CBC
CXR
Thoracentesis
Sputum Culture -- Acid Fast Bacilli (If TB suspected)
Pulse Ox
ABG interpretation
Blood Cultures
Aspiration of grossly purulent pleural fluid on thoracentesis and at least 1 of the following:
+ Gram stain or culture
WBC count > 50,000 cells/µL (or polymorphonuclear leukocyte count of 1,000 IU/dL)
Pleural fluid glucose <60
pH <7.2
LDH >1000 IU/mL
+ Gram stain or culture
WBC count > 50,000 cells/µL (or polymorphonuclear leukocyte count of 1,000 IU/dL)
Pleural fluid glucose <60
pH <7.2
LDH >1000 IU/mL
Empyema
Pneumonia
Atypical pneumonia
Sarcoidosis
Bronchiolitis 
Tuberculosis
Acute bronchitis
Pleural Effusion