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i forget how can i calculate a plasma osmolar gap(remember that it is not the same as anion gap calculation)
thanks in advance

normal is less than 25 but i don't remember the calculation ??????????????????????

nobody????

Na-(cl+Hco3)

good

syed:
i'm not asking for anion gap formulation (read my question ) my question is about PLASMA OSMOLAR GAP (it is the way to differentiate ethilene and methanol intox from the rest of anion gap elevation process.
any way thanks for replay and g/l

when anion gap is elevate(12+-4) the N E X T S T E P is: calculate the plasma osm gap ( but i don't remember how do it ) the only thing that i remember is that when it is high than 25 the answer will be ethanol or methanol intox and when it is less than 25 we need to see for the rest of high anion gap elevation process.

Plasma osmolality can be calculated by following formula:
2 x [Na ]+ Glucose/18 + BUN/2.8

where serum (Na) is expressed in mEq/L and glucose and BUN are expressed in mg/dL.
Plasma osmolality can be directly measured.
An osmolar gap exists when the measured plasma osmolality exceeds that calculated by the above formula by > 10 mOsm/L.

YES! ,THANK !!! :-)