Creatinine clearance, as renal failure is a significant risk factor for the development of lactic<unk>  from hyperlactemia. .
CBC
Liver Function Test, as hepatic dysfunction precludes oxidation of lactate, thus resulting in elevated lactate levels in the blood
Electrolytes
Urinalysis
Lactic Acid level
ABG
Lipase
CPK
HAART-induced lactic acidosis
Sepsis
Metformin-associated lactic acidosis
Ischemia
Infectious mononucleosis
HIV neurologic complications
Cerebral edema in DKA
Toxoplasmosis