CXR
May have negative CXR early in disease or in cases of dehydration; infiltrate may "blossom" after providing rehydration and repeat imaging
Absence of CXR findings does not preclude diagnosis; high clinical suspicion with adventitious breath sounds can be consistent with<unk> despite negative imaging
Immunocompromised patients may not manifest radiographic evidence of<unk> despite suggestive clinical findings
Clinical and radiographic findings do not necessarily correspond: the patient may be improving  cliniclly despite having a worsening appearance on the CXR
Ultrasound
Can be considered as an alternative to CXR
Sensitivity 82% and specificity 94%
CBC
Chemistry
IDSA does not support using initial serum procalcitonin levels to determine whether empiric antibiotics should be initiated. **Clinical judgement plus radiographic evidence alone should guide therapy (strong recommendation, moderate quality of evidence)
May have negative CXR early in disease or in cases of dehydration; infiltrate may "blossom" after providing rehydration and repeat imaging
Absence of CXR findings does not preclude diagnosis; high clinical suspicion with adventitious breath sounds can be consistent with<unk> despite negative imaging
Immunocompromised patients may not manifest radiographic evidence of<unk> despite suggestive clinical findings
Clinical and radiographic findings do not necessarily correspond: the patient may be improving  cliniclly despite having a worsening appearance on the CXR
Can be considered as an alternative to CXR
Sensitivity 82% and specificity 94%
If patient will be admitted:
Blood Cultures are ONLY indicated for CAP patients with:
ICU (required)
Multi-lobar
Pleural effusion
Cavitary lesions
Leukopenia
Prosthetic valves
IV drug users
Parenteral antibiotics in the last 90 days
Consider for higher-risk patients admitted with CAP
Liver disease
Immunocompromised
Significant comorbidities
Other risk factors
Sputum staining
If concern for particular organism
ICU (required)
Multi-lobar
Pleural effusion
Cavitary lesions
Leukopenia
Prosthetic valves
IV drug users
Parenteral antibiotics in the last 90 days
Consider for higher-risk patients admitted with CAP
Liver disease
Immunocompromised
Significant comorbidities
Other risk factors
Liver disease
Immunocompromised
Significant comorbidities
Other risk factors
If concern for particular organism
Malignancy
Tuberculosis
Pulmonary embolism - Hampton's hump
Pleural effusion
Atelectasis
ARDS
Diffuse alveolar hemorrhage
Multiple "cannonball" infiltrates
Metastatic disease
Septic emboli
Right sided endocarditis
Metastatic disease
Septic emboli
Right sided endocarditis
Legionella urine antigen test
ICU patients
Alcoholics
Outbreaks
Recent (within 2 weeks) travel history
ICU patients
Alcoholics
Outbreaks
Recent (within 2 weeks) travel history
Pneumonia 
Pulmonary
Pleuritis
Airway obstruction
Atypical pneumonia
Anaphylaxis
Lung abscess
Angioedema