Calculated total osmolality includes BUN, but BUN crosses membranes easily and does not contribute to osmotic shifts. Effective osmolality ("tonicity") determines water movement and risk of cerebral oedema.
Verified
Last Review: 2026
Kitabchi AE et al. • Diabetes Care. 2009;The consensus guideline defining osmolality targets in hyperglycaemic management.
Last Comprehensive Review: 2026
Clinical Context
We think this might be relevant to the clinical guidance for Effective Serum Osmolality.
Clinical Context
We think this might be relevant to the clinical guidance for Effective Serum Osmolality.
Clinical Context
We think this might be relevant to the clinical guidance for Effective Serum Osmolality.
