CXR
ECG
CBC, BMP
+/- BNP, D-dimer, Troponin to rule out other etiology
+/- Bedside lung ultrasound
Thoracentesis with classically white, odorless, milky fluid:
Differentiate from empyema and pseudochylothorax
In congenital<unk> , pleural fluid is serous and becomes chylous when milk feedings start
Pleural fluid analysis:
Triglycerides > 110 mg/dL
Cholesterol
LDH
Chylomicron analysis
Protein
Culture and gram stain
Cell differential and count
Serum LDH, total cholesterol, and total protein comparison
Ratio of pleural fluid : serum cholesterol < 1.0 in<unk> 
In pseudochylothorax, this ratio will exceed 1.0
Differentiate from empyema and pseudochylothorax
In congenital<unk> , pleural fluid is serous and becomes chylous when milk feedings start
Pleural fluid analysis:
Triglycerides > 110 mg/dL
Cholesterol
LDH
Chylomicron analysis
Protein
Culture and gram stain
Cell differential and count
Triglycerides > 110 mg/dL
Cholesterol
LDH
Chylomicron analysis
Protein
Culture and gram stain
Cell differential and count
Ratio of pleural fluid : serum cholesterol < 1.0 in<unk> 
In pseudochylothorax, this ratio will exceed 1.0
Chylothorax
Pulmonary
Hemothorax
Airway obstruction
Tension pneumothorax
Anaphylaxis
Spontaneous pneumothorax
Angioedema