ABSTRACT
The normal plasma osmolality ranges from 280 to 295 mOsm kg-1 The calculated plasma osmolality accounts for the most prevalent solutes contributing to the osmolality:
where glucose and BUN are measured in mg dl-1. If the measured plasma osmolality exceeds the calculated plasma osmolality by more than 10 mOsm kg - 1 then unmeasured solutes are present. A high osmolal gap is seen in methanol and ethylene glycol intoxication.
