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Flashcards in Community Acquired Pneumonia Deck (36)
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pathogenesis of pneumonia?

-inflammation of parenchymal structures of the lung in the lower respiratory tract (alveoli and bronchioles)

-defect in the usual respiratory defense mechanisms (cough, cilia, immune response)

-large infectious inoculum or a virulent pathogen overwhelms the immune system


Pneumonia may be community or nosocomial acquired, what timeline do we use to determine this?

Community Acquire:
-pneumonia occurred outside of the hospital or within 48hrs of hospital admission.
-in a person who has not resided in a nursing home or hospital in the prior 2 weeks.

Nosocomial Pneumonia:
-hospital acquired
-ventilator associated
-health care associated


What is the most common bug to cause CAP, how about NAP?

both are most commonly caused by strep pneumo.


Pneumonia may be typical or atypical, what are the differences?

typical pathogens: caused by bacterial that multiply in the alveoli

atypical pathogens: -caused by infectious agents that multiply in the spaces between the alveoli (septum and interstitum) *destruction of alveolar walls, because the air spaces arent all filled up with pus and bacteria they will not have as hard of a time exchanging gases.
-viral infections


Definition of CAP?

-pneumonia infection occurred outside of the hospital or within 48hrs of hospital admission.


What is the most common infectious cause of death world wide?



When is PNA most commonly occuring? in what population?

-peaks in winter months
-more common in older adults >65yo


Risk factors of PNA?

-advanced age
-tobacco use
-Regular contact with children
-frequent visits to the healthcare provider
-gastric acid therapy (suppression can allow pathogens to survive in the gastric contents that normally would be killed by the acid)


Most common etiologies of bacterial PNA?

-strep pneumoniae
-h. flue
-chlamydia pneumoniae
-staph aureus


Most common viral causes of pneumonia ?

-influenza A & B
-Respiratory syncytial virus (RSV)
-parainfluenza virus


Can fungus cause PNA?

yes, if insidous onset with a possibility of immunocompromise consider fungal etiologies


What factors may lead you to believe your pt has legionella caused pneumonia?

-recent travel within 2weeks, hotel stays or cruise ships

-high fever (104 F)

-multilobar involvement

-GI sx (water diarrhea)

-Neuro involvement

-diffuse parenchymal involvement on xray


Tip to determine mycoplasma pna?



General Sx of PNA

-+/- sputum production
-rigors (abdominal rigidity and shaking of the limbs)
-pleuritic chest pain
-abdominal pain


Signs of PNA?

-appear acutely ill
-may have hypothermia (elderly)
-decreased SpO2
-bronchial breath sounds
-dullness to percussion


Elderly presentation of PNA?

-more likely to have subtle sx
-decline in functional status
-confusion or change in mental status


Out patient diagnostic test for PNA?

CXR +/-
Urinary ag testing +/-
CBC +/-
BMP +/-

*you generally dont have to do a big work up on outpatient, BUT if this is an older person we would want to get all of this stuff. Younger person with no comorbidities you wouldnt necessarily need these.


Inpatient Diagnostic Tests for PNA?

-Sputum gram stain
-Urinary antigen testing
--s. pneumonia
-rapid Ag test for influenza
-prior to abx tx: sputum culture, blood culture (x2)
-CBC w/ diff
- HIV testing in all adult pts


What type of CXR do you order for PNA? If positive pneumonia what would you see on xray?

-always order a PA and Lateral xray

-patchy opacities, lobar consolidation w/ air bronchospasms, diffuse alveolar or interstitial opacities, pleural effusion, cavitation


PNA pt may present with pleural effusion, how do you remove this fluid and what are you looking for in this fluid?


-looking at glucose, LDH, total protein, leukocyte count, pH, gram stain, and culture.


On CXR, if you see cavitary opacities what is the most likely cause of PNA?

-most likely fungal


Whats all the fuss between community acquired and hospital acquired MRSA?

-they are genetically different.


What is the admission criteria for PNA?

C: confusion
U: BUN>19mg/dl
R: RR>30min
B: BP1, the higher the number of points the higher the mortality.

*BUN: measure of kidney function- dehydration status. if BUN high you could be dehydrated because it should be more dilute.


What is CURB 65 good for determining?

-who will die from PNA, but not at whos going to need ventiallary support in the ICU.


Empiric Abx Tx PNA
-Not hospitalized, no co-morbidities

-Not hospitalized + comorbidities

-Hospitalized, not in ICU

-Hospitalzed, in the ICU

No hosp. no comorbid-Azithromycin**, or clarithromycin, or doxycycline (best for pt w/ hx of smoking)

Not hosp. + comorbid:
-Respiratory FQ**, or azithromycin, or clarithromycin + high dose amoxicillin, or high dose amoxicillin-CL (augmentin), or cefdinir, cefpodoxime, cefprozil

Hosp. no ICU
-Respiratory FQ*, or Macrolide + Cefriaxone, ampicillin, cefotaxime

Hosp. In ICU
-Res. FQ or Azithro + cefotaxime, ceftriaxone, ampicillin/sulbactam
*ask if at risk for pseudomonas; add antipseudomonal beta-lactams (piperacillin/tazobactam, cefepime, imipenem, miropeneim) + cipro/levo
antipseudomonal beta lactam + aminoglycoside + azithro or resp FQ


Best outcomes if abx are started within how many hours of admission for pna?



Duration of PNA treatment

-min 5 days
-afebrile for 48-72hrs
-avg for other meds other than azithromycin 5-7days unless severe infection or other sites infected
*azithromycin has a very long half life so duration of therapy studies dont equate to other drugs


how to prevent pna?

-pneumococcal vaccine
-seasonal flu vaccine


risk factors for anerobic pulmonary infection?

- decreased level of conciousness d/t drug or ETOH
-general anesthesia
-CNS disease
-impaired swallowing
-Hiatal hernia
-tracheal tubes
-NG tube
-periodontal disease
-poor dental hygiene


Pathogenesis of anerobic pulm infection?

-inhalation of oropharyngeal secretions colonized by pathogenic bacteria
-goes to the depenedent lung zones (posterior segments of the upper lobes, superior and basilar segments of lower lobes)