Varies widely depending on clinical presentation
CBC
Chemistry
Urine pregnancy
LFTs
Lipase
APAP, ASA, digoxin levels
Urinalysis
?Abdominal xray
?CT
?Ultrasound
Nausea and vomiting
ACS/MI
Fever and rash
Boerhaave's
Abdominal pain 
DKA
Abdominal pain
Intracranial Hemorrhage