneumonia
coxiella burnetii
cause of atypical pneumonia, esp. in famrers and veterinarians (spores are deposited on cattle by ticks or are present in cow placenta). it is classically associated with a HIGH fever (Q fever). it is a rickettsial infection, but is different from most others b/c it causes pneumonia and does not require an arthropod vector, and does not produce a skin rash
What causes aspiration pneumonia? Where is the pneumonia most common?
anaerobic bacteria in oropharyns (bacteroides, fusobacteriu, peptococcus). usually in right lower lobe abcess
What is seen in primary TB?
focal caseating necrosis in the lower lobe of the lung and hilar lymph nodes. foci undergo fibrosis and calcification to form a Ghon complex (area of fibrosis and calficifation). usually asymptomatic. Ghon complex classically subpleural. Ghon complex can reactivate
What is seen with secondary TB?
reactivation, at the apex of lung. forms cavitary foci fo caseous necrosis, or miliary pulm TB with lots of scattered locations, to TB bronchopneumonia
Stain for TB?
red organisms on AFB stain
Where can TB go?
meninges, usually at the BASE of the brain, cervical lymph nodes, sterile pyuria with spread to the kidneys, lumbar vertebrae (pott disease)
What conditions cause lung abscesses? Organisms?
bronchial obstruction (think cancer), or aspiration of oropharyngeal contents (esp. in pts predisposed to aspiration). usually S. aureus or anaerobes (like bacteroides, fusobacterium, peptostreptococcus)
What is often seen on CXR for lung abscesses?
air fluid levels
