Osmolar gap

Serum osmolar (osmolal) gap

Screens for an unmeasured osmole such as a toxic alcohol. Measured osmolality minus calculated (2 x Na + urea + glucose); a gap above about 10 is raised.

Loading calculator...

Appears in these tutorials

See this calculator worked on a real patient, then read the teaching around it.

Poisoning and drug overdose11_026
Worked example: Jarrod Douglas, 46
Open tutorial
Metabolic acidosis15_101
Worked example: Goran Horvat, 46
Open tutorial