Pearls Flashcards
Osmotic concentration
The osmotic concentration, or osmolality, of a solution is the total number of solute particles in each liter and is usually expressed in osmoles per liter (Osm/L) or milliosmoles per liter (mOsm/L).
If each liter of a fluid contains 1 mole of dissolved particles, the solute concentration is 1 Osm/L, or 1000 mOsm/L. Body fluids have an osmotic concentration of about 300 mOsm/L.
Ion concentrations are often reported in milliequavalents per liter (mEq/L). Milliequivalents indicate the number of positive or negative charges in solution, rather than the number of solutes.
Multiply mmol/L by the charges on each ion to get mEq/L. For example, each sodium ion bears one charge only, so for Na+, 1 mmol/L = 1 mEq/L; for Ca2+, each ion bears two charges, so 1 mmol/L = 2 mEq/L.
