AG = Na - (Cl  +  HCO3)
Calculated Osm = 2 x Na + (glu/18) + (BUN/2.8) + (ethanol/4.6) + (methanol/2.6) + (ethylene glycol/5) + (acetone/5.5) + (isopropanol/5.9)
Normal = 275-295<unk> <unk>  = measured osm - calculated osm
Normal = (-)14-10 mOsm/L
Anion Gap and Osmolar Gap 
Methanol
Osmolal or Osmolar Gap
Ethanol glycol
Anion gap
Aspirin 
Reflexes
Iron