CBC, leukocytosis
CRP elevated
LDH elevated
ABG with hypoxemia, hypercapnea
ECG
CXR with likely need for CT
Echo to assess for<unk>  hypertension, rule out CHF
BAL in ICU to rule out infection
Idiopathic pulmonary fibrosis
Interstitial pneumonias 
Bronchiectasis
Lung malignancy
Sarcoidosis
Aspiration pneumonia or pneumonitis
CMV pneumonia
Bacterial, viral, or fungal pneumonia