Pneumonia

Question 1

What is the definition of pneumonia?

Answer 1

Pneumonia is an infection of the pulmonary parenchyma from the alveoli

Question 2

What are the differential diagnoses of respiratory infections?

Answer 2

Sinusitis
Pharyngitis
Bronchitis
COPD exacerbation
Pneumonia

Question 3

What is the typical presentation of pneumonia?

Answer 3

Systemic symptoms:
Acute onset, fever, tachypnea

Respiratory symptoms:
Cough, purulent sputum, lung consolidation

Chest X-ray:
Infiltrate (Lobar = typical, patchy/diffuse = atypical)

Question 4

What are the three settings that pneumonia cases are categorized by?

Answer 4

Community acquired (acute or sub-acute)
Healthcare Associated (eg, nursing homes)
Hospital/Ventilator acquired (nosocomial)

Question 5

What are the common signs and organisms of typical CA-pneumonia?

Answer 5

• Purulent sputum
• Gram’s stain may show organism (60%)
• Lobar infiltrate on CXR

Pneumococcus
H. influenza
Moraxella catarrhalis
S. aureus (CA-MRSA)

Question 6

What are the common signs and organisms of atypical CA-pneumonia?

Answer 6

• Cough prominent, ± purulent sputum
• Gram’s stain with PMNs, but few organisms
• Patchy or diffuse infiltrate on CXR

Mycoplasma pneumonia
Chlamoydophila pneumoniae
Legionella pneumophila
Influenza; RSV, adenovirus

Question 7

What are common fungal causes of pneumonia?

Answer 7

Histoplasmosis, 
Blastomycosis, 
Coccidiomycosis, 
Apergillus)
(not Candida- lower virulence; “less bad bug”)

Question 8

What bacteria are commonly associated with aspiration pneumonia?

Answer 8

Anaerobes (only with aspiration)

Question 9

What are some non-infective causes of pneumonia?

Answer 9

Reactive (chemicals, drugs, Farmers' lung); 
Radiation;
Autoimmune; 
infiltrative cancer; 
congestive heart failure

Question 10

What is the definition of HCAP and what are some common bacterial agents?

Answer 10

Nursing home;
Hospital, dialysis, Chemo in 30 days,
hosp. in 180d

• Less S. pneumo,
• atypicals (x/c influenza) (Mycoplasma pneumonia,
  Chlamoydophila pneumonia, Legionella pneumophila, RSV, adenovirus), ± H. flu
• Some GNR and Staphylococcus aureus

Question 11

What is the definition of HAP/VAP and what are some common bacterial agents?

Answer 11

Hospital-acquired (HAP) or ventilator-associated (VAP)

• Little pneumococcus and few atypicals
• GNR (inc. Ps. aeruginosa) and Staphylococcus aureus prominent
• Increased Multi-drug resistance (MDR) (e.g., GNR, MRSA)

Question 12

What are the symptoms, risk groups, and anti-microbial susceptibility of pneumococcal pneumonia?

Answer 12

Classic presentation of community-acquired pneumonia (acute, local, alveolar, sputum)

Risk groups:
- Elderly - Alcoholism - Liver disease - Hematologic malignancy - Immunosuppression (esp. HIV-1) - Smoking

Antimicrobial susceptibility:

• Increasing incidence of decreased penicillin susceptibility (5-25%) (may not affect response to therapy of pneumonia)
• Penicillin-resistance associated with multiple drug resistance
• Other streptococci - Group A β streptococci (acute, very ill, pleural effusions)
• Not Enterococcus (less bad bug; limited virulence)

Question 13

What are the symptoms, risk groups, and anti-microbial susceptibility of H. influenza pneumonia?

Answer 13

Symptoms:
cough, purulent sputum, fever, but NO PULMONARY INFILTRATE on CXR
- 2nd most common of “typical” pneumonia
- Invasive adult disease often caused by non-encapsulated strains (50%) (non-type b)
Antimicrobial susceptibility:
- 36% ampicillin-resistant (b-lactamase)

Question 14

What are the symptoms, risk groups, and anti-microbial susceptibility of S. aureus pneumonia?

Answer 14

Symptoms:

• Increased severity; necrotizing pneumonia, shock, abscess, empyema, respiratory failure
• Virulent organisms with significant tissue injury;

Risk groups:

• Often in children, Native Americans; gay men; crowding (jail, barracks); HIV; homeless youth
• May follow and complicate influenza

Therapy:
IV – Linezolid, Vancomycin,; Not daptomycin (binds surfactant and inactivated)
Oral – TMP-SMX, mino/doxycycline, + clindamycin
- Classically health-care-associated MRSA are more MDR organisms

Question 15

What are three causes of atypical pneumonia?

Answer 15

Mycoplasma pneumonia:
- “walking pneumonia;” CXR worse than pt.

Chlamydia pneumoniae (TWAR)

Legionella pneumophila:

• Regional; Uncommon in Colorado - Suspect if immunocompromised,
• Sputum culture - low yield (@ 10%); urine antigen is best test (> 70% if type 1)

Question 16

What are some pulmonary and infectious complications of CAP?

Answer 16

Pulmonary complications: 
Effusion 
Respiratory failure 
Cavitation 
Pneumothorax 
Pulmonary embolism 

Infectious complications:
Nosocomial
Empyema
Arthritis
Abscess
Endocarditis

Question 17

What tests are appropriate for patients hospitalized with CAP?

Answer 17

• CXR
• O2 SAT (if ↓, ABG)
• CBC
• Cr, LFT
• Blood culture
• Gram’s stain, culture of sputum, ± AFB and culture, tests for Legionella (culture, DFA test, or urinary antigen assay), and measurement of mycoplasma IgM
• Pleural-fluid analysis*
• HIV (if 15-54 y.o.)

Question 18

What are the parameters of the CURB-65 criteria?

Answer 18

Age at or above 65 years
Confusion
BUN above 19 mg/dl
Respiratory Rate at or above 30/min
BP - hypotension (Less than 90 or diastolic less than 60)

Score of 2 = hospitalization
Score of 3+ = ICU

Question 19

What drugs should be prescribed for pneumonia in a previously healthy patient with no antibiotic use in the past three months?

Answer 19

Macrolides (Azithromycin, Clarithromycin, Erythromycin)
and
Doxycycline

Question 20

What drugs should be prescribed for pneumonia in a patient with significant co-morbidities or antibiotic use in the past three months?

Answer 20

Fluoroquinolone (Moxifloxacin, gemifloxacin, levofloxacin)
or
B-Lactam plus a Macrolide

Question 21

What drugs should be prescribed for pneumonia in an in-patient (non-ICU)?

Answer 21

Fluoroquinolone (moxifloxacin, gemifloxacin, levofloxacin)
or
B-Lactam plus a macrolide

Question 22

What drugs should be prescribed for pneumonia in a patient in the ICU?

Answer 22

B-Lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam)
plus either
azithromycin or fluoroquinolone

Question 23

What drugs should be prescribed for pneumonia in a patient where pseudomonas is suspected?

Answer 23

Anti-Pseudomonas B-lactam (Pip-Taz, Cefepime, imipenem, meropenem)
+/- amino glycoside and azythromycin
or
+/- amino glycoside and anti-pneumococcal fluoroquinolone

Question 24

What drugs should be prescribed for pneumonia in a patient where MRSA is a concern?

Answer 24

Add vancomycin or linezolid to therapy

Question 25

Four methods to prevent community acquired pneumonia?

Answer 25

Limit - Aspiration, Smoking / Environmental smoke exposure (esp. cooking in home) Vaccine – S. pneumoniae; H. influenza b; Influenza Passive Immunity – RSV Antimicrobial – Influenza (oseltamavir)

Question 26

What are the two pneumococcal vaccines?

Answer 26

1) 23-valent polysaccharide for adults; | 2) 13-valent conjugate (Prevnar) for children

Question 27

What is a significant limitation of the adult pneumococcal vaccine?

Answer 27

It does not prevent pneumonia. Only effective against bacteremia.

Question 28

How are influenza vaccines indicated for?

Answer 28

Indicated for patients with high-risk conditions, in chronic care facilities, healthy ≥ 65 years; almost everyone - Medical care personnel – protect yourself, protect patients Asymptomatic people can transmit to others Decreased illness - 60-80% in children/young adults; 30% institutionalized elderly Decreased serious illness and death: About 70% in elde

Question 29

What are the advantages of the childhood pneumococcal vaccine?

Answer 29

- Reduces colonization - Reduces bacteremia >90% - Reduces bacterial pneumonia - ≤ 37% in African children - Some reduction in serious otitis and meningitis