Absence of tachypnea, respiratory distress, and rales/decreased breath sounds rules-out with 100% sensitivity
Imaging
CXR is not the gold standard!
Cannot differentiate between viral and bacterial (but lobar infiltrate more often bacterial)
Consider for:
Age 0-3mo (as part of sepsis workup)
<5yr with temperature >102.2, WBC >20K and no clear source of infection
Ambiguous clinical findings<unk> that is prolonged or not responsive to antibiotics
Consider rapid assays for RSV, influenza
Blood/nasal culture are low yield
in prospective study, 91 blood cultures needed for one positive result for CAP; but in ICU one child had bacteremia for every 24 cultures obtained, one for every 12 with parapneumonic effusion 
consider for sicker ones, those with effusions
CXR is not the gold standard!
Cannot differentiate between viral and bacterial (but lobar infiltrate more often bacterial)
Consider for:
Age 0-3mo (as part of sepsis workup)
<5yr with temperature >102.2, WBC >20K and no clear source of infection
Ambiguous clinical findings<unk> that is prolonged or not responsive to antibiotics
Age 0-3mo (as part of sepsis workup)
<5yr with temperature >102.2, WBC >20K and no clear source of infection
Ambiguous clinical findings<unk> that is prolonged or not responsive to antibiotics
in prospective study, 91 blood cultures needed for one positive result for CAP; but in ICU one child had bacteremia for every 24 cultures obtained, one for every 12 with parapneumonic effusion 
consider for sicker ones, those with effusions
Pneumonia 
Upper respiratory infection 
Pleuritis
UTI
Atypical pneumonia
Sepsis
Lung abscess
Meningitis