EXAM #2: COMMUNITY-ACQUIRED PNEUMONIA Flashcards
If a patient presents with a likely pneumonia, what do you need to consider, and what do you need to ask about when taking a history?
1) Local epidemiology
2) Ask about travel hx.
3) Hobbies (caving)
4) International outbreaks
5) Recent hospitalization
What three groups of patients have a greater prevalence of pneumonia?
- Elderly
- Male
- African Americans
Generally, what presdisposes one to pneumonia?
Anything that impairs the normal defenses of the respiratory tract, especially:
1) Impaired cough reflex
2) Damage to mucociliary escalator
3) Mucus plugging
What type of organism is most likely to cause pneumonia in patients with aspiration pneumonia?
Anaerobic organsims
*These are anaerobic bacteria from the oropharynx and may cause lung abscess and empyema
What is the most commonly identified pathogen to cause CAP and secondary pneumonia?
Streptococcus penumoniae
What is the most common virus to lead to pnuemonia?
Influenza virus
*Note that the virus impairs the mucociliary escalator and sets up a nidus for infection
In patients with a history of recent influenza, what pathogen do you need to consdier as a superimposed infection?
Staphylococcus aureus
*Note that this is technically the 2nd most common cause of superimposed pneumonia
What is the most common cause of pneumonia in patients with CF?
Pseudomonas aeruginosa
What bacterial pathogen commonly causes pneumonia superimposed on COPD?
Haemophilus influenza
What organism causes atypical pneumonia among college students and military recruits?
Mycoplasma pneumoniae
How is Legionella transmitted?
Inhalation of aerosols from contaminated water sources
What are the symptoms that are associated with pneumonia?
1) Productive cough (yellow-green sputum)
2) Fever
3) Dyspnea
4) Pleuritic chest pain*
*Note that pleuritic chest pain is mediated by bradykinin and PGE2
What are the physical signs of pneumonia?
1) Fever
2) Tachypnea
3) Tachycardia
4) Crackles
What lab sign on CBC is associated with pneumonia?
Leukocytosis with a left shift
What is the gold standard for diagnosing a pneumonia?
CXR with infiltrate
What is an air-fluid level with density below and transparency above associated with?
Lung abscess caused by an anaerobic organism i.e. seen more commonly in aspiration pneumonia
What is the current recommendation for the treatment of most cases of CAP?
1) Outpatient treatment
2) Empiric abx
What are the situations in which identification of the specific organism is critical?
1) Legionella pneumophila
2) Influenza A/B virus
3) MRSA
4) Agents of bioterrorism
When is sputum stain and culture recommended in cases of CAP?
1) ICU admit
2) Failure of abx therapy
3) Cavitary changes on CXR
4) Immunocompromised
5) Alcoholism
When is sputum testing useful?
1) Severe COPD
2) Evidence of pleural effusion
3) Cases of epidemic pneumonia
4) Likelihood of drug resistance (epidemiologically)
What types of pneumonia have a urinary test?
1) Legionella pneumophila
2) Streptococcus pneumoniae
In a previously healthy patient with no comorbidities, what is the recommended treatment for CAP?
Oral macrolide OR doxycycline
1) Azithromycin
2) Clindamycin
3) Erythromycin
In patient with comorbidities and CAP, what is the recommended treatment?
1) Oral quinolone OR
2) Macrolide + Beta-lactam
What are the treatment recommendations for non-ICU inpatient therapy for CAP?
1) Respiratory quinolone
2) Anti-pseudomonal beta lactam PLUS a macrolide
What are the treatment recommendations for ICU patients with CAP?
1) Antipseudomonal Beta-Lactam PLUS asithromycin, OR
2) Antipseudomonal Beta-Lactam PLUS respiratory quinolone
What is added as an up-and-coming treatment for severe penumonia in the ICU?
Systemic corticosteroid
What are the three classic patterns of pneumonia on CXR?
1) Lobar= involves the entire lobe of the lung
2) Bronchopneumonia= consolidation around the bronchioles
3) Interstitial/atypical= involves the connective tissue between the alveolar walls*
*Note that this is more likely to be VIRAL vs. bacterial
What are the most common causes of lobar pneumonia?
1) Streptococcus pneumoniae
2) Klebsiella pneumoniae
What patient populations are most likely to have CAP associated with Klebsiella pneumoniae?
- Alcoholic
- DM
- Elderly nursing home patient
How is the sputum from Klebsiella induced pneumonia described?
Currant jelly
List the organisms that are associated with bronchopneumia.
1) Staphylococcus aureus
2) Haemophilus influenza
3) Pseudomonas aeruginosa
4) Moraxella catarrhalis
5) Legionella pneumophila
List the organisms that are associated with atypical pneumonia.
1) Mycoplasma pneumoniae
2) Chlamydia pneumoniae
3) RSV
4) CMV
5) Influenza virus
6) Coxiella burnetii
What are the two most common atypical pneumonias in young adults?
1) Mycoplasma pneumoniae
- College kids
- Military recruits
2) Chlamydia pneumoniae
What is the most common cause of atypical pneumonia in infants?
RSV
What organism is associated with pneumonia in post-transplant immunosuppressive therapy?
CMV
What organism causes Q fever?
Coxiella burnetii
Who are the typical patients that get Q fever? Why?
1) Farmers
2) Veterinarians
*Coxiella burnetii spores are deposited in cattle ticks or cattle placenta
