Osmolal or osmolar gap
Revisión del 18:08 19 feb 2016 de Neil.m.young (discusión | contribs.) (should be considered a different subtitle than calculations; full spelling)
Definitions
- Osmolarity = the total number of particles in solution per liter
- Osmolality = the number of particles per kilogram of solvent
Calculations
Calculated Osm
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
Osmolal Gap
- Osmolal Gap = measured osm - calculated osm
- Normal = (-)14-10 mOsm/L
Differential Diagnosis
- EtOH
- Ethylene glycol
- Methanol
- Isopropyl alcohol toxicity
- Diethylene glycol
- Propylene glycol
- Mannitol
- Glycerol
- Smaller gaps possible in:
- Ketoacidosis
- Lactic acidosis
- Chronic kidney disease