The osmol gap is the difference between the calculated serum osmolality and measured osmolality |
Calculated serum osmolality = (Sodium x 2) + (Glucose/18) + (Blood urea nitrogen/2.8) |
An elevated osmol gap indicates osmotically active solutes in plasma that are not typically present under normal conditions, such as ethylene glycol, diethylene glycol, methanol, and their many metabolic products |