Community Acquired Pneumonia (CAP)
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Diagnosis
The diagnosis of pneumonia should be considered in any patient who has newly
acquired respiratory symptoms (cough, sputum production, and/or dyspnea),
especially if accompanied by fever and abnormal breathing sounds and crackles.
In patients with advanced age or an inadequate immune response, pneumonia
may present with non-respiratory symptoms such as confusion, failure to thrive,
worsening of an underlying chronic illness, or falling down. In these patients,
fever may be absent, but tachypnea is usually present.
Diagnosis studies
Chest radiograph
 Standard PA and lateral chest radiographs are valuable in patients whose
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symptoms and physical examination suggest the possibility of pneumonia.
The radiographic findings may suggest specific etiologies or conditions
which as lung abscess, or tuberculosis.
The radiograph can also identify coexisting conditions such as bronchial
obstruction or pleural effusion.
Radiography is also useful for evaluating severity of illness by identifying
multilobar involvement.
Sputum Gram’s stain and culture
 Routine bacterial cultures of sputum often demonstrate pathogenic
organisms, but sensitivity and specificity are poor, and findings should be
correlated with the predominant organism identified on Gram’s stain.
 When drug-resistant pneumococci, other resistant pathogens, or organisms
not covered by the usual empiric therapy options are anticipated, sputum
culture and sensitivity results may be useful.
Direct staining of sputum (non-Gram method) may be diagnostic for some
pulmonary infection, including those due to Mycobacterium sp., endemic fungi,
Legionella sp., and Pneumocytic carinii.
Specialized cultures for Mycobacterium sp., Legionella sp., and endemic fungi
may be valuable in the appropriate clinical circumstance.
Viral culture is not useful in the initial evaluation of patient with CAP and should
not be routinely performed.
 In the appropriate season, testing of respiratory secretions for influenza
antigens, using rapid detection methods, may be helpful in guiding
decisions about the use of new antiviral agents.
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PORT Prediction Rule Model
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Age over 65 y/o
Presence of coexisting illness
 Chronic obstructive lung disease
 Bronchiectasis
 Malignancy
 Diabetes mellitus
 Chronic renal failure
 Congestive heart failure
 Chronic liver disease
 Chronic alcohol abuse
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 History of hospitalization within the past year
Physical finding
 Respiratory rate ≥ 30 breaths/min
 Diastolic BP ≤ 60 mmHg or systolic BP ≤ 90 mmHg
 Pulse ≥ 125/min
 BT < 35 or ≥ 40°C
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Confusion or decreased level of consciousness
 Evidence of extrapulmonary sites of infection
Laboratory findings
 WBC < 4 × 109/L or > 30 × 109/L, or ANC < 1 × 109/L
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PaO2 < 60 mmHg or PaCO2 > 50 mmHg while breathing room air
Serum creatinine > 1.2 mg/dl or BUN > 20 mg/dl
Presence of certain unfavorable chest radiograph findings
 More than on lobe involvement, presence of a cavity, rapid
radiographic spreading
 Presence of a pleural effusion
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Evidence of sepsis or organ dysfunction
 manifested by a metabolic acidosis or coagulopathy
Arterial pH < 7.35
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Malnutrition
Cerebrovascular disease
Post-splenectomy
Severe CAP
Minor
 PaO2/FiO2 < 250
 Bilateral pneumonia or multilobar pneumonia
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Systolic BP ≤ 90 mmHg
Major
 Need for mechanical ventilation
 Septic shock or need for pressors for > 4 hrs
Meet 2 minor or 1 major criteria
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Recommended Tests
Chest radiograph
Complete blood count and differential count
Routine blood chemistry test
 Including glucose, liver and renal function, and electrolytes
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Oxygen saturation assed by oximetry
Artery blood gas
 In patient with severe illness or chronic lung disease
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Sputum culture and smear
Blood culture
 Two sets, before initiation of antibiotic therapy
Pleural effusion
 To rule out empyema, or complicated parapneumonic effusion
 Including white blood cell count and differential count, measurement of
protein, glucose, lactase dehydrogenase (LDH), and pH, Gram’s stain and
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acid-fast stain, and culture for bacteria, fungi, and mycobacteria
Urine Legionella Ag (serogroup 1)
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CAP is present
OUTPATIENT
NO CARDIOPULMONARY
DISEASE, NO MODIFIERS
GROUP 1, TABLE 2
INPATIENT
HISTORY OF
CARDIO-PULMONARY
DISEASE, AND/OR
MODIFIERS
MILD-MODRATE ILLNESS
SEVERE CAP
GROUP II, TABLE 3
CARDIOPULMONARY
DISEASE
AND/OR
MODIFIERS
NO CARDIOPULMONARY
DISEASE, NO
MODIFIERS
NO RISKS FOR
PSEUDOMAS
AEROGINOSA
RISKS FOR
PSEUDOMAS
AEROGINOSA
GROUP IIIA
TABLE 4A
GROUP IIIA
TABLE 4B
GROUP IIIA
TABLE 5A
GROUP IIIA
TABLE 5A
Table 1. MODIFYING FACTORS THAT INCREASE THE RISK OF INFECTION
WITH SPECIFIC PATHOGENS
Penicillin-resistant and drug-resistant pneumococci
Age > 65 yr
β-Lactam therapy within the past 3 mo
Alcoholism
Immune-supressive illness (including therapy with corticosteroids)
Multiple medical comorbidities
Exposure to a child in a day care center
Enteric gram-negatives
Residence in a nursing home
Underlying cardiopulmonary disease
Multiple medical comorbidities
Recent antibiotic therapy
Pseudomonas aeruginosa
Structural lung disease (bronchiectasis)
Corticosteroid therapy (> 10 mg of prednisone per day)
Broad-spectrum antibiotic therapy for > 7 d in the past month
Malnutrition
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Table 2. GROUP I: OUTPATIENTS, NO CARDIOPULMONARY DISEASE, NO
MODIFYING FACTORS
Organisms
Streptococcus pneumoniae
Mycoplasma pneumoniae
Clamydia pneumoniae
(alone or as mixed infection)
Hemophilus influenzae
Respiratory viruses
Miscellaneous
Legionella spp.
Therapy
Advanced generation macrolide:
azithromycin or clarithromycin
or Doxycycline
Mycobacterium tuberculosis
Endemic fungi
Table 3. GROUP II: OUTPATINT, WITH CARDIOMPULMONARY DISESE,
AND/OR MODIFYING FACTORS
Organisms
Therapy
Streptococcus pneumoniae (including
β-Lactam (oral cefpodoxime,
DRSP)
Mycoplasma pneumoniae
Chlamydia pneumoniae
Mixed infection (bacteria plus atypical
pathogen or virus)
Hemophilus influenzae
Enteric gram-negatives
Miscellaneous
Moraxella catarrhalis, Legionella spp.,
aspiration (anaerobes), Mycobacterium
cefuroxime, high-dose amoxicillin,
amoxicillin/clavulanate; or parenteral
ceftriaxone followed by oral cefpodoxime)
plus
Macrolide or doxycylline
or
Antipneumococcal fluoroquinolone (used
alone)
tuberculosis, endemic fungi
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Table 4. GROUP III: INPATIENTS, NOT IN ICU
Organisms
Therapy
A. Cardiopulmonary Disease and/or Modifying Factors (Including Being from a
Nursing Home)
Streptococcus pneumoniae (including
DRSP)
Hemophilus influenzae
Mycoplasma pneumoniae
Chlamydia pneumoniae
Mixed infection (bacteria plus atypical
Intravenous β-lactam (cefotaxime,
pathogen)
Enteric gram-negatives
Aspiration (anaerobes)
Viruses
fluoroquinolone alone
ceftriaxone, ampicillin/sulbactam,
high-dose ampicillin)
plus intravenous or oral macrolide or
doxycyline
or intravenous antipneumococcal
Legionella spp.
Miscellaneous
Mycobacterium tuberculosis, endemic
fungi, pneumocystic carinii
B. No Cardiopulmonary Disease, No modifying factors
S. pneumoniae
Intravenous azithromycin alone
H. influenzae
M. pneumoniae
C. pneumoniae
Mixed infection (bacteria plus atypical
pathogens)
Viruses
Legionella spp.
Miscellaneous
M. tuberculosis, endemic fungi, P. carinii
If macrolide allergic or intolerant:
Doxycyline and a β-lactam
or
Monotherapy with an antipneumococcal
fluoroquinolone
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Table 5. GROUP IV: ICU-ADMITTED PATIENTS
Organisms
Therapy
A. No risk for Pseudomonas aeruginosa
Streptococcus pneumoniae (including
DRSP)
Legionella spp.
Hemophilus influenzae
Enteric gram-negative bacilli
Staphylococcus aureus
Mycoplasma pneumoniae
Intravenous β-lactam (cefotaxime,
cefriaxone)
plus either
Intravenous macrolide (azithromycin)
or
Intravenous fluoroquinolone
Respiratory viruses
Miscellaneous
Chlamydia pneumoniae,
Mycobacterium tuberculosis,
endemic fungi
B. Risks for Pseudomonas aeruginosa
All of the above pathogens plus P.
aeruginosa
Selected intravenous anti-pseudomonal
β-lactam (cefepime, imipenem,
meropenem, piperacillin/tazobactam) plus
intravenous anti-pseudomonas quinolone
(ciprofloxacin)
Or
Selected intravenous anti-pseudomonal
β-lactam (cefepime, imipenem,
meropenem, piperacillin/tazobactam) plus
intravenous aminoglycoside
Plus either
Intravenous macrolide (azithromycin)
Or intravenous non-pseudomonal
fluoroquinolone
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Antibiotic Therapy
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Administer the first dose in 8 hrs from the time of arrival to the hospital.
Length of therapy: 7-14 days
Switching to oral therapy
 Patient who is clinically stable, may switch to oral therapy on day 3 of
hospital stay, if:
1. Improvement in cough and dyspnea
2. Afebrile on 2 occasions 8 hrs apart
3. WBC is decreased
4. GI tract is functioning with adequate intake
 Organism-specific if etiologic pathogen is known
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If specific pathogen is not known, continue treatment with parenteral agent
with wide spectrum of activity.
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